identifier: Vassallo, Leonard Francis <https://research.library.mun.ca/view/creator_az/Vassallo=3ALeonard_Francis=3A=3A.html>   (1979) Survival and growth of young Gammarus Lawrencianus Bousfield at different temperatures and on different diets in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Survival, growth and egg production of Gammarus lawrencianus  was determined for newly released young kept without food and maintained on diets of TetraMin, the Blue Mussel (Mytilus edulis)k, and the algae Dictyosiphon foeniculaceus, Pilayella littoralis and Enteromorpha intestinalis, at 15°C. Similar experiments were performed on animals fed TetraMin at 5°, 10°, 12° and 15°C. concurrent field collections were made at Witless Bay Pond and North Arm Holyrood, Newfoundland. The selectivity of immature and adult G. lawrencianus were also investigated and the energy and amino acid content of the diets determined. -- Survival was inversely proportional and growth directly proportional to temperature. Temperature also significantly influenced fecundity and age at maturity, but not maturation size in the range of the temperatures tested. Higher temperatures reduced the maturation age and increased the number of eggs produced. Diet significantly influence survival, growth, fecundity as well as size and age at maturation. Survival was enhanced by fine algae but growth, fecundity and age, and size at maturation were optimized on a diet of Mytilus. Size in maturity in the field was comparable to animals fed diets of TetraMin or Mytilus, but diets of filamentous algae produced a much larger maturation size. Maturation size in the filed decreased as the summer progressed, probably due to changes in the quality of the available diet. -- The total energy content of the food appeared to be an important variable in the quality of the diet. Texture probably had a large influence on the amount of energy actually available to the animals, especially when algae were a major part of the diet. -- No obvious correlation between the quality or quantity of amino acids in the diet and the growth, survival and fecundity was found except in the case of TetraMin. TetraMin was deficient in a great number of amino acids when compared to G. lawrencianus. Animals fed TetraMin had a very low survival rate when compared to the other diets, but growth and fecundity were similar to Mytilus, the diet that most closely corresponded to the amino acid makeup of G. lawrencianus.


identifier: Genge, Peter D. <https://research.library.mun.ca/view/creator_az/Genge=3APeter_D=2E=3A=3A.html>   (1985) The ecology of net-spinning caddisflies in a Newfoundland lake outlet.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

format: application/pdf application/pdf

abstract: The community of dominant species of net-spinning caddisflies found in the Axes Pond outlet - an oligotrophic lake-stream system near Torbay, Newfoundland was investigated.  The dominant species in the system included: Cheumatopsyche pettiti, Hydropsyche betteni, Hydropsyche slossonae, Hydropsyche sparna, Neureclipsis crepuscularis and Chimarra aterrima.  Zonation existed in the abundance and distribution of these species along the stream within short distances from the lake outlet.  H. betteni, C. pettiti and N. crepuscularis were predominant at the immediate lake outlet while 60 meters downstream H. slossonae and H. sparna were predominant with large numbers of C. pettiti and N. crepuscularis present.  Downstream from this point, C. aterrima was predominant.  Biomass of net-spinning caddisfly larvae varied throughout the year and between stations.  Highest values were generally reached at the immediate outlet during late spring or late fall and winter.  Lowest values were observed at the sampling station furthest from the outlet during mid summer. -- It is strongly suspected that density dependent drift resulted in a developmental gradient within the densest populations at the outlet.  For any one generation, the modal instar number for a species population decreased with distance below the outlet. -- Life history patterns of the net-spinning caddisflies studied at Axes Pond were not necessarily comparable with those described for the same species on the mainland.  Larvae of most species of hydropsychids studied at Axes Pond were larger at a given larval instar and overwintered in earlier larval instars than the same species studied on the mainland.  With the exception of H. slossonae, which had a univoltine life cycle, all species studied had univoltine and/or semivoltine life cycles.  This is the first report of a semivoltine life history in net-spinning caddisflies. -- Large particles of lake-derived seston disappeared from the stream faster than smaller particles.  This reduction in mean food particle size over distance downstream from the outlet corresponded with the feeding habits and zonation of the net-spinning caddisflies.  In addition to differences in feeding habits it is postulated that these species may be able to exist together as a result of several other factors including temporal variation in life history and differences in habitat preference.  These factors permit the existence of a complex guild of net-spinning caddisflies at a lake outlet.


identifier: Clarke, Keith <https://research.library.mun.ca/view/creator_az/Clarke=3AKeith=3A=3A.html>   (1995) Numerical, growth and secondary production responses of the benthic macroinvertebrate community to whole-lake enrichment in insular Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: A whole-lake enrichment (N + P) experiment was conducted over a three-year period to evaluate the feasibility of boosting benthic productivity in insular Newfoundland lakes.  Response of the benthic community to enrichment was monitored by a combination of biomonitoring (artificial substrate) and quantitative dredge sampling in both the enriched lake and two control lakes. -- Observations of benthic abundance through biomonitoring approaches revealed a continuum of positive numerical responses to enrichment.  Responses were most rapid in short-lived herbivores such as chironomids, gastropods and sphaeriid clams while longer-lived detritivores (mayflies, amphipods) and predators (flatworms, leeches and dragonflies) demonstrated a slower, more modest numerical response.  The benthic macroinvertebrate communities of the study lakes were composed of cosmopolitan species from the North American fauna in relatively low densities.  Benthic biomass was dominated by gastropoda and the odonate Cordulia.  Secondary production estimates were relatively low when compared to mainland systems.  Short-lived herbivores (Amnicola, Phryganea) were observed to have increased secondary production in the enriched pond.  Secondary production estimates were similar in the three study ponds for the other macroinvertebrate taxa.  Some of these taxa were observed to have increased growth (Cordulia) and/or recruitment (Enallagma) late in the study.  This pattern indicates that benthic macroinvertebrate community production was still increasing in the enriched pond.


identifier: Martin, Frances R. <https://research.library.mun.ca/view/creator_az/Martin=3AFrances_R=2E=3A=3A.html>   (1987) The spatial distribution of host-seeking mammalophilic black flies (Diptera- Simuliidae) in relation to terrestrial habitats on the Avalon Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Female host-seeking black flies were collected using dry ice baited sticky traps, unbaited sticky traps and a sweep net to assess abundance in six habitats.  Females of the Simulium venustum/verecundum complex were most abundant in peatlands and regrowth, whereas P. mixtum and St. mutata females were most abundant in balsam fir and black spruce forest, followed by regrowth and peatlands.  Few black flies were collected on pastureland.  Spatial distributions described were observed throughout the sampling day, and between sampling days and sampling years.  The distribution of S. venustum/verecundum complex among the six habitats was similar in June and August, but in July there was a relative increase in the abundance of females in the forest.  The paucity of females in the pasture was associated with relatively high wind speeds while the relatively small catches of S. venustum/verecundum complex in the forest in most months may be related to the low light levels in that habitat.  Generally, the meteorological conditions 1 m above ground level were not good indicators of black fly spatial distribution.  The relationships between black fly distribution and certain topographical factors, resting sites and nectar sources were discussed.


identifier: Ebsary, B. A. (Barry Alan) <https://research.library.mun.ca/view/creator_az/Ebsary=3AB=2E_A=2E_=28Barry_Alan=29=3A=3A.html>   (1973) The mermithid (Nematoda) and other endoparasites of simuliidae (Diptera) in insular Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: In 1971 and 1972, 198 streams in insular Newfoundland were examined for blackfly endoparasites.  Forty streams yielded one or more species of the microsporida-- Thelohania bracteata, T. fibrata, Plistophora simulii, Caudospora simulii and C. brevicauda.  The fungus Coelomycidium simulii was found in 14 streams.  The blackfly mermithids Gastromermis viridis, Isomermis, wisconsinensis and Neomesomermis flumenalis were recovered from 59 streams.  Central Newfoundland had higher frequencies of mermithid infections (47.3-75.0%) than the more coastal areas (11.7-36.3%).  The  longitudinal distribution of mermithid infected blackflies within the stream showed that the upper 400 m. of the stream were devoid of mermithids, while the lower reaches of the stream harboured mermithids.  Current, depth and chemical parameters of the stream water in streams with and without mermithids were examined.  Mermithid parasitism did not appear to be significantly affected by these factors.  Neomesomermis flumenalis was redescribed in light of the finding of eggs and pre-parasites.  Adult males of G. viridis  and I. wisconsinensis were also redescribed.  The life cycle of N. flumenalis was described.  Following emergence from the host, male and female post-parasites molt to adults in 9-15 days at 12°C., 10-13 days at 18°C., 37-40 days at 6°C., and failed to molt at 22-24°C.   A double pre-adult molt and a parasitic molt were noted.  Mating lasted for 12-24 hours, and usually occurred within a few hours of molting to adults.  Eggs were laid 36-59 days after mating.  Females laid 600-650 eggs over 3 days.  The incubation period was 35-55 days at 12°C.; heaviest egg hatching occurred 4-11 days after the onset of hatching.  No eggs were laid at 3°, 7°, 18°, or 22-24°C.  Pre-parasites live 2-3 days.  The period from emergence from the host to egg laying was 45-74 days, and from emergence to egg hatching, 80-129 days.  Mixed infections involving microsporida, mermithids and coelomycidians were noted.  Seasonal fluctuations of host/parasite populations in Half Moon Brook and Long Pond Tributary were studied, Neomesomermis flumenalis infected the Prosimuliums in October and the early summer Simuliums in late May-early June.  Carryover of mermithids to adult simuliids, based on extrapolated data from late larval and pupal infections, indicated that N. flumenalis probably carried over to the Prosimuliums and Simuliums at a rate of .026 and .062% respectively.  Gastromermis viridis and I. wisconsinensis probably infect 1.3-26.8% of their adult simuliid hosts.  Host specificity appeared to be related to the asynchronous life cycles of the host parasite populations.  Sex ratios of 1.4:1 males to females were noted for the mermithids from the Prosimuliums in Half Moon Brook.  Female to male mermithid ratios of 1.33:1 and 9.2:1 for the Prosimuliums and Simuliums in Long Pond Tributary and 2.7:1 for the Simuliums in Half Moon Brook were also noted in 1972.


identifier: Parsons, Marion Grace <https://research.library.mun.ca/view/creator_az/Parsons=3AMarion_Grace=3A=3A.html>   (1986) The Middle Cambrian, Upper Cambrian, and Lower Tremadoc acritarchs of Random Island, Trinity Bay, Southeastern Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: In the Random Island area on the west side of Trinity Bay, eastern Newfoundland, there are three NNE-SSW oriented Lower Palaeozoic basins.  The southern part of the westernmost basin underlies the northern end of Random Island; it includes, apart from minor fault-bounded remnants of Lower Cambrian rocks, an almost complete, succession of Middle Cambrian to lowermost Ordovician (Tremadoc) rocks.  Outcrops are largely confined to coastal cliffs. -- Two sections were sampled for acritarchs.  The first, on the west side of the island in rocks of Middle Cambrian to early Tremadoc age, extends from Cock and Hen Point northward for 6.5 km to an unnamed point 2.5 km beyond the village of Elliott's Cove.  The second, on the east side of the island, is a short section (a few hundred metres in length) in Upper Cambrian rocks 2 km north of Snooks Harbour.  The Upper Cambrian rocks of this section complement those present in the section north of Cock and Hen Point where the former are unrepresented due to faulting.  Descriptions are given of 102 species, belonging to 33 genera; 38 species and one genus are new finds.  A second new genus represents a reassignment of a previously-known species. -- The acritarch microfloras of the Middle Cambrian to Tremadoc rocks on Random Island have been divided, on the basis of the successive first appearances of distinctive species, into a series of nine acritarch assemblages, RI 1 to RI 9.  Two of the assemblages, RI 6 and RI 7, in rocks of late Upper Cambrian age, have not previously been found elsewhere, and assemblage RI 8, in rocks of latest Upper Cambrian age has until now been recorded only from the Obolus Beds of the  northwestern part of the Russian Platform and the Obolus Zone of northern Norway.  These Obolus-bearing beds, although presently  included in the Tremadoc are shown to be of latest Upper Cambrian age. -- The Middle Cambrian to Tremadoc acritarch assemblages of Random Island are compared with those that have been distinguished in rocks of comparable age in England and Wales, Belgium, Spain, northern Norway, the Russian Platform, North Africa, and elsewhere.  This comparison shows that those successions are incomplete due to stratigraphic breaks.  Furthermore, many of the acritarch assemblages (or zones) erected elsewhere have not been accurately dated using established trilobite zones; most of the Random Island acritarch assemblages have been directly related to such zones.  Thus, outside Random island, none of the sequences of acritarch assemblages (or zones) established for Middle Cambrian to Tremadoc rocks is as complete, or has as many of its assemblages as accurately dated, as that described in this study.  The succession of acritarch assemblages on Random Island should, therefore, become the standard as far as rocks of Middle Cambrian to early Tremadoc age are concerned for purposes of biostratigraphic correlation.


identifier: Browne, Shelley Marie <https://research.library.mun.ca/view/creator_az/Browne=3AShelley_Marie=3A=3A.html>   (1979) The response of Culicidae to visual stimuli.  Masters thesis, Memorial University of Newfoundland.

abstract: Response of Culicidae to visual stjmuli of various colours and shapes was studied in the Tintamirre National Wildlife Area, New Brunswick, in 1977 and 1978.  Culicidae were collected from three-dimensional, cube-shaped, funnel target traps of five different colours.  The collections indicated a differential preference for the five colours.  Aedines and Mansonia perturbans preferred black, red and blue as the most attractive colours, while yellow and white were consistently unattractive.  M. perturbans showed substantial colour differentiation in the day and night time collections.  The percent luminous reflectance of the light reflected from each colour-stimulus target was inversely proportional to the numbers of Culicidae trapped in the target (i.e. a decrease in the luminous reflectance, the more mosquitoes collected).  This trend was fairly consistent throughout 1977 and 1978 but discrepancies did occur. -- M. perturbans landed in greater numbers of filters transmitting wave-lengths of 480-600 nm and 400-480 nm.  A secondary response occurred to 300-400 nm.  Low numbers landed on 620 nm and all longer wavelengths. -- Four species of Aedes and M. perturbans were shown to respond in greater numbers to cube targets than pyramids while A. punctor was collected in greater numbers from pyramids.  While no species were taken exclusively at any of the levels, most mosquitoes were collected in cube and pyramid targets exposed at the 122 and 183 cm levels.  Aedines and M. perturbans differentially selected the end or projecting parts of the rectangular (oblong) targets.  Few numbers were collected from the center portion. -- Recommendations for further studies are discussed as well as suggested for the application of these findings for personal protection against mosquitoes.


identifier: Bradbury, Wayne Claude <https://research.library.mun.ca/view/creator_az/Bradbury=3AWayne_Claude=3A=3A.html>   (1972) Experiments and observations of the near-host orientation and landing behavior of simuliidae (Diptera).  Masters thesis, Memorial University of Newfoundland.

abstract: Records of the seasonal succession and seasonal range of several species of adult female mammalophilic Simuliidae of insular Newfoundland are presented. -- Collections of mammalophilic Simuliidae on colored-shaped two-dimensional silhouettes indicated that various species orient and land on certain 'preferred' radiation compositions. The Prosimulium mixtum complex and Cnephia mutata were attracted  consistently to black silhouettes; the Simulium venustum complex were attracted to silhouettes composed of 'blue' radiations while Simulium vittatum were orienting and landing on both red and black silhouettes. Black, 'blue' and  red radiation compositions per ovdinem were most attractive while yellow was the least attractive for all species, which indicated that radiation compositions reflecting the least amount of light were the most attractive, but, depending on the species composition of the simuliid population, this generalization tended to become obscure. -- Responses of simuliiids to simple geometric shapes indicated individual contours were equally attractive while the various 'points of convergence' of the silhouette shapes attracted large numbers. -- Collections of flies orienting upwind to C0₂ obtained from a 'grid' of silhouettes indicated a decrease in the number of flies toward the row of silhouettes located  downwind from the C0₂ point of emission. Depending on the individual silhouette 'colors' the flies were orienting to the C0₂ from as much as ten meters downwind. -- Simuliids landed on black, disc-shaped silhouettes of different areas  in proportion to the surface area exposed. -- The responses of Simuliidae to 'attractive' and 'non-attractive' silhouettes and controlled release of gaseous C0₂ indicated a marked ability of simuliids to visually discriminate the targets largely on the basis of their individual radiation compositions and independant of the concentration of C0₂ or olfactory mechanisms. Discrimination coefficients indicated that distances approximating four meters downwind from the C0₂ source would appear to be a limiting distance for the simuliids' effective use of vision. -- Long-range, medium-range and near-orientation mechanisms are presented for the Simuliidae in terms of the sensory make-up through which they are mediated.


identifier: So, Bernard Kai-Fai <https://research.library.mun.ca/view/creator_az/So=3ABernard_Kai-Fai=3A=3A.html>   (1971) Marine fish haematozoa from Newfoundland waters.  Masters thesis, Memorial University of Newfoundland.

abstract: Of 797 fish of 28 species, 159 of 12 species yielded blood parasites. -- Eight species of protozoan parasites are reported - three each of Trypanosoma and Haemogregarina, and two of Haemohormidium. -- Trypanosoma rajae Laveran & Mesnil is recorded from Raja radiata.  Undetermined trypanosomes are reported from Glyptocephalus cynoglossus and Gadus morhua respectively. -- Haemogregarina myoxocephali Fantham et al. was found in Myoxocephalus octodecemspinosus.  The occurrence of haemogregarine sporozoites (perhaps of this species) in the gut of a piscicolid leech (Malmiana nuda) from Myoxocephalus scorpius represents the first discovery of a potential vector of any fish haemogregarine.  New hosts are listed for H. delagei Laveran & Mesnil and H. platessae Lebailly. -- Haemohormidium terraenovae n. sp. is described from six hosts:- Ammodytes americanus, Urophycis tenuis, Melanogrammus aeglefinus, Limanda ferruginea, Glyptocephalus cynoglossus and Hippoglossoides platessoides; and Haemohormidium beckeri n.sp. from Myoxocephalus octodecemspinosus. -- Intraerythrocytic inclusions of unknown origin were common in Clupea harengus and Argentina silus, and myxosporidans occurred as blood film contaminants in Raja radiata and Gadus morhua (in the latter case the parasite was referable to Kudoa sp.).  Other artifacts reported were bacterial contaminants from Squalus acanthias and Limanda ferruginea.


identifier: Stephen, Stephen J. <https://research.library.mun.ca/view/creator_az/Stephen=3AStephen_J=2E=3A=3A.html>   (1985) The systematics of the pelagic squid genus Octopoteuthis Ruppell, 1844 (Cephalopoda: Teuthoidea) with emphasis on species in the north Atlantic.  Masters thesis, Memorial University of Newfoundland.

abstract: The systematics of the pelagic squid genus Octopoteuthis Ruppell, 1844 is reviewed.  Four hundred and fifty-six specimens were examined from museum sources worldwide ranging in size from 1.3 mm - 240 mm dorsal mantle length (ML).  Of the nine nominal species five are found to be invalid or considered nomina dubia.  All species are found to bear photophores in a variety of body locations.  Characters used to separate species include presence of one or two photophores on the posterior-ventral portion of the mantle; presence or absence of anterior eyelid photophores; presence or absence of an eyeball photophore; and presence or absence of accessory cusps (booklets) on the arm hooks.  Larval specimens (those less than approximately 25 mm ML and still bearing tentacles or remnants of them) could not be separated into species at present because of the late development of the characters defined above.  Discriminant analysis run on morphometric data on each specimen supported the species separation proposed here.  Geographic and vertical distribution is also discussed.


identifier: Barker, Duane Edward <https://research.library.mun.ca/view/creator_az/Barker=3ADuane_Edward=3A=3A.html>   (1993) Evidence of chronic stress in winter flounder, Pleuronectes (= Pseudopleuronectes) americanus living adjacent to a pulp and paper mill in St. George's Bay, Western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Winter flounder, Pleuronectes (= Pseudopleuronectes) americanus, living adjacent to a pulp and paper mill at Port Harmon, Stephenville, Newfoundland, were compared with flounder from a reference site, St. George's, 12 km from the mill, for signs of chronic stress.  Several bioindicators of stress in fish were employed, including condition factor, organ somatic indices, haematological values, external lesions, and parasitofauna.  Winter flounder from Port Harmon, (effluent site) showed significantly lower condition factors (K-factors) and hepatosomatic indices (HSI) indicative of depleted energy reserves, and physiological impairment, than those from St. George's.  Delayed spawning was evident in both male and female winter flounder from Port Harmon compared with those from St. George's.  Blood haemoglobin, haematocrit, and lymphocyte levels were significantly lower at Port Harmon, than in samples from St. George's.  Fin necrosis of the caudal, dorsal and anal fins, was greater (in terms of prevalence and intensity) in flounder from Port Harmon.  The prevalence and intensity of intestinal nematodes was significantly higher at Port Harmon, than St. George's; possibly the result of differences in diet.  Conversely, the prevalence and intensity of intestinal acanthocephalans was significantly lower at Port Harmon, and was possibly related to effluent discharge.  No differences were found in a comparison of prevalence and intensity of intestinal digeneans.  The prevalence and severity of infection of a parasitic microsporan protozoan, Glugea stephani, and the encysted metacercaria of the digenean, Cryptocotyle lingua, were, however, significantly higher among flounder from Port Harmon.  Anaemia, low lymphocyte levels, a high prevalence of fin necrosis and parasitemias (Glugea stephani, Cryptocotyle lingua) are all suggestive of immunosuppression.  Since the above differences were not attributed to differences in basic water parameters (temperature, salinity, conductivity, pH, and dissolved oxygen) at the two sites, the chronic stress evident in winter flounder from Port Harmon is most likely attributed to pulp mill effluent discharged at Port Harmon.


identifier: Hughes, Glenys Anne <https://research.library.mun.ca/view/creator_az/Hughes=3AGlenys_Anne=3A=3A.html>   (1990) A molecular genetic analysis of hybridization between two species of deer (Odocoileus) in western Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: Hybridization between two species of deer (Odocoileus) in western Canada has been postulated for many years.  Mitochondrial and nuclear components of the genomes of deer from this and other regions in North America were analyzed to test whether these deer constitute reproductively isolated species or whether interspecies genetic exchange has occurred by hybridization. -- The polymerase chain reaction (PCR) was used to amplify a 359 base pair fragment of the mitochondrial cytochrome b gene from 81 white-tailed deer (O. virginianus), mule deer (O. hemionus hemionus), and Sitka black-tailed deer (O. hemionus sitkensis).  Direct DNA sequencing of a 302 base pair block of the PCR-amplified products revealed 34 variable nucleotide positions.  These variants define 13 distinct mitochondrial DNA (mtDNA) sequence genotypes.  Twelve of these are confined to one or the other species:  five genotypes were found only in white-tailed deer and seven only in mule deer or black-tailed deer.  In only one instance is a genotype shared between species: a single deer that had been identified as a mule deer possessed a white-tailed deer-type mtDNA. -- Allelic variants at the albumin locus also distinguish the two species.  Of 53 animals sampled from British Columbia, Alberta, and Saskatchewan, 25 white-tailed deer and 27 mule deer were homozygous for slow and fast albumin alleles, respectively.  Only one animal showed the heterozygote albumin pattern characteristic of hybrid deer.  This individual is the same mule deer that possessed an mtDNA genotype found otherwise only in white-tailed deer. -- These data suggest there is little genetic introgression between mule deer and white-tailed deer in western Canada.  Similar findings have been reported for Odocoileus in Montana, but high levels of hybridization have been documented between the same species in west Texas.  Habitat disturbance and mating behaviour are factors that may affect the frequency and direction of hybridization in different localities. -- Phenetic and cladistic analyses of sequence differences among white-tailed deer, mule deer, and black-tailed deer reveal a discordance between mtDNA genotype and species affinity.  Interspecies hybridization, random phylogenetic sorting of mtDNA lineages, and differential rate of mtDNA evolution are considered as hypotheses to explain the relationships among mtDNA genotypes of these species.


identifier: Mlewa, Chrisestom Mwatete <https://research.library.mun.ca/view/creator_az/Mlewa=3AChrisestom_Mwatete=3A=3A.html>   (1996) A comparative study of the growth and feeding of underyearling (0+) Brown Trout (Salmo trutta Linn.) in disturbed and undisturbed stream habitats in the Avalon Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Although natural freshwater bodies on insular Newfoundland are oligotrophic, high growth and biomass of salmonids has been reported in streams within the city of St. John's. This  study compared the growth and feeding of underyearling (0+) brown trout (Salmo trutta Linn.) from Juniper Brook, a headwater tributary of the Rennies River, which flows through the city; and a tributary of the Broad Cove River, outside the metropolitan area. Zero plus trout were obtained  by electrofishing once every three weeks during the summer and fall of 1994 and 1995, with one sample collected in the intervening winter. In both years, fry in Juniper brook emerged later from the redds but grew at a faster rate and attained a slightly bigger size by the end of the growing season. Arithmetic growth curves for trout in each stream approximated the characteristic sigmoid curve. Within streams, growth rates were highest in early summer. Stream water temperatures showed consistent differences, with Juniper Brook warming up faster in the summer and cooling faster in the fall. -- The composition of 0+ trout diet varied between streams and seasons and was related to changes in the food available both in the streams and adjacent terrestrial vegetation. Benthic samples from Juniper Brook had fewer taxa and were dominated by chironomid larvae, whereas those from Broad Cove River had a   higher taxonomic diversity but fewer numbers per taxon. Chironomids were consumed almost exclusively by 0+ trout in Juniper Brook during the summer but those in Broad Cove River had a much broader diet. Stomach contents were at times dominated by a single prey, suggesting opportunistic feeding, probably on the most abundant and available prey in  the feeding environment. The higher abundance of chironomids  in Juniper Brook was related to higher chemical richness resulting from the input of liquid and solid urban wastes. Thus the human disturbance that has occurred on Juniper Brook has altered the ecology of the stream resulting in higher stream temperatures in the summer and higher chemical  richness which promoted the growth of 0+ trout in this stream.


identifier: Brown, Cynthia Joan <https://research.library.mun.ca/view/creator_az/Brown=3ACynthia_Joan=3A=3A.html>   (1995) An investigation of environmental parameters influencing the distribution of Platanthera blephariglottis (Willdenow) Lindley and P. clavellata (Michaux) Luer (Orchidaceae) in peatlands, and some aspects of their population dynamics.  Masters thesis, Memorial University of Newfoundland.

abstract: Populations of two terrestrial species of orchids, P. blephariglottis and P. clavellata, were investigated for two  field seasons (1991-1992) to observe population dynamics and  to explore what environmental factors (peat constituents, water pH and water level, endophytic fungi) may influence their distribution within a peatland. The dynamics of the populations were similar to each other and to that observed for other North American and European orchid species. Both populations increased in plant numbers, while showing a marked decline in flowering percentages in 1992. The populations, while having a net gain of individuals, also lost individuals, but it was not determined if these plants had died or returned to a subterranean stage. P. blephariglottis did not set any capsules, and capsule set was very low for P. clavellata due to a late frost at the time of flowering in both years. -- Peat constituent values associated with P. blephariglottis and P. clavellata were, for the most part, not significantly different, although the values associated with P. clavellata tended to be higher and  to have a greater range than those associated with P. blephariglottis. Water level values were significantly different between species, suggesting that it is on this basis that these species partition the habitat. This is similar to the results of Boland and Scott (1992) for other peatland orchids. The relationship of water level and crown depth implies that P. clavellata can spend a significant period of time, when actively growing and flowering, with the crown submerged. -- Two mycorrhizal fungi were isolated and found to be associated with both species, suggesting that the fungi do not play a role in the distribution of these species.


identifier: Hall, Anthony David <https://research.library.mun.ca/view/creator_az/Hall=3AAnthony_David=3A=3A.html>   (1996) Aspects of the biofouling of salmon aquaculture nets in southwestern New Brunswick.  Masters thesis, Memorial University of Newfoundland.

abstract: A study of net fouling at three geographically distinct salmon farms in southwestern New Brunswick showed that during the summer production period (May-October), fouling communities were comprised of common members of the local flora and fauna. These results were similar to the observations of local salmon farmers, which suggests the potential value of these anecdotes as a source of fouling data. Analyses of relative abundance showed that the composition of communities was variously influenced by the time of year, location, and depth, but not by surface treatment. The application of a nontoxic antifouling wax to the nets showed no significant impact on species abundance, but did significantly reduce accumulated biomass throughout the production period. Also, the growth form of fouling organisms suggested that algae recruit to nets as spores and vegetative fragments, and invertebrates recruit as larvae and juveniles. The results also showed that biomass is not a  particularly useful measure of fouling for operational purposes. Resistance to water flow due to the growth form of  organisms is the primary operational impact of net fouling, and future research efforts should concentrate on quantification of this factor.


identifier: Piatt, John F. <https://research.library.mun.ca/view/creator_az/Piatt=3AJohn_F=2E=3A=3A.html>   (1987) Behavioural ecology of common murre and Atlantic puffin predation on capelin : implications for population biology.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Relationships between capelin (Mallotus villosus), common murres (Uria aalge), and Atlantic puffins (Fratercula arctica) were studied at Witless Bay, Newfoundland, during the summers of 1982 to 1984. Capelin occurred inshore from May to August, but abundance peaked during periods of maximal tidal oscillations and increasing water temperatures  in late June and early July. From 1982 to 1984, capelin abundance declined by an order of magnitude, but school densities remained similar. Capelin size varied by 30-40% seasonally, and up to 20% annually, partly due to temporal variations in age-class composition of schools. Capelin dominated by weight in diets (4842 items identified) of murres (adult:82.7% and chick:90.8%) and puffins (78.8% and 93.2%), but juvenile cod (Gadus morhua) and sandlance (Ammodytes dubius) were also important prey. Numbers of capelin in bird stomachs declined from 1982 to 1984, and were seasonally correlated with local capelin density; suggesting sigmoidal (Type III) functional responses. Numerical proportions of capelin in diets (from gizzard contents or chick meals) were not correlated with seasonal or annual variations in local capelin density. Variations in  size of prey eaten by birds generally reflected natural variations in prey size. Bird diet overlap was extremely high, and diet diversities were low (puffin > murre). Numbers and flock sizes of birds were best correlated with capelin abundance and density, respectively. Murres were best correlated with higher density capelin schools in deeper offshore waters, and formed larger, more aggregated flocks than puffins. Both murres and puffins exhibited sigmoidal (Type III) aggregative responses to capelin density, with murres having a significantly higher prey density threshold. Density thresholds varied with overall capelin density. Murres had a larger maximum foraging range than puffins, and ranges varied annually with capelin abundance. Murre and puffin feeding ecology and behaviour may be best explained within the context of optimal foraging  and predation theory. Ecological differences between murres and puffins may be largely due to their differing body sizes  (murre > puffin). Implications for population biology of the  Atlantic Alcidae are discussed.


identifier: Regehr, Heidi <https://research.library.mun.ca/view/creator_az/Regehr=3AHeidi=3A=3A.html>   (1994) Breeding performance of black-legged kittiwakes on Great Island, Newfoundland, during periods of reduced food availability.  Masters thesis, Memorial University of Newfoundland.

abstract: The breeding success of Black-legged Kittiwakes (Rissa tridactyla) was investigated on Great Island, Witless Bay, Newfoundland, in 1992 and 1993, following two years of breeding failure. Egg production was low in both years. High  egg mortalities (90% and 89%) and high chick mortality in 1992 (93%), but not in 1993 (32%), resulted in a breeding success of 1% in 1992 and 7% in 1993. Timing of breeding was  later than in previous years and clutches and eggs were smaller. Failure was extensive throughout the colony. The degree of failure varied consistently among regions between years which was probably related to cliff structure and therefore to nest predation. Comparison of egg shape indices  among years suggested that a higher proportion of older individuals were breeding in years of poor productivity. This is consistent with the hypothesis that older breeders are more able and willing to expend effort and incur cost. -- Egg predation, primarily by Great Black-backed Gulls (Larus marinus), accounted for most egg mortality. Results suggest that egg predation in both years and poor chick survival in 1992 were related to food shortage. Capelin (Mallotus villosus) arrived inshore for spawning up to 1 month later than normal, which, in conjunction with a lack of fish offal, was associated with food shortage in kittiwakes and in other gulls. Kittiwake incubation and chick-rearing shifts were shorter and survival time of chicks was longer after capelin arrival than before in 1992,  indicating increased food availability. Observations and growth measurements indicated that chicks hatching before capelin arrival were starving. The effect of hatchdate on chick survival was less pronounced in 1993 than in 1992. Unattended eggs and chicks were uncommon and adults endured long nest shifts, probably in response to high predation risk. Incubation and chick-rearing shifts were shorter and feeding rates were greater in 1993 than in 1992, suggesting greater food availability in 1993. The seasonal migration of capelin into inshore waters in Witless Bay provides an important resource to kittiwakes, affecting their time budgets and survival of their chicks.


identifier: McCarthy, James H. <https://research.library.mun.ca/view/creator_az/McCarthy=3AJames_H=2E=3A=3A.html>   (1997) Brook trout (Salvelinus fontinalis Mitchell) movement, habitat use, and potential impacts of forest harvesting activity in the Copper Lake Watershed, Corner Brook, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Seasonal movements of brook trout (Salvelinus fontinalis Mitchell) within a treatment and control stream in a forested area near Corner Brook, Newfoundland were determined using counting fences and tagging. Trout movement  was weakly or uncorrelated with habitat parameters. Most trout moved in association with increased discharge associated with storm events. Two patterns in upstream movement were observed: 1) an apparent 'preferred' velocity range of 0.395-0.462 m˙s⁻¹ in the treatment and 0.206-0.409 m˙s⁻¹ in the control stream; and 2) an increase in upstream movement after the storm peak if the peak was greater than 0.474 and 0.421 m˙s⁻¹ in the treatment and control stream, respectively. Downstream movement in the treatment stream occurred most at lower velocity ranges and trout moved more before and after storm peaks than during the peak. Downstream movement in the control stream occurred at all velocity ranges and trout moved throughout the storms. -- Increased movement out of the treatment stream was recorded in 1995 after a limited forest harvest of approximately 9.0% of the drainage basin (20% of the stream-length). Trout from  the treatment stream did not appear to change their distance of migration but moved out of the treatment stream and into Copper Lake. This increase appeared to have been due to subtle changes in stream habitat. -- Discharge, maximum stream temperature, mean stream depth, velocity, and temperature were not altered by forest harvesting and dissolved oxygen did not reach critical levels even after the cut. The minimum daily water temperature was affected by  harvesting with a significantly higher number of days with minimum temperatures less than 11°C. In addition, total suspended sediment appeared to have been increased, however,  statistical evidence is lacking. -- Radio telemetry of mature trout in the lakes of the study area showed that lacustrine spawning represents a large proportion of the reproduction in certain areas of the watershed. This has rarely been documented in Newfoundland and needs to be considered in the context of effects from forest harvesting practices.


identifier: Hooper, Laura R. E. <https://research.library.mun.ca/view/creator_az/Hooper=3ALaura_R=2E_E=2E=3A=3A.html>   (1997) Carrot (Daucus carota L.) cultivar resistance to carrot rust fly (Psila rasae Fab.) with a note on the seasonal history of the adult and its distribution in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The role of adult host preference as a mechanism of carrot (Daucus carota L. cultivar resistance to carrot rust fly (Psila rosae F. [Diptera: Psilidae]) attack was examined via  an ovipositional preference study in the laboratory and a damage assessment in the field. Laboratory studies were conducted to determine if P. rosae had a propensity to oviposit on a specific cultivar. Cultivar pairs were exposed  to adult P. rosae for seven days to two weeks in controlled temperature chambers and were examined for the number of eggs deposited by P. rosae through floatation and filtration of the samples. There was a significant difference (P = 0.0015) between the number of eggs found on cv. Danvers Half  Long 126 and on cv. Flyaway. There were no significant deviations from the expected 50:50 ratio in the tests comparing oviposition on Danvers and Nantes, Danvers and Chantenay, Nantes and Chantenay, and Nantes and Flyaway. -- The resistance of the same four carrot cultivars to carrot rust fly attack was investigated in field studies at two sites in 1995 and 1996. Four carrot cultivars were planted in mid-June at two sites (Memorial University of Newfoundland Botanical Garden (BG) and Agriculture and Agri-Food Canada Research Centre, St. John's (RC)), in a randomized block design, and assessed for the damage caused by P. rosae larvae. At the BG site in 1995, significant damage was found on cv. Danvers Half Long 126 (1.2%), Nantes Half Long received 1.1% damage, Chantenay had 0.9% damage and Flyaway received 0.3% damage. No significant damage was found at this site in 1996 or at the RC site in 1995 or 1996. -- Adult carrot rust flies were monitored with marigold-yellow sticky traps at home gardens and commercial sites in the St. John's area from mid-June to November in 1995 and 1996. One distinct period of adult activity was observed in 1995 whereas two distinct periods were observed in 1996. This reflects the occurrence of one generation per year typically and the possibility of another generation depending upon the season. Two-year means for cumulative air degree-days (DD) above 3°C after 1 April for first, 10%, maximum, and 90% trap catch of the overwintering generation were 308,418,590, and 752 DD, respectively. -- Adult carrot rust flies were trapped in carrot production areas in the regions surrounding Conception Bay, Placentia Bay, Bonavista Bay, Notre Dame Bay, and Bonne Bay. However, even though traps were placed in field in the area around St. George's Bay and in Labrador, no flies were trapped. -- Damage caused  by the larvae of the carrot rust fly was reduced in areas exposed to wind compared to more sheltered areas thus it is possible that carrot rust fly damage can be reduced by planting the carrot crop in exposed areas of the garden or field where the adult will have difficulty flying. -- The study of the seasonal history and distribution of the carrot  rust fly in Newfoundland provides valuable information to producers because it has alerted producers to a potential pest in their production area. The information will provide the farmer with the tools required to understand the activity of the carrot rust fly in the field and consequently accurately time controls. Although many studies have investigated the activity of the carrot rust fly in other parts of Canada and the world, the pest has never been  studied in a climate similar to that found in Newfoundland.


identifier: Jagdale, Ganpati Baburao <https://research.library.mun.ca/view/creator_az/Jagdale=3AGanpati_Baburao=3A=3A.html>   (1993) Catecholaminergic and peptidergic nervous systems of a mermithid nematode, Romanomermis culicivorax, Ross and Smith, 1976.  Masters thesis, Memorial University of Newfoundland.

abstract: The nervous system of the mermithid nematode, Romanomermis culicivorax, was investigated at different developmental stages for the distribution of catecholamine(s) and the neuropeptide FMRF-amide. A glyoxylic acid-induced fluorescence method was used to locate catecholamines, while  FMRF-amide was detected by immunohistochemistry. -- The distribution of sense organs was elucidated by scanning electron microscope studies. Six cephalic sensory papillae (two lateral, two dorso-lateral and two ventro-lateral) and two amphids were found in the head tips of adult nematodes. In males, each lateral papilla contained two pores and each of the dorso-lateral and ventro-lateral cephalic papillae contained three pores. Three pores were present in each of the six cephalic papillae of females. Several caudal sensory  papillae were present in the tails of males, each of which contained one pore. Caudal sensory papillae were absent in the tail of females. -- The catecholaminergic and peptidergic nervous systems increased in complexity during development. In the adult nematode, catecholamine(s) occurred in the nerve ring, ganglia of the nerve ring, cephalic nerves, ventral and dorsal nerve cords and mid-body  region ganglia. The distribution of catecholaminergic ganglia in the tail region was different for each sex. The tail region of males contained 16-20 catecholaminergic ganglia, whereas the tail of females contained only two ganglia. The catecholamine widely distributed throughout the  nervous system of R. culicivorax is not dopamine, since immunoreactivity to dopamine was observed only in the amphids. -- The role of the catecholamine(s) in reproduction  was studied by measuring the fluorescence intensity of catecholamine(s) in the nervous systems of males and females  under different rearing conditions. A significantly greater concentration of catecholamine was recorded in the nervous system of adult males and females than in post-parasitic juveniles. A significantly higher concentration of catecholamines was observed in adults that were reared in physical contact with the opposite sex than in those reared in isolation. Adult males that were reared with females in the same water rearing medium, but physically separated by a barrier, displayed a significantly greater concentration of catecholamines in their nervous systems than did males reared in isolation, but the catecholamine staining intensity of such males was less than in males that were allowed physical contact with females. In adult males, the fluorescence intensity of catecholamines declined progressively during and after copulation. However, in adult  females, the intensity of catecholamines remained constant before, during and after copulation. It is suggested that the catecholamine(s) may play a role in regulating copulatory behaviour, egg production and/or oviposition. -- In adults, FMRF-amide-like peptide was present in the nerve ring, cephalic papillary ganglia, cephalic nerves, amphids, ganglia posterior to the nerve ring, longitudinal nerve cords and several mid-body region ganglia. The distribution of peptidergic ganglia in the tail region was different for each sex. Four clusters of ganglia were present in the tail of females, whereas such ganglia were absent in the tail of males. -- The results suggest that catecholamines and FMRF amide like peptides are widely distributed within the nervous system of R. culicivorax. These substances might function as neurohormones and neurotransmitters in controlling physiological and developmental processes.


identifier: Maddock, Dawn M. <https://research.library.mun.ca/view/creator_az/Maddock=3ADawn_M=2E=3A=3A.html>   (1997) Circumstances of energetic use of white muscle protein in two flatfish species, Hippoglossoides platessoides and Pleuronectes americanus: starvation, natural variation and reproductive demands on white muscle.  Masters thesis, Memorial University of Newfoundland.

abstract: White muscle moisture was examined in two species of flatfish indigenous to Newfoundland waters, the winter flounder (Pleuronectes americanus) and American plaice (Hippoglossoides platessoides), in relation to seasonal cycles and experimentally induced energetic stress. Natural elevation of white muscle moisture observed during the spawning season in H. platessoides reflects protein usage and is probably due, in part, to energetic demands imposed by batch spawning. The observation of developing yolky oocytes coinciding with evidence of recent spawning suggests  the potential to increase fecundity during the spawning season by recruitment of immature oocytes for release in the  current season. This might require further depletion of white muscle protein resulting in the significantly higher muscle hydrations observed at this time. -- Experimental conditions which imposed energetic stress on H. platessoides  as a result of high temperatures caused restricted gonad development if condition of the fish was less than 0.85 prior to setup and allowed maintenance of low white muscle moisture. Low condition fish which underwent reproductive development despite unfavourable conditions, experienced high muscle hydration and resorption of vitellogenic oocytes  was evident upon termination. Those fish with high condition  prior to setup developed their oocytes to a mature, vitellogenic state and maintained significantly lower muscle  moisture than low condition fish which were in similar state  of reproductive development at termination. -- Depletion of white muscle protein is a reversible process. After only four months of refeeding, a rebound in condition and lowered  white muscle moisture was observed in winter flounder, P. americanus, in which low condition and high white muscle moisture had been induced by starvation. The ability to selectively use and rebuild white muscle suggests an energetic storage system which has been developed to deal with energetic demands the fish might face in the wild, including reproductive development and dealing with food shortages. -- Glycerinated single fibre preparations were studied for contractile ability and sarcomere characteristics. Both H. platessoides and P. americanus have  sarcomeres that are considerably shorter than those of mammalian tissue. Intrafibre sarcomere differences were also  noted as sarcomeres near the insertion were shorter than those in the central fibre region. Comparisons between contractile ability of starved versus fed P. americanus were  not quantitative since it was difficult to discern sarcomeres in fibres from starved fish. Contraction was observed in some fibres from starved flounder, probably the result of conservation of individual fibres or groups of fibres.


identifier: Hicks, Barry J. <https://research.library.mun.ca/view/creator_az/Hicks=3ABarry_J=2E=3A=3A.html>   (1992) Laboratory evaluation of the efficacy of the juvenile hormone analog fenoxycarb for controlling the eastern spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae).  Masters thesis, Memorial University of Newfoundland.

abstract: Topical application of the JHA, Fenoxycarb, to various developmental stages of Choristoneura fumiferana (Clms.) showed it to be an extremely promising compound for development as a control agent. Eggs 0 to 24 hr-old were most sensitive; eggs 48 to 12 hr-old and fifth instar larvae  were less sensitive while third instar larvae were refractory. -- Treatment of fifth instar larvae produced morphogenetic effects such as larval-pupal intermediates, supernumerary moulting and deformed pupae and adults. -- Failure of hatching was the most striking effect when C. fumiferana eggs were treated with Fenoxycarb. Embryonic development was blocked by the compound at an early stage, or completed by embryos developing from the same egg mass. Observations of deformed unhatched embryos and some that completed embryogenesis, but died during hatching while partially emerged, suggests that Fenoxycarb disrupted the muscular/exoskeletal system that is needed to allow eclosion  from the egg. Choristoneura fumiferana eggs treated with Fenoxycarb produced numerous abnormalities in the developing  embryos such as miss-orientation and absence of walking appendages. -- Treated eggs that, nevertheless, hatched developed increased mortality in post-embryonic development.  Eggs that were treated with Fenoxycarb and reared to the adult stage exhibited increased mortality prior to or during  the overwinter diapause stage (hibernacula). The overall mortality to the adult stage was significantly higher in treated insects than in controls. -- Temperature and relative humidity altered the efficacy of Fenoxycarb toward early eggs of C. fumiferana. Treated and control eggs were not affected by photoperiod. The optimum temperature to achieve greatest effects of the compound on eggs was 15°C. Relative humidity only became an influencing factor when the  temperature was at 20°C. At that temperature a relative humidity of 60% was shown to be most effective.


identifier: Piercey-Normore, Michele D. <https://research.library.mun.ca/view/creator_az/Piercey-Normore=3AMichele_D=2E=3A=3A.html>   (1993) Effects of damage-induced and developmental changes of white birch (Betula papyrifera Marsh.) on populations of birch casebearer (Coleophora serratella L.) (Lepidoptera: Coleophoridae).  Masters thesis, Memorial University of Newfoundland.

abstract: Insects feeding on a plant may induce changes within the leaves which affect success of insects subsequently feeding on that plant. The objective of this study was to demonstrate if birch casebearer feeding on birch leaves induced changes in the tree that would deter subsequent feeding by the same insect species. -- White birch trees were divided into four treatment groups of five trees each. Treatments consisted of birch leaves being severely damaged by insect feeding, lightly damaged by insect feeding, mechanically damaged with no insects present, and control with neither type of damage. Comparisons were made among treatment groups for 1) changes in the leaves, 2) population size of the birch casebearer at various times of the season,  and 3) effects of damage-induced leaf changes on larval size. Damage-induced changes in the leaves were evident in nitrogen and phosphorus levels between 1991 and 1992, long-shoot length and number of buds, and bud development and leaf senescence. These changes were likely a result of nutrient depletion by insect feeding the previous year, reducing the tree's ability to compensate for losses. Population size of the birch casebearer between treatment groups changed very little throughout 1991 and 1992 suggesting that moths did not move far from the site of pupation. Positive correlation between nitrogen levels and egg density suggested that female moths might be able to distinguish between high and low leaf nitrogen levels, though this could occur within the same tree. Since headcapsule widths of Instar II larvae did not differ significantly between treatment groups, it appeared that damage-induced changes of white birch had no measurable effect on larval size. -- Leaf developmental changes, measured as water potential, water content, and fresh and dry leaf weights, were compared with seasonal changes in plant and insect life history stages. Egg hatch coincided with second leaf flush. Since eggs were laid on old leaves, it was suggested that Instar I larvae took advantage of nutrients being mobilized out of the older leaves and moving into younger leaves. -- The study showed no evidence for damage-induced leaf changes affecting success of the birch casebearer. However, there was speculation that the unusual life history pattern of the birch casebearer was adapted so that Instar I and II larvae could take advantage of mobilized leaf nutrients, lower water contents, and water potentials late in the season. Instar III and IV larvae, with faster growth, could take advantage of high leaf nutrients early in the season.


identifier: Thatcher, Sarah Janice <https://research.library.mun.ca/view/creator_az/Thatcher=3ASarah_Janice=3A=3A.html>   (1987) Effects of macrograzers and micrograzers on enclosed, in situ phytoplankton assemblages in a Newfoundland lake.  Masters thesis, Memorial University of Newfoundland.

abstract: The effects of macrograzing and micrograzing on enclosed, in situ phytoplankton assemblages were examined in a Newfoundland lake. Chambers with inner and outer compartments, were deployed in Hogan's Pond during three experiments each lasting 13 days. Samples were collected every other day from both chamber compartments and the lake water. In two experiments, the macrograzer Diaptomus minutus  (Copepoda) was initially added to the outer compartment of the grazed chamber, and in a third experiment Bosmina longispina (Cladocera) was added. Macrograzer metabolites were able to pass through fine gauze between the two compartments. Thus the chemical effects of the macrograzers were observed in the inner compartment while the physical effects were the dominant treatment in the outer compartment. Micrograzer effects were investigated in chambers without added macrograzers in all three experiments. -- Micrograzing effects, the physical effects of macrograzers, and the chemical effects of macrograzer metabolites on phytoplankton assemblages were evaluated. Grazing effects were examined in each experiment by a priori  comparisons of phytoplankton densities between the chamber compartments and the lake water. -- Densities of some of the  desmid species were depressed by the physical effects of macrograzers. Some individual taxa, such as Arthrodesmus triangularis var. rotundatus and Mesotaenium sp., were augmented under the chemical effects of the macrograzer metabolites. Physical effects of macrograzers were more marked than the micrograzer effects on the Chlorophyceae and  the microflagellates. Micrograzers may affect the species composition and abundance of the chlorophycean taxa within phytoplankton assemblages. -- With the exceptions of Synedra sp. and Tabellaria fenestrata var. lacustris the diatoms were unaffected by the grazers. The Chrysophyceae were little affected by micrograzing and physical effects of macrograzers, in contrast to chemical effects of macrograzer  metabolites that were evident for individual species. Several of the Cyanophyceae were augmented in the presence of micrograzers; some individual species, e.g., Microcystis aeruginosa, were augmented by both physical and chemical effects of macrograzers. -- Key words: Macrograzers; micrograzers; phytoplankton; assemblages; Newfoundland; lake.


identifier: Young, Terry-Lynn <https://research.library.mun.ca/view/creator_az/Young=3ATerry-Lynn=3A=3A.html>   (1988) Effects of several insect growth regulators on the cabbage maggot, Delia radicum Linnaeus (Diptera: Anthomyiidae).  Masters thesis, Memorial University of Newfoundland.

abstract: A procedure was developed for maintaining a stock colony of the cabbage maggot, Delia radicum (Linnaeus), in the greenhouse, A petri dish rearing method producing a high yield of adults was developed for laboratory screening of insect growth regulators against this pest. -- Topical application of the chitin synthesis inhibitor, diflubenzuron  (Dimilin ®), at a rate of 1.0 μg per egg significantly reduced hatch of 24-28 hour old eggs and caused 100% mortality of first instar larvae before they could feed on rutabaga slices. Diflubenzuron had no effect on mature larvae or pupae of D. radicum. Methoprene (Alttosid ® 5E), a  juvenile hormone analogue, applied at the same dose, did not  adversely affect egg hatch but prevented the eclosion of adults from pupae that subsequently developed from treated eggs. Pupal-adult intermediates were, observed inside treated puparia. Treatment of mature, post-feeding larvae and recently formed pupae with methoprene also produced non-eclosing pupal-adult mosaics. A dose of 0.05 μg per larva completely suppressed adult eclosion. However, diflubenzuron  applied to third instar larvae or pupae did not affect adult  eclosion. Juvenile hormone I and the anti-juvenile compound,  precocene II, did not affect D. radicum when applied to the egg, larval or pupal stages. -- Thin-layer chromatography and colorimetric analysis of hemolymph metabolites 36 hours after treatment of post-feeding larvae demonstrated that methoprene caused a significant reduction in trehalose, the predominant carbohydrate in the hemolymph. Methoprene did not disrupt hemolymph amino acid or protein concentrations. -- This study suggests that methoprene and diflubenzuron are  potential insecticides against D. radicum and that further studies on their effectiveness in the field and basis of disrupted development in D. radicum and other non-target insects is warranted.


identifier: Metusalach, 1960- <https://research.library.mun.ca/view/creator_az/Metusalach=3A1960-=3A=3A.html>   (1995) Effects of stocking density on performance, proximate composition and pigmentation of cultured arctic charr (Salvelinus alpinus).  Masters thesis, Memorial University of Newfoundland.

abstract: The effects of stocking density on performance, proximate composition and pigmentation of cultured Arctic charr (Salvelinus alpinus) were studied. Results indicated that specific growth rate (SGR), feed conversion ratio (FCR), and  protein efficiency ratio (PER) of fish were significantly (p<0.05) influenced by stocking densities, but no significant (p>0.05) effects were evident in the hepatosomatic index (HSI) of fish. These performance parameters of fish correlated inversely with stocking density at 40, 50 and 75 kg/m³ (r = -0.9522 for SGR, -0.9696  for FCR, -0.9886 for PER, and -0.9059 for HSI). Although SGR, FCR and PER of fish from different stocking densities varied significantly (p<0.05), their final weights did not. -- Results also indicated that while the moisture content decreased, protein and lipid content increased as fish grew;  the mineral content remained relatively unchanged over this period. Analyses indicated that moisture, protein and lipid content varied significantly (p<0.05) among density groups while ash content did not. Regression analysis showed that moisture and ash content were directly related to stocking density (r = 0.9440 and 0.9994, respectively), whereas protein and lipid content were not (r = -0.5394 and -0.7030,  respectively). -- The total amino acid content of fish varied significantly (p<0.05) according to stocking density and sampling dates. Aspartic acid, glutamic acid, leucine and lysine were the most abundant amino acids present, whereas hydroxyproline was the least abundant. The free amino acid content of the fish also varied significantly (p<0.05) and inversely with stocking density (r = -0.9441) and sampling dates. The major free amino acids were anserine, taurine, glycine and alanine. -- Lipid fatty acid composition of charr flesh was relatively unchanged over the course of the experiments. Among density groups, fatty acid contents of fish flesh were also relatively similar. Unsaturated fatty acids were the dominant fatty acids, accounting for up to 75% of the total lipids. Saturated and monounsaturated fatty acids correlated inversely with stocking density (r = -0.9914 and -0.9963, respectively), whereas polyunsaturated fatty acids correlated directly with stocking density (r = 0.9984). -- The Hunter L*. a*, b* values varied significantly (p<0.05) among density groups. For belly skin, these colour parameters decreased with increasing stocking density. No correlation was observed between the total carotenoid contents of fish skin and these  colour parameters. On the other hand, the Hunter L* values of fillets and homogenized tissues were inversely correlated  with their carotenoid contents (r = -0.9245 to -0.9844, respectively), whereas their Hunter a* and b* values were directly correlated with total carotenoid contents (r = 0.9040 to 0.9824 for a* values and 0.9527 to 0.9924 for b* values, respectively). -- The content of carotenoid pigments  in flesh and skin of charr increased with duration of feeding on pigmented diets. After 11 to 16 weeks of feeding on a canthaxanthin-pigmented diet, fish flesh attained the required level of carotenoids (3-4 mg/kg wet tissue) considered sufficient for providing a satisfactory colour impression. However, stocking density did not correlate with  flesh carotenoid concentration (r = -0.6034). Canthaxanthin,  echinenone, 4'-hydroxyechinenone, lutein and its esters, isocryptoxanthin and β-carotene were identified in different  organs of charr. Canthaxanthin was the main carotenoid in charr flesh, whereas β-carotene, lutein esters and 4'-hydroxyechinenone, and echinenone were the dominant carotenoids in charr skin, gonads and liver, respectively. Canthaxanthin was not detected in the liver of fish. Therefore, dietary carotenoids may be deposited in different  organs as such or may undergo reductive changes.


identifier: Lu, Chung-Cheng <https://research.library.mun.ca/view/creator_az/Lu=3AChung-Cheng=3A=3A.html>   (1968) Determination of growth and related phenomena in Illex Illecebros Illecebrosus (LeSeur) (Decapoda: Cephalopoda) from Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Sampling of the short-finned squid, Illex illecebrosus illecebrosus was undertaken during October and November, 1965; and July through October, 1966, at Holyrood, Conception Bay, Newfoundland. A total number of 1,262 squid was involved in the study of growth, sexual maturity, food, and various morphometrical indices associated with growth. From these squid, 400 mandibles were chosen to study with respect to the morphometry, pigmentation, and possible growth marks. -- Monthly samples show an increase in mantle length from July through October. A decrease in the mantle length occurs in the November samples, suggesting the appearance of a younger generation or second population. It is proposed that the spawning season for this species is from December through May of the following year. The spawning ground is postulated to be in the deeper water (i.e., 200 fathoms) of the various bays, or the deep water on the adjacent continental shelf. -- Analyses of the gastric and caecal contents indicate that fish is the main item in the diet. Cannibalism is found to be predominant in larger squid late in the inshore season. The wide variety of  food items found in the alimentary canal, suggests that this  squid demonstrates little selectivity in choice of prey. -- Morphometric indices HLI, HWI, MWI are found to decrease as the animal grows, indicating the growth of this animal is faster in length than in width. Index MEI also decreases as the animal grows, indicating the rapid development of the gonad and liver in this animal during its inshore migration.  The decrease in MEI differs in rate with sex beyond a mantle  length of 195 mm. in that the males mature earlier. The fin configuration is maintained unchanged throughout the size range studied, and therefore is identical in growth pattern to that described elsewhere for Lolliguncula brevis. -- The mandibles present an interesting field of future study. The growth of the mandible is isometric and detailed analysis indicates that a more valid relationship can be demonstrated between the size of the mandible and mantle length, than can  be between mandible size and total body weight. The pigmentation of the wing of the lower mandible was studied by microprojection and microplanimeter and it is evident that a major change in the degree of pigmentation is correlated with an increase in mantle length, gonad weight and the advent of sexual maturity in both sexes. -- Microrings have been found on both the lateral wall of the lower mandible and as concentric lines in the otolith. Although the number of these mandibular microrings increases  with size of the mandible, and therefore with age and maturity of the squid, no pattern or cyclic nature to their groupings could be distinguished at this time.


identifier: Smedbol, R. Kent <https://research.library.mun.ca/view/creator_az/Smedbol=3AR=2E_Kent=3A=3A.html>   (1994) Evidence for inshore spawning of Atlantic cod (Gadus morhua) in Trinity Bay, Newfoundland, from 1991 to 1993.  Masters thesis, Memorial University of Newfoundland.

abstract: The objective of this thesis was to determine if northern Atlantic cod (Gadus morhua) spawn in Trinity Bay, Newfoundland. Prior to this study, only indirect evidence existed for inshore spawning by cod along the northeast coast of Newfoundland. Research reported here confirms that Atlantic cod spawn in Trinity Bay, Newfoundland, during the early summer on an annual basis. This conclusion is supported by evidence from three lines of investigation. These are 1) the observed progressive maturation of inshore cod from spawning to spent condition, 2) direct observation of a spawning aggregation of cod in Trinity Bay, and 3) the presence of recently spawned cod eggs (≤ 10 days old) in the  bay. A spawning "window" in Trinity Bay from mid-June to early July is estimated for the period of 1991-1993. This timing of spawning was delayed relative to offshore spawning  components of Atlantic cod at similar latitudes. A simple model was proposed to explain this delay based upon the temperature to which inshore cod were exposed during the winter. Predictions of oocyte development times in female Atlantic cod were in phase with observed spawning times. Predictions using cumulative degree-days calculated from monthly seawater temperature profiles were less able to explain the temporal component of the spawning window in Trinity Bay.


identifier: Potter, Tracy Marie <https://research.library.mun.ca/view/creator_az/Potter=3ATracy_Marie=3A=3A.html>   (1995) Exfoliation of epithelial cells in the scallop, Placopecten magellanicus (gmelin)-seasonal variation and the effects of elevated water temperatures.  Masters thesis, Memorial University of Newfoundland.

abstract: It has previously been shown that large numbers of ciliated and non ciliated cells (6-15μm) were released by adult sea scallops, Placopecten magellanicus, during summer months in Newfoundland. Proportions of scallops exfoliating cells was closely correlated with maximum water temperatures and peak gametogenic activity in this area. These results suggested that epithelial sloughing could be a response to stresses associated with elevated water temperatures and/or spawning activity. Scanning electron microscopy (SEM) was used to illustrate the damage to the pallial structures, particularly the disappearance of ciliated cells from the gills, mantle and gonad in specimens known to have sloughed cells. -- In the first component of this study, juvenile and adult sea scallops were monitored during 1992-93 to establish whether or not this species exfoliated epithelial cells throughout the year. An electronic particle counter was used in this seasonal study to distinguish epithelial cells from natural particulate matter and instantly determine which scallops were exfoliating cells, Both juvenile and adult scallops released relatively small amounts of epithelial cells during most months of the year. This observation for juveniles and for adults monitored during months when gametogenic activity was minimal, indicated that exfoliation does not occur as a result of reproductive activity alone. SEM analysis revealed little difference in surface characteristics of the gills, mantle and gonad from scallops observed to have sloughed small numbers of cells when compared to tissues from scallops that had apparently not sloughed any cells at all. These low rates of epithelial exfoliation throughout the entire year and lack of damage to the pallial tissues were considered to be consistent with cellular turnover and normal physiological function. -- In the second component of this study, adult scallops were monitored to determine the effects of elevated water temperatures (14-21.0°C) on the frequency (proportion) of scallops sloughing cells and the rates of cell release. A baseline sloughing rate of approximately 5,300 cells minute⁻¹ was established for scallops held at ambient temperatures of approximately 8.0 to 10.0°C. Sloughing rates greater than this were considered to be a measurable response to stress associated with elevated water temperatures. Only at the highest experimental temperature (21.0°C) were sloughing rates significantly higher than baseline levels. SEM analyses revealed some damage to gills, mantle find gonad tissue when scallops were exposed to relatively high temperatures for short periods of time, less than five days. -- This is the first study to establish that a species of marine bivalve is exfoliating cells throughout most of the year and that an environmental stressor, such as elevated water temperatures, can produce a detectable increase in sloughing rates. The determination of exfoliation rates using this technique may prove to be a useful quantitative of environmental stress, including anthropogenic pollutants, not only for this species but possibly for many others.


identifier: Riehl, Michael Wilfred <https://research.library.mun.ca/view/creator_az/Riehl=3AMichael_Wilfred=3A=3A.html>   (1993) Elemental analyses of Oikopleurids and factors affecting house production rate of Oikopleura vanhoëffeni (Tunicata, appendicularia) in coastal Newfoundland waters.  Masters thesis, Memorial University of Newfoundland.

abstract: Oikopleura vanhöeffeni and O. labradoriensis are cold-water pelagic tunicates that are abundant in coastal Newfoundland waters. The oikopleurid feeding apparatus or ‘house’ is a secreted structure which can be discarded and replaced in response to animal disturbance or house clogging. This study examined the energy costs associated with house production and factors that affect the frequency of house abandonment. -- The elemental content of O. vanhöeffeni and O. labradoriensis increased at about the third power of trunk and tail length. The mean C:N ratio of O. vanhöeffeni in this study was 3.51 (n=203) and for O. labradoriensis. 3.57 (n=12). These values are similar to others reported in the literature. -- Elemental analyses of 11 newly-secreted O. vanhöeffeni houses showed that ‘new’ houses had a mean carbon content of 8.38 μg C (7.5% of body carbon) and a mean nitrogen content of 2.60 μg N (20.1% of body nitrogen). No relationship was found between carbon measures of ‘new’ houses and of the animals that produced them; similar- sized animals showed a five-fold variation in house carbon content. Upwards of 88 μg C of natural particulate material were trapped within a single house. -- The mean house production rate (HPR) for O. vanhöeffeni was 1.7 houses day⁻¹ (n=104), and for the somewhat smaller O. labradoriensis. the average was 2.3 houses day⁻¹ (n=8). HPR between species was not significantly different. Food availability was the most important variable affecting HPR. No relationship could be determined for temperature vs HPR, and POC vs HPR. -- The O. vanhöeffeni house elemental content and HPR from this study indicated that a mean daily carbon investment of 14.3 μg C (13% of body carbon day⁻¹) was required for the house structure. Additional energy investment would be required for house secretion, expansion and other metabolic processes.


identifier: Srivastava, Rakesh Kumar <https://research.library.mun.ca/view/creator_az/Srivastava=3ARakesh_Kumar=3A=3A.html>   (1990) Measures of egg quality and hatchery performance of Arctic charr (Salvelinus alpinus L.) and Atlantic salmon (Salmo salar L.).  Masters thesis, Memorial University of Newfoundland.

abstract: The present study examined how morphological, biological and biochemical characteristics of eggs correlated with overall performance (survival, growth) of eggs and alevins of Arctic charr (Salvelinus alpinus) and Atlantic salmon (Salmo salar). In addition, the effect of time of stripping on biochemical composition of laboratory-reared charr eggs was studied, and the biological, morphological and biochemical egg quality criteria of cultured and wild Atlantic salmon (anadromous) were compared and evaluated. Fertilization and hatching success, growth and survival of developing embryos, alevins and fry were recorded as biological measures of egg quality. These measures were compared to levels of protein, lipid, carbohydrate, moisture, ash, total and free amino acids as potential biochemical indicators, and to egg size, yolk-sac volume at hatching, alevin size at hatching and age at hatching as potential morphological indicators of egg quality. -- For Arctic charr, eggs collected in the middle of the spawning period had the highest protein, lipid, carbohydrate and energy content, which were associated with higher fertilization and hatching success, and growth and survival of embryos, alevins and fry, than that of eggs collected early or late in the spawning period. Eggs collected from wild Atlantic salmon had higher protein, lipid, carbohydrate and energy content and concomitantly higher fertilization and hatching success, faster development and greater growth and survival of embryos, alevins and fry than those collected from cultured stock. The total amino acid pool, and the protein, lipid, carbohydrate and energy content of eggs, alevins and fry decreased simultaneously during embryonic development of both Arctic charr and Atlantic salmon because they were utilized in metabolic processes. -- Egg diameter and alevin length were positively correlated with egg weight and alevin weight, respectively. There was no correlation between egg weight and alevin weight or egg diameter and alevin length at hatching for either Arctic charr or Atlantic salmon. -- The amino acids, serine, valine, tryptophan, lysine, isoleucine and threonine were important for growth and survival of embryos, alevins and fry of Arctic charr. However, alanine, aspartic acid, histidine, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tyrosine and valine were important for growth and survival of embryos, alevins and fry of Atlantic salmon. -- It is suggested that energy level and/or amino acid content of eggs could be used as a condition index for the future development, growth and survival of embryos and alevins of salmonids.


identifier: Norman, John E. <https://research.library.mun.ca/view/creator_az/Norman=3AJohn_E=2E=3A=3A.html>   (1995) Molecular systematics of Plicaria and Peziza (Pezizaceae: Ascomycetes): taxonomic implications and pattern of adaptation to postfire habitats.  Masters thesis, Memorial University of Newfoundland.

abstract: Morphological similarity between Plicaria, which has spherical spores, and Peziza, which has elliptical spores, has lead to a great deal of disagreement over the recognition of Plicaria as a valid genus. The first objective of this study was to determine if Plicaria represented a phylogenetic grouping of taxa distinct from Peziza. Both taxa also show similarity in having adapted to occur in burned habitats following fires. The second component of this study was to compare the pattern of adaptation to burned habitats in Plicaria and Peziza. -- To determine the phylogenetic relationships of Plicaria to Peziza and selected members of Pezizaceae, DNA sequences were obtained from the Small Subunit (SSU) gene, 3’ Internal Transcribed Spacer region (ITS-1) and Large Subunit (LSU) gene of the nuclear-encoded ribosomal DNA. -- Parsimony analysis of nucleotide characters showed that Plicaria and elliptical-spored Peziza species with a similar suite of morphological characters (Plicaria-like-Peziza) formed a closely-related monophyletic group distinct from other Peziza species. This makes Peziza paraphyletic, which can be dealt with by allowing Peziza to subsume Plicaria, merging Plicaria-like- Peziza species with Plicaria, or assigning members of the Plicaria-like-Peziza group to a separate genus. -- Mapping of burn association character on the inferred phylogeny revealed that several monophyletic groups have evolved in association with postfire sites. All taxa that branch basally within the Plicaria/Plicaria-like-Peziza clade are postfire species. This suggests that the ancestral condition is association with burns. A similar relationship was found within the Peziza clade but only a small number of taxa were sampled from this group


identifier: Therriault, Thomas Wayne <https://research.library.mun.ca/view/creator_az/Therriault=3AThomas_Wayne=3A=3A.html>   (1996) Mercury concentration in fish as a function of change in reservoir size.  Masters thesis, Memorial University of Newfoundland.

abstract: Increased fish mercury concentrations are often observed following impoundment of a reservoir. Following impoundment, there is a flux of organic matter and nutrients from the flooded soil, providing food to bacterial communities which methylate inorganic mercury. Based on the hypothesis that mercury enters a reservoir via the flooded soil, I investigated whether the change in fish mercury concentrations could be predicted from the change in reservoir size. Mercury monitoring data for three fish species, northern pike (Esox lucius), walleye (Stizostedion vitreum), and lake whitefish (Coregonus clupeaformis) from reservoirs in northen Manitoba and northern Quebec were used to derive parameter estimates for four models. Models were evaluated on their ability to predict cases not used in the model development. Models were applied for predictive purposes to assess the impact of creating a reservoir and to assess the impact of altering the size of an existing reservoir. Skill (closeness of predicted and observed values) and explained variance were also used to assess the models. The preferred models consisted of a single enrichment term (a measure of change in flooded area) that successfully predicted the mercury ratio. This study also demonstrated that parameter estimates for one species could be applied successfully to predict the mercury ratio for species with comparable food habits.


identifier: French, Kenneth J. <https://research.library.mun.ca/view/creator_az/French=3AKenneth_J=2E=3A=3A.html>   (1997) Mercury evolution in freshwater fish from reservoirs in Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: Return times of 7-12 years have been recently hypothesized for salmonids collected from recently (post-1980) created reservoirs in NF. These return times have been primarily based on reservoir age though factors such as the flooded riparian zone and acidity have all been postulated to affect return times. It was the goal of this study to improve upon predictions of return times for Newfoundland by expanding the current database of mercury in fish and by incorporating several of these factors. -- An investigation into sediment mercury levels in 34 non-impounded headwater lakes across NF indicated that acidity had no effect on the amount of mercury accumulated at the lake bottom. Watershed area to lake area ratio (WA:LA) was found to be significant in explaining the variation observed in sediment mercury levels. This suggested that large watershed can deposit significant amounts of mercury sorbed to organic material to small lakes that then act as sinks for this metal. This relationship was further supported by the positive correlation between lake colour and WA:LA. -- The slope of the relationship between mercury concentration and fork length for salmonids was found to change significantly over time. Reservoir age and conductivity were found to be significant in predicting the slope of the relationship between fish mercury levels and fork length for ouananiche (Salmo salar) and brook trout (Salvelinus fontinalis). Only the per cent Area Flooded was significant in predicting the slope for arctic charr (Salvelinus alpinus). Slope variability between the three control ponds and between pre-impoundment and post-impoundment mercury data precluded determination of return times for either species. -- An investigation into mercury time series data for a number of impounded and non-impounded sites indicated that high slopes may be characteristic of non-impounded sites and of old reservoirs. Results suggested that impoundment lowers the slope during the first 4 to 5 years following inundation by increasing mercury levels in smaller fish more so than in larger fish. Slopes appeared to return to pre-impoundment levels approximately 5 to 6 years after inundation. Weighted regression indicated that mercury increase in a selected size interval following impoundment was 8 to 73 times faster than the decline after mercury levels peaked.


identifier: McKelvie, Douglas Scott <https://research.library.mun.ca/view/creator_az/McKelvie=3ADouglas_Scott=3A=3A.html>   (1984) Mesopelagic fishes of the Newfoundland basin: the discreteness of pelagic faunas.  Masters thesis, Memorial University of Newfoundland.

abstract: Samples collected with a large midwater trawl were used to describe the mesopelagic fish fauna of the Newfoundland Basin. This fauna was found to be depauperate relative to fish faunas to the south. Cluster analysis, ordination and recurrent groups analysis of samples from the Newfoundland Basin, slope “Water and Gulf Stream revealed a gradation between faunas rather than discrete groups. The higher diversity of the Slope Water fauna suggested it was an ecotone between a subarctic and subtropical fauna. The results question the presence of communities in pelagic environments. -- Comparisons of species composition among samples supported the hypothesis that the North Atlantic Current is an extension of the Gulf Stream with a substantial influence of the Slope Water. Differences in the size composition of faunas were found between the Newfoundland Basin and the Slope Water.


identifier: Chadwick, E. M. P.(Edward Michael Pakenham) <https://research.library.mun.ca/view/creator_az/Chadwick=3AE=2E_M=2E_P=2E=28Edward_Michael_Pakenham=29=3A=3A.html>   (1982) Dynamics of an Atlantic salmon stock (Salmo salar) in a small Newfoundland river.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Dynamics of an Atlantic salmon stock (Salmo salar L.) were studied in a small Newfoundland river, Western Arm Brook. The study examined dynamics of smolts, parr and adults. Smolt production was influenced by annual variation in year-class strength, smolt age, sex ratio and size. Year-class strength was significantly correlated with egg deposition. This was the first stock-recruitment relationship to be developed for Atlantic salmon. Supportive evidence was found  on two other Newfoundland rivers, Indian and Little Codroy. On Little Codroy River, year-class strength of smolts was correlated (P < 0.01) with potential egg deposition of adults counted as kelts. On Indian River, egg to fry survival was correlated (P < 0.01) with winter temperature and discharge. On Western Arm Brook, smolt age was significantly correlated (P < 0.01) with annual mean monthly  air temperature. Evidence was presented for density-dependent influence on both smolt age and sex ratio. Size of  smolts had the lowest annual variation of all biological characteristics. Fork length, weight, ovarian weight and especially annual instantaneous growth rates of smolt were significantly (P < 0.01) different between smolt ages. Ovarian weight of smolts was inversely correlated (P = 0.01)  to sea age of adult salmon in 34 Newfoundland rivers. -- Biological characteristics of parr were significantly different between the four habit types: steadies, riffles, outflows and lakes. Parr from riffles were smaller and younger. Parr in outflows grew most during the summer season. However, parr did not remain within habitats and there was a net downstream movement. Downstream movement of parr was significantly correlated with the size of the smolt  run in the same year. Mean production in lake and steady habitats was 0.07 g m⁻² y⁻¹, and it was 2.23 g m⁻¹ y⁻¹ in riffles and outflows. Maximum production was estimated to be  5.47 g m⁻² y⁻¹. Only 33% of smolts were produced in riffles and outflows; the remainder were produced in lakes and steadies which comprised 98.6% of habitat accessible to salmon. Production was correlated with standing stock and over 50% was contributed by the second and third age groups. -- This paper presented the first evidence that a commercial  fishery selected larger and older 1SW salmon. 1SW salmon spend one year at sea before first spawning. Grilse taken in  the local fishery of St. Barbe Bay were significantly (P < 0.01) greater in fork length, whole weight, condition and smolt age than grilse entering the river. Selection for older smolt ages was due to a significant correlation between size and smolt age. The fishery also selected a greater proportion of repeat spawners and almost all 2SW salmon. Consequently fish which spawned were smaller and younger than in unexploited populations. There was also a considerable loss of iteroparity as a result of exploitation. -- A model was proposed to describe Atlantic salmon stocks in exploited and unexploited states. The model  was based on density-dependent growth in freshwater. At low stock densities, salmon parr grew faster and went to sea at younger smolt ages. Faster growth induced precocity in male parr and shifted the sex ratio of the smolt migration to be predominantly female. At carrying capacity, smolt ages increased and smolt production was stabilized due to overlapping of year-classes. The economic benefit of increased stream biomass was a stable yield to the fisheries. The model was compared to trends in the commercial fisheries which included a 40 yr cycle of abundance, and declines in sea age and smolt age. A significant correlation between stock abundance and smolt age corroborated the proposed biomass model.


identifier: Arulnayagam, Daisy Chandrika <https://research.library.mun.ca/view/creator_az/Arulnayagam=3ADaisy_Chandrika=3A=3A.html>   (1995) Effect of clear-cutting on the diversity and distribution of Collembola in western Newfoundland balsam fir-Dryopteris and Equesetum-rubus forests.  Masters thesis, Memorial University of Newfoundland.

abstract: The diversity and distribution of Collembola in western Newfoundland balsam Ill- forests were studied to determine if these forests return to their original conditions in respect to their biota, especially the collembolan community, when they regenerate after clear-cutting. The study was carried out in two different balsam fir forests of three different ages. They included balsam fir Dryopteris (FD) and balsam fir Equisetum-Rubus (FE) forest of 40 year old regrowth, 60 year old regrowth and old uncut forests. Within each type of forest two replicate sites of each of the three different ages were selected. Three types of samples, pitfall trap samples, microhabitat samples, and soil samples, were collected from the FI) forest. Soil samples were collected from the FE forest. -- Pitfall traps were used in the FD forest in summer 1992. Most of the species collected in pitfall traps were large, surface dwelling collembolans. Fifteen species were collected in the old forest and 14 and 19 species were collected in 40 and 60 year old forests, respectively. Tomocerus flavascens, T. minor, Entomobrya multifasciata, Orchesella cincta and Neanura muscorum were the dominant species in all sites. Pitfall traps did not reveal differences in collembolan communities between the different aged forests. -- Various microhabitats were sampled in the FD forest in summer 1993, including rotten wood, tree holes, deciduous leaves, moss from live and dead tree, lichen from live and dead tree, and bark from live and dead tree. Thirty-five species of Collembola were collected from all microhabitats in the old forest. Twenty-seven and 32 species were collected in 40 year and 60 year old forests respectively. Folsomia penicula and Isotomiella minor were the dominant species in the microhabitats on the ground. One species, Uzelia setifera, was collected only in the microhabitats on trees. -- Soil samples were collected in summers 1992, 1993 and June 1994 in the FD forest and in summer 1994 in the FE forest. Ten samples, each a cube of surface litter and soil, 10cm x 10cm x 10cm deep, were collected from each site on each sampling date. Each sample was cut into two horizontal halves, and each half was extracted separately in modified Berlese funnel. A total of 53 species representing 29 genera of Collembola were collected from the soil samples. The mean densities and diversity of the Collembola collected in the upper halves of the soil samples were higher than those of the lower halves on each sampling date, except Tullbergia granulata was more abundant in the lower halves. Mean densities of Collembola in the FD forest varied between 174.4 to 849.2/1000cm³ and in the FE forest 209.0 to 572.0/l000cm³. Seasonal patterns were observed in the proportion of Collembola occurring in the lower half of the samples and in the total number of Collembola collected in the FD forest. In the late summer the proportion of Collembola in the lower half of the samples was higher than that of the early summer, and the total abundance was higher in June and August than in July. -- In both FD and FE forests, old sites had the highest species diversity and abundance. In the FD forest, the 40 year old site had the lowest species diversity and the 60 year old forest had the lowest density. In the FE forest, 40 year old sites had both lowest species diversity and density. Two species, Folsomia penicula and Isotomiella minor were the dominant species in both forest types, comprising about 50-70% of the total number of Collembola. Tomocerus flavascens, Stenogastrura hiemalis and Isotoma (Desoria) beta were collected only in the old forest. T. minor and Willowsia buski were restricted to the regrowth forests, lsotomurus palustroides, Neelus minutus and Neelus incertus were collected only in the FE forest. -- This study indicates that clear-cutting does have a long term effect on the abundance and diversity of Collembola. Forty year old forests had the least diversity, and species diversity increased with forest age. Old forests contained three Collembola species that were not collected from regrowth forests.


identifier: Methven, David Alan <https://research.library.mun.ca/view/creator_az/Methven=3ADavid_Alan=3A=3A.html>   (1983) Identification, growth and ecology of larval and juvenile Urophycis chuss (Walbaum, 1792) and Urophycis tenuis (Mitchill, 1815) (Pisces: gadidae).  Masters thesis, Memorial University of Newfoundland.

abstract: Pelagic Scotian Shelf Urophycis chuss and U. tenuis and Gulf of St. Lawrence Urophycis tenuis were identified using meristic, morphometric and pigment characters. These characters identify U. chuss and U. tenuis larvae as small as 5-7 mm SL. Pelagic U. tenuis are deeper bodied, have a higher caudal finray count and one less epibranchial gill raker than U. chuss. Adult complement of vertebrae, finrays and epibranchial gill rakers are developed for both species by 15.6 mm SL. -- Pelagic Scotian Shelf Urophycis chuss grow 0.9 mm per day or ca. 28 mm per month. Young-of-the-year demersal U. tenuis grow 1.4 mm per day or 42 mm per month reaching ca. 250-280 mm by December. Inquiline U. chuss, associated with the sea scallop Placopecten magellanicus grow 0.4 mm per day or 11 mm per month. Post-inquiline one-year-old U. chuss average a minimum of 200 mm SL. -- Nearshore arrival of pelagic juvenile Urophycis tenuis is delayed with increasing latitude. U. tenuis, a member of the summer ichthyofaunal arrive and remain nearshore when water temperatures are highest. Time of nearshore arrival and growth data indicate a winter-spring spawning period. U. chuss larvae are pelagic during summer and become inquiline during September-October on the Scotian Shelf. The presence of a larger U. chuss size mode may indicate that two different year classes occupy scallops at the same time. U. chuss prefer larger scallops.