identifier: Dwyer, Eileen E. <https://research.library.mun.ca/view/creator_az/Dwyer=3AEileen_E=2E=3A=3A.html>   (1995) The long term effects of clearcutting on the diversity and abundance of Oribatid (Cryptostigmata) mites of Western Newfoundland balsam fir (Abies balsamea) forests.  Masters thesis, Memorial University of Newfoundland.

abstract: In an attempt to assess long-term effects of clearcutting on oribatid mite populations, oribatid species diversity and distribution were examined in three different aged forest stands (old - uncut, 60 years and 40 years old regrowth) within balsam fir (Abies balsamea) - fern (Dryopteris) (FD) and a balsam fir - horsetail (Equisetum) (FE) forest types.  A total of 360 and 120 soil samples (10 cm x 10 cm x 10 cm) were taken from the two forest types, respectively.  Each sample was subsequently divided into upper and lower 5 cm halves to assess vertical distribution of mites.  Both species diversity and abundance decreased with increasing soil depth.  In addition, relative abundances of smaller oribatid species such as Oppiella washburni and Suctobelbella spp. increased in the lower layers whereas larger species such as Parachipteria travei decreased. -- A series of microhabitat samples were also collected in the balsam fir - fern forest to include as many oribatid species as possible.  One species, Eueremaeus marshalli, occured only in microhabitat samples.  Average abundances of oribatid mites per sample ranged from 344 to 1894 in FD and from 501 to 886 in FE forest types. -- In total, 91 species representing 41 families were collected including 17 new generic and 35 new species records for Newfoundland.  Haplozetes sp. was also collected representing a new genus record for Canada.  The ecology of all species collected is described.  The number of species occurring in any one site ranged from 55 to 65 in the FD sites and from 51 to 59 in the FE sites.  Populations in both forest types were dominated by the same common species: Eniochthonius minutissimus, Synchthonius crenulatus, Steganacarus thoreani, Nanhermannia bryophila, Tectocepheus velatus, Oppiella washburni, Suctobelbella spp. and Parachipteria travei.  Several species were collected from only one forest type and may be useful indicators of differing environmental conditions.  In particular, Epidamaeus longitarsalis, Eupterotegaeus sp., Fuscozetes setosus and Dentachipteria sp. were characteristic of FD sites whereas Gozmanyina majestus, Ceratozetes gracilis, Sphaerozetes arcticus, Eupelops sp. and Propelops canadensis were characteristic of FE sites. -- Separation of the sample sites through cluster and TWINSPAN analysis indicated differences in species diversity and relative abundances between age classes of both FD and FE forests.  However, this separation was most pronounced between the sites of FD forest.  Species richness and diversity tended to be highest in the forty year old sites of the FD forest and in the old sites of the FE forest. -- Oribatid population data from the FD forest was further assessed in relation to soil and vegetation data from the sites using principle components and discriminant function analysis.  This indicated that different forest ages were associated with different soil and vegetation characters as well as different mite species. -- Long-term effects of clearcutting vary between forest types and are more obvious in species diversity and relative abundances than in total oribatid abundances.  These variations in oribatid community structure between the forest age classes are apparently related to successional changes in the maturing forests.


identifier: Richard, Jocelyn Marie <https://research.library.mun.ca/view/creator_az/Richard=3AJocelyn_Marie=3A=3A.html>   (1987) The mesopelagic fish and invertebrate macrozooplankton faunas of two Newfoundland fjords with differing physical oceanography.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

format: application/pdf application/pdf

abstract: Mesopelagic fish and macrozooplankton assemblages were compared between two Newfoundland fjords which contain predominantly different deep-water masses and which differ in the nature and frequency of deep water exchange.  Samples were collected using a 3 m Isaacs-Kidd Midwater Trawl in May 1982 and June 1983.  The species composition of mesopelagic fishes was found to be dissimilar while the macrozooplankton fauna was largely the same.  Melanostigma atlanticum and Benthosema glaciale were the most abundant fishes in Bay d'Espoir while Mallotus villosus was the most abundant fish collected from Fortune Bay.  The macrozooplankton fauna in both fjords consisted largely of Thysanoëssa raschii, T. inermis, Meganyctiphanes norvegica and Sagitta elegans.  Differences in species composition and relative abundances were partly attributed to the difference in deep water properties. -- The structure and persistence of the mesopelagic fish assemblage were related to environmental stability.  In Bay d'Espoir six of thirteen (46 %) species were collected in both years compared to two of eleven (18 %) species in Fortune Bay.  Percentage similarity between years was high in Bay d'Espoir (91.5) and low in Fortune Bay (43.6).  Species composition and rank over abundances within and between years were less variable in Bay d'Espoir than in Fortune Bay, as were catch rates for the dominant species.  These results suggest that the faunal assemblage in Bay d'Espoir was regulated primarily by in situ biological processes while advective processes were more important in Fortune Bay.  Similar results were not obtained for the macrozooplankton assemblage which was thought to respond primarily to short-term or seasonal changes in environmental conditions. -- Species diversity and evenness, and average species richness of mesopelagic fishes was greater in Bay d'Espoir than in Fortune Bay.  Similar results were not obtained for the macrozooplankton faunas and species diversity and evenness were higher in Fortune Bay than in Bay d'Espoir while average species richness was comparable between the fjords.  These indices were not found to be useful in identifying the underlying processes structuring the fjord faunal assemblages.  A comparison of biomass size spectra between the fjords showed no major differences. -- The fish fauna in Bay d'Espoir was probably derived in part from the Laurentian and Hermitage Channels while that of Fortune Bay was probably derived from the St. Pierre and Hermitage Channels.  A small fraction of the fish and macrozooplankton faunas in both fjords was derived from the offshore continental slope region.


identifier: Bourgeois, Charles Edward <https://research.library.mun.ca/view/creator_az/Bourgeois=3ACharles_Edward=3A=3A.html>   (1980) The metazoan parasites of three species of scoters (Melanitta perspicillata (Linnaeus, 1758), M. nigra (Linnaeus, 1758) and M. fusca (Linnaeus, 1758)).  Masters thesis, Memorial University of Newfoundland.

abstract: One hundred and seventy-five (94 surf, 36 white-winged and 45 black) scoters from four localities (British Columbia, New Brunswick, Labrador and Norway) were examined for metazoan parasites, with 91% (159 birds:  86 surf, 33 white-winged and 40 black scoters) being infected.  Approximately 55 species of parasites were found (43 from the surf, 29 from the white-winged and 34 from the black), including 45 which were new host records.  There were 4 new North American records, 4 new Canadian records and 1 new European record.  A checklist of parasites harboured by these birds is presented. -- The number and percent of birds infected, range of numbers and mean number of parasites per infected bird are given.  Also for each host species the number and percent of each sex and age class infected by individual parasites is given.  Parasite species are discussed indiviudally with regard to topics such as location within host, new host records and minor variations from their original description. -- The ecology of the parasites is discussed; the preferred habitat, their geographical distribution and their preference for marine or freshwater, environments are presented.  A short discussion of host specificity is included and the parasites of each host are categorized.  Six parasites were found to occur across the geographic area sampled, with 23 helminths cycling through the marine environment and 19 through the freshwater environment.  Throughout the work the parasite burdens of each host species are contrasted.  In addition the number and percent of species occurring in each geographic locale is compared and contrasted.  Cluster analysis revealed that neither individual birds of a species nor species of birds could be distinguished using parasite fauna and geographical locality as criteria. -- One species of parasite, Polymorphus botulus, was noted to cause damage to its host but was not considered to be lethal.


identifier: Thompson, Bruce Hunter <https://research.library.mun.ca/view/creator_az/Thompson=3ABruce_Hunter=3A=3A.html>   (1989) The ingestion and digestion of algal and other foods by larval black flies (Diptera: simuliidae) of Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Feeding selectivity in larval simuliids of several Newfoundland species was studied by comparing relative abundances of algal taxa in the guts of field-collected larvae with those in the associated seston and periphyton.  With the exception of the first instar of Prosimulium mixtum Syme & Davies, larvae of P. mixtum, Stegopterna mutata Malloch, Cnephia ornithophilia Davies et al., Simulium vittatum Zetterstedt, Simulium venustum Say and S. verecundum Stone & Jamnback utilized the seston almost exclusively for provision of food.  No evidence was found to suggest that algal particles were selected on a qualitative basis, nor did the data indicate striking dissimilarities among species of similar physiological age, as to selectivity based on particle size.  However, differing selectivities on the basis of particle size were observed among conspecific larvae of different physiological age.  C. ornithophilia appeared to be exceptional, showing selectivity for relatively large diatom particles over much smaller bacterial particles, as compared to other species of larvae tested.  Selectivity for particles within a certain intermediate size range (5-15 µm) was comparatively high for this species. -- Measurements of gut passage rates in the eurythermal S. vittatum indicated that feeding rates increased generally with increased temperature and particulate matter (PM) concentration.  Feeding efficiency, however, decreased with increased PM concentration and with increased current velocity.  The completeness of digestion, studied by using diatoms as indicators, increased generally with increasing temperature in S. vittatum and the warm stenothermal S. verecundum.  In P. mixtum, a cold stenothermal species, the reverse temperature relationship was shown.  Algae of different taxa varied markedly in susceptibility to digestion. -- Larvae of different species were capable of utilizing a wide variety of particulate foods, including algae, bacteria and detritus.  In feeding trials, overall larval growth was highest when fed on diatoms, lowest when fed on leaf litter and intermediate when reared on green algae or bacteria.  The nutritional importance of various classes of suspended particulate matter is a function of its availability in the seston, its susceptibility to ingestion, its inherent digestibility and its nutrient content. -- Key words:  Simuliids; filter-feeding; selectivity; grazing; algae; bacteria; digestion; productivity; nutrition; feeding rates.


identifier: Walsh, Stephen J. <https://research.library.mun.ca/view/creator_az/Walsh=3AStephen_J=2E=3A=3A.html>   (1990) Variation and covariation in life-history traits of sharks.  Masters thesis, Memorial University of Newfoundland.

abstract: I used the comparative method to examine the interspecific variation of seven life-history traits across Euselachiians, the modern sharks, in relation to adult body size, phylogeny, mode of reproduction, and ecology.  Life-history traits included adult female length, length at maturity, birth length, fecundity, gestation, age at maturity, and life span.  Body size accounted for a significant amount of explained variation.  Phylogenetic history (order, family, and genus) explained only a small amount of variation and covariation of these life-history traits.  Genera within families and families within orders tended to show similar levels of variation in most life-history traits, but a larger proportion of the variance occurred at the family level of analysis.  Principal component analysis on a reduced number of traits defined an axis ordering sharks from large fecund forms giving birth to many large offspring and small forms with low fecundity and small offspring.  The analysis also defined a secondary gradient in which many small offspring versus few large offspring resulted in an inverse relationship between fecundity and birth length.  Perception of these patterns of covariation fit r/K selection theory.  Analysis within individual families revealed differences from family to family in distribution along the first principal component.  Patterns of covariation at the family level appeared also to be constrained by mode of reproduction (oviparity vs viviparity strategies) interacting with size.  There is some evidence to indicate that the patterns of covariation may be partitioned according to the mode of reproduction, with a separate axis defining each mode.  Ecological associations appeared to have some effect on the evolution of life-history traits, independent of size and phylogeny.  Dietetic and habitat differences were linked to the pattern of covariation of life-history traits.  Birth length differences were associated with geographic distribution, and gestation differences were associated with inshore or offshore residency.  The comparative method was useful in suggesting the kinds of attributes and ecological relationships that could be used in detailed comparisons of life-histories at the intraspecific level.


identifier: Deng, Langtuo <https://research.library.mun.ca/view/creator_az/Deng=3ALangtuo=3A=3A.html>   (1987) The Mycoplasma pneumoniae origin of DNA replication : a study of its ability to function in Escherichia coli.  Masters thesis, Memorial University of Newfoundland.

abstract: Please see thesis for abstract.


identifier: Clark, Kirsten Jane <https://research.library.mun.ca/view/creator_az/Clark=3AKirsten_Jane=3A=3A.html>   (1992) The population dynamics, reproductive biology and geographic distribution of Boreomysis nobilis G.O.Sars 1879 in coastal fjords of Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: The hyperbenthic mysid, Boreomysis nobilis G.O. Sars 1879, is reported from nine new locations around the island of Newfoundland in eastern Canada.  It is most common within and at the mouths of deep fjords and is less common or absent outside these fjords.  Its absence from two bays where the depths, temperatures and salinities are all within the range inhabited by B. nobilis in other bays indicates that other factors are likely influencing local distribution patterns. -- Boreomysis nobilis breeds throughout the year, since all developmental stages were present on all sampling dates.  However, there is a period of increased breeding activity in the late spring and early summer.  An examination of the relationship between brood size, body volume of ovigerous females, and number of stage 1 larvae (eggs) indicates that B. nobilis produces a smaller number of larger eggs than is predicted by the regression calculated for epipelagic and coastal mysids by Mauchline (1980).  This agrees with the conclusion of Wittmann (1984) for epipelagic cold-water species of mysids.  Thus B. nobilis exhibits a more K-selected strategy than its epipelagic counterparts from warmer water. -- The catch rates for B. nobilis are highest in the deep water within 150m of the bottom.  However, no differences are found in the vertical distribution of the different life history stages of B. nobilis and no evidence is found for large-scale diel vertical migrations. -- The parasite Thalassomyces boschmai (Nouvel 1954) is reported from B. nobilis and from Newfoundland waters for the first time.  Its localized distribution in two bays is suggested to be a result of the restricted geographic distribution pattern of its host.


identifier: Sklepkovych, B.O. <https://research.library.mun.ca/view/creator_az/Sklepkovych=3AB=2EO=2E=3A=3A.html>   (1986) The predatory behaviour and impact of red foxes (Vulpes vulpes) on the seabird colonies of Baccalieu Island, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The predatory behaviour of red foxes (Vulpes vulpes) in relation to a large multi-species seabird community was studied on Baccalieu Island, Newfoundland, from 1983-1986.  Fox diet was assessed by examining faecal composition, avian prey remains and larder hoarded prey.  Leach’s Storm-Petrels (Oceanodroma leucorhoa) made up of 75% of scat by wet weight, 89% of remains and 95% of prey items in and scattered about larders.  Black-Legged Kittiwakes (Rissa tridactyla), Atlantic Puffins (Fratercula arctica), Common Murres (Uria aalge) Northern Gannets (Sula bassanus) and Herring Gulls (Larus argentatus) formed 19% of scat by wet weight and 11% of remains.  Comparisons are drawn between seasons and different methods of analysis. -- The Leach’s Storm Petrel population was estimated at 3,360,000 ± 317,000 adult breeding pairs.  Based on harvest levels and the estimated energy requirements of the resident fox population, 31,000 ± 3,000 adult storm-petrels would be taken annually.  Factors which tend to keep predatory impact at low levels are (1) the massive size of the storm-petrel colony and (2) the scarcity on lack of winter food for the foxes.  The high availability of Leach's Storm-Petrels also appears to hold impact on each of the other seabird species nesting on Baccalieu Island at < 1% of their adult breeding populations.  The presence of foxes on Baccalieu Island may also deter ground-nesting avian predators (i.e. Herring Gulls and Great Black-Backed Gulls (Larus marinus)) from nesting and from preying extensively on the resident burrow-nesting seabirds on the island. -- Experiments on the scatter hoarding behaviour of red foxes were conducted in a semi-natural enclosure at Salmonier Nature Park.  At low levels of food deprivation, increased levels of prey abundance were found to decrease the time spent in search of a cache site by foxes.  Increased levels of food deprivation and prey abundance were also suggested to increase the motivation to hoard as evidenced in the decrease in mean time of prey pickup to cache initiation interval.  The time spent caching and subsequent return to the prey patch were not significantly altered by the manipulations and possible reasons for the lack of experimental effect are discussed.  Ninety-seven percent of all prey items set out were cached, of which, 75% were later recovered.  On average, 54% of the available caches were recovered within 192 h of being set out, at a mean rate of 9.3% recovery/day.  These present findings are considered in light of optimal foraging theory.


identifier: Turner, Bruce <https://research.library.mun.ca/view/creator_az/Turner=3ABruce=3A=3A.html>   (1974) The parasite fauna of the green-winged teal (Anas crecca L.) and blue-winged teal (Anas discors L.).  Masters thesis, Memorial University of Newfoundland.

abstract: One hundred and forty-eight ducks (87 Anas crecca Linnaeus; 61 Anas discors Linnaeus) collected from three localities in eastern Canada were examined for parasites.  Ninety-five per cent of the A. crecca were infected; twenty-three parasite species being represented.  Four are new host records and six are new records for A. crecca in North America.  One hundred per cent of the A. discors were infected; twenty-one parasite species being represented, including eight new host records. -- The number and percentage of each sex and age group of both host species infected, and mean and range of parasite numbers per infected bird is given.  Parasite species are discussed with regard to incidence and intensity of infection, location of parasites within host, host records, authorities used in specific determination and minor variations, if any, from previous descriptions.  Infections in the two hosts are compared and differences, if any, are discussed.


identifier: MacDonald, B.A. <https://research.library.mun.ca/view/creator_az/MacDonald=3AB=2EA=2E=3A=3A.html>   (1984) The partitioning of energy between growth and reproduction in the giant scallop, Placopecten magellanicus (Gmelin).  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Populations of the giant scallop Placopecten magellanicus were collected from different water depths at several locations in Newfoundland.  The major objective of this study was to determine whether growth and production differed between populations and, if so, whether such differences were attributable to food availability and temperature regimes.  Population reproductive characteristics such as the annual cycle of gametogenesis, fecundity, reproductive effort, and reproductive cost were also measured to determine if they were directly influenced by environmental variables. -- Additional information was obtained by examining scallops from New Brunswick and New Jersey to determine whether growth and reproductive characteristics are altered by conditions such as temperature known to vary with latitude.  Scallops grown in suspended culture provided an opportunity to study age related growth and reproduction in a population of Placopecten magellanicus introduced to a more favourable but somewhat artificial environment. -- More rapid shell growth rates greater somatic and gamete production, and higher reproductive effort values were recorded for populations growing under more favourable conditions of food and temperature associated with shallow water and suspended culture conditions.  Clearance rates and metabolic rates were well correlated with seasonal changes in environmental variables.  Estimates of reproductive cost suggested that populations P.magellanicus from Newfoundland are generally restrained in their reproductive patterns. - Local environmental conditions strongly influenced production estimates.  This is especially important in any consideration of geographical trends in growth and reproductive characteristics, as the presence or absence of such trends appeared to depend on which characteristic was compared and the methodology used.  Scallops from Newfoundland grew as fast as those collected from more southerly locations and were more productive especially when the apparent temperature advantage available to the latter populations was taken into account.


identifier: Birt, T.P. <https://research.library.mun.ca/view/creator_az/Birt=3AT=2EP=2E=3A=3A.html>   (1985) Parr-smolt transformation in nonanadromous Atlantic salmon Salmo salar and effects of sexual maturation on the parr-smolt transformation in male anadromous Atlantic salmon.  Masters thesis, Memorial University of Newfoundland.

abstract: The parr-smolt transformation was compared in male and female anadromous (SRxSR), nonanadromous (LLxLL) and hybrid (SRxLL) Atlantic salmon, Salmo salar. Seasonal patterns in total lipid content, moisture content, condition factor, silvering, and branchial Na+-K+ ATPase activity indicate that smoltification occurred in immature SRxSR females while previously mature SRxSR males did not smoltify. It was also apparent that, in general, smoltification was not completed in either sex of the SRxLL or LLxLL salmon. Histological examination of gill tissue revealed that chloride cells appeared to decline in number over the summer in fish retained in freshwater, whereas seawater acclimated fish, at this time, had numerous well developed chloride cells. -- Wild anadromous smolts of the Exploits River stock had high branchial Na+-K+ ATPase activity and adapted to seawater without marked elevation of plasma sodium or chloride1 ion concentration. Mortality was high in LLxLL salmon during the course of exposure to seawater and the group exhibited elevated plasma ion concentrations. Induction of branchial Na+-K+ ATPase activity did not appear to lower plasma ion concentrations in LLxLL salmon exposed to seawater. It appears that genetic differences in smolting patterns occur in mature male salmon from anadromous populations. As well, differences appear to exist in adaptability to seawater among stocks of nonanadromous Atlantic salmon. Differences in smoltification patterns in anadromous and nod anadromous salmon are discussed in terms of the evolution of the different life history patterns observed in the two forms.


identifier: Christian, John R. (John Robert) <https://research.library.mun.ca/view/creator_az/Christian=3AJohn_R=2E_=28John_Robert=29=3A=3A.html>   (1995) Patterns of Diel activity and movements of the American lobster, Homarus americanus, as determined by ultrasonic telemetry.  Masters thesis, Memorial University of Newfoundland.

abstract: The diel activity and nocturnal movements of the American lobster, Homarus americanus, were studied using a fixed hydrophone array tracking system at Broad Cove, Conception Bay, Newfoundland. Twenty lobsters tagged with ultrasonic transmitters were monitored at various times between September, 1987 and August, 1990, providing 291 nights of tracking data of which 246 were complete (i.e. an animal was monitored for the entire period of darkness). Positional information on active lobsters was recorded every two minutes, providing both temporal and spatial information on activity and movements. It was assumed that lagging did not have a pronounced or prolonged effect on the activity or movements of subjects. -- Lobsters were active on 28.5 % of all tracking nights. Time of onset of activity in the initial shelters averaged 1.5 h after sunset while time of onset of movement from them averaged 2.4 h after sunset. Lobsters were active at or within the final shelter an average of 52 min while the average time of cessation of activity at the final shelter was 5.7 h after sunset. The duration of the activity period, which corresponded to the interim between onset of activity at the initial shelter and cessation of activity at the final shelter, ranged from 6 min to 12.8 h with a mean of 4.0 h. Total out-of-shelter time ranged from 4 min to 12 h with a mean of 2.3 h. The out-of-shelter period was characterized by movement or stationary behaviour. Behaviour was considered stationary if the transmitter position remained the same for a minimum of five minutes. Otherwise, the lobster was considered to be moving. Average movement times and out-of-shelter stationary times were 1.3 h and 1.2 h, respectively, while respective ranges were 4 min to 6 h, and 0 to 10.2 h. -- There was also considerable variation within and between individual lobsters with respect to distance moved. Two measures of distance were calculated; the maximum distance (MD) of a lobster from its initial shelter and the approximate total distance (ATD) moved by a lobster while out-of-shelter. The averages of maximum distance from the initial shelter and approximate total distance moved were 24 m and 64 m, respectively. The respective ranges of these two variables were 2 to 74 m and 5 to 361 m. On average, large lobsters (> 81 mm carapace length) moved a maximum distance of 27 m from the initial shelter compared to 21 m for small individuals (< or = 81 mm carapace length). Average approximate total distance moved was essentially the same for both size groups. Movements were either simple (mostly straightline movement with little or no path crossover) or complex (numerous abrupt direction changes with much path crossover). Both types were characterized by extensive, wide-ranging patterns and restricted, light patterns. -- Thirty percent of the lobsters returned to the same shelter on the same night while 25% of the lobsters returned to a particular shelter after periods of absence exceeding one day. Certain shelters appeared to be preferred by either one individual or numerous individuals. Shelter fidelity was quite variable between individuals. Some lobsters used the same shelter numerous times while others changed shelters during each activity boul. The average entrance height: width ratio of shelters occupied (0.96) by monitored lobsters was only slightly lower than that of unoccupied shelters (0.97). -- Over seventy percent of the total stationary time occurred in areas with boulder and outcrop substrate. The greatest percentage of total stationary time (49 %) occurred in areas with scattered horse mussel and green sea urchin distributions. Large lobsters (> 81 mm carapace length) moved more frequently (32.5 % vs. 28.X %) than smaller ones (< or = 81 mm carapace length) but the smaller individuals averaged longer activity bouts (5.1 h vs. 2.8h). Large males (35.3 %) and small females (38.7 %) were active more frequently than small males (21.4 %) and the large female (21.3 %). Tagged ovigerous and molted individuals displayed activity consistent with the behaviour described in literature for lobsters in these physiological conditions. Tagged individuals were less active at times of oviposition and molting. In general, activity was greatest at times when water temperature exceeded 8° C (after July 1). Storm events sometimes resulted in the downslope movement of tagged individuals. Lobster activity was slightly higher at times of new moon and first quarter moon compared to times of full moon and last quarter moon.


identifier: Billiard, Sonya Marie <https://research.library.mun.ca/view/creator_az/Billiard=3ASonya_Marie=3A=3A.html>   (1996) A bioindicator approach to measurement of chronic stress in territorial populations of cunner, Tautogolabrus adspersus (Walbum, 1792), adjacent to a non-chlorinated pulp and paper mill in the Humber Arm Estuary, Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: Signs of pathogenicity were quantified in cunner, Tautogolabrus adspersus, living adjacent (Birchy Cove and Summerside) to a non-chlorinated pulp and paper mill in the Humber River Estuary, western Newfoundland, compared with a reference site (Gillams) approximately 12 kilometers downstream of effluent outfall(s).  Several bioindicators of pulp toxicity were utilized, including condition factor, organ somatic indices, macroscopic and microscopic irregularities, parasitofauna, age structure and induction of hepatic mixed function oxygenases.  Condition factors were nonsignificant among sites in contrast to exaggerated growth at impact sites compared to Gillams' fish.  Male and female gonadosomatic indices (GSIs) and histological analyses suggested a delay in spawning and/or gametogenesis of impacted fish versus mature, reference cunner.  However, consideration of the short reproductive cycle of this species it is possible that polluted fish may have been sampled at the beginning of the maturational phase in comparison to Gillams' counterparts.  Hepatosomatic indices (HSIs) were exaggerated at polluted sites and may reflect proliferation of hepatic smooth endoplasmic reticulum (SER).  This was consistent with significant induction of 7 ethoxyresorufin deethylase at the Birchy Cove site, since SER is the site of both Phase-I and Phase-II enzymes.  However, increased liver size may be attributed to vitellogenesis of female fish.  No consistent differences were observed in visceralsomatic indices (VSIs), but splenosomatic indices (SSIs) were, in general, larger at Birchy Cove and Summerside than at Gillams.  Percent splenic deposits did not demonstrate site significance.  Histological surveys indicated more pronounced tissue pathology at Birchy Cove and Summerside.  Quantification of Cryptocotyle lingua did not establish any site-specific trends, however, enteric parasitization was considerably more intense at the reference site compared to Birchy Cove and Summerside, possibly due to voiding or reduced proliferation in effluent-exposed cunner.  Otolith analysis (1994) showed the mean age of the Gillams' sample to be significantly greater than at polluted sites.  Chronic stress observed in cunners suggests that evidence of pulp-induced toxicity in this population is not necessarily due to chlorine constituents.


identifier: Lawson, John W. <https://research.library.mun.ca/view/creator_az/Lawson=3AJohn_W=2E=3A=3A.html>   (1993) A descriptive and quantitative comparison of the communication of grey seals, Halichoerus grypus, at three sites in the North Atlantic Ocean.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Detailed, comparative studies of pinnipeds are rare, particularly between breeding and non-breeding groups of phocids. During 1988 and 1989 I observed two breeding colonies of the land-breeding grey seal, Halichoerus grypus, at North Rona, Scotland (59° 08’ N; 5° 49' W), and Sable Island, Nova Scotia (43° 55' N; 59° 48' W). I also observed a non-breeding aggregation during the summers of 1986 to 1988 on the island of Miquelon (45° 45’ N; 56° 14’ W). At these sites, from distances as little as one metre, I videotaped sequences of behavioural interaction that occurred between seals of all age classes and both sexes. During frame-by-frame analyses of the video records I quantified 34 measures (one of which included 33 behavioural acts in an ethogram) for each behavioural act within the sequences. -- Although behaviour types in the ethogram were robust, and clearly discernible by a naive observer, grey seal behaviour was individually variable. Except for the male Open Mouth Display, coefficients of variation for a number of measures (e.g., duration and inter-seal distance) were large, and behavioural acts were often used in a variety of contexts. Most behaviour types were of short duration (< 5 sec) and were performed in close proximity to other interactants (< 1 m). Except during play, copulation or unusually aggressive interactions, grey seals avoided physical contact and normally oriented their bodies and heads in a parallel or head-on configuration to emphasise the mouth, eyes and enlarged snout. -- While sex, age and reproductive stage affected patterns of communication, topographic and meteorological features of the local habitats had little effect. Though many aspects of interactive behaviour were similar at all three locales, significant differences included: 1) differences in the form, frequency and inter-seal distance of behaviour categories among the colonies (which may be explained by the differing social structure of seals on Miquelon and Sable Island), 2) male-male interactions were briefer than male-female or female-female, 3) play occurred almost exclusively in the non- breeding group and had many behaviour types in common with aggressive interactions and 4) a male behaviour common at breeding sites, Open Mouth Display, was not seen at Miquelon. -- Markov analyses established that grey seal communication was structurally variable, but that succeeding acts (intra-individual) or responses (inter-individual) were predictable on the basis of immediately antecedent acts (first-order), but primarily during interactions between males at all sites (and male-female bouts at North Rona). -- These data establish significant behavioural differences between breeding and non- breeding grey seals, and support a prediction of game theory that suggests animals engaged in agonistic interactions minimise the quantity of information they transmit about their intentions, and react less predictably to the signals of cohorts. Differences in communication between breeding and non-breeding grey seals were greater than those between the breeding sites on opposite sides of the Atlantic Ocean. These dissimilarities were small relative to the marked individual variability in behaviour at all sites.


identifier: Taylor, David M. (David Michael) <https://research.library.mun.ca/view/creator_az/Taylor=3ADavid_M=2E_=28David_Michael=29=3A=3A.html>   (1996) Aspects of multiparous snow crab (Chionoecetes opilio) fecundity in insular Newfoundland waters.  Masters thesis, Memorial University of Newfoundland.

abstract: The fecundity of multiparous snow crab (Chionoecetes opilio) females from eight Newfoundland snow crab management areas is reported.  Specimens were obtained between 1983 and 1985 when exploitation of the snow crab resource was at a very high level.  Three study areas were virgin, while five were heavily fished.  Basic biological data such as size (carapace width) age (shell condition) and mating status (presence of new ejaculate in the spermathecae) of each individual were collected at the time of sampling.  Gravid female size ranged from 44 to 85mm carapace width (mean 65.8 mm).  Fecundity was positively correlated with size ranging from 8,589 to 103,112 eggs (mean 44,658).  Females from virgin areas had a higher size-specific fecundity than did those from exploited areas.  Also, females utilizing new spermatophores had a higher size-specific fecundity than did those using old or a mixture of old+new spermatophores.  Physical factors such as depth or latitude did not appear to affect fecundity. -- The accuracy of utilizing external grasping marks as indicators of recent mating was investigated.  The grasping mark status of females from three sources: nearshore time-series trapping surveys, offshore trapping and offshore trawling surveys was determined and correlated with spermathecal condition as determined by dissection.  Grasping marks were found to be relatively reliable indicators of mating frequency/recency, correctly predicting spermathecal condition -70-80% of the time.  The proportion of new-shelled multiparous females that had recently mated was 1.5 times that of old-shelled multiparous females. -- Fishery exploitation generally had little effect on the proportion of multiparous females bearing eggs but did have a highly significant negative impact on size-specific fecundity.  Part of this effect is likely due to reduced mating frequency in exploited populations which leads to a greater reliance on stored sperm for egg fertilization.


identifier: Rideout, Rick M. <https://research.library.mun.ca/view/creator_az/Rideout=3ARick_M=2E=3A=3A.html>   (1999) Aspects of the reproductive cycle of Atlantic cod, Gadus morhua L., from inshore Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Data on maturity, condition and gonad histology were collected to give insight into the reproductive biology of Atlantic cod, Gadus morhua L., in Placentia and Trinity Bay, Newfoundland.  Female cod in Placentia Bay spawned between April and August, with some spawning probably occurring later in the fall.  Oocytes began to ripen for the next season 1-2 months after spawning with cortical alveoli appearing as early as July and exogenous vitellogenesis starting as early as August.  Oocyte development continued throughout the winter.  Spawning was usually determinate but the ability to boost fecundity by recruitment of oocytes into vitellogenesis during spawning was noted.  Atresia of previtellogenic and vitellogenic oocytes existed as a mechanism to downgrade fecundity. -- The testes of Placentia Bay cod were filled with spermatozoa between January and August and spermiation was likely possible over most of this period.  Recovery from spermiation and the subsequent advance of the testes to spermiogenesis occurred quickly, probably over 2-4 months.  Spermatogenesis was completed prior to the winter reduction in feeding intensity. -- Seasonal changes in condition indices differed slightly for female and male cod from Placentia Bay.  Female somatic condition factor increased from April right up until October as the fish fed and decreased throughout the winter, as oocyte development continued.  The pattern was similar for males but maximum somatic condition factor was reached in August and then maintained until November, after which it decreased.  Female condition and gonadosomatic index was maximum during spawning.  Male gonadosomatic index was also high immediately prior to and during spawning but there were two peaks in condition factor, one during spawning and one in November at the start of spermiogenesis. -- The existence of non-reproductive cod suggests that spawning is not always annual for some individuals.  In Smith Sound, Trinity Bay, over 30% of the female cod that had started to ripen were resorbing all developing oocytes by January and would have missed spawning in 1999.  Spawning omission may have been triggered by food shortage during a critical period for gonad development.  A small percentage of male cod had delayed gonad development but may still have been able to spawn in 1999.  Data to support small percentages of cod with multiple year interruptions in oocyte development and ovarian senescence were also collected.


identifier: Yao, Zuxu <https://research.library.mun.ca/view/creator_az/Yao=3AZuxu=3A=3A.html>   (1994) A study of reproductive biology of the ocean pout (Macrozoarces americanus L.) in captivity.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The reproductive biology of the ocean pout (Macrozoarces americanus L.) was studied. This included (1) the biochemistry of vitellogenin (egg yolk protein precursor), (2) the seasonal reproductive cycle and the associated endocrine changes, (3) the regulation of fish reproduction and (4) the biology of egg fertilization. -- Synthesis of vitellogenin in the liver of ocean pout was induced by administration of the ovarian steroid 17β-estradiol. Vitellogenin was isolated from the plasma by gel filtration and characterized biochemically. It is a glycolipophosphoprotein, 577.8 KD in molecular weight, and contains 17.92% lipid and 3.56% total phosphorus, of which 80.34% (or 2.86% of total vitellogenin) is in the form of lipid-bound phosphorus and the rest (19.1%, equivalent to 0.68% of vitellogenin) is protein bound-phosphorus. The vitellogenin protein contains high levels of the essential amino acids, including arginine, lysine, isoleucine and leucine, valine, threonine and phenylalanine, and some non-essential amino acids, such as aspartic acid, serine, glutamic acid and alanine. With the isolated vitellogenin, antisera were prepared in rabbits and a vitellogenin radioimmunoassay was developed and used for sex determination and for studies of the seasonal changes in plasma vitellogenin. -- The seasonal reproductive cycle of female ocean pout was found to be organized into 4 successive phases of reproduction: 1) a post-spawning quiescent phase (August- September to February), in which the small ovaries (GSI 1.21 ± 0.25) are inactive and predominated by small previtellogenic oocytes (ca. 1.0 mm diameter); a low level of both sex steroids (testosterone and 17β-estradiol) and vitellogenin occurs in the plasma; 2) the reproductive preparatory phase (March - May), in which the ovaries develop slowly (GSI 4.61 ± 2.34) and consist of both previtellogenic and small vitellogenic oocytes (4-5 mm diameter); plasma levels of sex steroids and vitellogenin begin rising slowly; 3) the rapid ovarian growth phase (June - August), in which both the diameter of the vitellogenic oocytes (7 - 8 mm); the GSI (16.76 + 6.54) and levels of sex steroids in the plasma rapidly increase and 4) the ovulation and spawning phase (August - September), when fish spawn and the plasma sex steroids return to basal levels. The females spawn once per year, producing a single batch of 1200 - 1700 eggs (8-9 mm diameter). The seasonal reproductive cycle in males was found to be composed of two phases, (1) a quiescent phase (October - May) and (2) the reproductive phase (June - September). The spawning season of males (occurrence of spermiation) starts with rapid testicular development, following a dramatic increase in both testosterone and 11-ketotestosterone in the plasma. -- Increasing water temperature in the winter stimulated feeding activity but did not alter the timing of the reproductive cycle of the ocean pout. However, lengthening the photoperiod in the winter stimulated steroidogenesis and vitellogenesis and advanced the spawning season. Administration of gonadotropic hormone releasing hormone analog to mature females advanced and synchronized spawning through accelerating the preovulatory decline of plasma testosterone and 17β-estradiol. -- Sperm motility, pH, osmolarity and ionic composition of the ocean pout seminal plasma were studied. Milt collected from the reproductive tract (sperm duct) of mature males contained highly motile spermatozoa (sperm) in a very low concentration. Motility of the sperm was enhanced in ovarian slime collected from the ovaries of prcspawning females but was immobilized instantly upon dilution with seawater, suggesting that the ocean pout is an internal fertilizer. pH and osmolarity of the seminal plasma were in a range of 7.2-7.5 and 365-406 mOsM, respectively. Various ions including Na+, K+, Ca1+, Mg++ and Cl- as well as glucose were detected and quantified in the seminal plasma. Fertilized eggs were produced by artificial insemination, both in vivo (injecting sperm directly into the ovary of mature females) and in vitro. The in vitro insemination necessitated a contact period of 5 hours between the eggs and sperm for fertilization of the eggs before the eggs could be transferred into seawater for incubation. Larvae hatched from in vivo artificially inseminated eggs. -- Studies of copulation and spawning behaviours of the ocean pout showed that males developed a papilla (protrusion of the genital pore) and fish copulated through direct genital contact for internal fertilization of eggs. Females spawned spontaneously in captivity, 6-17 hours after copulation. A complete spawning process was determined to consist of 4 successive steps, including (1) oviposition (spawning), (2) wiping the eggs with skin mucus, (3) wrapping herself around the eggs and (4) guarding the egg-mass. Wiping the eggs with skin mucus could be an effective means for preventing leech and fungal infection of the eggs. Parental care and fanning increased water flow to the eggs, which is important for egg survival during a lengthy period (3 months) of incubation.


identifier: Morris, Corey John <https://research.library.mun.ca/view/creator_az/Morris=3ACorey_John=3A=3A.html>   (2000) Biology of a resident cod (Gadus morhua) population in Gilbert Bay, Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: I studied the biology of a resident population of Atlantic cod (Gadus morhud) in Gilbert Bay (52° 35' N, 55° 52' W), Labrador. Gilbert Bay has an area of approximately 34 km2, and is generally less than 30 m deep. Water temperatures are sub-zero in winter but surface water warms rapidly after ice leaves the bay, usually in early May. Gilbert Bay cod spawned from mid-May to mid-June, 1999, and eggs hatched in about 24 days. A steep density gradient in the upper 5 m of the water column in The Shinneys, an arm of the bay where most data were collected, may be important in keeping eggs in the bay. Larvae and pelagic juveniles appeared to be more abundant in 1998 than in 1999. Cod ranging in size from 15 to 100 cm (2-15+years of age) were captured in shallow water (< 5m) throughout the summer. Tagging indicated that some Gilbert Bay cod move to the mouth of the bay during summer, but others were recaptured at the same location as tagged. Sexual maturity can be attained at 32 cm TL, and 4 years of age, but some females were not sexually mature at a length of 42 cm and age of 8 years. Gilbert Bay cod grow more slowly than adjacent offshore cod. Histological evidence indicates that some females may not spawn every year after reaching sexual maturity. Differences in life history characteristics of this population compared to other Atlantic cod within the North Atlantic Fisheries Organization (NAFO) divisions 2J 3K and 3L is further evidence of reproductive isolation. This resident population of Atlantic cod could be easily over exploited and should be managed separately from other northern cod.


identifier: Armstrong, Stephen Mark <https://research.library.mun.ca/view/creator_az/Armstrong=3AStephen_Mark=3A=3A.html>   (1992) Characterization of the degradation pathway of phloroglucinol (1,3,5-trihydroxybenzene) by a Rhodococcus sp. BPG-8.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Rhodococcus sp. BPG-8 was isolated from oil rich soil in Newfoundland and found to utilize numerous aromatic compounds as sources of carbon and energy. Chemical analysis of cell wall composition which included amino acids, sugars, and fatty acids showed complete homology with Rhodococcus erythropolis. Identical profiles for acid production and growth on various substrates occurred. Growth of the isolate on phloroglucinol occurred in the pH range 5-8; with substrate and temperature optima of 8.0 mM and 25°C, respectively. Phloroglucinol induced cells when fed phloroglucinol or resorcinol produced 1,2,3,5-tetrahydroxybenzene and 1,2,4-trihydroxybenzene, respectively. Cell-free extracts of cells grown on phloroglucinol contained a phloroglucinol hydroxylase that also hydroxylated resorcinol. Dioxygenases present in the induced cells carried out the ortho-cleavage of 1,2,3,5- tetrahydroxybenzene while meta-clevage of 1,2,4- trihydroxybenzene appeared to be constitutive. Cell-free extracts also showed inducible activity for the metabolism of acetopyruvate with the accumulation of formate in the supernatant. Tentative degradative pathways for phloroglucinol and fortuitous resorcinol metabolism are discussed. This is the first reported case in which phloroglucinol is metabolized by an oxidative rather than a reductive pathway. The oxidations of 1,2,3,5-tetrahydroxybenzene and 1,2,4- trihydroxybenzene produce superoxide radicals that may have potential deleterious effects on cellular integrity. It has been shown that both superoxide dismutase and catalase retard the auto-oxidation of these molecules by hindering their free radical reaction mechanism with superoxide. A non-inducible NAD(P)H dependent reductase appeared to convert the 2-hydroxy- 1,4-benzoquinone back to 1,2,4-trihydroxybenzene; although similiar effects were not found for 1,2,3,5- tetahydroxybenzene. These novel findings suggest that constitutive non-pathway enzymes may participate in stabilization of intermediates. Partial purification of the phloroglucinol hydroxylase was performed using ammonium sulfate percipitation, ion exchange chromatography, and gel filtration. The pH, temperature, and substrate optima for phloroglucinol hydroxylase were 7.0, 25°C, and 68.0 μM for the substrates phloroglucinol and resorcinol. NADH+H was the primary reductant and FAD stimulated the hydroxylase activity by 300 %. The enzyme had a native molecular weight of 155,000 daltons and an apparent Km of 8.3 μM and 12.5 μM for phlorglucinol and resorcinol respectively. Chloride ion along with numerous metal ions appeared to inhibit phloroglucinol and resorcinol hydroxylase activities. This is the first reported case for the partial purification of a phloroglucinol hydroxylase.


identifier: Mahoney, Shane Patrick <https://research.library.mun.ca/view/creator_az/Mahoney=3AShane_Patrick=3A=3A.html>   (1979) Breeding biology and behaviour of the common murre (Uria aalge aalge (Pont.)) on Gull Island, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The breeding biology and behavior of the Common Murre (Uria aalge aalge (Pont.)) was studied on Gull Island, Newfoundland during May through July in 1977 and 1978. -- The origin of the Gull Island population was discussed as were the ledge population changes recorded over the breeding season. Reasons for the different patterns of attendance were suggested. -- Breeding phenology was studied in detail. Eggs were weighed and measured and a number of the attributes (shape, volume etc.) were determined. Eggs of known age were collected, their embryos removed and their developmental patterns determined. Numbers of eggs laid and the chronologies of laying for both seasons were compared. Weights of eggs from replacement clutches and the time required to replace a clutch were defined. -- Chicks were measured to calculate growth curves for weight and a number of other body parameters. Numbers of chicks were compared for both seasons as were the growth curves of chicks from both years. Fledging of chicks was recorded and observations were made on adult and chick behavior at fledging. Different fledging schedules for both years were noted and possible reasons for the differences were suggested. -- Breeding success, expressed as the numbers of pairs successfully fledging a chick, was recorded. Causes of egg and chick loss were recorded and the influence of predation was discussed in detail. -- Observations were made on behavior with particular attention being paid to those displays which involved characters of aggression. These displays were noted and their postures illustrated. The effects of high density nesting on the evolution of behaviour was discussed. -- Results indicated that murres on Gull Island attained breeding success rates comparable with other areas but lower than most. Birds breeding at higher densities and on longer-established of “safe” ledges were most successful. Murres in this colony demonstrate a wide range of conflict behaviours with numerous appeasement displays functioning to maintain low levels of high intensity aggression.


identifier: Lomond, T. M. (Tammy M.) <https://research.library.mun.ca/view/creator_az/Lomond=3AT=2E_M=2E_=28Tammy_M=2E=29=3A=3A.html>   (1997) Can a naturally impoverished boreal Ephemeroptera, Plecoptera, and Trichoptera (EPT) fauna serve as an indicator of water quality?  Masters thesis, Memorial University of Newfoundland.

abstract: Biomonitoring of small boreal water-catchments has become increasingly important for small human communities in Newfoundland, Canada.  Benthic macroinvertebrate fauna are commonly used to assess conditions of water-catchments.  However, Newfoundland has a very impoverished freshwater fauna due to isolation of the island from the mainland (faunal source), reduced habitat diversity and recent glaciation of the island.  Questions addressed by the study were: how sensitive is this fauna to different environmental gradients, and will the fauna be useful in biomonitoring programs on the island? -- The study examined the relative diversity and abundance of the Ephemeroptera, Plecoptera and Trichoptera (EPT) component of the benthic macroinvertebrate fauna in 23 lake-outlets in six water-catchments of northeastern Newfoundland.  Faunal composition and structure were related to gradients of natural and human impacted environmental variables of the sites sampled.  Sixteen environmental variables were measured during May and July 1995, and May and July 1996 collection trips. -- Principal Components Analysis (PCA) of the environmental data indicated that the 23 sites represented a broad range of stream and drainage basin characteristics.  This was expected from sites that ranged from highly urbanized sites to sites with little human disturbance.  Concentrations of several chemicals, conductivity, and pH were correlated with disturbance on axis one. -- Analysis of the EPT data showed shifts in community structure related to chemical variables, disturbance level, and study area.  Generally, EPT diversity and abundance were lower in the physically disturbed and polluted urban sites, and were highest in physically disturbed but relatively unpolluted rural sites.  Principle Components Analysis also showed trends in taxa diversity and abundance.  Taxa correlated with presence-absence PC-I included B. pygmaeus, B. macdunnoughi, E. prudentalis, Paraleptophlebia spp., S. vicarium, Leuctra spp., Polycentropus spp. and Platycentropus sp., which occur in a wide variety of running water habitats, but have low tolerances of disturbance (Edmunds et al. 1976; Larson and Colbo 1983; Lenat 1993; Lang and Reymond 1995).  These taxa tended to be absent from the highly disturbed St. John's sites, but present at most remaining sites.  Taxa correlated with relative abundance PC-II were H. sparna and Chimarra sp., which have low tolerances to pollution (Bargos et al. 1990; Lenat 1993).  These taxa had low abundances at St. John's sites.  Therefore, it was concluded that the impoverished EPT fauna of Newfoundland can serve as an indicator of water quality.


identifier: Neuman, Josephine Ann <https://research.library.mun.ca/view/creator_az/Neuman=3AJosephine_Ann=3A=3A.html>   (1993) Aspects of the behaviour and ecology of black-legged kittiwakes, Rissa tridactyla, breeding at two sites in Newfoundland, 1990-1991.  Masters thesis, Memorial University of Newfoundland.

abstract: An examination of variability in the breeding success of Black- legged Kittiwakes, Rissa tridactyla, was the focus of this research. An attempt was made to relate this variability to ecological conditions, in particular food availability. Apparent food shortages in 1991 provided a natural experiment as data were collected from two Newfoundland colonies, Cape St* Mary's and Gull Island in Witless Bay, in 1990 and 1991, comparisons were also made with previous Newfoundland studies. -- At both colonies, timing of breeding was later, there was a greater amount of non-breeding, and clutch sizes were smaller in 1991, the year with the most apparent food shortages. Observer access to the nests was only possible on Gull Island and there egg volumes were smaller, and chick survivorship and growth rates were lower in 1991. The behavioural evidence for food shortages on Gull Island in 1991 was also compelling. Chicks begged more intensely and had fewer successful begging bouts in 1991, but chick feeding rates in the two years were similar. As the few chick growth rates obtained in 1991 clearly showed that chicks were starving, future studies should incorporate estimates of bolus size and food type in addition to determining feeding rates. Chicks were seldom left unattended in 1990 (for all ages combined, less than 3% of the time), and in 1991 they were not seen left alone at all. Adults may have been responding to increased predation by Herring Gulls, Larus arqentatus. -- Courtship feeding, a significant event in the pre-laying period, was the subject of special emphasis at Cape St. Mary's in 1990. One of the hypothesized functions of courtship feeding is its nutritional significance, providing the female with extra food prior to egg laying. The phenology of courtship feeding in relation to egg laying, and the substantial amount fed (at the peak, 8 boluses per pair per day) circumstantially confirmed the nutritional importance of courtship feeding. Courtship feeding rate was not significantly correlated with timing of breeding, clutch size, hatching success or fledging success. -- An examination of inter-observer reliability was made in the context of the courtship feeding study. Two of the seven variables were scored reliably, while the remaining variables were affected by either systematic error or random error and influenced conclusions differently depending on the questions asked. The difficulties inherent in obtaining adequate observer agreement in field studies of animal behaviour indicate that an assessment of inter-observer reliability should be a part of every behavioural study.  -- In general, seabirds represent extreme “K-selected” species and this pattern was clearly exemplified by Black-legged Kittiwakes in a year of apparent food shortages, as they attempted to maximize adult survival rates by reducing their investment in reproduction.


identifier: Whitaker, Darroch M. <https://research.library.mun.ca/view/creator_az/Whitaker=3ADarroch_M=2E=3A=3A.html>   (1997) Composition and conservation of riparian bird assemblages in a balsam fir ecosystem.  Masters thesis, Memorial University of Newfoundland.

abstract: Undisturbed riparian zones are typically viewed as the highest quality habitat available to wildlife in forested landscapes and, in keeping with this, are seen as having the highest biodiversity. Riparian buffer strips are retained during clearcutting throughout most of the boreal forest, a practice promoted as a means to reduce the impact of harvesting on terrestrial fauna. Current perceptions of the importance of riparian zones to wildlife originated from studies in southwestern North America, yet their generalization to boreal forests remains relatively untested. Furthermore, little research has been conducted to quantify the extent to which buffer strips are used by wildlife. This study was designed to evaluate the relative importance of riparian habitat for breeding birds in a boreal forest ecosystem and to assess the conservation potential of riparian buffer strips in areas of extensive clearcutting. -- Breeding birds were surveyed in riparian edge, non-riparian edge (clearcut or access road), interior forest and buffer strip habitats in balsam fir (Abies balsamea) forests in western insular Newfoundland. Observations from riparian edge, non-riparian edge and interior forest transects were compared in order to describe the assemblages associated with each of these habitat types and to group species into habitat selection guilds. Several distinguishing species were associated with each of these habitat types, and five habitat guilds were differentiated. Total abundance and species richness did not differ between riparian and interior forest transects, but were significantly higher on non- riparian edge than riparian transects. Different habitat features lead to the development of distinct bird assemblages along the two edge types. Based on this and other recent studies, it is apparent that relatively high riparian biodiversity may be the exception for bird assemblages in coniferous and coniferous-deciduous mixed forests, where interior forest species form an important component of the avifauna. -- Comparisons were made between bird assemblages (grouped by habitat guild) observed along undisturbed shorelines and buffer strips. Total avian abundance was higher in buffer strips than riparian controls, largely due to significantly higher counts of birds from the ubiquitous and open/edge guilds. Abundance of forest generalise interior forest and riparian species were similar between the two shoreline types. Counts of riparian species did not increase in wider buffers, likely due to the association of these birds with habitat adjacent to the water, which does not increase in proportion to strip width. Riparian buffer strips did, however, provide habitat for a diverse avian assemblage, and retained many riparian and woodland species in areas of intensive clearcutting. Interior forest species, many of which are declining in northeastern North America, were more abundant in wider buffers. However, even in the widest strips (40-50 m) they were rare when compared to local interior forest habitat, and three of six species in the guild were not observed in any buffer strip. It is clear that separate (but complementary) conservation strategies are required to protect riparian and interior species. Interior species are likely not afforded adequate protection in boreal forests, where conservation efforts focus largely on preserving riparian habitat.


identifier: Hiscock, Martha Jean <https://research.library.mun.ca/view/creator_az/Hiscock=3AMartha_Jean=3A=3A.html>   (1998) Kin discrimination in juvenile brook trout (Salvelinus fontinalis): possible fitness trade-offs associated with kin-biased behaviour.  Masters thesis, Memorial University of Newfoundland.

abstract: Kin discrimination abilities and possible fitness trade-offs associated with kin-biased behaviour were investigated in juvenile brook trout (Salvelinus fontinalis). Three experiments were conducted to determine: 1) if juvenile brook trout have the ability to discriminate kin based on water-borne chemosensory cues, 2) the effect cue water concentration, as an indicator of shoal size, has on kin preferences, and 3) a possible trade-off in kin-biased behaviour with respect to social status. -- In the first experiment individual kin spent a significantly greater proportion of time in water conditioned by kin and did not discriminate between familiar and unfamiliar kin. This preference indicates that juvenile brook trout have the ability to discriminate kin based on water-borne chemosensory cues. Individuals in the second experiment based cue water preferences on both concentration and kinship. When cue water concentrations were equal individual kin preferred water conditioned by kin. However, if given a choice between high and low concentrations, individual kin preferred the high concentration independent of kinship. Individuals may perceive the various cue water concentrations as an indicator of shoal size and base preferences on these differences (Chapter 2). -- The third experiment demonstrated that kin in two size class introductions 1) spent a significantly greater proportion of time nearest kin, 2) were generally less aggressive toward kin, and in the same-size introductions, 3) introduced kin had significantly greater mean weight gain than introduced non-kin (Chapter 3). -- Evidence from the present study suggests that juvenile brook trout may be able to maximize 'inclusive fitness' benefits through kin-biased behaviour under both shoaling and territorial conditions. A fitness trade-off may be associated with perceived shoal size but there was no apparent trade-off in kin-biased territorial behaviour with respect to social status in this study.


identifier: Curren, Kristina Charlotte <https://research.library.mun.ca/view/creator_az/Curren=3AKristina_Charlotte=3A=3A.html>   (1992) Designs for swimming : morphometrics and swimming dynamics of several cetacean species.  Masters thesis, Memorial University of Newfoundland.

abstract: Swimming is the only mode of locomotion available to whales and dolphins. Although all cetaceans live in an aquatic environment, large differences exist between the behavioural ecologies of different species: corresponding variation in morphology and in dynamical swimming characteristics is expected between species. -- Morphological variation was examined within a sample (n=35) of harbour porpoise (Phocoena phocoena) to determine the values of several geometric parameters (including body volume, body surface area, volumetric coefficient, fineness ratio, fluke surface area, fluke aspect ratio and fluke sweep angle) for mature animals. Harbour porpoise showed significant variation in several non-dimensional parameters with age, suggesting that other cetacean species may display similar variation. In general, juvenile harbour porpoise displayed lower fineness ratios and lower fluke aspect ratios than adult harbour porpoise: these results imply a lower propulsive efficiency for juvenile porpoise. -- The morphologies of sexually mature harbour porpoise were statistically compared with a sample (n=3) of Atlantic white-sided dolphins (Lagenorhynchus acutus). Harbour porpoise were found to have  significantly lower fineness ratios than Atlantic white-sided dolphins, indicating a fatter body and a higher drag coefficient. Harbour porpoise also displayed higher fluke aspect ratios. This suggests that the flukes of the harbour porpoise may have a higher propulsive efficiency than those of Atlantic white-sided dolphins, although the white-sided dolphins' high fluke sweep angles may compensate for their lower aspect ratio. -- The morphologies of harbour porpoise and Atlantic white-sided dolphins were qualitatively compared with several other cetacean species. The largest between-species differences were observed for volumetric coefficient, fluke aspect ratio and the ratio of body surface area : fluke area. These morphological differences may reflect differences in relative swimming performance. -- Dynamical swimming parameters, including swimming speed, fluke oscillation frequency, and stride length, were measured from videotape for a harbour porpoise, an Atlantic white-sided dolphin and two long-finned pilot whales (Globicephala melas). Limited data on heave amplitude and maximum pitch angle of the flukes were also measured for the harbour porpoise and the white-sided dolphin. The results were compared with data from fish and cetacean swimming studies. The observed animals displayed a linear relationship between swimming speed and fluke oscillation frequency. Stride lengths were found to remain constant within species, and to vary significantly between species. The upstroke and downstroke of the flukes were found to be equally long for all speeds measured. -- Finally, a statistical method to test the hypothesis of wave energy absorption by whales was developed, and the method was applied to the track of a long-finned pilot whale when corresponding wave conditions were known. The whale was not found to increase its swimming speed or to adjust its heading with respect to wave direction in response to favourable wave conditions. Possible reasons for these results are reviewed.


identifier: Mills, Frederick H.J.(Frederick Herbert Jewer) <https://research.library.mun.ca/view/creator_az/Mills=3AFrederick_H=2EJ=2E=28Frederick_Herbert_Jewer=29=3A=3A.html>   (1984) Determination of the vibration sensitivity of harbour seal (Phoca vitulina) vibrissae.  Masters thesis, Memorial University of Newfoundland.

abstract: Psychophysical techniques were employed to measure the sensitivity of the vibrissae of a harbour seal (Phoca vitulina) to sinusoidal vibrations ranging between 100 and 2500 hertz. A control test ensured that the seal was not responding to auditory or other extraneous components of the  signal. Vibration detection thresholds were found to decrease with increased frequency up to 1000 hertz and remain relatively constant thereafter. These data were used for evaluation of some previous hypotheses of vibrissae function. Calculations revealed that seals should be able to use their vibrissae to detect objects such as swimming fish vibrating underwater at close range and tactually discriminate between objects (like fish with different scale patterns). Also, vibrissae could theoretically detect underwater sounds produced by fish, but at too close a range  to have any practical value.


identifier: Lacoste, Karine <https://research.library.mun.ca/view/creator_az/Lacoste=3AKarine=3A=3A.html>   (1997) Distribution of harp seals, Phoca groenlandica, off Newfoundland and Labrador in relation to abiotic and biotic conditions.  Masters thesis, Memorial University of Newfoundland.

abstract: This study provides the first quantitative assessment of the  yearly distributions of harp seals in the northwest Atlantic, particularly during the winter. Recent abiotic and  biotic changes in the northwest Atlantic concurrent with reports of seals sighted further offshore have prompted this  investigation on harp seal distributions in relation to environmental factors. Seal sighting data were collected from 1991 to 1995 using line-transect techniques. Data were standardized for effort and sighting conditions and grouped by subareas of 1 degree². Numbers of seals observed were estimated using a relative group size category. Visual appraisals of data were made using a Geographical Information System. The winter distributions of harp seals were overlaid onto maps of sea ice, sea floor inclination, sea surface temperature, and several prey distributions. The  influence of these variables was tested using a generalized linear model, ANOVA, and correlation, respectively. The influence of water depth at location of seal sightings was also investigated. -- Offshore areas are an important habitat for harp seals. The winter distributions of harp seals showed similar patterns during 1991-1993, but shifted slightly to the southeast during 1994-1995. Water temperatures were found to be within the thermoneutral limits for this species at all locations and for all winter years. Although there was a tendency for seals to be observed along the continental slope edge and in specific ice conditions, no significant differences were found between locations of seals and sea floor inclination or ice characteristics. Seals were mainly seen in waters of depths ranging from 300 to 500 m, values known to be within their diving range. Sea floor topography and water depth were the only environmental variables that remained constant throughout the 1991-1995 winter distributions. The spatial distribution of prey investigated concurred with the documented diet of harp seals. Further investigations will be needed to quantify the relationship existing between them.


identifier: Ross, Sue-Anne <https://research.library.mun.ca/view/creator_az/Ross=3ASue-Anne=3A=3A.html>   (1992) Food and feeding of the hooded seal (Cystophora cristata) in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Knowledge of diet is fundamental to studies of seal ecology and especially to any understanding of their role as predators in the northwest Atlantic marine ecosystem. Hooded seals (Cyostophora cristata ) are one of the largest of the northern phocids and are abundant in the north Atlantic and Arctic seas, but very little quantitative data is available on their feeding behaviour and dietary preferences. The main objective of this study was to determine the diet of hooded seals in Newfoundland waters. -- Otoliths of six common prey  species, determined from a previous study on diet of hooded seals, were used to determine fish length / weight - otolith  length / height regressions. For all species except Greenland halibut, the strongest correlations between otolith size and fish length / weight were established using  maximum otolith length. For Greenland halibut, maximum otolith height gave a better correlation with fish length and weight. Least squares linear equations were used to derive fish length for Arctic cod, Atlantic herring and capelin, while second order polynomial models were used for Greenland halibut, redfish spp., and Atlantic cod. Fish weight estimates were derived using power (log - log) models for all six fish species. -- Stomach contents of 67 hooded seals collected from inshore and offshore waters off Newfoundland were examined to determine the types of prey eaten by hooded seals. The majority of stomachs (73%) came from the nearshore region along the northeast coast of Newfoundland and were taken in April. Over half of the samples collected were female (64.2%). -- Fourteen prey groups were identified in stomachs (10 fish, 4 invertebrate). The relative importance of prey, expressed as  the percent total wet weight of prey recovered, indicated that Greenland halibut (Reinhardtius hippoglossoides) was the most important species, followed in order of importance by redfish (Sebastes spp.), Arctic cod (Boreogadus saida), Atlantic herring (Clupea harengus ), squid (Gonatus spp.), Atlantic cod (Gadus morhua ) and capelin (Mallotus villosus). -- Using otoliths from a previous study and from this study, lengths and weights of fish were estimated from a total of 72 stomachs. Hooded seals fed mainly on fish of 25 - 35 cm length for the larger species, and 15 - 25 cm for  the smaller ones. Fish consumed by seals caught incidentally  from offshore trawlers were larger than those taken elsewhere. The estimated lengths, and proportions (% weight)  of fish found per stomach did not differ significantly between male and female hooded seals. -- The proportions (percent weight) of redfish and Atlantic herring consumed by  hooded seals were significantly larger in the summer months,  whereas a higher proportion of Arctic cod was consumed in the winter months. No seasonal differences were found in actual lengths of fish eaten. -- Total energetic values for fish eaten were calculated from estimated wet weights and energy densitites (kJ/g). Greenland halibut, Atlantic herring and Atlantic cod had the highest average energetic values (kJ), followed by redfish, Arctic cod, capelin and squid. Relative contributions of prey, expressed as the percent total energy of prey recovered, showed that Greenland halibut contributed approximately 53% of the total energy consumed, followed by redfish, Atlantic herring, Arctic cod, squid, Atlantic cod and capelin. These proportions corresponded with those obtained from percent total wet weight of prey recovered. -- The relative abundance of the fish species has a strong influence on the composition of the food in the diet of seals. Hooded seals spend some time in areas that are exploited by commercial fisheries, and consume commercial fish species of commercial size. However, in order to evaluate the impact of local predation on individual fish stocks, more information on behavioural and physiological characteristics of seals and fish are needed.


identifier: Gosse, John W. <https://research.library.mun.ca/view/creator_az/Gosse=3AJohn_W=2E=3A=3A.html>   (1997) Relative abundances of birds of prey in different forest habitats in the Western Newfoundland Model Forest.  Masters thesis, Memorial University of Newfoundland.

abstract: Balsam fir forests in western Newfoundland are intensively managed for pulpwood production resulting in a fragmented landscape of different-aged forests and clearcuts. Prior to this research, the ecology of woodland birds of prey had been unstudied on insular Newfoundland, and knowledge regarding consequences of forestry practices on aspects of their biology was lacking. As top-level carnivores, raptors are susceptible to both natural and human induced perturbation and may effectively be used as indicator species of environmental health in boreal forest ecosystems. -- During the breeding seasons of 1993 and 1994, the diversity and relative abundances of birds of prey were investigated in the Western Newfoundland Model Forest (WNMF). The primary research objectives were to: 1) develop reliable, standardized techniques with which to census birds of prey in different-aged forests and clearcuts in the WNMF,  2) determine the species diversity and relative abundances of birds of prey in uncut old growth, second growth forest, clearcuts and pre-commercially thinned areas, 3) develop density estimates of selected species of birds of prey, 4) identify nest-sites of birds of prey and quantify habitat characteristics at these sites, 5) identify knowledge gaps with respect to Newfoundland birds of prey, and in doing so to develop research objectives and management strategies for  future studies. -- Surveys using conspecific vocalization playbacks were conducted along forest access roads and lake shorelines that transected different forest habitats. Ground searches were made for raptor activity sites (i.e. nests, roosts, prey-plucking-sites), and habitat measurements at these sites and unused control sites were obtained. The vocalization playback method used was reasonably effective for locating owls but less effective for other woodland raptors. -- Nine species of birds of prey were recorded in the area: Merlin, American Kestrel, Osprey Rough-legged Hawk, Sharp-shinned Hawk, Northern Goshawk, Boreal Owl, Great Horned Owl, and Northern Hawk-Owl. Uncut old growth forests contained more species than second growth forests and clearcuts, however abundances in all forest types were low. Boreal Owls and Northern Goshawks were found exclusively in uncut old growth, and Sharp-shinned Hawks mainly in this habitat type. Three species of birds of prey were recorded in second growth forests in the study area, one of which, the Great Horned Owl, was found only in this habitat type. Clearcut areas were utilized by four species of raptors and Northern Hawk-Owls and American Kestrels used  clearcuts extensively. Merlins were the most commonly detected bird of prey and unlike any other species were found in all forest habitats. -- Predator-prey relationships  influence the occurrences of birds of prey in different habitats. A comparison of avian-dependent birds of prey (i.e. Sharp-shinned Hawks, Merlins) and small mammal specialists (i.e. Boreal Owls, Northern Hawk-Owls, Rough-legged Hawks) indicated that between 1993 and 1994, the numbers of avian predators remained identical whereas the numbers of rodent predators declined significantly. This population decrease is likely a result of the simultaneous decline in small mammals in this region and reflects the importance of food resources in influencing population dynamics of birds of prey in different habitats. -- Density comparisons made between western Newfoundland and a range of locations throughout boreal forest systems in North America and Scandinavia indicate that raptor populations are extremely variable. Although lacking rigorous empirical analysis, such comparisons provide an index of raptor populations at different spatial and temporal scales. In western Newfoundland, the low diversity and numbers of small  mammals likely limits the densities of birds of prey dependent on this food resource, (Boreal Owl, Northern Hawk-Owl, Rough-legged Hawk). Great Homed Owls and Northern Goshawks may also have been food limited as their major prey  species (Snowshoe Hare, Ruffed Grouse) were uncommon in this  region. These predator-prey relationships may be responsible  for the low densities of birds of prey found in the boreal forests of western Newfoundland. -- Habitat selection theory  postulates that species are preferentially associated with particular habitats in which they can optimally survive and reproduce. For birds of prey, the mechanisms that elicit selection of habitats are not well understood yet this information is needed in order to effectively manage forests  to maintain the natural biodiversity and abundance of birds of prey. Sample sizes of raptor activity sites were small, however trends of habitat selection were apparent and consistent with research conducted elsewhere. -- In recent years, the management of non-game wildlife has become an important issue in light of approaches to preserving forest ecosystems that go beyond the primary objective of fibre and timber production. In North America, birds of prey are protected under governmental legislation, and conservation measures for them have been implemented in forest management  strategies. In Newfoundland, however, a previous lack of knowledge regarding the distributions and abundances of woodland raptors has resulted in minimal attention with respect to forestry planning. Based on census results of this present study, I suggest that large tracts of remaining  uncut old growth forests be preserved from timber harvesting  and that the existence of this habitat type be ensured at a landscape level in future years. Furthermore, research and systematic monitoring of woodland raptor populations should continue in an attempt to better understand impacts of forest harvesting operations.


identifier: Perry, Elizabeth Anne <https://research.library.mun.ca/view/creator_az/Perry=3AElizabeth_Anne=3A=3A.html>   (1986) The role of the vocalization of harbour seal (Phoca vitulina) pups in preventing separation from their mothers.  Masters thesis, Memorial University of Newfoundland.

abstract: Interactions between harbour seal (Phoca vitulina concolor) mothers and pups were observed, and recordings were made of pup vocalizations, on the island of Miquelon near southeastern Newfoundland, Canada.  Pup vocalizations were individually distinct on the basis of several physical parameters, most importantly the frequency of the major harmonic.  These data and analyses of contextual variables indicated that the mothers might use these vocalizations for individual recognition of their offspring and for ensuring that contact is maintained.  Calls can be transmitted simultaneously in air and underwater and it is hypothesized that differences between these versions of the calls increase the accuracy with which the mothers can localize their pups.


identifier: Marques, Fernanda F. C. <https://research.library.mun.ca/view/creator_az/Marques=3AFernanda_F=2E_C=2E=3A=3A.html>   (1996) Baleen whale distributional patterns and the potential influence of biological and physical processes.  Masters thesis, Memorial University of Newfoundland.

abstract: Processes influencing baleen whale distribution have been traditionally inferred from correlations with behavioural, physical or biological variables.  Such variables are often not directly linked to any particular process or mechanism, and hypotheses based on well established physical or biological models are rarely tested.  In addition, the effects of measurement scale are seldom explicitly considered. -- One way to incorporate reasoning about scale in descriptions of baleen whale distributional patterns is via a comparison of results obtained across a range of spatial and temporal scales.  This approach was exemplified through a description of spatial and temporal patterns of humpback, finback and minke whale distribution in Placentia Bay, Newfoundland.  A multi-scale comparison of results indicated that local patterns of abundance are unlikely to reflect large-scale, population trends.  Spatial patterns of baleen whale distribution were found to be highly variable, and no consistent trends are apparent.  Differences in the seasonal timing of humpback and finback abundance are considered to reflect the exploitation of different food resources elsewhere during the spring, and reiterate the importance of the timing of sampling. -- Dimensionless ratios were then used to evaluate the relative importance of somatic growth, demographic and kinematic processes on northwest Atlantic humpback whale biomass concentration.  Changes in humpback biomass concentration resulting from changes due to their own locomotory behaviour dominated over all other processes across a wide range of spatial and temporal scales.  A review of current research knowledge of northwest Atlantic humpbacks indicated that limited data on growth rates and age structure of the population, calf survival and recruitment are available. -- An examination of humpback whale aggregative response to prey availability as a function of scale indicated that humpbacks were associated with prey at small (2.5-7.5 km) spatial resolutions.  This suggests that whales may be continuously tracking prey.  Maximum coefficients of association between whales and prey obtained at relatively small spatial scales (10-22.5 km) suggest that studies examining interactions between humpback whales and their prey can be conducted at relatively small scales, but repeated sampling may be necessary before any patterns can be detected. -- Other authors have suggested that episodic oceanographic events influencing prey distribution may indirectly influence baleen whale distribution and movements.  An examination of water temperature profiles obtained in Placentia Bay indicated the occurrence of a localized coastal upwelling event during the summer of 1994.  This event coincided with observations of large patches of euphausiids and schools of mackerel, and also with the peak in humpback whale relative abundance.  These findings are speculated to indicate a potential response of humpback whales to concentrations of prey resulting from changes in oceanographic conditions.  Additional experiments are needed to confirm these observations.


identifier: Cook, Arthur M. <https://research.library.mun.ca/view/creator_az/Cook=3AArthur_M=2E=3A=3A.html>   (1988) Pyrolysis of 1-methyl-2-phenyldiazene.  Masters thesis, Memorial University of Newfoundland.

title: Pyrolysis of 1-methyl-2-phenyldiazene

abstract: The question of whether diazenes lose nitrogen through one or two bond scission has been a subject of study for over fifty years.  Using recently available data on azobenzene and previously published Arrhenius parameters for azomethane a kinetic approach was taken to this problem using 1-methyl-2-phenyldiazene. -- In the first part of this thesis the synthesis and purification of 1-methyl-2-phenyldiazene is described. -- The next section deals with the construction of the vacuum line and its associated apparatus.  The problems with the original design are discussed and modifications which were made to the line are outlined. -- In the results section are presented the definition of the rate constant for nitrogen formation and a table of products of reaction, which, with the associated appendices show how the products were identified and measured.  The yield-time, order, and Arrhenius plots are then presented for both the unpacked and packed reaction vessels as well as results for experiments in which propene was present. -- A summary of the observations is first given in the discussion section.  The possibility of direct decomposition of 1-methyl-2-phenyldiazene with no contribution from the chain is next discussed, along with a consideration of the trans to cis isomerization.  Both are shown to be implausible, using aguments based on the results obtained. -- Based on the effect of propene, the orders of reaction, and the values of the Arrhenius parameters, two mechanisms are then proposed.  The simple one is written to show that nitrogen may be formed by a chain reaction as well as by simple fission of 1-methyl-2-phenyldiazene.  It is solved to show that it is first order with respect to nitrogen formation.  The second mechanism accounts for the products of reaction and also adds a second chain to the pyrolysis.  Speculation on the formation and reaction of diradicals is then made.  The complete mechanism is then solved to show that it too is first order with respect to nitrogen formation. -- Possible Arrhenius parameters of the simple fission of 1-methyl-2-phenyldiazene are then proposed based on the propene results.  These parameters agree quite well with what Forst and Rice obtained for azomethane and suggest one bond scission of 1-methyl-2-phenyldiazene. -- Speculation as to why, in the initial series of propene experiments, no inhibition of the rate of nitrogen formation appeared is then made.  The possible role of phenylhydrazone is also considered. -- Finally, the erratic behavior of the reaction after the initial series of propene experiments is commented on, and further directions for the study of this reaction are presented.


identifier: Poole, Ronald Thomas <https://research.library.mun.ca/view/creator_az/Poole=3ARonald_Thomas=3A=3A.html>   (1973) Some pentafluorophenyl derivatives of selenium.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The preparations of a number of pentafluorophenyl derivatives of selenium are described. Reactions of transition metal ions with excess of the anion C₆F₅Se⁻ in aqueous solution generally give complex ions of the type [M(SeC₆F₅)x]y⁻ but sometimes only simple salts of the type M(SeC₆F₅)₂ are obtained. The electronic spectra of these compounds are discussed. The ligand C₆F₅Se has been incorporated into transition metal organometallic compounds giving the derivatives (π-C₅H₅)Fe(CO)₂SeC₆F₅, {(π-C₅H₅)NiSeC₆F₅}n, (π-C₅H₅)Ni(PPh₃)SeC₆F₅, C₆F₅SeMn(CO)₅ and C₆F₅SeRe(CO)₅. Unsymmetrical selenides, C₆F₅SeR, where the substituents, R, are various alkyl and aryl groups, are prepared by a variety of methods. Preparations of the compounds C₆F₅SeN(CH₃)₂, C₆F₅SeN(C₂H₅)₂, (C₆F₅Se)₂NH and C₆F₅SeOCH₃ are also described. The preparations of various penta-fluorophenyl derivatives of higher valent selenium are  attempted resulting in the formation of the compounds C₆F₅SeCl₂CH₃, C₆F₅SeCl₂C₆H₅, C₆F₅Se(O)C₆H₅, (C₆F₅SeO)₂O and C₆F₅Se(O)Cl. No pentafluorophenyl derivatives of six valent selenium are obtained. Vibrational spectra of the compounds prepared are briefly discussed and SeO stretching mode assignments made. ¹⁹F n.m.r. spectra are also discussed. -- The properties of pentafluorophenyl derivatives of selenium are compared with those of organoselenium compounds, particularly perfluoroalkyl derivatives of selenium, and with pentafluorophenyl derivatives of sulphur.


identifier: Brown, William Larry <https://research.library.mun.ca/view/creator_az/Brown=3AWilliam_Larry=3A=3A.html>   (1984) Studies directed toward the total synthesis of gascardic acid.  Masters thesis, Memorial University of Newfoundland.

abstract: Various reactions directed toward the total synthesis of gascardic acid have been delineated.  Unfortunately trisubstituted cyclopentadienes of type 31a and 31b would not partake in the desired intramolecular Diels-Alder reactions.  In contrast, compounds 68 and 73 in which the sidechain substituents differ, cyclized to the requisite tricyclic skeletons. -- A general method for inverting the stereochemistry of vinyl alcohols such as 20 and 37 has been developed.  This involved a [2,3] sulfoxide rearrangement and will permit a broader application of the oxy-Cope rearrangement as illustrated by the conversion of 37 to 53 to 54. -- Model studies of a suitable cyclohexane-cycloheptane ring expansion in which the keto-ester functionality is retained were commenced.


identifier: Smith, Ralph Stephen <https://research.library.mun.ca/view/creator_az/Smith=3ARalph_Stephen=3A=3A.html>   (1984) Studies directed toward the total synthesis of retigeranic acid.  Masters thesis, Memorial University of Newfoundland.

abstract: Studies directed at the total synthesis of retigeranic acid (1) have revealed that compounds of type 81a and 87 cyclize in intramolecular fashion to give the conjoint ring systems 91 and 90 rather than the fused bicyclo [3.3.0] octanes 48 and 88.  Increasing the acidity of the γ-proton did not result in alkylative cyclization. -- The Wittig reagents 124, 125, and 126 have been synthesized and shown to react in normal fashion with aldehydes to give enol-ether-dienes such as 128 and α,β-unsaturated ketones 129 after hydrolysis.  A route to a suitable triene 111 for the construction of the hydrindane portion of retigeranic acid has been developed, but unfortunately conditions were not found that allowed the intramolecular Diels-Alder reaction to proceed.


identifier: Strickland, Dean W. <https://research.library.mun.ca/view/creator_az/Strickland=3ADean_W=2E=3A=3A.html>   (1996) 1,2-bis(trimethylsilyloxy)cyclobutene : a study of acylation methodology and synthetic application.  Masters thesis, Memorial University of Newfoundland.

abstract: Kuwajima and co-workers have reported that the reaction of a  ketal and 1,2-bis(trimethylsilyloxy)cyclobutene (1) in the presence of a Lewis acid catalyst with subsequent rearrangement of the cyclobutanone intermediate with trifluoroacetic acid affords 2,2-disubstituted 1,3-cyclopentanediones in reasonable yields. We have found that substituents, such as methyl groups, in the α-position to the spiro center significantly reduce the yield of product. In addition, substitution of the 1,2-ethanediol moiety of the ketal with groups such as methyl and phenyl also reduces product yields. -- Synthesis of the precursors of the juvenile hormone 6-ethyl-10-methyldodeca-5,9-dien-2-one of the moth Cecropia in our first approach involved the addition of an ethyl group to 2-ethyl-2-methylcyclopentane-1,3-dione (71) and reduction with sodium borohydride to afford 80 as a precursor for a Grob-type fragmentation. Analysis of 80 using nmr and X-ray crystallography indicated  the structure shown in Figure 5. The alternative approach to  the precursors or the juvenile hormone involved the reduction of 71 with sodium borohydride with subsequent introduction of the ethyl moiety to generate 89. However, introduction of the ethyl group proved to be irreproducible.  Both of our strategies focused on the construction of the correct relative stereochemistry to enable a Grob-type fragmentation to produce the correct double bond isomer of 69. -- Model studies toward the synthesis of fredericamycin A focused on [2+2] photochemical additions of 1 with various enones, in particular with spiro[3-cyclopentene-1,1'-indan]-2,5-dione (99). However, while tests carried out between a simple enone and 1 provided limited results, the reaction between 99 and 1 afforded only starting material.