Marine vertebrate species face unprecedented and ever increasing pressures as a result of human activity, primarily fishing, in the global oceans. One area of growing concern has been for the impacts of small-scale fisheries on these species. Over the past decade it has become increasingly clear that these under-studied fisheries have sizeable levels of catch and bycatch of many threatened and endangered species of sea turtles, seabirds and small cetaceans. This thesis presents a collection of chapters that investigate aspects related to the interactions of small-scale fisheries with threatened marine vertebrates. We identify sizeable rates of bycatch of small cetaceans and seabirds for multiple small-scale longline and gillnet fisheries in both Peru and Ecuador. Catch rates of small cetaceans by the Peruvian small-scale driftnet fleet are estimated to exceed 10,000 dolphins and porpoises annually. A trial of acoustic alarms (pingers) in this same fishery showed a 37% reduction in small cetacean bycatch while not reducing target catch and represents a promising bycatch mitigation measure. Seabird bycatch was also found to be high in both longline and gillnet fisheries and included a wide range of seabird species including the critically endangered waved albatross (Phoebastria irrorata). Through post-capture satellite tracking of loggerhead turtles (Caretta caretta) we show that these turtles are present in pelagic waters off the coasts of Peru and Chile for extended periods during which they are at risk of repeat interactions with small-scale longline fisheries operating throughout their foraging habitat. Through scan and focal sampling of the endangered marine otter (Lontra felina) we also show that otters making den sites in human fishing communities face additional risks due to entanglement in fishing gear or interactions with feral animals but, if properly managed, these sites could serve as stepping stones for marine otters along the coast. The results presented here, gathered using a wide range of techniques, including onboard observer and shore-based monitoring, satellite tracking, bycatch quantification, and bycatch mitigation experiments, represent an attempt to better characterize and quantify the interactions of small-scale fisheries with threatened marine vertebrates toward identifying solutions that can lead to sustainable fisheries and populations of these protected marine species.

All wildlife populations harbour parasites. However, seabirds are likely to play a particularly important role in the maintenance and dispersal of infectious agents as a result of their colonial breeding habits. Seabird colonies are also known to be highly spatially structured, but little is known about the effects of this spatial structuring on seabird parasite dynamics. In this thesis, I use a tick-borne virus, Great Island virus (GIV), found in a large common guillemot (Uria aalge) colony bordering the North Sea as a model system to explore this relationship. I use a multidisciplinary approach, framed by a simple epidemiological model of the guillemot-tick-virus system. In Chapter 2, I describe a novel epidemiological model and parameterise it using the existing literature. The model suggests the importance of spatial structure within the guillemot colony, but also identifies a key missing parameter, the rate of virus transmission between pre-breeding and breeding areas. In Chapter 3, I go on to test the potential role of independent tick movement in driving transmission between these two areas, by quantifying the mobility of host-seeking seabird ticks, Ixodes uriae. I show the potential for ticks to walk ranges described anecdotally in the literature, in just a few minutes, but stress the importance of further experiments in the field. Chapter 4, I test the potential role of guillemot-mediated tick movement between pre-breeding and breeding areas. I show that pre-breeding guillemots spend a limited proportion of time ashore during daylight hours, which increases significantly as the season progresses and varies between individuals. A similar pattern is observed when considering how often they enter breeding areas when ashore; generally infrequently but varying spatiotemporally and between individuals. In Chapter 5, I apply finite mixture modelling techniques to improve existing estimates of age- and strain-specific GIV seroprevalence and force of infection in the guillemot colony. I also provide the first estimates of these parameters for eight strains, and highlight the importance of understanding strain-specific differences in GIV dynamics in future studies. Finally, I bring all four data chapters together in Chapter 6, by inputting my new parameter estimates (Chapters 3-5) into my existing model (Chapter 2). Taken together, my results suggest that GIV transmission within the guillemot colony may increase in the future as a result of declining breeding abundance and success, with more frequent or extreme disruption leading to a higher risk of infection within the colony. More generally, my results suggest that seabird colonies can be highly sensitive to changes in their spatial structure, and that endemic parasites have the potential to substantially impact, and hence to be an added threat to, their seabird hosts.

Seabirds commonly nest colonially on cliffs or inaccessible islands, so that oceanic effects on the quality or quantity of prey fed to chicks more often determine nest success than does terrestrial predation. However, when predators can access nests, impacts can be dramatic. In Kittlitz’s murrelet (KIMU), a rare and recently declining seabird, nests are widely dispersed in poorly accessible areas, growth rates are exceptionally high, and nestling periods are very short. This unique strategy may offset the vulnerability of their ground nests to predators but demands adequate deliveries of high-energy prey. We investigated whether variations in energy content of prey fed to chicks could alter growth rates and resulting duration of exposure to predators, and whether extending predator exposure had important effects on nest success. From 2009‒2016, we measured fish length with cameras, modeled prey energy content from chick energy needs, and measured chick growth rate and nest survival. We monitored an average 17 nests/year (139 total), of which 49% were depredated (almost all by red fox) and 25% survived to fledging. Prey were mainly Pacific sand lance (80%) and capelin (19%), with capelin having 2.3× higher energy per unit length. In a year of slow growth, sand lance energy density needed to increase by 31% from 4.29 to 5.64 kJ/g (within published values), or the proportion of capelin in the diet needed to increase from 5.6% to 27.2%, to achieve maximum chick growth. Adults could supply the energy required for maximum growth by delivering only 1.9 capelin/day versus 5.5 sand lance. Slow growth increased time to fledging by 5 days. This extended exposure to predation could decrease overall nest survival from 14.2% to 13.1%, a relative decrease of 7.7%. With reported breeding propensity of KIMU averaging only 20% and sometimes much lower (range 5 to 45%), even small effects on nest success may be consequential. Although direct predation was the main limitation to nest success, effects of ocean conditions on prey quantity and quality can have overriding effects in some years, and apparently small but substantive indirect effects in other years by mediating exposure to predation. Continued climate warming that adversely affects availability of high-energy fish and allows range expansion of terrestrial predators may have disproportionate effects on species such as KIMU with accessible nests and demands for energy-rich prey.

Animal movement is a ubiquitous process and can have consequences ranging from an individual’s energy expenditure to ecosystem dynamics. This study uses biologgers, primarily accelerometers, to record and examine the at-sea behaviours of black-legged kittiwakes (Rissa tridactyla) during their breeding period. Accelerometers record the acceleration of an instrumented animal to give an indication of their behaviour and movements, yet their output can be particularly difficult to interpret. As such, this thesis begins with a method developed for the assignation of coarse-scale behaviours to accelerometry data. The method is a simple yet objective approach intended to be widely applicable. Using this method, we construct time-activity budgets for incubating and chick-rearing kittiwakes and apply activity-specific estimates of energy expenditure to these behaviours. We identify how kittiwakes allocate their time and what the energetic consequences of variation in time-allocation are. We present empirical evidence for chick-rearing kittiwakes expending more energy than incubating birds and identify that kittiwakes exhibit behavioural compensation whereby they limit energy expenditure across both foraging trips and days. We also examine the flight behaviour of kittiwakes in relation to extrinsic conditions. We find that wind conditions do not seem to influence broader scale patterns in movements during foraging trips, however kittiwakes do display behavioural plasticity in response to wind conditions by optimising their flight speeds towards maximum range speeds. We also identify that to optimise flight speeds, kittiwakes change the strength at which they flap their wings, rather than the frequency. Finally we present a serendipitous observation of predation of kittiwake chicks by a peregrine falcon. Although not directly related to movement ecology, this study documents novel predatory behaviour and highlights the importance of biological forces other than movement. Overall, the work presented in this thesis demonstrates that by examining the movement of individuals, it is possible to gain insights into various important aspects of their biology.

Data collected by Australian observers, combined with logbook data supplied by all Japanese vessels fishing in the Australian Fishing Zone were used to estimate the total seabird catch and catch rates (and associated variances) within the Australian Fishing Zone by season and area. The species composition of subsamples of captured seabirds was used in conjunction with the estimates of total by-catch to provide estimates of by-catch by species. The total by-catch of all seabird species by Japanese longline within Australian waters was estimated to be 2,981 (cv 17%) for the 1992 fishing year, 3,590 (cv 15%) in 1993 and 2,817 (cv 19%) in 1994. However, the observed seabird bycatch may underestimate the total number of seabirds killed by 27%. The increase in total seabird by-catch between 1992 and 1993 is partly due to the use of monofilament nylon longline gear by two vessels in 1993, and the decrease from 1993 to 1994 was mainly due to a corresponding reduction in fishing effort. For the three years examined, 78% of the total seabird by-catch was albatrosses, with black-browed albatross (Diomedea melanophrys) and shy albatross (D. cauta) caught in the greatest numbers. Catches of yellow-nosed albatross (D. chlororhynchos), wandering albatross (D. exulans}, and grey-headed albatross (D. chrysostoma) were also substantial. The proportions of individual species caught showed considerable inter-annual variability. Most seabirds caught and killed by longline fishing are captured during line setting. Data collected by the observers were also used to determine the influence of various environmental factors and mitigation measures on seabird catch rates. Generalised linear models were used to determine the statistical significance of the effect of each factor on the seabird catch rate. Results show that the environmental factor that has the most influence is whether line setting was carried out at night or during the day. For the data examined, the chance of catching seabirds during day sets was five times greater than for night sets. For night sets, the chance of catching seabirds during the full half-phase of the moon was five times greater than during the new half-phase. Other environmental factors with significant effects were the area and season fished. Wind, cloud and sea conditions were not found to have a significant influence. Considerable variation in the seabird by-catch rate among vessels was found, which is probably due to differences in their implementation of mitigation measures, as well as the clumped distribution of seabirds by area and time. Interannual variation in the by-catch rate was found to be statistically significant but the differences among years was small in comparison to other factors. An examination of the influence of mitigation measures for sets made during the day in summer in the Tasmanian area showed that the level of bait thawing and unidentified factors related to individual vessels were most significant in determining the seabird by-catch rate, followed by the use of a bait throwing device. It was not possible to examine the influence of the use of bird scaring tori poles and lines as these were used during all sets examined in detail. For this data set, the amount of cloud cover had an influence, while moon phase, sea conditions and wind strength did not.

<p>Under the increasing threat of climate change, it is imperative to understand the impact that environmental phenomena have on the demography and behavior of natural populations. In the last few decades an ever increasing body of research has documented dramatic changes in mortality rates and breeding phenology for a large number of species. A number of these have been attributed to the current trends in climate change, which have been particularly conspicuous in bird populations. However, datasets associated to these natural populations as well as to the environmental variables that affect their biology tend to be partial and incomplete. Thus, ecological research faces the urgent need to tackle these questions while at the same time develop inferential models that can handle the complex structure of these datasets and their associated uncertainty. Therefore, my dissertation research has focused on two main objectives: 1) to understand the relationship that demographic rates and breeding phenology of a colony of seabirds has with the environment in the context of climate change; and 2) to use and develop models that can encompass the complex structure of these natural systems, while also extending the process not only to inference but to building predictions. I divided this work in three research projects; for the first one I developed a hierarchical Bayesian model for age-specific survival for long lived species with capture-recapture data that allows the use of incomplete data (i.e. left-truncated and right-censored), and builds predictions of years of birth and death for all individuals while also drawing inference on the survivorship function. I compared this method to more traditional ones and address their limitations and advantages. My second research chapter makes use of this method to determine the age-specific survivorship of the Dry Tortugas sooty tern population, and explores the effect of changes in sea surface temperature on their cohort mortality rates. Finally, my third research chapter addresses the dramatic shift in breeding season experienced by the Dry Tortugas sooty tern colony, the most unprecedented shift reported for any bird species. I explore the role of climatic and weather variables as triggering mechanisms.</p> / Dissertation

<p>Oceanographic features, such as fronts, eddies, and upwellings, provide important foraging areas for marine predators. These areas serve as important "hotspots" of marine life, by aggregating weakly swimming lower and mid-trophic level species which, in turn, attract foraging predators. Despite the importance of these dynamic features, we lack a comprehensive understanding of how they create foraging habitat for seabirds and other marine predators. In the first part of this dissertation, I review current knowledge of how seabirds use oceanographic features with an emphasis on developing a more mechanistic understanding of these features, and identify important considerations for future studies. I use the findings of this review to inform two field research projects in the Bay of Fundy, Canada and Onslow Bay, North Carolina. In these two projects, I examined seabird abundance and distribution in relation to oceanographic features that occur at different spatial and temporal scales. In the first project, I examined foraging habitat of red-necked phalaropes (<italic>Phalaropus lobatus</italic>) in relation fine-scale tidal forcing near the Brier Island ledges in the Bay of Fundy. This research demonstrated the importance of biophysical interactions in creating phalarope habitat, and characterized red-necked phalarope habitat in both space and time. In Onslow Bay, I investigated the effects of Gulf Stream fronts and eddies on the abundance and distribution of seabirds using both remotely sensed and in situ data. I used fisheries acoustics surveys to investigate prey distribution within Gulf Stream frontal eddies. I then developed habitat models for the six most commonly sighted species or species groups (Cory's shearwaters, <italic>Calonectris diomedea</italic>; greater shearwaters (<italic>Puffinus gravis</italic>; Wilson's storm petrel, <italic>Oceanites oceanicus</italic>; Audubon's shearwaters, <italic>Puffinus lherminieri</italic>; black-capped petrels, <italic>Pterodrama hasitata</italic>; and red and red-necked phalaropes, grouped together as <italic>Phalaropus</italic> spp.) using multivariate modeling techniques. Gulf Stream frontal eddies influenced the abundance and distribution of seabirds in Onslow Bay, although frontal features were not as important in predicting seabird habitat as demonstrated in previous studies in the South Atlantic Bight. Prey availability in Gulf Stream frontal eddies was highest in eddy cold core regions, particularly in those regions close to the Gulf Stream. Taken together, the results of my dissertation: underscore the importance of conducting standardized surveys to assess dynamic environmental variables; demonstrate the use of multivariate methods to examine seabird foraging in relation to oceanographic features; emphasize the need to evaluate both prey distributions and physical regimes within oceanographic features at depth; and highlight the importance of temporal aspects of oceanographic features, such as the persistence and age of the features, when assessing the role that these features play in creating seabird foraging habitat.</p> / Dissertation

Characterizing the population genetic structure of a species can provide insight into isolating effects of local adaptation and genetic drift, and homogenizing effects of gene flow. The relative interplay between gene flow and genetic drift can indicate whether multiple conservation units are needed to preserve biodiversity. Baja California, Mexico is a biodiversity hotspot where many individuals are genetically differentiated from conspecific individuals breeding elsewhere. Cassin’s auklet (Ptychoramphus aleuticus), a zooplanktivorous seabird, breeds in colonies along the Pacific coast of North America. One subspecies, P. a. australe, is described from Baja California and another, P. a. aleuticus, is described from the rest of its range to the Aleutian Islands, Alaska. Many of the colonies throughout its range have been declining in numbers likely as a result of decreases in food availability in cold-water upwellings along the coast. The mitochondrial control region and eleven nuclear microsatellites were analyzed using programs based on coalescent and Bayesian theory to determine how the southern subspecies compares genetically to the main subspecies. First, population genetic structure was characterized throughout Cassin’s auklet’s breeding range using pairwise genetic differentiation indices, hierarchical analysis of variance, statistical parsimony and Bayesian clustering methods. The two subspecies were genetically differentiated but individuals breeding in the Channel Islands were more genetically similar to P. a. australe individuals. Population genetic differentiation was not evident within the two genetic groups. Second, gene flow between the two genetic groups was estimated using coalescent and Bayesian methods. Significant gene flow was estimated from the northern group (Aleutian Islands to Southeast Farallon Islands) into the southern group (Channel Islands to San Benito Island) but not from the southern group into the northern group since the time of divergence, possibly as a result of the non-breeding distribution. Results show that the two genetic populations diverged recently and the populations have experienced a recent population change in size. Restrictions in home range and foraging range may cause population genetic differentiation, resulting in two distinct management units. Genetic differentiation of the southern population provides support for Baja California and southern California being a biodiversity hotspot. / Thesis (Master, Biology) -- Queen's University, 2012-09-28 14:02:24.007

Information about tropical seabird communities is less abundant in the literature than for those that occur at higher latitudes. In research papers examining seabird breeding communities in tropical environments, it has been found that food availability was temporally and spatially variable in comparison to higher latitudes. This environmental variability would be expected to influence the life-history traits of tropical seabird species, and in turn, the structure of the communities in which they occur. To examine the impact of environmental variability upon the life-history traits and community structure of tropical seabirds, a comparative study of the breeding strategies of three tropical tern species and an outlier, shearwater species was carried out, at the Lowendal Islands, Western Australia (20o39’52S; 115o34’44E) between 1996 and 2000. Bridled Terns Sterna anaethetus and Wedge-tailed Shearwaters Puffinus pacificus shared the life-history traits of migration or dispersal from the breeding colony and east-Indian Ocean metapopulation when not breeding, a summer breeding schedule, nest-site fidelity, concealed nest-sites, clutch size of one, offshore and pelagic foraging regime, and protracted post-natal growth. Crested Terns Sterna bergii and Lesser Crested Terns Stern bengalenis bred within the same colony and shared the life-history traits of presence at the breeding colony when not breeding, an autumn breeding schedule, change in colony site each season, open dense nest-sites, brood size of one. inshore foraging regime (as well as offshore for Crested Terns) and rapid post-natal growth. It was found that each species experienced variation in nest-site occupancy and/or colony size, as well as variation in timing of breeding and breeding success between years. The effects upon each species seemed to operate independently, as concurrently breeding species did not appear affected by the same events, with the exception of cyclones. Late and/or poor breeding success in a species often coincided with oceanographic changes in the north-west region, such as fluctuations in the strength of flow and temperature of the Leewin Current. The Leewin Current is a warm water, low salinity current flowing southwards along most of the Western Australian coastline and has a stronger, warmer flow during El Nino Southern Oscillation (ENSO) events. Cyclone activity is also influenced by ENSO induced changes in the region’s water temperature. Changes in the Leewin Current affected the timing of breeding for Wedge-tailed Shearwaters, and feeding conditions for all study species, presumably as a result of changes in prey availability, while cyclone events delayed breeding for Crested Terns and Lesser Shearwaters in the years studied. Cyclone events were the most obvious cause of re-laying in the case of Crested Terns and Lesser Crested Terns, and breeding failure in the case of Bridled Terns and Wedge-tailed Shearwaters. Breeding failure was common among later breeders in the Crested Tern colonies. Breeding success was relatively high for lesser Crested Terns in all years studied, as they hatched and fledged their chicks within the Crested Tern colony among the first wave of breeders. There was some overlap in the diets and foraging grounds of the four study species. Crested terns and Lesser Crested Terns had the most similar diet, however, Crested Terns appeared to be the most opportunistic foragers, with the highest diversity of dietary prey, while Lesser Crested Terns diet consisted of a high proportion of atherinids. Bridled Terns has the next highest prey diversity, while half the diet of Wedge-tailed Shearwaters in this region, similar to conspecifics elsewhere, consisted of squid. Wedge-tailed Shearwaters were observed to be offshore and pelagic foragers. Their distribution in the waters surrounding the Lowendal Islands ranged to the full extent of observation transects(63 Km), and most likely beyond, excluding inshore waters (i.e. within 5 km of islands). They were not present in the vicinity of the Lowendal Islands when they were not breeding. Bridled Terns were observed to be offshore foragers, also ranging to the full extent of transects, and most likely beyond, occasionally including inshore waters. They were rarely observed when not breeding, with the exception of a small number of fledglings at the end of the breeding season. Crested Terns were observed to combine inshore and offshore foraging grounds, only ranging to the full extent of transects during their breeding season. Lesser Crested Terns were observed foraging inshore only. Chick provisioning, in terms of meal size and frequency, varied between years and within seasons for all species. It was demonstrated that there were differences in mean corrected meal sizes between years for Wedge-tailed Shearwaters, and the same was inferred from chick growth curves for Bridled Terns. Wedge-tailed Shearwaters provisioned their chicks with larger meal sizes and a higher occurrence of double feeds in 1996/97 than in other years studied. The amount of time spent feeding chicks in the burrow by Wedge-tailed Shearwaters adults became shorter as the breeding season progressed. It was demonstrated that all three tern species increased the meal size delivered to chicks as they grew. Wedge-tailed Shearwaters did not increase meal size as the season progressed, however they did increase feeding frequency. The feeding frequency of Crested Terns was highest in 1999, nearly doubling that observed in 1997 and 1998. In 1998 Lesser Crested Terns fed their chicks up to six times more frequently than Crested Terns. Chick growth varied for Wedge-tailed Shearwaters and Bridled Terns between seasons. Bridled Tern chicks grew more rapidly in 1997/98, were heavier and reached higher asymptotes for all linear parameters, the exception of wing length, than in 2000. On the other hand, Wedge-tailed Shearwater chicks grew more rapidly in 1999/2000 than in 1997/98, however, they attained similar asymototes for all parameters in both years. In the absence of repeat measures of same individuals, Crested Tern and Lesser Crested tern growth was examined using age categorization based on wing and tail feather development. Both species appeared to attain similar sizes at similar rates in each year. Wedge-tailed Shearwaters accumulated weight up to 30% in excess of mean adult weight in all seasons. This is a common trait exhibited in procellarigorms, and some weight loss occurs prior to fledging. It is suggested, based upon evidence from other studies in which weight loss prior to fledging was found to be water loss, that lipid accumulation acts as an insurance for the period after fledging when young are leaning to forage for themselves. The information gathered for this project found no direct evidence of competition among the species comprising the seabird community if Lowendal Islands. Niche overlap occurred amongst all species, particularly in the case of lesser Crested Terns and Crested Terns, which shared breeding phenology, breeding colonies, foraging grounds and dietary overlap. Niche overlap also occurred between Wedge-tailed Shearwaters and Bridled Terns, which shared breeding phenology and foraging grounds.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Sport Management in the Faculty of Business and Management Sciences at the Cape Peninsula University of Technology / Volunteer tourism, as a form of leisure and/or recreation, is one of the fastest growing forms of tourism globally. It has also become a critical human resource for many organisations in the Western Cape, South Africa who rely on the support of volunteer tourists. A review of the current literature showed that most volunteer tourism research studies is volunteer-tourist-centred and focus on the motivations for participation and the benefits of participation to the volunteer tourist. Very few studies consider the effect of volunteer tourism on the host organisation and within the South African context only two volunteer tourist profile studies exist. Both studies excluded host organisation factors that indicated how host organisations benefited from hosting volunteer tourists. This research study focussed on creating a comprehensive profile of volunteer tourists at SANCCOB (a non-profit seabird rehabilitation centre) in Table View, Western Cape, South Africa. The profile included demographic factors, motivational factors and SANCCOB specific information. Data were collected through an anonymous, self-administered, online questionnaire and from the data, five conclusions were made. Firstly, the demographic factors of volunteer tourists that participated in SANCCOB’s international volunteer programme was similar to other South African based volunteer tourism studies. Secondly, to experience something different and new was the most important motivational factor for volunteer tourists. Thirdly, volunteer tourists derived considerable benefit from volunteering at SANCCOB. Fourthly, volunteer tourists continued to support SANCCOB through social and financial activities after completing the programme, indicating that SANCCOB (as a host organisation) benefited from hosting volunteer tourists and that as a result, a mutually beneficial relationship exists between this host organisation and the volunteer tourist. Lastly, this study provided SANCCOB with valuable information for volunteer management, as well as future marketing and fundraising campaigns.