Oceanic pelagic shark species are under threat worldwide as fishing effort increases and they are taken as both targeted and bycatch. It is widely recognized that the life history characteristics of sharks make them inherently susceptible to overexploitation and as a result many shark-directed fisheries have collapsed. It is therefore essential that good-quality data are collected and analyzed in order to provide fisheries managers with the right information to manage these species sustainably. South Africa has a pelagic longline fishery which includes tuna-, swordfish-, and shark-directed vessels. This study analyzed logbook (1998 – 2010) and observer data (2002 – 2010) provided by the Department of Agriculture, Forestry and Fisheries in order to assess the catch composition and standardized catch-per-unit-effort (CPUE) of sharks captured as both targeted catch and bycatch. The study area consisted of four zones moving east of the 20°E meridian: the Agulhas Bank (20°E – 24°E), South Coast (25°E – 29°E), East Coast 1 (30°E – 32.8°E), and East Coast 2 (32.9°E – 36.5°E). The majority of fishing effort targeted at tuna was focused on the Agulhas Bank and consisted of foreign vessels which operated over the winter months, whereas local vessels targeted swordfish with consistent year-round effort along the upper east coast. Sharks made up 13% of total catches according to logbook data and catch composition was dominated by blue shark (Prionace glauca) and shortfin mako shark (Isurus oxyrinchus). Observer data identified a larger number of shark species than shown by logbooks, and notably, the crocodile shark (Pseudocarcharias kamoharai) made up 22.5% of shark bycatch on swordfish-directed vessels operating along the upper east coast. In addition, the observer data showed that although blue and mako shark dominated catches in the Agulhas Bank and South coast zones, carcharhinid sharks were more prevalent further east. Generalized linear models explained 54% of the variation in CPUE of shark bycatch, with year and target species being the two most important explanatory variables. The standardized CPUE index based on logbook data suggested a slightly increasing shark abundance trend between 1998 and 2010, but conversely, the index based on observer data suggested a decline between 2002 and 2010. Assuming that the observer data best reflected the actual CPUE trend (i.e. a declining trend), the increasing trend shown by logbooks over the same period most likely stems from initial under-reporting of shark capture events by skippers, followed by improved reporting in later years, thus masking the declining trend. Catch by target species revealed that swordfish vessels caught significantly more sharks per 1000 hooks than tuna vessels. The shortfin mako shark was one of the most common bycatch species, and also the primary target species of the shark-directed fishery. Generalized linear models of shortfin mako shark CPUE using the delta method produced similar trends than models of total shark bycatch; i.e. trends based on logbook data appeared stable but observer data showed a declining trend over time. Shortfin mako sharks were more abundant in the Agulhas Bank and South coast zones than along the East coast. A total of 817 shortfin mako shark samples were collected onboard a South African shark-directed pelagic longline vessel operating out of Cape Town and by the KwaZulu-Natal Sharks Board bather protection nets, set close inshore. Sharks collected inshore (from nets) were significantly larger than those collected offshore. More males than females were collected from the nets (2.3 males : 1 female), whereas the ratio for offshore samples was 1.1 : 1. Age and growth parameters were estimated from 89 sectioned vertebral samples consisting of 43 females and 46 males ranging in size from 90 cm to 299.4 cm fork length (FL). Annual band-pair deposition was assumed and growth was analyzed by fitting 3-parameter von Bertalanffy and Gompertz growth models. Parameter estimates for the Gompertz model were: K = 0.152 year¯¹ for males and 0.127 yearˉ¹ for females; L0 = 85 cm; L∞ = 295 cm for males and 315 cm for females; and longevity was 17 and 21 years for males and females respectively. Estimates for the von Bertalanffy model were: K = 0.08 yearˉ¹ for both sexes; L0 = 85 cm; L∞ = 354 cm for males and 321 cm for females; and longevity was 34 and 31 years for males and females respectively. Using these data, age and length at 50% maturity were calculated at 7 years and 199.1 cm FL for males, and 14 years and 252.8 cm for females. Litter size was in agreement with previous studies (9 to 14 pups). The gestation period was not estimated but parturition may be in late winter to spring. The stomach contents of 817 sharks showed that shortfin mako sharks are opportunistic feeders; elasmobranchs dominated in stomachs collected from sharks caught in nets near the shore (%F = 63.54%) whereas shark stomachs collected from the offshore contained mainly teleosts (70%). Length-frequency analyses revealed that large and reproductively active shortfin mako sharks were more common along the upper east coast and in the inshore environment, whereas juveniles and subadults preferred the oceanic environment, particularly over the Agulhas Bank and South Coast zones. The findings from the present study are a significant step forward towards developing a management strategy for protecting shortfin mako sharks in the South West Indian Ocean region. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-10-17T12:41:14Z No. of bitstreams: 1 Lucas Eduardo Comassetto.pdf: 1687527 bytes, checksum: 29eaaeb964c01c96c752e0cb5735009f (MD5) / Made available in DSpace on 2017-10-17T12:41:14Z (GMT). No. of bitstreams: 1 Lucas Eduardo Comassetto.pdf: 1687527 bytes, checksum: 29eaaeb964c01c96c752e0cb5735009f (MD5) Previous issue date: 2016-08-25 / This work aims to contribute information on the spatiotemporal variation and its relationship to environmental variables and the weather also determine the impact on the distribution of species increase scenarios of sea surface temperature (SST). Were evaluated in this study the information on the Brazilian oceanic fisheries operating in the South Atlantic and Equatorial in the period 1978-2012 in order to generate information on catch rates per unit effort (CPUE) standard from a linear model Mixed generalized (GLMM) using a Delta Lognormal approach, to contribute to the correct evaluation of the stock. Based on the results it was observed that the standardized series of CPUE of the mako shark showed a trend of gradual increase, especially after the year 2000 and this trend is not clear, it may be related to several factors: a real increase in abundance, increase in catchability, change in fishing strategy or even an improvement in data communication. It was also observed that the mako shark shows temperature preferably in the South Atlantic and Equatorial in the range between 17 and 22 ° C the temperature showing the highest rate 19 ° C and its greater abundance located below 20 ° S in water away from the coast in the months of January and February, the months of May and June the lowest rates. Once dummy increased TSM was observed that with increasing by 1 ° C decreases by 3-5% 2 ° C 15-20% reduction of 3 ° C reduction by 25 and 28% and the abundance focusing on a area bounded between 30 ° S-35ºS / 40ºW-25ºW and 4 ° C increase the reduction of up to 96%. In this sense these results will be used to understand the spatial-temporal distribution and the proper assessment and management of the species. / Este trabalho visa contribuir com informações sobre a variação espaço-temporal e sua relação com variáveis ambientais e o clima, ainda verificar o impacto causado sobre a distribuição da espécie em cenários de aumento da temperatura da superfície do mar (TSM). Foram avaliadas no presente trabalho as informações sobre a pesca oceânica brasileira que atua no Atlântico Sul e Equatorial, no período de 1978 a 2012 no sentido de gerar informações sobre os índices de captura por unidade de esforço (CPUE) padronizada a partir de um Modelo Linear Generalizado Misto (GLMM) usando uma abordagem Delta Lognormal, para contribuir na correta avaliação do estoque. Baseando-se nos resultados obtidos foi possível observar que a série padronizada da CPUE do tubarão mako mostrou uma tendência de aumento gradual, especialmente após o ano 2000 e essa tendência não é clara, podendo estar relacionada a diversos fatores: aumento real na abundância, aumento na capturabilidade, mudança na estratégia de pesca ou ainda, uma melhoria na comunicação de dados. Observou-se também que o tubarão mako apresenta preferência de temperatura no Atlântico Sul e Equatorial na faixa entre 17 e 22°C sendo a temperatura que apresenta o maior índice 19°C e com a sua maior abundância localizada abaixo de 20°S em agua afastadas da costa nos meses de janeiro e fevereiro, nos meses de maio e junho os menores índices. Quando simulado o aumento da TSM foi observado que com a elevação em 1°C ocorre redução de 3-5%, 2°C redução de 15-20%, 3°C redução de 25 e 28% e a abundância se concentrando em uma área limitada entre 30ºS-35ºS/40ºW-25ºW e 4°C de aumento a redução de até 96%. Neste sentido estes resultados servirão para compreender a distribuição espaço-temporal e a correta avaliação e gestão da espécie.

Ce projet vise la documentation et la description du mako, une langue autochtone parlée par environ 1200 personnes dans l’Amazonie vénézuélienne et pour laquelle le seul matériel accessible à date se limite à 38 mots. L’objectif principal est de créer une collection de textes ethnographiques annotés et, à long terme, une grammaire de la langue qui puisse servir comme point de départ pour des activités d’appui au maintien de la langue dans la communauté et pour avancer la recherche linguistique. Un objectif secondaire est d’établir le degré de vitalité de la langue telle que parlée chez les différentes communautés mako. Cette recherche mènera à une description des différents aspects de la grammaire de la langue, par exemple sa phonologie, sa morphologie et sa syntaxe. En plus de contribuer à l’étude et description des autres membres de la famille linguistique sáliba et à la reconstruction de leur proto-langue commune, les données du mako contribueront aussi à des discussions sur comment le langage fonctionne et seront donc un apport précieux pour la théorie linguistique. Cette recherche fera avancer la théorie de la documentation des langues et pourra donc faciliter les efforts de documentation et maintien des langues d’autres communautés indigènes. Le projet constitue une application du modèle de travail de terrain Community-Based Language Research. / This dissertation focuses on the documentation and description of Mako, an indigenous language spoken in the Venezuelan Amazon by about 1000 people and for which the only available published material at the start of the project were 38 words. The main goals of the project were to create a collection of annotated ethnographic texts and a grammar that could serve as a starting point for both language maintenance in the community and for further linguistic research. Additionally, the project sought to assess the language’s vitality in the communities where it is spoken and to understand the relationship of Mako to the two other extant Sáliban languages, namely Piaroa and Sáliba.This research has thus led to an assessment of language vitality in the Mako communities of the Ventuari River, a comprehensive description of the Mako language—heretofore undescribed—, and an evaluation of the genetic relationship between the three Sáliban languages. The description of the language covers a wide range of topics in areas such as phonetics and phonology, nominal and verbal morphology, and syntax of both simple and complex sentences. Discourse-level morphology and discourse-organization strategies are also covered. Aside from facilitating the study of other members of the Sáliban family and reconstruction of the common ancestral language, the description of Mako also contributes to the typology of Amazonian languages and to our understanding of the pre-history of this area of the Orinoco basin. The products of this project also have the potential to be mobilized in language literacy efforts in the Mako communities.