Since the 1950s, industrial fisheries have expanded globally, as fishing vessels are required to travel further afield for fishing opportunities. Technological advancements and fishery subsidies have granted ever-increasing access to populations of sharks, tunas, billfishes, and other predators. Wilderness refuges, defined here as areas beyond the detectable range of human influence, are therefore increasingly rare. In order to achieve marine resources sustainability, large no-take marine protected areas (MPAs) with pelagic components are being implemented. However, such conservation efforts require knowledge of the critical habitats for predators, both across shallow reefs and the deeper ocean. Here, we fill this gap in knowledge across the Indo-Pacific by using 1,041 midwater baited videos to survey sharks and other pelagic predators such as rainbow runner ( Elagatis bipinnulata ), mahi-mahi ( Coryphaena hippurus) , and black marlin ( Istiompax indica) . We modeled three key predator community attributes: vertebrate species richness, mean maximum body size, and shark abundance as a function of geomorphology, environmental conditions, and human pressures. All attributes were primarily driven by geomorphology (35%−62% variance explained) and environmental conditions (14%−49%). While human pressures had no influence on species richness, both body size and shark abundance responded strongly to distance to human markets (12%−20%). Refuges were identified at more than 1,250 km from human markets for body size and for shark abundance. These refuges were identified as remote and shallow seabed features, such as seamounts, submerged banks, and reefs. Worryingly, hotpots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations.
http://dx.doi.org/10.1590/1676-06032014011514Abstract: The phytal is characterized by the formation of seaweed beds and a great diversity of associated species, the malacofauna being one of its main components. Aiming to record the species of Gastropoda associated to the brown algae Sargassum sp. C. Agardh, 1820, this study was carried out in Sã o Sebastião Channel, northern coast of Sã o Paulo, and nearby areas. A total of 13945 individuals were identified, belonging to 35 families and 62 species. Cerithiidae, Phasianellidae and Columbellidae were the most abundant families, represented by 34, 33 and 17% of the total collected individuals, respectively. Bittiolum varium (Pfeiffer, 1840) (Cerithiidae) and Eulithidium affine (C. B. Adams, 1850) (Phasianellidae) are the dominant species, followed by the columbelids Mitrella dichroa (G. B. Sowerby I, 1844), Anachis fenneli Radwin, 1968 and Costoanachis sertulariarium (d'Orbigny, 1839). Among the least abundant species, some of them may be considered as of fortuitous occurrences, while others seem to be typical in those habitats, although rare. The presence of juvenile specimens was recurrent, this indicating that the algae can function as a nursery for most of these species. The expressive values found, for both abundance and number of species, illustrate the great ecological importance of the phytal habitats for the gastropod species.
As macroalgas associadas aos costões rochosos formam ambientes heterogêneos, que estão presentes em grandes áreas no ambiente marinho. São bem distribuídas na região entremarés e correspondem a um habitat favorável devido a sua complexidade estrutural, que está diretamente relacionada à diversidade de organismos associados a elas. Essa relação está provavelmente ligada à disponibilidade de refúgios e à capacidade de reter alimento. As macroalgas marinhas e sua fauna associada formam uma comunidade denominada fital. Os invertebrados são os principais animais associados às comunidades de fital, sendo a malacofauna bastante representativa neste sistema. No período de um ano realizaram-se quatro coletas de algas pardas Sargassum spp. em doze costões rochosos na região do Canal de São Sebastião, sendo seis na ilha de São Sebastião, e seis no continente, nos municípios de São Sebastião (5 costões) e Caraguatatuba (1 costão). Foram padronizados os números de frondes e a profundidade utilizada. O principal objetivo foi analisar a estrutura da comunidade de moluscos quanto à composição, a abundância e a riqueza de espécies, verificando se esses parâmetros diferiram entre ilha e continente.Foram registrados 15849 indivíduos, distribuídos em 72 espécies de moluscos, sendo 15 de Bivalvia e 57 de Gastropoda. As espécies com maior representatividade em relação ao número de indivíduos foram Bittiolum varium (Gastropoda), Eulithidium affine (Gastropoda), Pinctada imbricata (Bivalvia) e Mitrella dichroa (Gastropoda). A riqueza de espécies diferiu entre as localidades, 12 espécies de Bivalvia e 55 espécies de Gastropoda ocorreram na ilha somando 67 espécies e, 15 espécies de Bivalvia e 45 espécies de Gastropoda ocorreram no continente totalizando 60 espécies As curvas de rarefação também mostram que a comunidade de moluscos da ilha é mais rica que a do continente.viii O teste de escalonamento multidimensional não métrico demonstra um provável agrupamento entre as duas localidades, refletindo que pode haver diferenças na composição de espécies (ilha vs. continente), resultado sustentado pela análise de similaridade (R = 0,5333, p = 0,00415) e também representado pela Entropia de Renyi (α = 0). A porcentagem de similaridade indicou que as espécies que mais contribuem para a diferença entre ilha e continente são Eulithidium affine, Bittiolum varium, Pinctada imbricata,Mitrella dichroa e Anachis fenneli (Bray-Curtis 67,5%). Cerca de 50% dos gastrópodes são herbívoras ou carnívoras, e 20% dos bivalves são filtradores. As diferenças entre as comunidades de moluscos associados ao fital de ilha e continente podem ser atribuídas não somente à complexidade estrutural da alga parda, mas também à diversidade funcional entre algas e moluscos, à distribuição espacial devido aos fatores geográficos, às oscilações de temperaturas e chuvas, e fatores antropogênicos.Palavras-chave: Fital, Feófitas, Molusco, Estrutura da comunidade ecológica -São Sebastião Canal de (SP), Diversidade de espécies.
There are two textual errors in the published paper. In the Abstract, the last line reads "hotpots" instead of "hotspots." The same textual error is present in the Introduction. The last line of the Abstract should read as follows:Worryingly, hotspots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations.The first line of the last paragraph of the Introduction should read as follows:Here, we utilize an extensive data set of standardized and nondestructive baited video surveys from nine regions across the Indo-Pacific region to model predator diversity and abundance and to identify hotspots of vertebrate species richness, mean maximum body size weighted by abundance (hereafter "body size"), and shark abundance as a function of environmental conditions, geomorphology, human pressure, and management levels.
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