Atlantic reef fish biogeography and evolution

Copyright © 2007 The Authors.Journal compilation © 2007 Blackwell Publishing Ltd.AIM: To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to faunal enrichment. RESULTS: Phylogenetic (proportion of sister species) and distributional (number of shared species) patterns are generally concordant with recognized biogeographical provinces in the Atlantic. The highly uneven distribution of species in certain genera appears to be related to their origin, with highest species richness in areas with the greatest phylogenetic depth. Diversity buildup in Atlantic reef fishes involved (1) diversification within each province, (2) isolation as a result of biogeographical barriers, and (3) stochastic accretion by means of dispersal between provinces. The timing of divergence events is not concordant among taxonomic groups. The three soft (non-terrestrial) inter-regional barriers (mid-Atlantic, Amazon, and Benguela) clearly act as ‘filters’ by restricting dispersal but at the same time allowing occasional crossings that apparently lead to the establishment of new populations and species. Fluctuations in the effectiveness of the filters, combined with ecological differences among provinces, apparently provide a mechanism for much of the recent diversification of reef fishes in the Atlantic

Prevalence of pelagic dependence among coral reef predators across an atoll seascape

1)Coral reef food webs are complex, vary spatially and remain poorly understood. Certain large predators, notably sharks, are subsidised by pelagic production on outer reef slopes, but how widespread this dependence is across all teleost fishery target species and within atolls is unclear. 2)North Malé Atoll (Maldives) includes oceanic barrier as well as lagoonal reefs. Nine fishery target predators constituting ca. 55% of the local fishery target species biomass at assumed trophic levels 3‐5 were selected for analysis. Data were derived from carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) stable isotopes from predator white dorsal muscle samples, and primary consumer species representing production source end‐members. 3)Three‐source Bayesian stable isotope mixing models showed that uptake of pelagic production extends throughout the atoll, with predatory fishes showing equal planktonic reliance between inner and outer edge reefs. Median plankton contribution was 65‐80% for all groupers and 68‐88% for an emperor, a jack and snappers. 4)Lagoonal and atoll edge predators are equally at risk from anthropogenic and climate‐induced changes which may impact the linkages they construct, highlighting the need for management plans that transcend the boundaries of this threatened ecosystem

The Conservation Status of Marine Biodiversity of the Pacific Islands of Oceania

The Pacific Islands of Oceania are small islands and atolls occurring over a vast expanse of ocean that are characterized by immense biodiversity and endemism. This project represents a major expansion of the coverage of the Pacific Islands’ marine biodiversity on the IUCN Red List of Threatened Species. The threats to Pacific Island marine biodiversity are many. Results from IUCN Red List initiatives such as this can guide decision-making and conservation prioritization of Pacific Island governments, non-governmental organizations (NGOs) and the private sector. By shaping regional and national policies with these data in mind, priority sites for maintaining marine biodiversity can be identified and conserved

The Conservation Status of Marine Bony Shorefishes of the Greater Caribbean

The greater Caribbean biogeographic region covered in this report (representing 38 countries and territories) encompasses an outstanding marine bony shorefish richness of approximately 1,360 species, with many (53%) being endemic. This report provides an overview of the conservation status of greater Caribbean shorefishes, with detailed information available through the IUCN Red List, and gives recommendations

Conservation status of marine biodiversity of the Western Indian Ocean

The Western Indian Ocean is comprised of productive and highly diverse marine ecosystems that are rich sources of food security, livelihoods, and natural wonder. The ecological services that species provide are vital to the productivity of these ecosystems and healthy biodiversity is essential for the continued support of economies and local users. The stability of these valuable resources, however, is being eroded by growing threats to marine life from overexploitation, habitat degradation and climate change, all of which are causing serious reductions in marine ecosystem services and the ability of these ecosystems to support human communities. Quantifying the impacts of these threats and understanding the conservation status of the region’s marine biodiversity is a critical step in applying informed management and conservation measures to mitigate loss and retain the ecological value of these systems. This report highlights trends in research needs for species in the region, including priorities for fundamental biological and ecological research and quantifying trends in the populations of species. The assessments and analyses submitted in this report should inform conservation decision-making processes and will be valuable to policymakers, natural resource managers, environmental planners and NGOs

Distribution and abundance of carangid larvae in the southeastern Brazilian Bight during 1975-1981

Distribution and abundance of the carangid larvae collected during ten survey cruises in the southeastern Brazilian Bight were analyzed. Trachurus lathami was the most abundant species in the surveyed area with 58.54 % of total carangids taken, followed by Chloroscombrus chrysurus with 15.22 % and Decapteruspunctatus with 12.17 %. Larvae of T lathami and D. punctatus were found all over the continental shelf while the distribution of C. chrysurus larvae was limited to the coastal region. Most of the species occurred all year-around but remarkably during spring and summer. This intensive spawning period of most carangid species seems to be related to the seasonal variation of the hydrographie structure of the southeastern coast of Brazil.No presente trabalho estudaram-se a distribuição e a abundância de larvas de peixes da família Carangidae da costa sudeste do Brasil, entre Cabo Frio (23ºS) e Cabo de Santa Marta Grande (29ºS). As amostras foram coletadas com rede Bongô (malhagens de 0,505 mm e 0,333mm) em arrastos oblíquos, durante dez cruzeiros oceanográficos com o N/Oc. "Prof.W.Besnard", do Instituto Oceanográfico da USP e com N/Oc. "Cruz dei Sur", da PDP-SUDEPE. Foram identificados cinco táxons ao nível de espécie (Trachurus lathami, Chloroscombrus chrysurus, Decapterus punctatus, Selene setapinnis e Selene vomer), além de quatro ao nível de gênero (Oligoplites, Caranx, Serioia e Trachinotus). A espécie mais abundante foi T lathami (58,44% do total de larvas da família Carangidae), seguida por C. chrysurus (15,22%) e D. punctatus (12,17%). T. lathami e D. punctatus apresentaram distribuição ampla por toda a região nerítica, enquanto que C. chrysurus restringiu-se apenas às regiões mais próximas da costa. As larvas de carangídeos foram encontradas durante todas as épocas do ano, mas na primavera e no verão observou-se a maior abundância, o que caracteriza maior intensidade de desova durante estas estações. Esse período de pico de desova relaciona-se, aparentemente, à variação da estrutura hidrográfica da região