An updated reef fish checklist of the southernmost Caribbean reef system, with comments on the lionfish invasion

Chocó-Darien is an important biogeographic realm, as it is a terrestrial biodiversity hotspot and the southern limit of the Caribbean reefs. However, to date there are no compiled data on the reef fish assemblage of this region. We provide an updated checklist of marine fishes from the Chocó-Darien reef system (Colombia), with comments on their geographic distribution and conservation status. Peer-reviewed studies, unpublished data and in situ visual censuses were surveyed to compose this checklist. A total of 212 reef fish species across 57 families were compiled, eight of which had no previously published records, one of which (Trachinotus falcatus) is recorded for the first time. The most speciose families were Labridae (n = 21), Gobiidae (n = 18) and Serranidae (n = 17). Fourteen threatened species were recorded, including one critically endangered (Epinephelus striatus) and two endangered (Balistes vetula and Scarus coelestinus). This study contributes to fill the knowledge gaps on the reef fish diversity of the Caribbean southern limit and raises concern on the spread of the lionfish invasion into the Chocó-Darién reef system.

Patterns of reef fish assemblage distribution on a Brazilian subtropical rocky shore: an approach to benthic association

<p>Os ambientes recifais são caracterizados como formações de fundo consolidado de origem orgânica e/ou inorgânica. Em costões rochosos, fatores bióticos e abióticos determinam a sua biodiversidade. Na praia do Forno, onde o fenômeno da ressurgência ocorre, a assembleia de peixes recifais foi analisada por meio de censo visual. A cobertura bentônica do substrato foi classificada em quatro categorias. O uso do substrato foi determinado pela abundância relativa das espécies em cada um de seus tipos. Um total de 5414 indivíduos pertencentes a 31 espécies de peixes recifais foi observado. Os resultados demonstraram que a preferência por habitats, caracterizados pela cobertura por organismos bentônicos, foi um fator importante na determinação da composição da assembleia de peixes recifais, em uma microescala. A escolha de um habitat dentre os diversos tipos de substrato, poder ser em sua maior parte explicada pela disponibilidade de recursos alimentares.</p><p><strong></strong><strong>Palavras chave</strong>: Cobertura bentônica, padrões biogeográficos, interações bióticas, habitat, ictiofauna, costões rochosos.</p>

The influence of depth on the Mediterranean reef fish assemblage revealed by the new video on underwater scooter method

The new video on underwater scooter method in combination with rebreather diving techniques was introduced and applied for visual census of fish assemblages. The presently applied method facilitates deeper visual census studies below 40 m, where they have rarely been done before due to the increasing research challenges with depth. The video on underwater scooter method is also expected to be less disturbing and faster compared to swimming divers. The method was applied in visual census study of fish assemblages from 8 to 50 m depth conducted at two locations in the east Adriatic using 102 video transects. The environmental variables contributing to the variation of the reef fish community in the depth range of the infralittoral and upper circalittoral bottoms were also recorded. Thirty-one fish species were recorded on transects and 10.3% of all individuals were not identified to the species level. The average density on transects was 0.8 individuals/m², with C. chromis, C. julis and G. auratus being both the most abundant and the most frequent species. Three environmental variables, depth, bottom with zoocover and eastern orientation of the coast, were identified as highly significant for species occurrence. Abundance and species richness of fish assemblages showed no significant variation with depths, inclinations, orientations and sites. A significant difference in the fish assemblage structure was found among orientations, depths and inclinations with the gradient change of species composition with increasing depth and with increasing inclination.

Spatial assemblage structure of shallow-water reef fish in Southwest Australia

Bioregional categorisation of the Australian marine environment is essential to conserve and manage entire ecosystems, including the biota and associated habitats. It is important that these regions are optimally positioned to effectively plan for the protection of distinct assemblages. Recent climatic variation and changes to the marine environment in Southwest Australia (SWA) have resulted in shifts in species ranges and changes to the composition of marine assemblages. The goal of this study was to determine if the current bioregionalisation of SWA accurately represents the present distribution of shallow-water reef fishes across 2000 km of its subtropical and temperate coastline. Data was collected in 2015 using diver-operated underwater stereo-video surveys from 7 regions between Port Gregory (north of Geraldton) to the east of Esperance. This study indicated that (1) the shallow-water reef fish of SWA formed 4 distinct assemblages along the coast: one Midwestern, one Central and 2 Southern Assemblages; (2) differences between these fish assemblages were primarily driven by sea surface temperature, Ecklonia radiata cover, non-E. radiata (canopy) cover, understorey algae cover, reef type and reef height; and (3) each of the 4 assemblages were characterised by a high number of short-range Australian and Western Australian endemic species. The findings from this study suggest that 4, rather than the existing 3 bioregions would more effectively capture the shallow-water reef fish assemblage patterns, with boundaries having shifted southwards likely associated with ocean warming.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Most artificial reef deployments to date have been directed toward fish assemblage enhancement, with only a few that are fisheries- or species-specific. The ostensible rationale for this approach is that when the artificial reef fish assemblage increases in a given area, the component target species will also increase. This premise also implies that the target species is characteristically reef- or structure-associated. Targeted species may not be niche-specific with regard to their association with reef attributes; however, trophic groups may be niche generalists for a suite of reef attributes. Artificial reef designs could be directed toward trophic groups and not individual species or the entire assemblage. This would allow more efficient optimization of artificial reef designs directed toward generalized life history features common among species within a trophic group. The delineation of species according to reef niche should include attributes based on trophic features that will allow optimal management through trophic-group-oriented artificial reef deployments. If successful, trophic groups within an assemblage could be more efficiently managed to allow the full integration of artificial reefs into fisheries management on a worldwide basis. Thus, the application of artificial reef design principles could become universal for targeted trophic groups.