Association to vegetated habitats and different vulnerability to habitat degradation for two fish species, Epinephelus areolatus (Serranidae) and Siganus canaliculatus (Siganidae), from the western Arabian Gulf.

Epinephelus areolatus and Siganus canaliculatus are two species of fisheries importance associated with vegetated habitats, which are in turn threatened by human activities such as land filling. We tested their associations with vegetated habitats in the Arabian Gulf and examined essential life history traits to infer their vulnerability to the degradation of vegetated habitats. Epinephelus areolatus is found to be more abundant at deeper offshore vegetated habitats, while S. canaliculatus has higher abundance at shallow nearshore habitats. Epinephelus areolatus exhibits a longer life span, lower growth coefficient, larger size at 50% maturity, lower natural mortality, and protogynous sexual pattern, compared to Siganus canaliculatus. Accordingly, Epinephelus areolatus is expected to be more vulnerable to habitat degradation and environmental fluctuations. Different preferences in using vegetated habitats and degrees of vulnerability to habitat degradation for these two species could be further integrated to set priorities for management and conservation plans.

Low abundance of sharks and rays in baited remote underwater video surveys in the Arabian Gulf.

Data on the diversity and relative abundance of elasmobranchs (sharks and rays) in the Arabian Gulf have been limited to fishery-dependent monitoring of landing sites. Understanding the diversity and abundance of sharks and rays is, however, crucial to inform policy and management plans. Baited Remote Underwater Video Surveys (BRUVS) were conducted in 2015-2016 across the United Arab Emirates Arabian Gulf waters encompassing a range of depths and habitat types. Data from 278 BRUVS (757 hours soak time) were analysed to gather information on diversity, relative abundance, species distribution, and habitat associations. Surveys recorded 213 individuals from 20 species of sharks and rays at 129 stations. The frequency of occurrence of species usually discarded by fishers such as the Arabian carpetshark (Chiloscyllium arabicum) and stingrays (Himantura spp.) was high, accounting for 60.5% of observed elasmobranchs. Despite the large survey area covered and extensive sampling effort, the relative abundance of sharks and rays was low at 0.28 elasmobranchs per hour, 0.13 sharks per hour, and 0.15 rays per hour. This CPUE was reduced to one of lowest recorded abundance on BRUVS from around the world when removing the two discarded species from the analysis (0.11 elasmobranchs per hour). These results likely reflect the intense fishing pressure and habitat loss contributing to population declines of many elasmobranchs in the Arabian Gulf. Findings provide a baseline for future work and can support the design of conservation strategies for sharks and rays in the UAE.

Critical research needs for identifying future changes in Gulf coral reef ecosystems.

Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter 'Gulf') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms of scientific importance (i.e., filled a knowledge gap and was a research priority) and efficiency in resource use (i.e., was highly feasible and ecologically broad). Ten research questions, in six major research areas, were highly important for both understanding Gulf coral reef ecosystems and also an efficient use of limited research resources. These questions mirrored global evaluations of the importance of understanding and evaluating biodiversity, determining the potential impacts of climate change, the role of anthropogenic impacts in structuring coral reef communities, and economically evaluating coral reef communities. These questions provide guidance for future research on coral reef ecosystems within the Gulf, and enhance the potential for assessment and management of future changes in this globally significant region.