Quagga Catshark Halaelurus quagga

The Quagga Catshark (Halaelurus quagga) is a poorly-known catshark recorded from very few specimens. It has a fragmented known distribution occurring off southwestern India, and around the Socotra Archipelago (Yemen). This small shark (reaching ~37 cm total length) occurs at depths of 54-300 m, but appears to be a mostly deep-water species. The development of intense deep-sea bottom trawl fishing off southwestern India where the species is most likely to be taken as bycatch is a concern. Its small size means that it would be discarded at sea, but survivorship would be low. There are currently no deep-sea fishing activities around the Socotra Archipelago. Declines off southwestern India are suspected, but the extent to which fishing is affecting the species there is not known. Despite some concern, the species is assessed as Data Deficient, with a urgent need to assess bycatch rates in the Indian deep-sea shrimp trawl fishery

Oman Bullhead Shark Heterodontus omanensis

The Oman Bullhead Shark (Heterodontus omanensis) is known only from central Oman and Pakistan. Although information is limited on its habitat and ecology, based on known habitats of other Heterodontus species it likely inhabits a rocky reef substrate, reducing its vulnerability to bottom trawl fisheries. However, there are trawl caught records of this species, and it is a potential bycatch of demersal line fisheries operating within its range, although no specific information is currently available. More information is required on its biology, abundance and full range, capture in fisheries and population trends. While the limited number of individuals recorded to date may suggest this species occurs in areas not fished heavily, there is currently insufficient information at assess how fisheries in the region are interacting with the species, and as such it is assessed as Data Deficient

Smallbelly Catshark Apristurus indicus

The Speckled Catshark (Halaelurus boesemani) is a relatively small (to 48 cm total length), data-poor catshark. It is known from a limited number of specimens collected from four locations along an ~900 km stretch of Somali coastline. It occurs on continental and insular shelves at depths of 29-91 m. Its entire distribution has been subject to at least four decades of unregulated commercial benthic trawling; shelf-occurring catsharks are very susceptible to capture in this fishing gear. The new Somali Fisheries Law bans benthic trawling, but it is suspected that past declines have already occurred given the long history of unregulated fishing across its entire range. Furthermore, enforcement of this new regulation will be a challenge. While specific data are lacking, a population size reduction of 30-50% is suspected over the past three generations (~45 years) based on actual levels of exploitation (bycatch) and the species is assessed as Vulnerable A2d. It is of concern that there have been no records since 1991, although it is acknowledged that research and monitoring have been limited in Somalia. Further investigation of this species is required to accurately define its range, biology, extent of catches in local fisheries and levels of declines. This assessment should be revisited as soon as this is available

Speckled Catshark Halaelurus boesemani

The Speckled Catshark (Halaelurus boesemani) is a relatively small (to 48 cm total length), data-poor catshark. It is known from a limited number of specimens collected from four locations along an ~900 km stretch of Somali coastline. It occurs on continental and insular shelves at depths of 29-91 m. Its entire distribution has been subject to at least four decades of unregulated commercial benthic trawling; shelf-occurring catsharks are very susceptible to capture in this fishing gear. The new Somali Fisheries Law bans benthic trawling, but it is suspected that past declines have already occurred given the long history of unregulated fishing across its entire range. Furthermore, enforcement of this new regulation will be a challenge. While specific data are lacking, a population size reduction of 30-50% is suspected over the past three generations (~45 years) based on actual levels of exploitation (bycatch) and the species is assessed as Vulnerable A2d. It is of concern that there have been no records since 1991, although it is acknowledged that research and monitoring have been limited in Somalia. Further investigation of this species is required to accurately define its range, biology, extent of catches in local fisheries and levels of declines. This assessment should be revisited as soon as this is available

Ctenacis fehlmanni, Harlequin Catshark

The Harlequin Catshark (Ctenacis fehlmanni) is a small (to at least 52 cm total length) outer shelf dwelling catshark, known from 70 m to over 300 m depth off Somalia in the Arabian Sea. Little is known about the biology or ecology of this species. This poorly-known deep-sea shark occurs in an area where no deep-sea trawling fisheries take place and there are no other known threats. Due to the depth of occurrence and the lack of deep-sea fisheries in the region the species is assessed as Least Concern

Gymnura poecilura Longtail Butterfly Ray

The Longtail Butterfly Ray (Gymnura poecilura) is a medium-sized (to at least 104 cm disc width) coastal ray that is widespread in the Indian and Northwestern Pacific Oceans from the Red Sea and Arabian/Persian Gulf to southern Japan. It is demersal in on the continental shelf at depths of 0–75 m. Its meat is considered to be of good quality and is consumed locally and traded internationally. There is a long history of overfishing of inshore populations and fishing pressure remains high, and may be rising, across the species’ entire range

Assessment of the Red Sea ecosystem with emphasis on fisheries

A comprehensive assessment of the Red Sea large marine ecosystem (LME), with emphasis on fisheries, was carried out using several approaches. The assessment started with a multidisciplinary rapid appraisal of the sustainability of the fisheries using standardized attributes in ecological, economic, social, technical and ethical fields. Then a time-series assessment of the fishery was carried out using data from interviews and the reconstruction of catch from 1950 - 2006. A case study to estimate the unreported catch by quantifying qualitative information on incentives to misreport was carried out for Eritrean fisheries. Finally, a comprehensive and detailed assessment was done in an ecosystem-based framework using the modelling tool Ecopath with Ecosim (EwE), which quantifies the trophic interactions of the organisms and fisheries. It was used to predict the impact of different scenarios of fisheries on the ecosystem and explore the conflict between artisanal and industrial fisheries. Uncertainty analysis was carried out for the different assessment methods employed. The results of the assessments have varying levels of detail: relative ranking of the sustainability of fisheries in the rapid appraisal assessment, relative quantitative changes over time in the interview analysis, actual historic quantitative assessment of the catches in the catch reconstruction, and finally a quantitative assessment with potential to predict future scenarios using ecosystem modelling. The results give a holistic understanding of the Red Sea ecosystem and its fisheries. The data and resources needed increased as the details of the outputs increased. The assessments complemented each other and there are similarities in the results. They all showed declines in all fisheries, except for beach seining. Sharks, the top predator of the system, showed the worst decline in all the assessments; and the interview and catch reconstruction methods gave strikingly similar results for sharks. The ecosystem modelling did not show direct impact between artisanal and industrial fishery sectors due to the lack of trophic interactions. In addition, the thesis demonstrates that fishery researchers and practitioners can utilize different assessment tools, given the resources at their disposal, to assist the management of resources to conserve ecosystems and livelihoods.Science, Faculty ofResources, Environment and Sustainability (IRES), Institute forGraduat

Fisheries Centre Research Reports, Vol. 20, No. 1

Science, Faculty ofOceans and Fisheries, Institute for theUnreviewedFacultyGraduat

Not Available

Not AvailableThe Quagga Catshark (Halaelurus quagga) is a poorly-known catshark recorded from very few specimens. It has a fragmented known distribution occurring off southwestern India, and around the Socotra Archipelago (Yemen). This small shark (reaching ~37 cm total length) occurs at depths of 54-300 m, but appears to be a mostly deep-water species. The development of intense deep-sea bottom trawl fishing off southwestern India where the species is most likely to be taken as bycatch is a concern. Its small size means that it would be discarded at sea, but survivorship would be low. There are currently no deep-sea fishing activities around the Socotra Archipelago. Declines off southwestern India are suspected, but the extent to which fishing is affecting the species there is not known. Despite some concern, the species is assessed as Data Deficient, with a urgent need to assess bycatch rates in the Indian deep-sea shrimp trawl fishery.Not Availabl