|Scientific Name:||Epinephelus gabriellae Randall & Heemstra, 1991|
|Red List Category & Criteria:||Vulnerable B1ab(v) ver 3.1|
|Assessor(s):||MacIlwain, J., Ferreira, B.P., Choat, J.H., Craig, M.T., Rocha, L. & Bertoncini, A.A.|
|Reviewer(s):||Sadovy, Y. & Moss, K. (Grouper and Wrasse Red List Authority)|
Epinephelus gabriellae is listed as Vulnerable (VU) because of its restricted distribution (known from only two locations) and because of the increasing fishing pressure. Catches of serranids have already shown signs of decline, with targeting of the species throughout its distribution and depth range.
|Previously published Red List assessments:|
|Range Description:||The distributional range for Epinephelus gabriellae extends from the coast of Oman (Muscat) to the eastern border of Yemen, as well as Socotra (Yemen) and Somalia (Sommer et al. 1996). In 2001, one individual was collected at a landing site in northern Oman, approximately 100 km south of the Straits of Hormuz (the opening of the Persian Gulf). However the same landing site was sampled for 12 months (March 2004 to March 2005), with no record of E. gabriellae (Heemstra and Randall 1993).|
Native:Oman; Somalia; Yemen
|FAO Marine Fishing Areas:|
Indian Ocean – western
|Range Map:||Click here to open the map viewer and explore range.|
Epinephelus gabriellae is one of the most common species of grouper along the southern coast of Oman and is a major component of the grouper fishery. It is comparatively less common in shallow waters.
Epinephelus gabriellae forms a major component of the Omani grouper fishery and is caught by both traditional fishers using small (20 to 32 ft) fiberglass boats and by industrial trawlers operating in the Arabian Sea. Data were collected weekly from the major landing site at Muscat from March 2004 to March 2005. Epinephelus gabriellae made up approximately 11% of all grouper species measured during sampling (Jenny MacIlwain, Fishery Biologist, formerly of the Dept. of Marine Science & Fisheries, Sultan Qaboos University, Oman, unpub. data).
Unfortunately, the official Omani Ministry of Fisheries statistics do not differentiate between species of grouper that occur in landings. However, data suggest that the total grouper landings from Oman has actually shown a small increase over a 12 year period (on average 3,800 t/yr for 1991-2002). In contrast, many fishers suggested that catch-per-unit-effort and grouper landings had decreased by approximately 75% over the same time period. This coincides with a dramatic increase in the numbers of fishers over the past 20 years, coupled with heavy subsidies provided by the government that go towards providing new vessels, outboard engines, etc. This apparent increase has probably come from the industrial sector which is largely unregulated and is comprised of 12 to 20 foreign-owned and foreign-manned vessels (Jenny MacIlwain, Fishery Biologist, formerly of the Dept. of Marine Science and Fisheries, Sultan Qaboos University, Oman, unpub. data).
According to McIlwain, who conducted visual census at 46 sites along the entire Omani coast, Epinephelus gabriellae was rarely encountered. The census of grouper was conducted using strip transects (three transects per site), during which time E. gabriellae were counted at only four of the 46 sites, and usually found in very low densities. Three of these sites were situated at a group of small islands (the Halaniyats) 60 km offshore of southern Oman and east of the Oman/Yemen border. Here, counts averaged 2.2 individuals/90 sq. m, with a size range of 20 to 40 cm TL. One individual was recorded on a transect at Masirah Island in central Oman (the northern most distribution on the species map). Apparently juveniles/sub-adults prefer areas of high coral, then migrate into deeper water further offshore as they mature. This ontogenetic shift has been suggested from fisher interviews who stated that they catch small E. gabriellae (<40 cm TL) on the shallow reefs around Salalah (southern Oman) during the monsoon season when it is too rough to fish further offshore (Jenny MacIlwain, Fishery Biologist, formerly of the Dept. of Marine Science and Fisheries, Sultan Qaboos University, Oman, unpub. data).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||General|
Epinephelus gabriellae is a demersal species found over rocky bottoms.
Juveniles and sub-adults are the second most common species of grouper on inshore rocky areas along the southern coast of Oman (Heemstra and Randall 1993). Apparently juveniles/sub-adults prefer areas of high coral, then migrate into deeper water further offshore when they mature (McIlwain, J. pers. obs.).
Max size: 70.3 cm
Max weight: 5.3 kgs
Longevity: 26 yrs (oldest specimen examined using otolith sections)
|Generation Length (years):||About10years|
|Major Threat(s):||The major threat to Epinephelus gabriellae is increasing commercial and artisanal fishing pressure that coincides with a dramatic increase in the numbers of fishermen in the past 20 yrs. These fisher increases are coupled with heavy subsidies, apparently from the unregulated traditional sector, that provides funding for new vessels, outboard engines, etc. Recent new regulations have come into being to limit the number of fishing vessels in Oman. Whether this recent regulatory change is sufficient to reduce the observed (by fishers) declines in catch abundance and catch-per-unit-effort is not currently known (McIlwain, J., pers. comm.).|
|Conservation Actions:||There has been a recent regulatory change to impose effort control by limiting number of fishing vessels in Oman. There are no protected areas within the range of this species and no regulations specific for Epinephelus gabriellae. Because the species occurs in rocky reefs, some protection may be afforded to them from trawl fisheries.|
|Citation:||MacIlwain, J., Ferreira, B.P., Choat, J.H., Craig, M.T., Rocha, L. & Bertoncini, A.A. 2008. Epinephelus gabriellae. The IUCN Red List of Threatened Species 2008: e.T64401A12776107.Downloaded on 18 January 2018.|