Epinephelus Marginatus)

Figure 1. Dusky grouper official fisheries catch history information for the Azores Archipelago, Portugal, Macaronesia (from P. Afonso). Data from yearly official landings (in kg) at all nine islands of the Azores archipelago combined for Epinephelus marginatus indicate an estimated decline from 1999 onwards of around 60%. However, this trend is inconclusive as it was preceded by previous large increases and decreases in catches since records began in the late 1970s, possibly due to the influence of fleet behaviour and variations in catch reporting rates at official landing sites.

THE IUCN RED LIST OF THREATENED SPECIES™

Figure 2. Dusky grouper fisheries catch history information, both globally (figure 2a) and for a number of individual European and North and North-west African countries (figure 2b) (compiled by G. Ralph from the FAO 2015 FishstatJ database).

Dusky grouper fisheries catch history information for south- eastern Africa (from S. Fennessy and R. Mutombene).

South Africa Catches: Offshore skiboat fishing, kept fish only, per boat outing, recreationals, 1994-96: 0.02 (number of fish caught) and 0.07 kg; 2008-09: 0.06 (no. fish) and 0.25 kg; commercials, 1994-96: 0.51 (no. fish) and 1.49 kg; 2008- 09: 0.47 (no. fish) and 2.98 kg (Mann et al. 1997a, Dunlop 2011). Shore-fishing, fish/angler/day: 0.001 (1975-77) (Joubert 1981b); 0.0007 (1994-96) (Mann et al. 1997a); 0.001 (2008-09) (Dunlop and Mann 2012). This species contributed around 2% to spear-fishing catches in 1994-1996 (Mann et al. 1997a). In contrast, it was the ninth most-commonly caught species (~3% of total catch by numbers) by researchers while shore-fishing in the iSimangaliso MPA on the east coast of South Africa from 2001-2013, suggesting that its abundance outside of MPAs has been substantially reduced; this is further supported by Maggs et al. (2012) who showed that the catch per unit effort (CPUE) of E. marginatus was approximately four times greater in the Pondoland MPA compared to adjacent exploited areas in the Eastern Cape.

South Africa Catch composition: Offshore skiboat fishing, kept fish only, recreationals, 1994-96: 7.9% by no. and 7.9% by wt., decreasing to 3.4% by no. and 4.3% by wt. in 2008-09; commercials, 1994-96: 3.1% by no. and 7.2% by wt., declining only slightly to 2.5% and 4.9% in 2008-09 (Mann et al. 1997b, ORI unpubl. data). Recreational shore-angling, kept fish only, 1994-96: 0.1% by no. and 0.2% by wt. (Mann et al. 1997b), remaining much the same at 0.1% by no. and 0.3% by wt. in 2008-09 (Dunlop and Mann 2012).

Figure 3. Dusky grouper fisheries catch history information for south-eastern Africa (from S. Fennessy and R. Mutombene). Southern Mozambique catch data for E. marginatus based on onboard observer catches from semi-industrial line-fishing boats. Between 2002 and 2014, CPUE varied between 0.5 and 8.7 kg/boat/per day (figure 3a). Total (fleet) catch varied between 0.6 and 18 mtpa, with no particular trend being evident (R. Mutombene, Fisheries Research Institute, Maputo, Mozambique, unpubl. data). However, this fishery commenced in earnest in the mid-1990s, and the contribution of this species to the overall catch by numbers appears to have declined since then (with some caution required, as information prior to 2002 has unquantified biases) (figure 3b).

Figure 4. Dusky grouper fisheries catch history information for south-western South America (from A. Bertoncini). Data from official landings at Rio de Janeiro (FIPERJ) for Epinephelus marginatus showed an estimated decline of 31% in annual catch over the four year period for which data were available, from 9,277 kg in 2011 to 6,424 kg in 2014. Although there was an apparent stabilization in the total annual catch over the last three years of this period up to 2014 (at ~6,500 kg/y), this apparent stabilization resulted from a 2.6-fold increase in fishing effort during that period, in which CPUE (kg/boat trip) declined in the order of 74% from 2011 to 2014.

Figure 5. Dusky grouper fisheries catch history information for south-western South America (from A. Bertoncini). Data from official landings at Santa Catarina (CTTMar/UNIVALI) showed a decline in the fleet of 66% over the ten year period from 2002 (21 boats) to 2012 (7 boats). An estimated decline in total catch of 97% was observed there over the 20 year period from 1992 (total production 45,909 kg) to 2012 (total production 1,417 kg). For São Paulo, official landings showed an estimated decline in total catch of 47% over the 12 year period from 2003 (total production 22,851 kg) to 2015 (total production 11,389 kg), but the fluctuations in catch here did not appear to show any significant trend.