|Scientific Name:||Mycteroperca bonaci|
|Species Authority:||(Poey, 1860)|
Serranus bonaci Poey, 1860
Serranus bruneus Poey, 1860
Serranus cyclopomatus Poey, 1861
Serranus decimalis Poey, 1860
Serranus latepictus Poey, 1861
Trisotropis aguaji Poey, 1867
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor/s:||Ferreira, B.P., Rocha, L., Gaspar, A.L.B., Sadovy, Y. & Craig, M.|
|Reviewer/s:||Sadovy, Y. & Moss, K. (Grouper and Wrasse Red List Authority)|
Although it is a widespread and abundant species, Mycteroperca bonaci is assessed as Near Threatened as it has undergone nearly 30% population decline and is expected to continue to decline in the future if the current threat remains. This species is tolerant to habitat degradation.
Mycteroperca bonaci is a western Atlantic species distributed from Bermuda and Massachusetts (USA) to Brazil (Villa des Remedios Island (northeast of Natal), to about 28°S), including the Brazilian off-shore islands, the southern Gulf of Mexico, Florida Keys, Bahamas, Cuba and throughout the Caribbean. Adults are unknown from the northeastern coast of the USA.
Anguilla, Antigua and Bermuda, Aruba, Bahamas, Barbados, Belize, Bermuda, Brazil (Alagoas, Ceará, Espírito Santo, Paraíba, Pernambuco, Rio de Janeiro, Rio Grande do Norte, Sergipe, Trindade), Cayman Islands, Colômbia, Costa Rica, Cuba, Dominica, Dominican Republic, French Guiana, Grenada, Guyana, Haiti, Honduras, Jamaica, Martinique, México (Campeche, Quintana Rôo, Tabasco, Veracruz, Yucatán), Montserrat, Netherlands Antilles (Curaçao), Nicaragua, Panama, Puerto Rico, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Suriname, Trinidad and Tobago, Turks and Caicos Islands, United States of America (Alabama, Florida, Georgia, Massachusetts, Mississippi), British Virgin Islands, United States Virgin Islands, and Venezuela.
Native:Anguilla; Antigua and Barbuda; Aruba; Bahamas; Barbados; Belize; Bermuda; Brazil; Cayman Islands; Colombia; Costa Rica; Cuba; Dominica; Dominican Republic; French Guiana; Grenada; Guadeloupe; Guyana; Haiti; Honduras; Jamaica; Mexico; Montserrat; Netherlands Antilles; Nicaragua; Panama; Puerto Rico; Saint Kitts and Nevis; Saint Lucia; Saint Vincent and the Grenadines; Suriname; Trinidad and Tobago; Turks and Caicos Islands; United States; United States Minor Outlying Islands; Venezuela, Bolivarian Republic of; Virgin Islands, British; Virgin Islands, U.S.
|FAO Marine Fishing Areas:||
Atlantic – southwest; Atlantic – western central
|Range Map:||Click here to open the map viewer and explore range.|
Mycteroperca bonaci was probably the most abundant large grouper of the shallow water serranid-lutjanid complex throughout most of its area of occurrence. Black groupers are commonly landed in commercial grouper fisheries in the Gulf of Mexico and the south Atlantic Ocean. They are also very common in the recreational fishery. Commercial landings of black grouper exceed landings of any other grouper in the Florida Keys
Fisheries dependent data
In Bermuda the rapid development of trap fishing on grouper population in shallow waters in the 80’s led to decrease in grouper catches over a period of seven years; the decrease was from 90,000 lbs/yr to 15,000 lbs/yr for the black grouper (Bannerot et al 1987), a six-fold reduction.
Black grouper is an important species for the demersal fisheries in the Northeastern Brazilian coast, and is the most frequently caught serranid in the demersal bottom line fisheries of the northeastern coast (lat. 0 to 12° S) (MMA 2006). It is caught together with lutjanid species and is one of the species responsible for characterizing the typologies in the reef fishery of northeastern Brazil (Fredou et al. 2006). Teixeira et al. (2004) interviewed 40 fishermen based on their experience, that ranged from a period between 10 and 45 years along the northeastern Brazilian coast (lat. 0 to 12° S). According to the fishermen interviewed, Mycteroperca bonaci is probably already undergoing overfishing effects, as the capture of the black grouper has decreased these last two decades.
The bottom line fisheries in south of Bahia state, is one of the oldest in Brazil. It was the main source of income of Porto Seguro province, in the beginning of the XVI century, maintaining an industry of salted and dried fish that was exported to Portugal and to other provinces in Brazil (Bueno 1998). Abundances of large groupers declined, and nowadays snappers make up 38% of total catch, pelagic species accounted for 43% while Mycteroperca bonaci, represented 10% (Costa et al. 2002).
According to Martins et al. (2005), until the end of the 1980s, the bottom line fleet operating hand lines from dories in the Abrolhos region, between the lat 17 and 18° S, had as main target the large reef fishes badejo (Mycteroperca bonaci) and the red grouper (Epinephelus morio). The collapse of these fisheries in the 80’s led fishers to turn to other resources. By the end of the 1980s, a new market developed with the deep frozen or fast frozen techniques. The mains target for this fishery are lutjanids and smaller serranids, usually plate size (around 1 kg), caught and quickly dipped in frozen water, and exported. Between 997 and 2000 only 11% of the fleet operated with dories targeting black groupers, and the rest was targeting coney and lutjanids. Figure 1, taken from Martins et al. 2005, illustrates the shift in the catches from black grouper to coney and yellowtail snapper.
Follow the link below for Figure 1: catch comparison between yellowtail snapper (Ocyurus chrysurus) and black grouper (Mycteroperca bonaci) 1978-1998.
In Cuba, Nassau grouper is the main exploited grouper species. Catches for these species have gradually declined from an annual mean of 1,476 t (1959 to 1963) to less than 100 t (1992 to 1998). Reduction of yields was attributed to constant increase in fishing efforts (Fernandez 1984). Compared to Nassau grouper, other groupers were less significant in Cuba, all grouped in statistics as other fishes” (e.g. Mycteroperca bonaci) (Claro et al. 2001).
In the southern Gulf of Mexico, Mycteroperca bonaci can account for 40% of the grouper catch by weight for some commercial vessels, however in this area grouper fishery was considered deteriorated and lacked a well-defined management strategy (Brulé et al. 2003).
Fisheries independent data
The reef fish assemblages along the Brazilian continental margin (40 to 500 m depth), between 13° E 22°, were investigated exploring data sampled during two demersal surveys using bottom long-line (Olavo et al. 2006) and during four demersal surveys using bottom long-line between 100 and 500 m (Costa et al. 2005). During four cruises between 1996 and 1998, a 190,746 hooks were deployed. CPUE for the black grouper was 0.8 to 1.8 kg/1000 hooks – 1,3 in depths above 100 meters and 0.2 in areas between 100 and 300 m.
|Habitat and Ecology:||
Mycteroperca bonaci is a reef-associated, solitary species inhabiting rocky and coral reefs and can withstand some degradation in its habitat. Their depth ranges from anywhere from 19 to 250 feet (6 to 75 meters). Juveniles sometimes occur in estuarine seagrass and oyster rubble habitat in North Carolina and South Carolina (Keener et al. 1988; Ross and Moser 1995). In the Florida Keys, juveniles settle on patch reefs (Sluka et al. 1994), similar to those in Brazil (Rezende unpub. data, Schawnborn 2005).
Adults feed primarily on fishes, including grunts, snapper, and herrings. Juvenile black groupers feed solely on crustaceans.
According to Teixeira et al. (2004) fishing peaks occurs during a phenomenon known among local fishermen as the correção - which is an aggregation of these fish along the shelf break Northeastern coast during some periods of the year. The period of the correção – according to the interviews and the annual fishing reports from Brazilian Institute of Environment (www.ibama.gov.br/cepene) – indicated that, in the north area, the correção is expected between October and January; and, in the south area, between December and March. The correção, during the studied time, did not present any association with the phases of the moon.
The observations, during the correção, of the gonadal stages and the proportion of fat suggested that Mycteroperca bonaci was not in reproductive activity. All of the sampled gonads were in the resting stage presenting a large proportion of fat in the body cavity. This fat is used in the processing of the gonadal products and presents an inverse relation with the gonadal weight, as mentioned by Ferreira (1993) for Plectropomus and by Rajasilta (1992) for Clupea harengus membras.
Based on this assumption, it seems that the black grouper takes advantage of the reproductive aggregations of other species as an opportunity to feed. This can be observed during the correção with the Mycteroperca bonaci, in Caiçara do Norte, where its capture was associated to the reproductive aggregations of Lutjanus analis, Lutjanus jocu and Seriola spp. and confirmed by the presence of ripe gonads in these species (personal observation in situ). Thus the black groupers during the correção, coming from ever deeper and inaccessible sites to the fishing gears’, are vulnerable to fishing pressure and are massively caught, as recorded during sampling at the correção period and on the annual fishing reports of IBAMA (www.ibama.gov.br/cepene) (Teixeira et al. 2004).
Reproduction, age and maturity
The species is a monandric, protogynous hermaphrodite that forms spawning aggregations (Teixeira et al. 2004, Smith 1965, García-Cagide and García 1996, Crabtree and Bullock 1998, Brulé et al.2003). According to a study in Campeche Bank, females changed sex between 85.5 and 125.0 cm FL, with median length of 103.3 cm FL. At 114.5 cm FL, 50% of the females in the sample had transformed into males. The age at sex change was 15.5 years. The smallest size of M. bonaci in transition reported in Brazil by Teixeira et al. (2005) was 64 cm (LF). This size is similar to the size of the Cuban M. bonaci (LT of 65 cm) determined by García-Cagide and García (1996), but smaller than the Floridean type observed by Crabtree and Bullock (1998) with a LT of 94.7 cm (92.3 cm LF). In Campeche Bank the size at which 50% of the females transformed to males was 111.4 cm, and in Florida 119.9 cm (Brulé et al. 2003).
Black grouper probably spawn throughout the year, however, peak spawning of females occurs from January to March. In Brazil, histological results and the gonadosomatic index suggest that the spawning period occurs between April and September (Teixeira et al. 2004). The spawning period of the Cuban M. bonaci is from November to May with peaks recorded in November and February (García-Cagide and García 1996). In Florida, Crabtree and Bullock (1998) indicate that the peak of spawning of M. bonaci is from December to March. In Campeche Bank (Mexico), the spawning season for black grouper is also from December to March (Brulé et al. 2003).
Brulé et al. (2003) did not observe spawning aggregations for M. bonaci from the Campeche Bank. This grouper has been reported to form spawning aggregations in the Gulf of Mexico and Caribbean Sea (Fine 1990, Carter and Perrine 1994; Domeier and Colin 1997; Eklund et al. 2000). Off Belize, black grouper are believed to spawn in aggregations at the same sites used by Nassau grouper (Carter and Perrine 1994). Eklund et al. (2000) describe a black grouper spawning aggregation discovered during winter 1997-1998, less than 100 m outside a newly designated marine reserve.
In South Florida, Crabtree and Bullock (1998) indicate that black grouper appear to reach a maximum age of at least 33 years, and its growth was most rapid for the first ten years and then slowed considerably. The von Bertalanffy growth equation was TL = 1,306.2(1-e super((-0.169(Age+0.768)))). In Florida Keys, Manooch and Manson (1987) obtained the von Bertalanffy growth equation for black grouper using back-calculated data, which was Lt=1,352 (1-e-0.1156(t+0.927)). In this case growth was most rapid for the first three to four years, and then gradually trended downward throughout the remaining years, and the maximum age estimated was 14 years.
Age of first maturation was 5.2 at a size of 82.6 cm, and age of transition was 15.5 years by a length of 121.4 cm (Crabtree and Bullock 1998).
The size of first maturation for black grouper from Campeche Bank was 72.1 cm, from Florida was 82.6 cm, and from Cuba 84.4 to 108.7 cm (Brulé et al. 2003).
Natural mortality (M) is estimated to be 0.15 (Potts and Brennan 2001). Crabtree and Bullock (1998) found that black grouper live for at least 33 years and attain sizes as great as 151.8 cm (60.1 in) TL. Females ranged in length from 15.5 to 131.0 cm (6.1 to 51.9 in) TL and males range in length from 94.7 to 151.8 cm (38.3 to 60.1 in) TL.
|Major Threat(s):||Mycteroperca bonaci is heavily fished throughout its range and involved in international fishery. Spawning and feeding aggregations are commonly targeted. Sedimentation is a problem in nursery areas.|
Mycteroperca bonaci occurs in several marine protected areas throughout its range.
In southern and southeastern Brazil there is a minimum size of catch 45 cm (IBAMA 2003)
It is protected within the Conch Reef Research Only Area (a no-take marine reserve) in the northern Florida Keys National Marine Sanctuary (Lindholm et al. 2005).
Because grouper landings in the Campeche Bank decreased between 1991 and 1997, the Mexican government proposed management measures to protect the grouper resource, but without considering the biological characteristics and fishery aspects of each exploited species (Brulé et al. 2003, SEMARNAP 2000a, 2000b). Commercial fishing regulations for Gulf of Mexico Federal Waters consist of: an annual commercial quota of 4445 t for the shallow-water grouper complex, which includes the black grouper; commercial minimum size limits of 61.0 cm TL; a seasonal closure on commercial harvest and prohibition on sale of this species from 15 February to 15 March. Recreational fishing regulation in the same area consist of: minimum size limits of 55.9 cm TL; a recreational aggregate daily bag limit of five groupers per person; and also a seasonal closure on commercial harvest and prohibition on sale of this species from 15 February to 15 March (www.gulfcouncil.org).
In Brazil, Mycteroperca bonaci is listed under the regulatory instruction Number 5 (IN5) from 21/05/2004 revised in 08/2005 MMA- as overexploited or threatened of overexploitation: Overexploited are species considered to be under high levels of exploitation, enough to reduce the biomass, spawning potential and future catches beyond sustainable levels. For these species listed, management plans must be developed, under the coordination of the Brazilian Institute of Environment, within the next five years. These plans should promote stock recovery and sustainable fisheries.
|Citation:||Ferreira, B.P., Rocha, L., Gaspar, A.L.B., Sadovy, Y. & Craig, M. 2008. Mycteroperca bonaci. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 19 April 2014.|
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