Mycteroperca jordani 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Perciformes Epinephelidae

Scientific Name: Mycteroperca jordani
Species Authority: (Jenkins & Evermann, 1889)
Common Name(s):
English Gulf Grouper
Spanish Baya, Cabrilla De Astillero, Garlopa, Garropa, Mero Baya, Merou Golfe
Epinephelus jordani Jenkins & Evermann, 1889

Assessment Information [top]

Red List Category & Criteria: Endangered A2d+3d ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Craig, M.T., Choat, J.H., Ferreira, B., Bertoncini, A.A., Rocha, L. & Heemstra, P.C.
Reviewer(s): Sadovy, Y. & Moss, K. (Grouper and Wrasse Red List Authority)
Mycteroperca jordaniis listed as endangered (EN) because of an inferred population decline of at least 50% over the past 30 years, based on anecdotal evidence and directly attributed to intensive fishing pressure. This fishing pressure is likely to increase as greater investment in recreational fisheries occurs, hence it is predicted that this decline will continue in the future. In addition, it is a large species with probably high longevity and is caught at spawning aggregations, both factors that make the species particularly vulnerable to overfishing.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Mycteroperca jordani occurs in the Eastern Central Pacific from southern La Jolla, California (USA) to Mazitlan (Mexico). There are unconfirmed records of the species from the Revillagigedos Islands (Mexico).
Countries occurrence:
Mexico; United States
FAO Marine Fishing Areas:
Pacific – eastern central
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Mycteroperca jordani has a relatively restricted range and its population is currently in severe decline throughout the Gulf of California, Mexico. Once abundant, this species is now rare and interviews with fishermen indicated a 50 to 70% decline since 1950 in the Gulf of California. Naturally rare in the northern portion of its range.

Abundance: Combined fisheries-dependent and fisheries-independent data
Based on historical research, fishers’ anecdotes, systematic documentation of naturalist’ observation and grey literature, Sáenz-Arroyo et al. (2005a) revealed that Mycteroperca jordani in central Baja California was abundant in the past and probably dominated the rocky-reef fish community in terms of biomass. Mycteroperca jordani declined dramatically in the 1970s and is now scarce and in danger of complete disappearance. Based on changes in the numbers of individuals within spawning aggregations, the population decline from 1940s to present could be greater than 99%.

Based on the information from Reef Environmental Education Foundation (REEF), the sighting frequency (SF; a value calculated as dividing the number of surveys with Mycteroperca jordani encountered [n] by the total number of surveys carried out in a particular year [N]). The SF of Mycteroperca jordani in the tropical eastern Pacific ranged from 0.49% in 2002 to 2.97% in 2000, with a mean value of 1.2% (; accessed on 26th May 2006).

See the Supplementary Material for Table 1: Sighting frequency (SF; a value calculated as dividing the number of survey with M. jordani encountered [n] by the total number of survey carried out in a particular year [N]) of M. jordani in tropical eastern Pacific) (; accessed on 26th May 2006).

Fishery-dependent Data
Baja California Sur, Mexico
According to Sáenz-Arroyo et al. (2005a) stated M. jordani comprised 45% of the total state finfish production between 1959 and 1960. By early 1972, the percentage had dropped to 6% (Sáenz-Arroyo et al. 2005a). More recent estimates suggest that M. jordani comprises less than 1% of the total finfish catch (Rámirez-Rodriguez 1996).

Based on a questionnaire interview of 108 randomly selected fishers from three generations in 11 fishing communities of central Baja California in 2002, it was found that old (~ 55 years old) fishers caught up to 25 times as many M. jordani as younger (15 to 30 years old) fishers on their best-ever fishing day (regression r2=0.62, p<0.001) (Sáenz-Arroyo et al. 2005b). Sáenz-Arroyo et al. (2005b) also suggested a decline in the average size of the largest M. jordani, based on largest catch data: old fishers: 84 kg; middle-aged (31 to 54 years old): 72 kg; young fishers: 63 kg.
For further information about this species, see 14049_Mycteroperca_jordani.pdf.
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Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:General
Mycteroperca jordani is found on rocky reefs and in kelp beds (Heemstra and Randall 1993). Large adults are common in shallow water from southern California to Mexico (Rosenblatt and Zahuranec 1967). Juveniles are unknown in California waters and few large adults have been taken there, probably as expatriates from a more southerly breeding population (Rosenblatt and Zahuranec 1967).

Large adults feed on fishes. Reported to prey on juvenile hammerhead sharks (Thompson et al. 1979). Its large size makes it an intense object of game fishing.

Currently there is a skewed sex ratio (males significantly fewer than females) for Mycteroperca jordani in the Gulf of California, Mexico. Mycteroperca jordani is an aggregating spawner (Sáenz-Arroyo et al. 2005a) and Rosenblatt and Zahuranec (1967) suggested the breeding populations were restricted to the Mexican northwest.

Presumed to have slow growth rate. Sadovy (1996) suggested Mycteroperca jordani could mature at age of six or seven years. Recorded maximum size is 198 cm TL, with a maximum weight up to 91 kg (Eschmeyer et al. 1983).
Generation Length (years):>10years(probably15years)

Threats [top]

Major Threat(s): General
Mycteroperca jordani is heavily targeted by recreational and sub-national fisheries throughout its range (Heemstra and Randall 1993). It is also incidentally caught by shrimp-trawlers in the Gulf of California. Recreational fishers from the US are a major contributor to overfishing remaining stocks. Coastal development in northern Gulf of California, in particular, Bahia La Cholla Marina, is predicted to double the number of fishing boats and promote reef habitat destruction.

Classified as vulnerable by the American Fisheries Society based on the U.S. Fish and Wildlife Service (USFWS) concept of District Population Segments (DPS) (Musick et al. 2000) because it is seen, but not abundant and has probable low productivity and spawning aggregations are heavily fished.

Conservation Actions [top]

Conservation Actions: Mycteroperca jordani occurs in some protected areas throughout its range. The species occurs within the Alto Golfo Biosphere Reserve, however enforcement of that area is severely lacking.

Classifications [top]

9. Marine Neritic -> 9.7. Marine Neritic - Macroalgal/Kelp
9. Marine Neritic -> 9.2. Marine Neritic - Subtidal Rock and Rocky Reefs
2. Land/water management -> 2.1. Site/area management
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education
1. Residential & commercial development -> 1.3. Tourism & recreation areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.1. Intentional use: (subsistence/small scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.2. Intentional use: (large scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓   National : ✓ 

Bibliography [top]

Baillie, J. and Groombridge, B. (eds). 1996. 1996 IUCN Red List of Threatened Animals. pp. 378. International Union for Conservation of Nature, Gland, Switzerland and Cambridge, UK.

Eschmeyer, W.N., Herald, E.S. and Hammann, H. 1983. A field guide to Pacific coast fishes of North America. Houghton Mifflin Company, Boston, USA.

IUCN. 2008. IUCN Red List of Threatened Species. Available at: (Accessed: 5 October 2008).

Musick, J.A., Harbin, M.M., Berkeley, S.A., Burgess, G.H., Eklund, A.M., Findley, L., Gilmore, R.G., Golden, J.T., Ha, D.S., et al. 2000. Marine, estuarine, and diadromous fish stocks at risk of extinction in North America (Exclusive of Pacific Salmonids)..

Rámirez-Rodriguez, M. 1996. La Pesca de Escama, Estudio del Potencial Pesquero y Acuícola Baja California Sur, I. .

Rosenblatt, R.H. and Zahuranec, B.J. 1967. The eastern Pacific groupers of the genus Mycteroperca, including a new species..

Sáenz-Arroyo, A., Roberts, C. M., Torre, J. and Cariño-Olvera, M. 2005. Using fishers' anecdotes, naturalists' observations and grey literature to reassess marine species at risk: the case of the Gulf grouper in the Gulf of California, México. Fish and Fisheries 6(2): 121-133.

Saenz-Arroyo, A., Roberts, C.M., Torre, J., Cariño-Olvera, M. and Enriquez-Andrade, R.R. 2005. Rapidly shifting environmental baselines among fishers of the Gulf of California..

Thomson, D.A., Findley, L.T. and Kerstitch, A.N. 2000. Reef fishes of the Sea of Cortez: The rocky-shore fishes of the Gulf of California . University of Texas Press, Austin.

Citation: Craig, M.T., Choat, J.H., Ferreira, B., Bertoncini, A.A., Rocha, L. & Heemstra, P.C. 2008. Mycteroperca jordani. In: The IUCN Red List of Threatened Species 2008: e.T14049A4386048. . Downloaded on 22 May 2017.
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