Habitat and Biology
Climatic zone: Tropical; Temperate.
Water Area Overview
The Eastern Central Pacific (FAO Statistical Area 77) covers a total surface area of 48.90 million km2 including an estimated total shelf area of 0.81 million km2. Area 77 is bounded by the west coast of the Americas to the east and the 175°00’W parallel to the west. In the north, it is bounded by latitudes 40°00’N and 40°30’N off northern California, the United States of America. Area 77 extends south to latitude 7°12’N, except close to the coast off southern Panama, where it stops at 5°00’N. Farther offshore, it extends down to 25°00’S off South America (Figure B13.1). The continental shelves in Area 77 rarely extend more than 20 km from the coast. Some regions off San Francisco Bay in El Salvador, Nicaragua and the Gulf of Panama are the exception. In these regions, it can widen to as much as 60 km. The benthic habitats on the sea floor of the continental shelf tend to be heterogeneous. There are several areas suitable for trawling, although there is little trawling except for shrimps. Trawling for coastal demersal fishes is limited and deep-water trawling has been done only occasionally, mostly for exploratory and research purposes. Two of the main features along the coast are the Gulf of California and the Gulf of Panama. There are also a few small coastal islands off southern California and Panama, and some other larger island groups in oceanic waters such as the Hawaii Islands. These island chains also have very narrow continental shelves.
Area 77 is influenced by two major surface current systems: the California Current, which spreads from northern California to Baja California (Parrish et al., 1983); and, to the south, the great trans-Pacific equatorial surface current system. This system consists of the westward flowing North and South Equatorial Currents, with the eastwardflowing Equatorial Counter-current in between (Bakun et al., 1999). These current systems, together with the prevailing equatorial winds that blow parallel to the coast, cause major upwelling to occur along the coast of California, Baja California and the Gulf of Panama and smaller upwelling along the Central American coast and offshore in the Costa Rica Dome. The coastal upwelling is the most important source of coastal water nutrient enrichment in the northern, more temperate subtropical part of the region off the Californias. The more tropical regions off Central America can be enriched by both coastal upwelling, driven by southeast trade winds, as well as by the coastal runoff. Farther offshore, the Costa Rica Dome appears to be an important source of upwelling and nutrient enrichment (Wyrtky, 1964; Bakun et al., 1999).
The distribution and abundance of marine resources and fishing activities in Area 77 is strongly influenced by the different climates, the interaction of complex wind and water circulation patterns, and the nature of the enrichment processes. Fishing for small and large pelagic species is particularly important within and around the major upwelling regions. Inshore, fishing for shrimps and, to a lesser extent, for coastal demersal fishes sustains major local fisheries in the more tropical regions off Mexico, Central America and Panama. Fishing for squids is also important in the richest areas off California and Mexico. The El Niño-Southern Oscillation (ENSO) phenomenon is responsible for large interannual fluctuations in the conditions affecting marine populations in this region. It can cause natural perturbations that may take years to dissipate (Bakun, 1993). Some of the mid- to long-term fluctuations in annual catches of key species in Area 77 seem to be associated with these large interannual changes in environmental conditions (Lluch-Belda, Lluch-Cota and Lluch-Cota, 2005; Lluch-Cota et al., 2010).
|Figure B13.1 The Eastern Central Pacific (Area 77) |
Considered a single stock: No
PROFILE OF CATCHES
Fisheries production from the Eastern Central Pacific comes mostly from small and large pelagic species, followed by squid, shrimp, coastal demersal fishes and a variety of other fish species (Figure B13.2,Table D15). Pelagic fisheries are particularly important off southern California, Baja California, the Costa Rica Dome and the Gulf of Panama. Squid are important off southern California and Baja California. Shrimp catches are much lower in volume than those of pelagic fishes, but their high unit price makes shrimp the other major commercial fishery in Area 77. Shrimp are important off Mexico and particularly off Central American, where they can be the most important fishery for most of the coastal countries there.
The first major development of fisheries in Area 77 can be traced to the beginning of the twentieth century with the first recorded multidecadal bloom of the California pilchard (or sardine) (Sardinops caeruleus) fishery off the United States of America. This fishery built up more or less steadily from less than 2 000 tonnes in 1915 to more than 700 000 tonnes in 1936. It then declined dramatically in the late 1940s and in the 1950s and 1960s (Murphy, 1966; Gulland, 1970; Troadec, Clark and Gulland, 1980). The catch began to increase again in the late 1970s and in more recent years (Kawasaki, 1983; Csirke, 1995; Lluch-Belda et al., 1992; Csirke and Vasconcellos, 2005). Fishing for tunas also expanded steadily in the first half of the past century. By 1950, the total catch of tunas (mostly skipjack and yellowfin) was already 170 000 tonnes and remained more or less stable until 1960. Catch continued to increase further and has been about half a million tonnes in recent years.
After a record low of 320 000 tonnes in 1953, total catches for Area 77 had a period of sustained increase to peak at 1.8 million tonnes in 1981. Since then, catches by major species groups have fluctuated, with accumulated total catches varying between a minimum of 1.2 million tonnes in 1983, 1984 and 1993 and almost 1.9 million tonnes in 2002 and 2009. (Figure B13.2, Table D15).
|Figure B13.2 Annual nominal catches by ISSCAAP species groups in the Eastern Central Pacific (Area 77) |
Most of the year-to-year fluctuations in total production in Area 77 are dominated by changes in the abundance and overall production of small pelagic fishes. However, particularly strong El Niño events also tend to cause severe drops in the catches of larger pelagic species as well as in squid and several other species groups.
The collapse of the California pilchard (sardine) fishery off California in the late 1940s was partly compensated by an increase in the abundance of Californian anchovy (Engraulis mordax
) in the same general fishing areas. However, no substantial fishery for Californian anchovy developed until much later (MacCall, 1983). It was only by the 1970s that Mexico developed a major industrial fishery for California pilchard and Californian anchovy. With the development of this fishery, the total production of small pelagics in ISSCAAP Group 35 increased from the record lows of 41 000 tonnes and 34 000 tonnes in 1952 and 1963, to a peak of almost 900 000 tonnes in 1980 (Figure B13.3; Table D15
). Total catch of small pelagic species in this ISSCAAP group then remained in the range of 400 000 tonnes to 620 000 tonnes in 1990–1999, to increase to 853 000 tonnes in 2001 and reach a maximum of 1 million tonnes in 2009.
Most of these recent large total catches have been the result of an increase in the California pilchard catch, which peaked at 729 000 tonnes in 2009. This catch was the largest for this species in half a century. Increased catches of Pacific thread herring have also contributed to the recent large total catch from Area 77. The catch of Pacific threadfin herring reached a maximum of 233 000 tonnes in 2007, with 163 000 tonnes in 2009. The long-term fluctuations in the marine fish abundance and resulting catches of California pilchard seem to be associated with long-term changes in air pressure and sea water temperature in the Northern Hemisphere. Until the early 1990s, the California pilchard followed the same trend as other congeners in the Pacific (Bakun, 1997; Csirke and Vasconcellos, 2005). At that time, the catches of the other two Sardinops species in the Pacific declined and have remained at very low levels after peaking in 1985 and 1988. In contrast, catches of California pilchard also peaked at 509 000 tonnes in 1989, declined to 273 000 tonnes in 1993 and then increased again to the high 683 000 tonnes in 2002 and to 729 000 tonnes in 2009. Californian anchovy yielded fairly large catches throughout the 1970s and 1980s, with a peak catch of 424 000 tonnes in 1981 (Figure B13.3). Since the 1990s, total annual catches of this species have been below 30 000 tonnes except for 2006 when catches peaked at 61 000 tonnes, only to decline to 13 000 tonnes in 2009.
Other important small pelagic species of ISSCAAP Group 35 in Area 77 are the Pacific anchoveta (Cetengraulis mysticetus
) and the Pacific thread herring (Opisthonema libertate
). These species are caught mostly off Panama and, since 2005, also off Mexico. Catches of these two species are also highly variable. The maximum recorded catch of Pacific anchoveta was 241 000 tonnes in 1985. Since then catches have been lower and highly variable, fluctuating between the record lows of 39 000 tonnes in 1988 and 27 000 tonnes in 1999. The largest catches of these species were 121 000 tonnes in 1989 and 108 000 tonnes in 1998. In 2008, the catch of Pacific anchoveta was 85 000 tonnes, and it was 103 000 tonnes in 2009. The catch of Pacific thread herring varied between 5 000 tonnes and 50 000 tonnes until 2004. However, when a fishery for this species started off Mexico in 2005, catches jumped to a maximum of 233 000 tonnes in 2005, with 163 000 tonnes in 2009 (Table D15
|Figure B13.3 Annual nominal catches of selected species in ISSCAAP Group 35, Eastern Central Pacific (Area 77) |
The main mid-size pelagic species in Area 77 are the chub mackerel (Scomber japonicus) and the Pacific jack mackerel (Trachurus symmetricus) in ISSCAAP Group 37 (miscellaneous pelagic fishes). These two resources sustained important fisheries off Mexico and the United States of America in the first half of the twentieth century. Chub mackerel yielded peak catches of 67 000 tonnes in 1935. The Pacific jack mackerel fishery started later and peaked at 66 000 tonnes in 1952 (Leet et al., 2001). Since then, catches of both species have been highly variable. Catches of Pacific jack mackerel have shown a clear downward trend with only 2 000 tonnes caught in 2001 and no recorded catch in 2009. Catches of chub mackerel have had prolonged periods of high and low catches, with only 12 000 tonnes in 2009 after peaking at 78 000 tonnes in 1999 (Figure B13.4). The severe decline and current low catches of Pacific jack mackerel seems to be due mostly to lack of commercial interest in this species.
|Figure B13.4 Annual nominal catches of selected species in ISSCAAP Group 37, Eastern Central Pacific (Area 77) |
Tunas and other large pelagic species in ISSCAAP Group 36 are important components of the marine fisheries in Area 77 (Figure B13.5). These species are widely distributed and highly productive. Catches of tunas also started to increase in the early 1900s, long before FAO started to gather global fish catch statistics. The total tuna catch from the South Central Pacific reached 170 000 tonnes by 1950. Total catches remained stable until the mid-1960s when they increased rapidly, peaking at 482 000 tonnes in 1976 and levelling off at about 420 000 tonnes until the early 1980s. Total tuna catch declined and increased again in 1983 and 1984, probably as a result of the strong 1982–83 El Niño. Tuna catches fluctuated between minimums of 363 000 tonnes and 371 000 tonnes in 1993 and 1994 and record highs of 570 000 tonnes and 547 000 tonnes in 2002 and 2003, respectively. The most recent recorded catch was 487 000 tonnes in 2009 (Figure B13.5). The main species of tuna caught in Area 77 are the yellowfin tuna (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis) followed by bigeye tuna (Thunnus obesus)and albacore (Thunnus alalunga). The main nations fishing for tunas in Area 77 are Mexico and the United States of America, followed by Venezuela (Bolivarian Republic of), Japan, the Republic of Korea, Spain and other Asian countries. Other large pelagic species in this ISSCAAP group being exploited in Area 77 include swordfish (Xiphias gladius), striped, black and blue swordfish (Tetrapturus audax, Makaira indica and M. mazara) and the Pacific sierra (Scomberomorus sierra). All together these species yield from 30 000 to 50 000 tonnes/year.
|Figure B13.5 Annual nominal catches of selected species in ISSCAAP Group 36, Eastern Central Pacific (Area 77) |
Shrimps and prawns sustain particularly valuable and important fisheries throughout Area 77. Total shrimp (ISSCAAP Group 45) catches were already at 50 000 tonnes/year when FAO catch records started in 1950. Shrimp catches reached a maximum of 86 000 tonnes in 1961, 1962 and 1963 before declining and have since fluctuated between 45 000 and 80 000 tonnes. Recent catches have declined from 73 000 tonnes in 1995–97 to between 49 000 tonnes in 2002 and 58 000 tonnes in 2009. It is worth noting that these catches represent the accumulation of a large number of stocks and more than 15 species (mostly from the genus Penaeus but also Xiphopenaeus, Trachypenaeus, Heterocarpus, Pandalus, Pandalopsis and others). Catches of each species tend to vary widely, even if most official catch statistics fail to identify them to species. The decline in catches off Central America has been particularly critical. The low catches have caused Nicaragua and El Salvador to close their shrimp fisheries completely or almost completely in recent years. At the same time, important catches of pelagic red crab (Pleuroncodes planiceps) in ISSCAAP Group 44 (king crabs, squat lobsters) have also been obtained by some countries in Central America. Total catches of up to 14 000 tonnes were made in 2005 and 4 000 tonnes and 3 000 tonnes in 2008 and 2009, respectively.
There have been large and highly variable catches of squids in ISSCAAP Group 57 in the Eastern Central Pacific. Squids represent most of ISSCAAP Group 57 landings in Area 77. These catches increased gradually from 3 000 tonnes in 1950 to 30 000 tonnes in 1980 and then rapidly increased with large year-to-year fluctuations. They peaked at 202 000 tonnes in 2000 before declining with some fluctuations to between a maximum of 190 000 tonnes in 2002 and a minimum of 107 000 tonnes in 2007, with 152 000 tonnes in 2009. The most abundant squid species in Area 77 is the jumbo flying squid (Dosidicus gigas). There was a rapid increase in fishing for this species with wide fluctuations in total catch, peaking at 19 000 tonnes in 1980, 121 000 tonnes in 1996 and 1997 and 82 000 tonnes and 166 000 tonnes in 2000 and 2002. The total catch of jumbo flying squid was 58 000 tonnes in 2009 (Figure B13.6). Also important in Area 77 is the market squid or opalescent inshore squid (Loligo opalescens). This species has been the basis of an important commercial fishery in California since the 1850s. It had a significant expansion in southern California waters in the 1980s and 1990s, to the point where it was ranked as the largest California commercial fishery by volume in six years of the 1990s (Leet et al., 2001). In 1981, the NMFS reported a total United States catch of market squid of 24 000 tonnes, and, since then, catches of this species have been increasing while remaining highly variable. Peak catches of 118 000 tonnes were reported in 2000, with 92 000 tonnes in 2009. Unlike squid, catches of octopus have been almost negligible in the Central Eastern Pacific. No octopus catches were reported prior to 1985, with about 1 000 tonnes most years since then and 2 000 tonnes in 2009. There is not much of an ongoing deeper-water trawl fishery in Area 77, and the catch of flatfishes, hakes and other deep-water demersal fishes in ISSCAAP Groups 31, 32 and 34 is very low. Most of the reported catches of other more coastal demersal species (miscellaneous coastal fishes in ISSCAAP Group 33), such as croakers, groupers and snappers, are taken by small local fleets that target them or take them as bycatch in shrimp fisheries. Catches of this ISSCAAP group have been fairly stable, with 44 000 tonnes taken in 2009.
|Figure B13.6 Annual nominal catches of selected species in ISSCAAP Groups 45 and 47, Eastern Central Pacific (Area 77) |
Sport fishing is becoming an important activity throughout Area 77, even if catch volumes are low. Well established off the United States of America, sport fishing has expanded along the coasts of Mexico and lately also in Central America. Target species for this fishery include tunas, billfishes and other large and mid-size pelagic fishes, and also coastal demersal species.
Management unit: No
Tunas and other highly migratory species are exploited by both local fleets as well as distant-water fleets. Most of these tunas and other highly migratory species are assessed and managed through multinational efforts. The majority of these efforts have been made through the Inter-American Tropical Tuna Commission (IATTC). Fisheries for most other species groups are assessed and managed nationally. There have also been several regional and multinational initiatives to investigate, assess and manage some of the main shared, transboundary and high seas fisheries in the region.
The IATTC was established in 1950 and is responsible for the conservation and management of fisheries for tunas and other species taken by tuna-fishing vessels in the eastern Pacific Ocean. The IATTC is based in La Jolla, the United States of America. It has a long-standing tradition and experience in the resource assessment, monitoring and management of fisheries for the main tuna and other associated highly migratory species in Area 77. All main coastal States in Area 77 and most of the other States fishing for tunas in Area 77 are members of this regional organization. Of particular relevance in the fisheries research context is the California Cooperative Ocean Fisheries Investigation Program (CalCOFI) established in 1949. The programme is a partnership of the US Scripps Institution of Oceanography, the Coastal Fisheries Resources Division of the Southwest Fisheries Science Centre of NOAA/NMFS, and the California Department of Fish and Game. It aims at establishing and analysing long time-series of land-based and sea-going observations to monitor the physics, chemistry, biology and meteorology of the California Current ecosystem. It does so in cooperation with several Mexican institutions (including Centro de Investigación Científica y de Educación Superior de Ensenada, Universidad Autónoma de Baja California, Centro Interdisciplinario de Ciencias Marinas, Instituto Nacional de la Pesca, Centro de Investigaciones Biológicas del Noroeste, and Universidad Nacional Autónoma de México). These institutions are grouped under an interinstitutional project on Mexican Research of the California Current (Investigaciones Mexicanas de la Corriente de California). The project complements and extends the CalCOFI type of investigations to the southern part of the California current system.
There have also been a series of regional research activities covering fish stocks and fisheries further south, off Central America and Panama. Several of these activities were conducted with the technical or financial assistance of one or more international, regional or subregional organizations, such as the European Commission, FAO, Norwegian Agency for Development Cooperation, Swedish International Development Cooperation Agency, OLDEPESCA, Programa Regional de Apoyo al Desarrollo de la Pesca en el Istmo Centroamericano, and the United Nations Development Programme. Although more research needs to be done, particularly in terms of fisheries management, important progress has been made through these regional fisheries research and assessment programmes. Of particular relevance for the development of fisheries in Area 77 was the establishment of the Central American Organisation for the Fisheries and Aquaculture Sector (OSPESCA) in December 1995 by all the Central American States and Panama. This regional organization has the development and management of fisheries in Central America as one of its main objectives. It joined the General Secretariat of the Central American Integration System (Secretaría General del Sistema de la Integración Centroamericana [SICA]) in November 1999. It has been playing an instrumental role in promoting regional agreements for the adoption of harmonized approaches and coordinated fisheries research programmes and management measures by its members, particularly with respect to shared fish stocks. Its work is guided by a regional council of ministers composed of the ministers responsible for fisheries and aquaculture matters in the seven member countries of SICA-OSPESCA (SICA-OSPESCA, 2005). One of its main achievements has been the establishment of a common fisheries and aquaculture integration policy for the Central American isthmus, which has been implemented since 2005. Important progress is also being made towards the establishment of an integrated fishery and aquaculture central registry, the harmonization of fisheries management measures and other aspects of relevance for fisheries and aquaculture in the region. The knowledge and available information on the status of the main fish stocks in Area 77 varies widely. This status is summarized in Table D15. The state of knowledge is related to some extent to the importance of the fisheries involved and the research facilities available. Most fisheries are subject to some kind of fisheries management regulation, which may include one or more of the traditional management measures, such as limited access, catch limits or TAC, area or seasonal closures, or minimum size limits of fish. The implementation of these regulations has contributed to the healthy maintenance and, in some cases, to the rebuilding of several key stocks in Area 77. In others, poor management and loose enforcement have contributed to the overexploitation and depletion of some important local shrimp stocks. Some of the most recent fisheries management regulations adopted to recover depressed shrimp fisheries in Central America have apparently been hampered by adverse environmental conditions. These conditions have caused a decline in rainfall and coastal runoff, which are important for enrichment of coastal waters (FIINPESCA, 2010).
More detailed and comprehensive information on the state of the main tuna and tunalike highly migratory fish stocks and fisheries in Area 77 can be found in the IATTC assessment reports (IATTC, 2010, 2011) and in Chapter C1 of this review. Further information on the state of fish stocks and fisheries for these and other more coastal species can also be found in the California Department of Fish and Game, Living Marine Resources status reports (Leet et al., 2001; Ryan and Patyten, 2004; Barsky, 2008; Larinto, 2010), the Mexican stock assessment fisheries management reports (SEMARNAP-INP, 2000, 2003; SAGARPE-INP, 2006, 2010) and some working group reports presented in the context of regional meetings in the OSPESCA area. A brief status summary for the main stocks or species groups found in Area 77 based on these published reports and other information available is included in this section and in Table D15.
Biological State and Trend
To access all FIRMS State and Trend summaries available for this Area, please look at: Status and Trend Summaries (extracted from reports)Demersal fish species, Eastern Central Pacific
Deep-water demersal fishes, Eastern Central Pacific
As already noted, fishing for deeper-water demersal fishes is limited and almost non-existent in parts of the Eastern Central Pacific. Resource surveys seem to indicate that deeper-water demersal fishes in ISSCAAP Groups 32 and 34 including hakes, rockfishes and scorpionfishes are not particularly abundant. While some stocks may remain moderately or non-fully exploited and even unexploited, most stocks are believed to be fully exploited. A few local stocks, particularly rockfishes in ISSCAAP Group 34, appear to have been severely reduced through overfishing and are assessed as overexploited.
Pelagic fish species, Eastern Central Pacific
Coastal demersal fishes, Eastern Central Pacific
Most coastal demersal species in ISSCAAP Group 33 (miscellaneous coastal fishes) are in most cases underexploited if one considers their directed fisheries. However, when the indirect effects of shrimp fisheries on these species are taken into account, they tend to be overexploited. This is because demersal fish (particularly juveniles) form a large portion of the bycatch.
It is well known that populations of small pelagic species in ISSCAAP Group 35 (herrings, sardines, anchovies) are subject to large environmentally driven fluctuations in their abundance.
Californian pilchard, Eastern Central Pacific
Since their low biomass levels in the 1950s and 1960s, the Californian pilchard (sardine) stocks have been recovering, and overall California pilchard abundance and catches have been increasing with some noticeable fluctuations. The Californian pilchard (sardine) is thought to comprise three subpopulations or stocks with the more northern subpopulation ranging from British Columbia, Canada, to northern Baja California, Mexico. The southern subpopulation ranges from the outer coastal region of Baja California to southern California and there is a subpopulation confined to the Gulf of California. Although the ranges of the northern and southern subpopulations overlap, all United States, Canada and Ensenada (Mexico) landings are believed to be taken from the northern stock. The remaining Mexican landings are taken from the southern and Gulf of California stocks.
Research seems to indicate that the northern Californian pilchard (sardine) stock population has recovered from a biomass well below 100 000 tonnes in the early 1960s to a total biomass (of age 1+) estimated at 1.0–1.7 million tonnes in the late 1990s and early 2000s. After that, the biomass of pilchards stabilized and started to decline to an estimated 0.54 million tonnes in 2010 (Conser et al., 2002; Hill et al., 2007, 2010). The southern stock seems to be more stable and has even maintained a slight increasing trend. The Gulf of California stock, which supports most of the Mexican landings of this species, also started to increase in the mid-1970s. However, unlike the northern stock, it seems to have maintained its upward trend. Under the current fishing conditions, the three stocks are considered to be moderately to fully exploited.
Californian anchovy, Eastern Central Pacific
The total biomass and resulting catches of Californian anchovy had a noticeable increase in the early and mid-1970s but then declined in the early 1980s. This decline was partly the result of heavy fishing but also a consequence of adverse environmental conditions that are known to determine natural long-term fluctuations in stock abundance of this and similar species. In the recent past, the Californian anchovy has been fully to heavily exploited off Mexico and moderately to almost underexploited off the United States of America. There have been some signs of an increase in biomass of anchovy in the Gulf of California. Northern and central subpopulations are thought to be stable at lower biomass levels, mostly driven by environmental factors as fishing appears to be exerting only moderate pressure. Overall, the stocks of California anchovy are considered to be moderately to fully exploited.
Pacific anchoveta, Panama waters
The Pacific anchoveta stock has also been very variable, as reflected in the annual catches of the major industrial fishery in Panama. At the present level of exploitation (85 000 tonnes in 2008 and 103 000 tonnes in 2009), this stock is probably fully exploited.
Pacific thread herring, Central America waters
Historically, Pacific thread herring catches were only reported in substantial quantities by Panama, with occasional catches by Costa Rica. Since 2005, there have been significant landings of Pacific thread herring by Mexico. This species is probably fully exploited off Panama and Mexico, while it is either not exploited or underexploited elsewhere in its distribution range.
Tuna and others tuna species, Eastern Central Pacific
The status of tuna, bonitos, billfishes, etc. (ISSCAAP Group 36) is reviewed in another section (Chapter C1) considering their wider distribution in the Pacific Ocean. However, these stocks are considered overall to be moderately to fully exploited in Area 77.
Invertebrates, Eastern Central Pacific
Miscellaneous pelagic fishes, Eastern Central Pacific
Among the miscellaneous pelagic fishes (ISSCAAP Group 37), chub mackerel has recovered slightly although still remaining at a very low biomass after collapsing in the late 1960s. While the biomass has remained low, there were some indications of a slight increase in the abundance of the year class in 2000 and 2001 (Hill et al., 2002). Given the current catch rates, the stock is to be considered moderately exploited. There are no recent biomass estimates for Pacific jack mackerel for Area 77. However, there are some indications that its total biomass has declined substantially in the last three decades, probably owing to natural environmental causes. This species currently has a very low commercial value and minimum or no fishing effort is exerted on this stock. Given the small catches reported, with no catches reported in 2008 and 2009, it is most probable that the stock is moderately or even underexploited, although its biomass is small.
Crustaceans, Eastern Central Pacific
Among the invertebrates, there are some deepwater shrimps (mostly Galatheidae) within ISSCAAP Group 44 that are virtually unexploited. However, most of the main wild stocks of crabs and sea-spiders (ISSCAAP Group 42) and particularly shrimps and prawns (in ISSCAAP Group 45) are either fully exploited or overexploited. In some species, local stocks are showing signs of depletion. Other invertebrates such as squids (ISSCAAP Group 57) are also relatively abundant in Area 77.
Squids, Eastern Central Pacific
In particular, the jumbo flying squid (Dosidicus gigas) and the opalescens squid (Loligo opalescens) are abundant. Although the abundance and resulting catches of jumbo flying squid fluctuate widely, the stock is well monitored and management measures are applied to allow a 40 percent minimum spawning stock escapement, making the stock moderately to fully exploited. The abundance of the opalescens squid is also highly variable. Although there are no reliable biomass estimates, evidence from studies on paralarvae, egg beds, behaviour, genetics and catch data suggest that its biomass is large and may probably be moderately exploited.
Source of information
Marine and Inland Fisheries Service, Fisheries and Aquaculture Resources Use and Conservation Division. FAO Fisheries and Aquaculture Department “Review of the state of world marine fishery resources” FAO FISHERIES AND AQUACULTURE TECHNICAL PAPER.
No. 569. Rome, FAO. 2011.
The bibliographic references are available through the hyperlink displayed in "Source of Information".ACKNOWLEDGEMENTS
I would like to thank Renato Guevara, Instituto del Mar del Peru (IMARPE), Callao, Peru, Sergio Martínez, Programa Manejo de Recursos Pesqueros y Alternativas Económicas (Programa MAREA), San Salvador, El Salvador, and Traci Larinto, Department of Fish and Game, Los Alamitos, California, U.S.A. for their critical review and constructive comments that improved upon an earlier version of the manuscript.