Habitat and Biology
Climatic zone: Tropical; Temperate; Polar.
Water Area Overview
The Southeast Pacific (FAO Statistical Area 87) has a total surface of 30.02 million km2 including a total continental shelf of 0.5 million km2. It is located between longitude 120°00’W and the western coastline of South America, and between latitude 7°12’N on the coastline and along 5°00’N farther offshore off northern Colombia and latitude 60°00’S off southern Chile (Figure B15.1). Throughout most of Area 87, the continental shelf is narrow and with a steep slope. Some limited areas off southern Ecuador, northern Peru and central and southern Chile have a broader shelf, reaching a maximum width of 130 km for several hundred kilometres off southern Chile south of 41°00’S. The main oceanic islands in Area 87 are the Galapagos Islands off Ecuador and Juan Fernandez off Chile. The main regions suitable for bottom trawling are found off northern Colombia, Ecuador, northern Peru and central and southern Chile. The most productive regions are found in northern Peru and southern Chile. The coastline has two notable features: the Gulf of Guayaquil at 3°S in Ecuador and the zone of fjords south of 41°S in Chile.
The north of Area 87, off Colombia and Ecuador, has a tropical climate typical of lower latitudes. It has relatively low productivity, a mean SST of about 28 °C and salinity of 33 or lower in the rainy season and near the coast. The region is under the influence of surface equatorial currents that flow parallel to the equator. Further south, off Peru and northern and central Chile, the coastal areas are dominated by the Humboldt–Peru eastern boundary current system. Seasonally, this current generates the cold nutrient-rich coastal upwelling that makes this region highly productive. Even near the equator, water masses close to these coastal upwelling areas have low SSTs, usually ranging from 14 to 20 °C, with surface salinity about 35. These features are influenced by the Andes Mountain Ridge that runs parallel and close to the coastlines along Peru and Chile. The Andes strongly influence the air and water circulation in Area 87 and contribute to a notably dry climate, particularly at lower latitudes. Farther south off southern Chile, the water masses are much colder and more turbulent, yet still highly productive. In this region, SSTs remain well below 14 °C and salinity about 34, with the coastal area influenced by the freshwater inflow from the fjords (Schweigger, 1964; Jordán, 1979; Guillén, 1983; Bernal, Robles and Rojas, 1983; Strub et al., 1998). Another important feature in this region is the presence of an extremely shallow oxygen minimum zone (OMZ) off Peru. This is a consequence of the decay and sinking of the primary production in the surface and poor ventilation (Chavez et al., 2008). The longterm dynamics of this OMZ can help to explain part of the long-term variability of the living marine resources in this part of Area 87.
The distribution and abundance of fishery resources and the development of fisheries are strongly influenced by the local topography and prevailing environmental conditions. Shrimps, small coastal pelagic fish and large tropical migratory pelagic fish are the most abundant groups. They sustain the main fisheries off Colombia and Ecuador, while small pelagics are by far the most abundant and dominant species off Peru and northern and central Chile. Demersal fish and benthic invertebrates become more abundant and support the most important fisheries further south.
Large environmental variations within Area 87 are known to cause large year-to-year fluctuations as well as longer-term changes in fish abundance and total production of the main exploited species (Jordán, 1983; Zuta, Tsukayama and Villanueva, 1983; Serra, 1983, 1991a; Csirke, 1995). The adverse effects of El Niño events on the distribution, recruitment success and abundance of the world’s largest single-species fishery on anchoveta (Engraulis ringens) are well known. Similar negative impacts are also recorded on other fish populations as well as seabirds and mammals. However, El Niño events are not always negative for other marine fisheries that include other small pelagics, hakes, shrimps, cephalopods and shellfish (Arntz, Landa and Tarazona, 1985; Arntz and Fahrbach, 1996; Bakun and Broad, 2003; Csirke, 1980, 1989; Pauly and Tsukayama, 1987; Pauly et al., 1989; Valdivia, 1978).
Area 87 is under the influence of two phases of the ENSO cycle (known as El Niño and La Niña). These are the main source of interannual environmental variability, having noticeable regional and extraregional impacts on climate and on the productivity of fishery resources. This is particularly noticeable during the warm phase or El Niño that occurs with variable intensity every 3–7 years (Rasmusson and Carpenter, 1982; Arntz and Fahrbach, 1996). More subtle, longer-term environmental changes have also been proposed as explanations for the interdecadal shifts observed in the availability and abundance of some of the main living resources in Area 87 (Alheit and Bernal, 1999; Chavez et al., 2003; Lluch-Belda et al., 1989, 1992; Yañez, Barbieri and Silva, 2003; Klyashtorin, 2001; Csirke and Vasconcellos, 2005; Alheit, Roy and Kifani, 2009).
|Figure B15.1 The Southeast Pacific (Area 87) |
Considered a single stock: No
PROFILE OF CATCHES
The most striking fishery resource changes in Area 87 have been the collapse of anchoveta in the early 1970s, the bloom and severe depletion of South American sardine (or pilchard) (Sardinops sagax sagax) between the mid-1970s and late 1990s, the recovery of anchoveta in the 1990s, and the bloom of Chilean jack mackerel (Trachurus murphy) from the mid-1970s throughout the mid-1990s, with a significant decline in the 2000s. Catches of jumbo flying squid (Dosidicus gigas) also declined in 1995–98 before they increased sharply and levelled off at a much higher levels in the 2000s.
There have been wide fluctuations in the total catches from the Southeast Pacific in the past six decades. Major changes in catch volumes and species composition and abundance have been caused by changes in fishing effort and the effects of natural environmental fluctuation.
These fluctuations result from short-term (ENSO) and longer-term (interdecadal) changes in climate. In the 1960s, the total catch increased rapidly, peaking at 13.8 million tonnes in 1970. Catches were mainly based on anchoveta, until the sudden decline of this fishery in the early 1970s. In the mid-1970s, total catches started to increase again and became more multispecies. Small pelagics continued to dominate the catch, but with a wider variety of species including anchovies, sardines, herrings, jack mackerel and chub mackerels (Figure B15.2, Table D17). By the mid-1980s, the anchoveta had become the dominant species again and catches of other pelagic species stabilized or declined. Noticeable changes have also occurred in other species groups, particularly hakes, other demersals and, more recently, squids (especially jumbo flying squid). All this contributed to an increase in the total catch from Area 87 to a record high of 20.4 million tonnes in 1994. These catches probably corresponding to the upper limit of the yield range for the area. Following this peak in catches, the total catch declined to 7.4 million tonnes in 1998 (mainly owing to the strong 1997–98 El Niño). It has since fluctuated between 15.3 million tonnes in 2000 and 11.1 million tonnes in 2009.
|Figure B15.2 Annual nominal catches by ISSCAAP species groups in the Southeast Pacific (Area 87) |
The general trends and high variability of total catches from Area 87 are strongly influenced by the anchoveta, a major component of ISSCAAP Group 35 (herrings, sardines, anchovies). After reaching 13.1 million tonnes in 1970, the total catch of anchoveta fell to 1.7 million tonnes in 1973 and to a record low of only 94 000 tonnes in 1984. Since then, catches of this species have generally recovered, albeit with major declines during the 1997–98 El Niño and a subsequent very rapid recovery. In recent years, catches have been between 6 and 11 million tonnes per year with 6.9 million tonnes in 2009 (Figure B15.3).
Catches of other small pelagics, such as South American sardine, Chilean jack mackerel, and chub mackerel (Scomber japonicus), started to increase following the anchoveta fishery collapse in 1972–73. The catches of these species had been negligible (a few 10 000 tonnes per year) until the early 1970s. Now, these species have become major contributors to the total fish production in Area 87 with combined catches of several million tonnes per year. The South American sardine has now almost disappeared while the Chilean jack mackerel and the chub mackerel continue to maintain relatively high catches in Area 87, although with some noticeable fluctuations.
The South American sardine (pilchard) become a major contributor to the total production of ISSCAAP Group 35 and the total catch after anchoveta declined in the mid-1970s (Figure B15.3). Catches of South American sardine increased from under 10 000 tonnes/year prior to 1970 to a maximum of 6.5 million tonnes in 1985. Then, catches declined continuously, to only 27 000 tonnes in 2002 and to about 300 tonnes in 2008 and 2009. This sharp decline was apparently caused by the heavy fishing in the 1980s coinciding with the onset of the declining phase of an environmentally driven long-term “regime change” in abundance (Kawasaki, 1983; Lluch-Belda et al., 1989, 1992; Patterson, Zuzunaga and Cardenas, 1992; Schwartzlosse et al., 1999; Serra, 1991a).
Other main species in ISSCAAP Group 35 are the Araucanian herring (Strangomera benticki) and the Pacific thread herring (Ophisthonema libertate). Catches of these species have also been highly variable. The Araucanian herring or Araucarian (common) sardine is fished mainly between 34°S and 40°S off Chile. It has had two distinguishable periods of high production. One lasted from the mid-1960s to the mid-1970s, with peak catches of 159 000 tonnes and 183 000 tonnes in 1971 and 1974. The second period started with a rapid increase in catch after 1989. This period of high catch apparently still continues but with large fluctuations within lows of 127 000 and 281 000 tonnes in 1995 and 2007, and record highs of 584 000, 782 000 and 855 000 tonnes in 1991, 1999 and 2009, respectively. The Pacific thread herring is mostly fished to the north of 6°S. The highest recorded catch was 90 000 tonnes in 1989, followed by a decline with wide fluctuations to 6 900 tonnes in 2003 and then an increase to 25 000 tonnes and 22 000 tonnes in 2008 and 2009.
In the same group, the Pacific anchoveta (Cetengraulis mysticetus) is a small pelagic species associated with estuarial waters. It is mainly fished off Colombia and Ecuador and has yielded highly variable catches. These have fluctuated between peaks of 123 000 tonnes, 118 00 tonnes and 99 000 tonnes reported in 1981, 1997 and 2001, and lows of 4 000 tonnes, 15 000 tonnes and 13 000 tonnes in 1985, 2005 and 2009, respectively.
|Figure B15.3 Annual nominal catches of selected species in ISSCAAP Group 35, Southeast Pacific (Area 87) |
The other main species dominating total catches in recent years from Area 87 is the Chilean jack mackerel (ISSCAAP Group 37). There is no evidence that this species was in particularly high abundance prior to 1970 when annual catches were barely 30 000 tonnes per year. However, in the early 1970s, this species started to appear consistently as bycatch in local artisanal and industrial fisheries. Then, more specialized Chilean, Peruvian and then-Soviet-Union fishing fleets began targeting it in the mid-1970s and 1980s. Total catches increased rapidly to peak at almost 5 million tonnes in 1995. The catch then began to decline and reached a low of 1.2 million tonnes in 2009 (Figure B15.4).
Another important small pelagic in ISSCAAP Group 37 is chub mackerel (Figure B15.4). Catches of this species show two main periods of higher catches. The first period ran from the mid-1970s to the mid-1980s with a maximum catch of 836 000 tonnes in 1978 (65 percent off Ecuador), mostly caught closer inshore. The other period was from the mid-1990s onwards, with an increased portion of the catches being taken farther south and offshore with maximum catches of 676 000 tonnes in 1999 and 701 000 tonnes in 2003, with 317 000 tonnes in 2009.
|Figure B15.4 Annual nominal catches of selected species in ISSCAAP Group 37, Southeast Pacific (Area 87) |
The eastern Pacific bonito (Sarda chiliensis) (ISSCAAP Group 36) (Figure B15.5, Table D17) used to support an important coastal small pelagic fishery in the region, mainly off Peru. Catches were in the order of 60 000 tonnes per year in the 1950s and 1960s, with a record high of 109 000 tonnes in 1961. Following the collapse of the anchoveta (its main food source), catches of eastern Pacific bonito dropped to 4 300 tonnes in 1976. They recovered thereafter to almost 40 000 tonnes in 1990, but dropped drastically to 5 700 tonnes in 1998 and to only 500 tonnes in 2000 and 875 tonnes in 2002. More recently, catches have recovered to 43 000 tonnes in 2008 and 31 000 tonnes in 2009.
Within the same ISSCAAP Group 36 (Figure B15.5), catches of tunas have continued to show a general increasing trend with some fluctuations since the late 1980s. Skipjack tuna (Katsuwonus pelamis) catch peaked at 231 000 tonnes in 2008, with 175 000 tonnes in 2009. Bigeye tuna (Thunnus obesus) catch peaked at 63 000 tonnes in 2000, with 52 000 tonnes and 38 000 tonnes in 2008 and 2009, respectively. Catches of yellowfin tuna (Thunnus albacares) also peaked at 171 000 tonnes in 2001 but then declined to 72 000 tonnes and 77 000 tonnes in 2008 and 2009. Other tunas, bonitos and billfishes caught include the frigate and bullet tunas (Auxis spp.) and swordfish (Xiphias gladius) with catches of 35 000 tonnes and 15 000 tonnes, respectively, in 2009.
|Figure B15.5 Annual nominal catches of selected species in ISSCAAP Group 36, Southeast Pacific (Area 87) |
Total catches of demersal fish in ISSCAAP Group 32 generally increased with high variability until a maximum total catch of 752 000 tonnes was reached in 1996. Then, total catches began a decreasing trend to a low 196 000 tonnes in 2007 and 211 000 tonnes and 225 000 tonnes in 2008 and 2009. The main species in this ISSCAAP group (Figure B15.6) are South Pacific hake (Merluccius gayi), with two subpopulations (one off Peru and the other off Chile), southern (Patagonian) hake (Merluccius australis = polylepis) and Patagonian grenadier (Macruronus magellanicus). Total catches of South Pacific hake have been highly variable with sharp declines in the 1980s and the mid-2000s. There are two stocks of this species. Catches from the Peruvian stock of South Pacific hake have been very variable, with more than 300 000 tonnes in 1978 and 235 000 tonnes in 1996. Catches from this stock declined drastically to only 42 000 tonnes in 2002 as it became less abundant. The sudden decline in biomass and catch in 2002 led to an almost complete ban on fishing for South Pacific hake off Peru. This ban reduced total catches to only 8 000 tonnes in 2003, which was followed by a controlled recovery in catch off Peru to 47 000 tonnes in 2009. Catches of the Chilean stock of South Pacific hake have been less variable, with maximum recorded catches of 128 000 tonnes in 1968 and 121 000 tonnes in 2001. After 2001, catches declined to about 47 000 tonnes/year by 2005 and have remained at these levels since. These changes in catches of the two stocks of South Pacific hake are reflected in the overall high variability and the sharp declines of the total catch of in ISSCAAP Group 32 fishes in the 1980s and the mid-2000s.
Catches of Patagonian grenadier were also high from 1987 to 2002, with a record high of 379 000 tonnes in 1996. Since 2003, catches of this species have been under 85 000 tonnes per year, with 78 000 tonnes in 2009. Catches of southern hake increased to a record high of 69 000 tonnes in 1988 before then declining and levelling off at between 20 000 and 30 000 tonnes per year in the last decade, with 26 000 tonnes in 2009.
Until recently, the accumulated catch of all miscellaneous coastal species in ISSCAAP Group 33 (Figure B15.6) used to have a low variability with a slight increasing trend. Catches reached 60 000 tonnes by 2003 even with major fluctuations in the catches of several of the more than 30 individual species represented in this group. However, since 2004, catch totals of this ISSCAAP group have increased and become highly variable because of the noticeable increase in the catches of mote sculpin (Normanichthys crockeri) by Chile. Mote sculpin catch was 70 000 tonnes in 2004, a record high of 319 000 tonnes in 2006, and 67 000 tonnes and 170 000 tonnes in 2008 and 2009. It has become the dominant species in this species group, followed by mullets (Mugilidae spp.) and corvina drum (Cilus gilberti) with 19 000 tonnes and 10 000 tonnes in 2009, with other species reaching less than 6 000 tonnes per year.
|Figure B15.6 Annual nominal catches of selected species in ISSCAAP Groups 32 and 33, Southeast Pacific (Area 87) |
The first major increase in the total catches of squids and particularly of jumbo flying squid (Dosidicus gigas) in ISSCAAP Group 57 was reported in the early 1990s. However, this first period of high catches lasted only five to six years, reaching a maximum of 200 000 tonnes in 1994. It was followed by another period of high catches that seems to be lasting longer and yielding higher catches. These peaked at 787 000 tonnes in 2006 and 773 000 tonnes in 2008, with a decline to 571 000 tonnes in 2009 (Figure B15.7).
|Figure B15.7 Annual nominal catches of selected species in ISSCAAP Group 57, Southeast Pacific (Area 87) |
Management unit: No
All the main fish stocks in this region are exploited either by national fleets operating within their own EEZs or by land-based foreign fleets operating under a licence or fisheries agreement with a coastal State. These fisheries are also assessed and managed nationally, except for occasional shared stocks. This situation simplifies the assessment and management of these fisheries to some extent. It also helps in the allocation of responsibilities for the conservation and use of these living marine resources in Area 87. The exceptions to this pattern are the regional assessments of fisheries for tunas and other highly migratory species, Chilean jack mackerel fishery and jumbo flying squid. As a consequence, there is a well-established tradition of regional cooperation regarding general fisheries research issues. In the last five years, there have been major steps forward in the cooperation between coastal States and neighbouring or distant-water fishing countries. This is particularly in regard to the assessment and management of fish stocks that extend beyond the national EEZs in Area 87.Peruvian anchoveta, Southeast Pacific
Of particular relevance are the negotiations for the establishment of the SPRFMO and the adoption in 2009 of the Convention on the Conservation and Management of the High Seas Fishery Resources of the South Pacific Ocean (above). This organization is already undertaking valuable and intense work on the assessment and management of important fish stocks such as Chilean jack mackerel. Although the interim measures are pending ratification from member countries, they are paving the way for similar work to be undertaken on other important non-highly migratory fish stocks that are, or can be, exploited in the high seas in Area 87.
The fisheries for tunas and other highly migratory species in Area 87 are assessed and managed through the IATTC. This commission is also responsible for assessments of tuna fisheries that extend well beyond the northwest of Area 87. Other regional organizations such as the Permanent Commission for the Southeast Pacific and the Latin American Organization for Fishery Development (OLDEPESCA) are also active in supporting regional cooperation in fisheries and the marine environment in the region.
The anchoveta fishery started in the late 1950s and developed rapidly in the 1960s. At this time, management was ineffective and had an overoptimistic perception of the sustainable catches. This contributed to overexploitation of the stocks, followed by a dramatic collapse in the early 1970s. In fact, in the 1960s, the fishery grew rapidly, obtaining record high catches in several consecutive years. Fishing capacity expanded substantially and, for several years, managed to remove a total catch well in excess of the recommended ceilings. For the main northern-central Peruvian stock alone, the catch was in the order of 8 million–9 million tonnes per year (Schaefer, 1967; Boerema et al., 1967; Gulland, 1968; Csirke et al., 1996; Csirke and Gumy, 1996; IMARPE, 1970, 1972, 1973, 1974). Total catches of this species peaked at 13.1 million and 11.2 million tonnes in 1970 and 1971, just prior to the 1972–73 collapse. While overfishing did play a major role in the collapse of the anchoveta fishery in the early 1970s (IMARPE, 1974; Zuta, Tsukayama and Villanueva, 1983; Jordán, 1983), it is also recognized that the 1972–73 El Niño was a primary cause of recruitment failure and stock decline (Csirke, 1980). The lack of adequate management action to reduce fishing pressure drastically when this was most needed did not help. Moreover, it contributed to aggravating and prolonging the decline well into the 1980s. The anchoveta stock was already depleted and catches were already low when the much stronger 1982–83 El Niño hit the area. That is why the 1982–83 El Niño apparently did not have as severe an impact on the total regional fish production. However, it did have a severe impact on the marine ecosystem in the area and it did reduce the anchoveta stock to its historical minimum. The fortunate coincidence of favourable environmental conditions, a bankrupt industry with much reduced fishing capacity and reduced fishing effort allowed the stock to recover and catches to increase in later years (Csirke et al., 1992, 1996). By the early 1990s, the stock and the anchoveta fishery had recovered to its pre-1972 collapse state. However, poor management allowed fishing capacity to expand again well beyond advisable levels. Thus, by 1995, both the fishing vessels and fishmeal-processing factories were estimated to be at least 30 percent more than were needed or advisable (Csirke and Gumy, 1996). They continued to increase further, although at a slower rate, until there was another serious stock depletion in 1998. This depletion resulted from several years of heavy fishing and the adverse environmental conditions associated with the strong 1997–98 El Niño. By mid-1998, hydroacoustic surveys estimated the total biomass of anchoveta off Peru at one of its lowest levels (1.2 million–2.7 million tonnes; Castillo, Gutiérrez and Gonzales, 1998; IMARPE, 1998; Gutiérrez, 2000). However, the stock made a rapid recovery shortly afterwards. Particularly favourable environmental conditions and good recruitment, coupled with a tighter and more careful management and surveillance scheme, apparently contributed to the rapid recovery in the post 1997–98 El Niño years (Bouchon et al., 2000; Ñiquen et al., 2000). While the two stocks of anchoveta soon recovered from the El Niño 1997–98 depletion, there were still serious concerns over potential risks of overfishing because of the gross overcapacity of the fishing fleet (estimated to be 40 percent higher than required). The fishing pressure, SSBs and other stock values have been maintained within sustainable safe limits by keeping the fleet and processing factories idle for extended periods of time. More recently, the adoption of an individual quota system has apparently contributed to reducing the excess fishing capacity for anchoveta in Area 87. This approach has improved net economic returns from this fishery and reduced the potential excess pressure on the stock.Chilean jack mackerel, Southeast Pacific
In fact, in addition to the individual quota system, other measures such as minimum size at first capture, seasonal closures, area closures, and seasonal and annual TAC-type of regulations have been in force for the anchoveta fishery for decades in both Peru and Chile. The Government of Peru has applied an individual quota system per boat owner since 2009 for the northern-central Peruvian stock. It extended the same scheme to the southern anchoveta fishery in 2010 (PRODUCE, 2008a, 2008b, 2009). Meanwhile, the Government of Chile has already been applying an individual quota per boat owner (maximum catch limit per boat owner) for the anchoveta fishery off northern-central Chile since 2001. It expanded this in 2007 by applying a similar catch quota in the southern part of Chile (SUBPESCA, 2008a, 2008b, 2008c).
All this, coupled with closer monitoring and more careful management, has recently contributed to maintaining these stocks of anchoveta at near fully exploited. This level of exploitation has still been within safe sustainable limits despite the natural fluctuations characteristic of this species and its ecosystem. The exploitation rate and the mean total biomass and SSB of the northern-central Peruvian stock has been maintained within safe target limits in recent years (Guevara-Carrasco, Wosnitza-Mendo and Ñiquen, 2010; Oliveros-Ramos et al., 2010; Diaz et al., 2010). However, for the more southern stocks, there are indications of declining total biomass and SSB (GTE IMARPE-IFOP, 2010). These declines have led to adjustment of the TACs accordingly (SUBPESCA, 2010a, 2010b).
The first signs of a significant increased abundance of Chilean jack mackerel in Area 87 dates back to the early 1970s. This was just a few years prior to having large specialized industrial fleets from Chile, Peru and the then Soviet Union targeting this species in the mid-1970s and 1980s. A large, although variable proportion (65–95 percent) of the annual catch of Chilean jack mackerel was taken off Chile, which soon become the main fishing country of this species. Signs of overexploitation, including a noticeable reduction in the mean sizes in the catch, led the Government of Chile to establish tighter management measures in the late 1990s. These measures were followed by a drastic decline in the total catch and the introduction of a non-transferable individual quota system. Although the catch had stabilized by the early 2000s, there were still concerns about possible overexploitation of the stock and the sustainability of the fishery (Barría et al., 2003; Perez and Buschmann, 2003; Serra, 2001). By then, catches in Peru were much lower and more variable than in Chile. In 2002, the Government of Peru ruled that Peruvian catches of Chilean jack mackerel as well as those of chub mackerel and South American sardine could only be used for direct human consumption (PRODUCE, 2002). This was partly done with the aim of reducing fishing pressure on these species as well as increasing the supply for human consumption.South Pacific hake, Southeast Pacific
However, the distribution of Chilean jack mackerel extended to the high seas beyond the EEZs of Chile and Peru. In this region, the species was heavily exploited by fleets from several other nations. It became clear that proper management of this and other important fish resources exploited in the high seas of the South Pacific could only be achieved through international cooperation within the context of an RFMO. A first international meeting to discuss the establishment of such an RFMO took place in Wellington, New Zealand, in February 2006. After eight consecutive meetings, participating countries adopted the Convention on the Conservation and Management of High Seas Resources of the South Pacific Ocean in November 2009 (SPRFMO, 2009). Upon coming into force, this convention will close the gap in the international conservation and management of non-highly migratory fisheries. It will help protect marine biodiversity from the easternmost part of the South Indian Ocean through the Pacific towards the EEZs of South American countries. Most of the key mechanisms have already been implemented through a series of interim measures and the activities of the Interim Secretariat of the South Pacific Regional Fisheries Management Organisation SPRFMO based in Wellington, New Zealand (SPRFMO).
The total biomass of the Peruvian stock of South Pacific hake was estimated to be as high as 700 000 tonnes in 1978, with a second high peak estimated at 640 000 tonnes in 1994. However, it is now known that relaxed regulations coupled with overoptimistic assessments in the late 1990s contributed to overexploitation and severe depletion of the stock (Espino, Samamé and Castillo, 2001; Lleonart and Guevara, 1995; IMARPE, 2003, 2004a). The biomass declined to a low of 102 000 tonnes in 2002 and led the Government of Peru to decide on a total ban of this fishery. It took this closure almost two years to begin to have some effect two years. After that time, the stock began to show some signs of recovery (IMARPE, 2003, 2004a, 2004b). However, although severe management regulations are being adopted, these do not appear sufficient to ensure a high probability of recovery of the Peruvian South Pacific hake stock. The biomass of the Peruvian stock remains low, with reduced spawning potential and a total biomass estimated in 2008 of only 180 000 tonnes (IMARPE, 2008a, 2008b).
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)
The status of each fishery stock in Area 87 is shown in Table D17. Fishery resources in Area 87 are well known for experiencing large changes in their abundance and species composition (Csirke and Sharp, 1984; Sharp and Csirke, 1983). This feature of the fisheries tends to have major social and economic impacts on the communities in the region that rely on marine fisheries production. Moreover, as Area 87 is the secondlargest contributor to world capture fish production and the third-largest contributor to total world fish production (in 2009, the Southeast Pacific accounted for 14.5 percent of total world marine captured fish and 8.5 percent of total world fish production), the effects of changes in this region also tend to have noticeable effects on global fisheries trends and projections.Pelagic fish species, Southeast Pacific
The small pelagics complex formed primarily by anchoveta, South American sardine and Chilean jack mackerel provides a striking example of how these changes in abundance and species composition can affect local fisheries and national economies.
Peruvian anchoveta, Southeast Pacific
The most important, highly variable and best-studied species in Area 87 is the anchoveta (IMARPE, 1970, 1972, 1973, 1974, 2000; Tsukayama, 1983; Zuta, Tsukayama and Villanueva, 1983; Pauly and Tsukayama, 1987; Pauly et al., 1989; Csirke, 1980, 1988, 1989; Bertrand et al., 2008), this single species produces the largest catches worldwide, all from Area 87.
There are two main stocks of anchoveta in Area 87: the northern-central Peruvian stock that is found between 3° and 15°S, and the southern Peru–northern Chile stock that is found between 16° and 24°S (Tsukayama, 1966; Jordán, 1971; IMARPE, 1973; GTE IMARPE-IFOP, 2003). A smaller, third substock has been proposed for fish found in the southernmost part of the species range at 37°S (Serra, 1983). More recent reports have also documented increased spawning and catch of anchoveta as far south as 47°S (Bustos, Landaeta and Balbontin, 2008; SUBPESCA, 2008c).
The northern-central Peruvian stock is by far the most abundant and important, with an average biomass usually in the range of 3 million–16 million tonnes (Tsukayama, 1983; Pauly and Palomares, 1989; Csirke et al., 1996). The southern Peru–northern Chile stock has been estimated to reach a biomass in the order of 3 million–6 million tonnes (GTE IMARPE-IFOP, 2003). Most of the catches of anchoveta correspond to the northern-central Peruvian stock that is generally found within Peruvian waters and is usually exploited solely by Peruvian fleets. However, in some particularly cold years and under the influence of a stronger flow of the Humboldt–Peru current, part of the stock may migrate north into Ecuadorian waters where anchoveta may also be reported in commercial catches. In 2009, 5.4 million tonnes or 78 percent of the total anchoveta catch (within the historical 70–80 percent estimated for previous years) were produced by the northern-central Peruvian stock. The remainder is mostly produced by the southern Peru–northern Chile stock that is exploited by fleets from these two countries. The most southern stock that is exploited only by Chilean fleets forms a minor component of the overall catch.
South American sardine, Southeast Pacific
As noted above, the South American sardine had a period of particularly high abundance from the late 1970s through to the early 1990s before virtually disappearing from catches. At least three substocks are described for this species in the area (Parrish, Serra and Grant, 1989). The northern stock is found from 1°S to 15°S off Ecuador and Peru, with a probable separate substock around the Galapagos Islands. The central stock is found from 15°S to 25°S off southern Peru and northern Chile, and the southern stocks off Coquimbo (30°S) and off Talcahuano (37°S) in Chile. Serra and Tsukayama (1988) describe the one off Talcahuano as a separate stock. All the stocks of South American sardine are severely depressed. In periods (or regimes) of high abundance, the most abundant stocks have been the northern (Ecuador–Peru) stock, with a biomass peaking at 10 million tonnes in 1987, and the central (southern Peru–northern Chile) stock, peaking at 9 million tonnes in 1980.
The first recorded sudden increase in biomass and particularly high catches of the two main stocks of South American sardine started more or less simultaneously in the early 1970s (IMARPE, 1974; Serra and Zuleta, 1982; Salazar et al., 1984; Zuzunaga, 1985). The increase followed the 1972 collapse of the anchoveta. This increase in biomass lasted for almost two decades, but now the abundance of both stocks has declined to very low levels. They have supported only negligible catches in the last decade, with no catches reported at all since 2008. Total catches on the southern Peru–northern Chile stock started to decline in 1985, and the northern stock (Peru–Ecuador) started to decline in 1990. There are clear indications that in both cases these declines were preceded by three to four years of declining trends in recruitment and total biomass. Moreover, in both cases, managers allowed fishing pressure to build up rapidly and remain high, even while biomass and recruitments were declining (Csirke et al., 1996; GTE IMARPE-IFOP, 1994, 1999, 2003; Serra, 1991a). The high fishing pressure accelerated the decline in abundance caused by an environmentally driven long-term “regime change” (Kawasaki, 1983; Lluch-Belda et al., 1989, 1992; Schwartzlosse et al., 1999). This unfavourable phase of a longer-term regime will probably ensure that the catches remain negligible for some years. Therefore, even if fishing pressure and total catches are drastically reduced and remain very low, the stocks need to be considered as moderately to fully exploited. Given this situation, these sardine stocks need to be properly monitored to ensure that they do not become further overexploited.
Other small pelagics, Southeast Pacific
Among other small pelagics in the same ISSCAAP group, worth noting are Araucanian herring, Pacific herring and Pacific anchoveta, which also have large fluctuations in biomass in Area 87. Araucanian herring was considered to be fully exploited to overexploited in the late 1990s and early 2000s as biomass and recruitment levels declined (Cubillos, Bovary and Canales, 2002; Attica et al., 2007). However, recent stock assessments of Araucanian herring have shown that there have been substantial increases in recruitment, total biomass and spawning biomass of this species (SUBPESCA, 2010b). This has led to increases in the TACs and actual catches, despite the stock remaining fully exploited. Pacific thread herring and Pacific anchoveta are most likely moderately to fully exploited in most of their distribution range. They are mainly used to produce fishmeal and fish oil. In Colombia, the Pacific anchoveta is managed under a system of annual quotas and spawning bans (Beltrán and Villaneda, 2000; CPPS, 2003; FAO, 2003).
Chilean jack mackerel, Southeast Pacific
The Chilean jack mackerel is widely distributed in Area 87 and, because of its extensive migrations, it has been particularly difficult to establish distinguishable stock units. The possible existence of two or more subpopulations of this species was proposed in the early 1990s (Serra, 1991b; Arcos and Grenchina, 1994). All hypotheses suggesting up to four independent populations were discussed in 2008 (SPRFMO, 2008). More recent follow-up studies and genetic analyses show that there is a single population in the whole Pacific Ocean. These results suggest that the stock structure of Chilean jack mackerel is better described by a meta-population, with a source population creating several subpopulations that can remain separate for long periods depending on environmental conditions (Gerlotto et al., 2010).
Recent stock assessment studies suggest that fishing mortality (F) on Chilean jack mackerel has exceeded sustainable levels since at least 2002. They have confirmed that the current biomass levels are substantially lower than during the peak of the fishery in the 1990s. The total biomass has been estimated to have declined by almost 80 percent since 2001, to 2.1 million tonnes in 2010 (SPRFMO, 2010). Taking into account the scientific advice of its own advisory groups, member countries participating in the second session of the Preparatory Conference for the South Pacific Fisheries Management Organization (SPRFMO, 2011) recognized the overexploitation and seriously depleted state of the stock. They accepted a series of interim measures that include lowering the 2011 quotas for Chilean jack mackerel in Area 87 by at least 40 percent compared with those of 2010. These reductions are in addition to catch restrictions imposed in 2009 and previous years. The stock was considered fully exploited and now is overexploited. The proper implementation of the SPRFMO recommendations is expected to reduce catches and fishing pressure by all national fleets fishing in Area 87. This should also reduce the risk of further depletion and favour the recovery of the stock. The role and impacts of natural environmental changes in the Southern Pacific are however adding another important source of uncertainty regarding the recovery of this stock.
Chub mackerel, Southeast Pacific
Chub mackerel is mostly caught as bycatch in the jack mackerel fishery. While there is less information regarding its abundance and general state than for many other species, it is clear that it is also highly variable but far less abundant than jack mackerel. Currently, the stock is probably moderately to fully exploited.
Demersal fish species, Southeast Pacific
Eastern Pacific bonito, Southeast Pacific
The eastern Pacific bonito gave some signs of recovery in the early 1990s, most likely owing to the recovery of the anchoveta, its main food source. However, the severe 1997–98 El Niño, associated with some large catches as bycatch in the anchoveta and other fisheries, apparently caused the depletion of this stock again. As a result, this species was only occasionally reported as target or as bycatch in the Peruvian smallscale fisheries for several years in the late 1990s and early 2000s (Estrella et al., 2001). However, in recent years, catches have improved and the populations of Pacific bonito are showing some signs of recovery.
South Pacific hake, Southeast Pacific
Within the demersal fishes, the South Pacific hake has also shown large recruitment and stock size variability associated with changes in environmental conditions such as El Niño events (Samamé, Castillo and Mendieta, 1985; Espino, Castillo and Fernández, 1995). There are two distinct stock units corresponding to different subspecies of South Pacific hake: Merluccius gayi peruanus, found from 0°S to 14°S off Peru; and Merluccius gayi gayi, found from 19°S to 44°S off Chile (FAO, 1990).
The Chilean (southern) stock of South Pacific hake has had two periods of high abundance. One period lasted until the early 1970s, while the other started with an increasing trend from 1988 throughout the very early 2000s to an estimated peak biomass of 1.4 million tonnes in 1996 and about 1 million tonnes in 2000 (Payá, 2003). Until the late 1990s and early 2000s, the Chilean stock of South Pacific hake was considered fully exploited (Cerda et al., 2003; Pérez and Buschmann, 2003). However, it started to show signs of overexploitation and was severely depleted by 2004–05. The decline in abundance has been at least partially attributed to an increase in abundance of jumbo flying squid. Since tight management measures were adopted in 2005, the stock has shown no signs of recovery. Recruitment and SSB remain low and below the 250 000 tonnes set as a minimum safe biomass reference limit (SUBPESCA, 2010c).
Invertebrates, Southeast Pacific
Patagonian grenadier, Southeast Pacific
The Patagonian grenadier has been showing signs of heavy exploitation for several years (Payá et al., 2002) and is now considered to be overexploited (SUBPESCA, 2010d). Even in the late 1990s, the southern hake was considered fully exploited or overexploited owing to the high catch of juveniles and its low turnover rate (Payá et al., 2000). More recent analyses on southern hake suggest declines in the total biomass, recruitment and other population parameters associated with overfishing (SUBPESCA, 2010e). The Patagonian toothfish is also considered fully exploited to overexploited (SUBPESCA, 2010f). Most of the other commercially important species of toothfish are believed to be fully exploited, with some showing signs of overexploitation (Pérez and Buschmann, 2003). There are also some indications that the common eel (Ophichthus remiger) might be showing some signs of overexploitation off Peru.
Squids, Southeast Pacific
Squids are ecological opportunists whose dynamics are similar to those of desert locusts, and their abundance often fluctuates widely from one generation to the next (Rodhouse, 2001). This region is able to sustain large population of squids, and the jumbo flying squid is particularly abundant in some years. As a consequence, catches and fishing pressure have been building rapidly on this species. The jumbo flying squid has a wide distribution in the eastern Pacific, from California, the United States of America, to southern Chile (Nigmatullin, Nesis and Arkhipkin, 2001). Some catches have been reported as far north as off Oregon, the United States of America, in 1997 and off Alaska, the United States of America, in 2004. There are no clear indications of possible population subgroupings, mainly because of its active and extensive migrations. There has been a striking increase in abundance of jumbo flying squid since 1999, and the stock has extended its distribution and availability southwards from Peru to Chile (IMARPE, 2004c). The active and voracious predatory behaviour of this species has been a source of concern for Peruvian and Chilean authorities and fishers. This is mainly because of the probable impact of this species on the abundance of other high-value species in the region. Although catches have increased rapidly, the stock is probably only moderately exploited.
Other invertebrates, Southeast Pacific
Other invertebrates, such as tropical and more temperate water shrimps, tend to be fully exploited to overexploited. Some local populations of sea urchins, clams, scallops and other shellfishes have been overexploited and even depleted in some areas. Other invertebrate species are only moderately or very lightly exploited (Rabí, Yamashiru and Quiroz, 1996; Beltrán and Villaneda, 2000; Pérez and Buschmann, 2003). It is worth noting the apparent increase in abundance of some species such as the mote sculpin (Normanichthys crockeri) and jellyfish. Catches of mote sculpin, known as “bacaladillo” in Chile, have been higher than usual in recent years. The same species, known as “camotillo” in Peru, has also been reported in apparently higher than usual volumes in some recent pelagic acoustic surveys. The species has even been caught in lower latitudes where it had not previously been reported. The apparent higher incidence of jellyfish has also been reported as a problem affecting some fisheries in both Chile and Peru in recent years.
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 acknowledge Renato Guevara, Instituto del Mar del Peru (IMARPE), Callao, Peru, and Rodolfo Serra, Instituto de Fomento Pesquero (IFOP), Valparaiso, Chile for their review and providing constructive feedback that improved upon an earlier version of the manuscript.