Sometimes known as Pacific Calico Scallop, Catarina Scallop, Speckled Scallop

Transcription

1 MEXICAN BAY SCALLOPS Argopecten ventricosus (= circularis) Sometimes known as Pacific Calico Scallop, Catarina Scallop, Speckled Scallop SUMMARY Mexican Bay Scallops are distributed from Baja California, Mexico to Northern Peru, including both sides of the Baja California Peninsula. They grow quickly, reach sexual maturity around 6 months of age and produce many eggs. After heavy fishing pressure that caused numbers to drop considerably, Mexican Bay Scallops are now at healthy levels of abundance particularly in the main fishing area of Magdalena Bay, Mexico. In Magdalena Bay, they are collected by hand by commercial divers, causing no damage to the seafloor and little to no bycatch. Criterion Points Final Score Color Life History Abundance Habitat Quality and Fishing Gear Impacts Management 3.25 Bycatch 3.25 Final Score 3.00 Color

2 LIFE HISTORY Core Points (only one selection allowed) If a value for intrinsic rate of increase ( r ) is known, assign the score below based on this value. If no r-value is available, assign the score below for the correct age at 50% maturity for females if specified, or for the correct value of growth rate ('k'). If no estimates of r, age at 50% maturity, or k are available, assign the score below based on maximum age Intrinsic rate of increase <0.05; OR age at 50% maturity >10 years; OR growth rate <0.15; OR maximum age >30 years Intrinsic rate of increase = ; OR age at 50% maturity = 5-10 years; OR a growth rate = ; OR maximum age = years Intrinsic rate of increase >0.16; OR age at 50% maturity = 1-5 years; OR growth rate >0.30; OR maximum age <11 years. Mexican Bay Scallops grow quickly, live for two years and reach 6 cm in length (Haaker et al. 1984; Villalaz and Gomez 1997). Sexual maturity is reached between 6 and 12 months (Tripp-Quezada 1985; Villalaz and Gomez 1997) and around 5.8 cm length (Villalejo-Fuerte and Ochoa-Baez 1993). Points of Adjustment (multiple selections allowed) Species has special behaviors that make it especially vulnerable to fishing pressure (e.g., spawning aggregations; site fidelity; segregation by sex; migratory bottlenecks; unusual attraction to gear; etc.) Species has a strategy for sexual development that makes it especially vulnerable to fishing pressure (e.g., age at 50% maturity >20 years; sequential hermaphrodites; extremely low fecundity) Species has a small or restricted range (e.g., endemism; numerous evolutionarily significant units; restricted to one coastline; e.g., American lobster; striped bass; endemic reef fishes). Mexican Bay Scallops are distributed from Cedros Island and the Gulf of California to Paita, Peru in the Pacific Ocean (Keen 1971), in waters ranging from 1 to 135 m deep (Villalaz 1992). They are found on both sides of the Baja California Peninsula in Mexico (Cruz and Ibarra 1998). We consider this a small range.

3 -0.25 Species exhibits high natural population variability driven by broad-scale environmental change (e.g. El Nino; decadal oscillations). There is some evidence that broad-scale environmental changes impact Mexican Bay Scallops, as abundance often increases with La Nína weather patterns (Rosa-Meza 2005). The abundance of Mexican Bay Scallops is also influenced by the population dynamics of pelagic red crabs. Research suggests the establishment of Mexican Bay Scallop beds is linked to the recruitment period of this crab, which coincides with the Mexican Bay Scallops migratory cycle, which is dependent on the presence of cold waters from the California current (Maeda-Martínez et al. 1993; Leija-Tristán et al. 1996) Species does not have special behaviors that increase ease or population consequences of capture OR has special behaviors that make it less vulnerable to fishing pressure (e.g., species is widely dispersed during spawning) Species has a strategy for sexual development that makes it especially resilient to fishing pressure (e.g., age at 50% maturity <1 year; extremely high fecundity). Mexican Bay Scallops are hermaphrodites, meaning one scallop can release both sperm and eggs during a single spawning period (Villalaz 1992). Spawning can occur over several months, with maximum activity occurring from December to March in Baja California Sur (Haaker et al. 1984; Villalejo-Fuerte and Ochoa-Baez 1993) and northern Baja Magdalena (Felix-Pico et al. 1997). In central Baja Magdalena, spawning occurs from April to May and in August (Felix-Pico et al. 1997). Peak spawning occurs when water temperatures are between 16 and 22 C and with between 630 to 760 minutes of daily average illumination per month (Villalejo-Fuerte and Ochoa-Baez 1993). Mexican Bay Scallops can produce between 2 to 3 million eggs (Monsalvo-Spencer 1998) Species is distributed over a very wide range (e.g., throughout an entire hemisphere or ocean basin; e.g., swordfish; tuna; Patagonian toothfish) Species does not exhibit high natural population variability driven by broad-scale environmental change (e.g., El Nino; decadal oscillations) Points for Life History

4 ABUNDANCE Core Points (only one selection allowed) Compared to natural or un-fished level, the species population is: 1.00 Low: Abundance or biomass is <75% of BMSY or similar proxy (e.g., spawning potential ratio) Medium: Abundance or biomass is % of BMSY or similar proxy; OR population is approaching or recovering from an overfished condition; OR adequate information on abundance or biomass is not available. Mexican Bay Scallops have been commercially fished for over 100 years, with large declines in abundance in some areas (Sealifebase, 2011). Fishing of Mexican Bay Scallops began in Mexican waters in 1972 and today, most Mexican Bay Scallops are fished from Magdalena Bay where they are not considered overfished, with catch rates stable over the past 10 years (Anonymous personal communication, 2011). Because published information about their abundance is lacking, a score of 2 was awarded High: Abundance or biomass is >125% of BMSY or similar proxy. Points of Adjustment (multiple selections allowed) The population is declining over a generational time scale (as indicated by biomass estimates or standardized CPUE). The abundance of Mexican Bay Scallops decreased considerably since the start of the fishery over 100 years ago (Sealifebase, 2011). However, their abundance at least in the main fishing area appears to be stable, so no points were subtracted Age, size or sex distribution is skewed relative to the natural condition (e.g., truncated size/age structure or anomalous sex distribution). There is no published information about the age, sex and size distributions of Mexican Bay Scallops, so no points were subtracted Species is listed as "overfished" OR species is listed as "depleted", "endangered", or "threatened" by recognized national or international bodies Current levels of abundance are likely to jeopardize the availability of food for other species or cause substantial change in the structure of the associated food web The population is increasing over a generational time scale (as indicated by biomass estimates or standardized CPUE).

5 +0.25 Age, size or sex distribution is functionally normal Species is close to virgin biomass Current levels of abundance provide adequate food for other predators or are not known to affect the structure of the associated food web. Mexican Bay Scallop predators include fishes such as red snapper, snails, octopus and crabs (Villalaz and Gomez 1997; Ministerio de Desarrollo Agropecuario 2004). Mexican Bay Scallops feed on particulate organic matter (POM) of both phytoplanktonic and nonphytoplanktonic sources (Martinez-Lopez and Garate-Lizarraga 1994). The impact of Mexican Bay Scallops population size on the associated food web is not known, so we have not added any points Points for Abundance HABITAT QUALITY AND FISHING GEAR IMPACTS Core Points (only one selection allowed) Select the option that most accurately describes the effect of the fishing method upon the habitat that it affects 1.00 The fishing method causes great damage to physical and biogenic habitats (e.g., cyanide; blasting; bottom trawling; dredging) The fishing method does moderate damage to physical and biogenic habitats (e.g., bottom gillnets; traps and pots; bottom longlines) The fishing method does little damage to physical or biogenic habitats (e.g., hand picking; hand raking; hook and line; pelagic long lines; mid-water trawl or gillnet; purse seines). Mexican Bay Scallops are collected by commercial divers, using hooka s, at depths ranging from m (Maeda-Martínez et al. 1993; INP 2004). Divers collect the scallops by hand causing little damage to bottom habitat (Anonymous personal communication 2011).

6 Points of Adjustment (multiple selections allowed) Habitat for this species is so compromised from non-fishery impacts that the ability of the habitat to support this species is substantially reduced (e.g., dams; pollution; coastal development) Critical habitat areas (e.g., spawning areas) for this species are not protected by management using time/area closures, marine reserves, etc No efforts are being made to minimize damage from existing gear types OR new or modified gear is increasing habitat damage (e.g., fitting trawls with roller rigs or rockhopping gear; more robust gear for deep-sea fisheries) If gear impacts are substantial, resilience of affected habitats is very slow (e.g., deep water corals; rocky bottoms) Habitat for this species remains robust and viable and is capable of supporting this species. Magdalena Bay is located in Southern Baja California, Mexico and is the largest natural deep-water bay in Baja California (Hastings and Fischer 2001). The Mexican Bay Scallop is fished commercially from Mexico to Ecuador (Medina et al. 2007). The central and northern areas of Magdalena Bay have been greatly impacted by ecotourism, commercial fishing, boating, and pollution, while the southern and outer areas remain more pristine because of their remoteness (Hastings and Fischer 2001). There does not appear to be a loss of habitat due to non-fishing sources in the areas fished for Mexican Bay Scallops (Anonymous personal communication 2011). The state attempts to preserve habitat in this area and controls pollution through the use of shucking stations, which use port-a-potty units, and bury the waste in the dessert (Anonymous personal communication 2011). It appears that water temperature is an important determinant of growth for Mexican Bay Scallops, with the optimal temperature range being 19 to 22 C (Sicard et al. 1999). Mexican Bay Scallops settle and attach to submerged vegetation, with allows for protection from predators as well as increased recruitment and survival (Felix-Pico et al. 1989; Ekman 1987; Pohle et al. 1991). Mexican Bay Scallops are commonly found over muddy-sandy bottoms with crushed shells (Tristán et al. 1996) and in shallow bays and estuaries that contain eelgrass beds (Haaker et al. 1988). It is thought that eelgrass beds may serve as nursery grounds to Mexican Bay Scallops (Santamaria et al. 1999) Critical habitat areas (e.g., spawning areas) for this species are protected by management using time/area closures, marine reserves, etc. Magdalena Bay is broken into different sections and certain areas can be closed to Scallop fishing during different times of the year. For example, in 2009 three quarters of

7 the bay was closed to protect small Scallops (Anonymous personal communication 2011) Gear innovations are being implemented over a majority of the fishing area to minimize damage from gear types OR no innovations necessary because gear effects are minimal. Gear innovations are not needed because the gear effects are minimal If gear impacts are substantial, resilience of affected habitats is fast (e.g., mud or sandy bottoms) OR gear effects are minimal Points for Habitat Quality and Fishing Gear Impacts MANAGEMENT Core Points (only one selection allowed) Select the option that most accurately describes the current management of the fisheries of this species Regulations are ineffective (e.g., illegal fishing or overfishing is occurring) OR the fishery is unregulated (i.e., no control rules are in effect) Management measures are in place over a major portion over the species' range but implementation has not met conservation goals OR management measures are in place but have not been in place long enough to determine if they are likely to achieve conservation and sustainability goals Substantial management measures are in place over a large portion of the species range and have demonstrated success in achieving conservation and sustainability goals. In Mexico, the National Commission on Aquaculture and Fisheries (CONAPESCA) manages all fisheries (Cheffee 2004; OCED 2010). The National Institute of Fisheries provides scientific advice to the CONAPESCA and each state has a Fisheries Committee that presents information to stakeholders and relays recommendations back to the CONAPESCA (Cheffee 2004). The General Inspection and Supervisory Department makes sure the legal framework and standards are met (OCED 2010). In Magdalena Bay, Mexican Bay Scallops can be harvested from April through the middle of December and there are required vessel licenses and some shell size/meat count limits exist (INP 2004;

8 Seafish 2008). If catches become lower than 5,000 t in Baja California Sur, than management will take additional measures to protect the population (INP 2004). Points of Adjustment (multiple selections allowed) There is inadequate scientific monitoring of stock status, catch or fishing effort Management does not explicitly address fishery effects on habitat, food webs, and ecosystems This species is overfished and no recovery plan or an ineffective recovery plan is in place Management has failed to reduce excess capacity in this fishery or implements subsidies that result in excess capacity in this fishery There is adequate scientific monitoring, analysis and interpretation of stock status, catch and fishing effort Management explicitly and effectively addresses fishery effects on habitat, food webs, and ecosystems. Managers in Magdalena Bay address fishing effects on habitat, food webs and ecosystems (Anonymous person communication 2011). For example, the fisheries department studies the relationship between crabs and scallops, and tests for the adequacy of the food supply and sustainability of all species in the area (Anonymous personal communication 2011) This species is overfished and there is a recovery plan (including benchmarks, timetables and methods to evaluate success) in place that is showing signs of success OR recovery plan is not needed Management has taken action to control excess capacity or reduce subsidies that result in excess capacity OR no measures are necessary because fishery is not overcapitalized Points for Management

9 BYCATCH Core Points (only one selection allowed) Select the option that most accurately describes the current level of bycatch and the consequences that result from fishing this species. The term, "bycatch" used in this document excludes incidental catch of a species for which an adequate management framework exists. The terms, "endangered, threatened, or protected," used in this document refer to species status that is determined by national legislation such as the U.S. Endangered Species Act, the U.S. Marine Mammal Protection Act (or another nation's equivalent), the IUCN Red List, or a credible scientific body such as the American Fisheries Society Bycatch in this fishery is high (>100% of targeted landings), OR regularly includes a "threatened, endangered or protected species." 2.00 Bycatch in this fishery is moderate (10-99% of targeted landings) AND does not regularly include "threatened, endangered or protected species" OR level of bycatch is unknown Bycatch in this fishery is low (<10% of targeted landings) and does not regularly include "threatened, endangered or protected species." Mexican Bay Scallops are harvested by commercial divers and therefore bycatch is very limited but may consist of other scallop species (Seafish 2008; Anonymous personal communication 2011). Points of Adjustment (multiple selections allowed) Bycatch in this fishery is a contributing factor to the decline of "threatened, endangered, or protected species" and no effective measures are being taken to reduce it Bycatch of targeted or non-targeted species (e.g., undersize individuals) in this fishery is high and no measures are being taken to reduce it Bycatch of this species (e.g., undersize individuals) in other fisheries is high OR bycatch of this species in other fisheries inhibits its recovery, and no measures are being taken to reduce it. Mexican Bay Scallops are caught as bycatch in the shrimp fishery, which operates from September to January (Anonymous personal communication 2011). However, the amount of bycatch is unknown so we have not subtracted any points The continued removal of the bycatch species contributes to its decline.

10 +0.25 Measures taken over a major portion of the species range have been shown to reduce bycatch of "threatened, endangered, or protected species" or bycatch rates are no longer deemed to affect the abundance of the "protected" bycatch species OR no measures needed because fishery is highly selective (e.g., harpoon; spear). Magdalena Bay is part of the El Vizcaino Biosphere, which was created by Presidential decree in 1988 and protects two areas used by gray whales in Baja California Sur (Parkswatch 2011) There is bycatch of targeted (e.g., undersize individuals) or non-targeted species in this fishery and measures (e.g., gear modifications) have been implemented that have been shown to reduce bycatch over a large portion of the species range OR no measures are needed because fishery is highly selective (e.g., harpoon; spear) Bycatch of this species in other fisheries is low OR bycatch of this species in other fisheries inhibits its recovery, but effective measures are being taken to reduce it over a large portion of the range The continued removal of the bycatch species in the targeted fishery has had or will likely have little or no impact on populations of the bycatch species OR there are no significant bycatch concerns because the fishery is highly selective (e.g., harpoon; spear) Points for Bycatch REFERENCES Cheffe, C An MSC assessment of the red rock lobster fishery Baja California, Mexico. Final report, Scientific Certification Systems, Inc. 198 p. Cruz, P. and Ibarra, A.M Larval growth and survival of two catarina scallops (Argopecten circularis, Sowerby 1835) populations and their reciprocal crosses. Journal of Experimental Marine Biology and Ecology 212: Ekman, J.E The role of hydrodynamics in recruitment, growth and survival of Argopecten irradians (L.) and Anomia simplex (D. Orbigny) with eelgrass meadows. Journal of Experimental Marine Biology and Ecology 106: Felix-Pico, E., Tripp-Quezada, A. and Singh-Cabanillas, J Antecedentes en el cultivo de Argopecten circularis (Sowerby) en Baja California Sur, Mexico. Investigaciones Marinas CICIMAR 4:75-92.

11 Felix-Pico, E Estudio biologico de la almeja Catarina, Argopecten circularis (Sowerby, 1835) en Bahia Magdalena, B.C.S. Mexico. Tesis de Maestría Instituto Politecnico Nacional, Centro Interidsciplinario de Ciencias Marinas. 103 p. Felix-Pico, E.F., Tripp-Quezada, A., Castro-Ortiz, J.L., Serrano-Casillas, G., Gonzalez-Ramirez, P.G., Villalejo-Fuerte, M., Palomares-Garcia, R., Garcia-Domingues, F.A., Mazon-Suastegui, M., Bojorquez-Verastica, G. and Lopez-Garcia, G Repopulation and culture of the Pacific Calico Scallops in Bahia Conception, Baja California Sur, Mexico. Aquaculture International 5: Haaker, P.L., Duffy, J.M, Henderson, K.C. and Parker, D.O The speckled scallop, Argopecten circularis, in Agua hedionda lagoon, San Diego County, California. California Department of Fish and Game. 39p. Hastings, M.R. and Fischer, D.W Management priorities for Magdalena Bay, Baja California, Mexico. Journal of Coastal Conservation 7: Instituto Nacional de Pesca (INP) Update 2004 national fisheries. Online: google.com/translate?hl=en&sl=es&u= ticle/17-publicaciones/74-carta-nacional-pesquera&prev=/search%3fq%3dinp%2bmexico%26 hl%3den%26client%3dfirefox-a%26rls%3dorg.mozilla:en-us:official&rurl=translate.google. com&twu=1 Keen, A.M Sea Shells of Tropical West America. Stanford University Press. Second Edition. Stanford, California, USA. 208: 1064 p. Leija-Tristán, A., Solis-Marin, F.A., Aurioles-Gamboa, D. and Amador-Silva, E.S Natural stocks of the scallop Argopecten circularis, and relationships with the galateid crab Pleuroncodes planipes in the Pacific coast of Baja California Sur, Mexico. Cahier de Biologie Marine 37: Maeda-Martínez, A.N., Reynoso-Granados, T., Solís-Marín, F., Leija-Tristán, a., Aurioles- Gamboa, D., Salinas-Zavala, C., Lluch-Cota, D., Ormart-Castro, P. and Felix-Pico, E A model to explain the formation of catarina scallop, Argopecten circularis (Sowerby, 1835), beds, in Magdalena Bay, Mexico. Aquaculture Research 24: Martinez-Lopez, A. and Garate-Lizarraga, I Quantity and quality of the particulate organic matter in Conception Bay during the spawning season of the scallop Argopecten circularis (Sowerby, 1835). Ciencias Marinas, Ensenada 20: Medina, B., Guzman, H.M., Mair, J.M Failed recovery of a collapsed scallop fishery in Las Perlas Archipelago, Panama. Journal of Shellfisheries Research 26:9-15. Ministerio de Desarrollo Agropecuario Bases tecnologicas para el cultivo de la Conchuela en la Republica de Panama.

12 Monsalvo-Spencer, P Estudios sobre el cultivo de larvas y juveniles de almeja catarina Argopecten ventricosus (=circularis) (Sowerby II, 1842) en el laboratorio. Tesis de Maestría Centro Interdisciplianrio de Ciencias Marinas IPN, La Paz Baja California, Mexico. 90 p. Organization for Economic Co-operation and Development (OCED) Country note on national fisheries management systems-mexico, pp In: Review of fisheries in OECD countries 2009, policies and summary statistics. OCED Publishing. Parkswatch &page=sum Pohle, D.G., Bricelji, V.M. and Garcia-Esquivel, Z The eelgrass canopy: an above-bottom refuge from benthic predators for juvenile bay scallops Argopecten irradians. Marine Biology Progress Series 74: Rosa-Meza, K Fauna de Acompaňamiento del Camarón en Bahía Magalena, B.C.S. México. Tesis de Maestría, Centro Interdisciplinario de Ciencias Marinas IPN. 75 p. Santamaría-Gallegos, N.A., Esteban F. Félix-Pico, José L. Sánchez-Lizaso, J. Ricardo Palomares-García and Manuel Mazón Suástegui Temporal coincidence of the annual eelgrass Zostera marina and juvenile scallops Argopecten ventricosus (Sowerby II, 1842) in bahía Concepción, México. J. Shellfish Research, 18(2): Seafish Responsible sourcing guide: scallops. Version 1, May p. Sealifebase (2011) Pacific Calico Scallop, Argopecten ventricosus, summary/speciessummary.php?id=47326 Sicard, M.T., Maeda-Martinez, A.N., Ormart, P., Reynoso-Granados, T. and Carvalho, L Optimum temperature for growth in the catarina scallop (Argopecten ventricosus-circularis, Sowerby II, 1984). Journal of Shellfish Research 18: Shumway, S.E. and Parsons, G.J Scallops: biology, ecology and aquaculture. Elsevier, Amsterdam, Netherlands. Tripp-Quezada, A Explotación y cultivo de la almeja catarina Argopecten circularis in Baja California Sur. Tesis de Maestria, Centro Interdisciplinario de Ciencias Marinas-IPN, La Paz, B.C.S., Mexico. United Nations Environment Programme- World Conservation Monitoring Centre (UNEPWCMC) Islands and protected areas of the Gulf of California, Mexico. Online: o Villalaz, J Reproductive biology of Argopecten circularis. University of Delaware, Newark. Ph.D. thesis. 100 p.

13 Villalaz, J.R. and Gomez, J.A The history, present condition and the future of molluscan fisheries of Panama, In: C.L. Mackenzie, A. Rosenfield, and, W.L. Hobart (eds), The history, present conditions and future of molluscan fisheries of North and Central American and Europe. US Department of Commerce, NOAA Technical Report NMFS 128. Villalejo-Fuerte, M. and Ochoa-Baez, R The reproductive cycle of the scallop Argopecten circularis (Sowerby, 1835) in relation to temperature and photoperiod, in Bahia Concepcion, B.C.S., Mexico. Ciencias marinas, Ensenada 19: