Baja Scallops.com is a producer of high quality scallops from Mexico.  Our company takes an active role working with both state and federal agencies to assist with the safe use and protection of the resources and promotion of environmental awareness.  We make every effort not to harm or endanger marine life or the delicate ecosystem from which we harvest.  We have been working together with the Mexican National Fisheries Department (INAPESCA) in managing a sustainable fishery for the bays in Baja California.  All of our scallops are diver caught and hand shucked.  Most of our bay scallops come from Magdalena Bay located on the Pacific Ocean.  Magdalena Bay is located at the meeting point of two of the most influential currents of the Eastern Pacific, the cooler California current system from the north – an extension of the Alaska current – and the warmer Equatorial Counter current from the southern Pacific.  Magdalena Bay is one of the richest, if not the richest, estuarine waters of the world.

Also known as catarina scallops, Mexican Bay scallops (Argopecten ventricosus = circularis) reside in the North Pacific and South Pacific oceans from the Baja California Peninsula in Mexico south to Peru.  Along both coasts of the Baja California Peninsula, these scallops are harvested by divers.  A federal law mandates that the National Fisheries Institute (Instituto Nacional de Pesca, INAPESCA) is responsible for performing surveys and stock management, distributing geographically specified permits (required in order to harvest), and setting annual quotas for this fishery.  Although the intrinsic rate of population increase is unknown for this species, other life history characteristics of the Mexican Bay scallop have been well studied.  These scallops have fast growth rates, a short time to maturity (less than 1 year), short lifespan (2–3 years), high reproductive output, and a broad species range.  The habitats of this species in Magdalena Bay and along the coasts of Baja California Sur have been moderately altered, and the species may depend on low temperatures to help establish populations of eelgrass and a certain red crab species that are both beneficial to the Mexican Bay scallop.  Eelgrass beds, specifically, provide suitable substrates for larval recruitment.

The Mexican Bay scallop fishery in the state of Baja California Sur is being harvested at maximum sustainable yield according to the Ministry of Agriculture, Livestock, Rural Development, Fisheries and Food (Secretaría de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación, SAGARPA).  Many fishery measures for assessing the status of wild stocks are unknown, including biomass relative to BMSY, current fishing mortality relative to FMSY, biomass trends, and the current age/size distribution.  The quantity of by-catch from the diver-caught Mexican Bay scallop fishery is minimal because individual scallops are hand harvested by divers using small boats equipped with outboard motors and compressors.  As a result of this method, the effects of the Mexican Bay scallop fishery on the population and ecosystem should also be minimal.  The nature and extent of discarded by-catch in the Mexican Bay scallop fishery is considered to be a low conservation concern.  The shallow mud and sandy bottom habitats of Mexican Bay scallops are moderately resilient; furthermore, the Mexican Bay scallop fishery causes minimal habitat damage because of the nature of the extraction method: hand selection of individual scallops by divers.  The ecosystem and food web impacts of this fishing method are unknown; however, impacts are likely low as the fishery causes minimal habitat damage and the removal of this target species is not known to disrupt the food web.  

The Mexican Bay scallop, Argopecten ventricosus (previously known as A. circularis), is known as the catarina scallop (la almeja catarina) in Mexico and as the Pacific Calico Scallop.  It is an epibenthic bivalve of the family Pectinidae.  Shells vary from almost all white to the inclusion of blotches and streaks of solid dark orange, brown or purple.  The maximum shell length is 81 mm, with an average maximum length of 60 mm.  At 60 mm long, whole weight is about 70 g with the adductor muscle (the edible part) weighing around 8 grams.  The natural distribution of the Mexican Bay scallop ranges from both sides of the Baja California Peninsula in Mexico down to Peru.  A functional protandrous hermaphrodite, the Mexican Bay scallop spawns twice a year by releasing both eggs and sperm into the water where fertilization occurs.  Spawning is seasonal and temperature dependent, with stocks in warmer waters generally spawning twice a year from April–May and September–December, and stocks in colder waters only spawning once a year, around May–June.  The depth range of these scallops is 6–35 m in the bays where they are harvested and up to 150 m in the open ocean.

Mexican Bay scallops are harvested in several locations throughout the states of Baja California and Baja California Sur. This report focuses on the Mexican Bay scallop fishery of Magdalena Bay (Bahía Magdalena) on the Pacific west coast of Baja California Sur. The commercial fishery for these scallops in Magdalena Bay began in 1975.  The Mexican Bay scallop is the most important scallop to the overall scallop fishery in Mexico in terms of weight landed, followed by the Mexican Sea scallop (AKA Lion’s paw scallop).  Harvest of Mexican Bay scallops accounted for over 50% of the total scallop live weight caught in 1986–2001, mostly from Baja California Sur.  The Mexican Bay scallop fishery is regulated by a federal law established in 1993 that set a minimum size limit of 60 mm shell length.  This law also prohibits harvesting these scallops during the spawning season, December 15 – March 31, and specifies that the National Fisheries Institute (Instituto Nacional de Pesca, INAPESCA) is responsible for performing surveys and stock management, setting quotas based on stock assessments, and distributing geographically specified permits that are required in order to harvest.  In practice, surveys and stock assessments are completed by Regional Fishery Centers (Centro Regional de Investigación Pesquera, CRIP) that are subdivisions of INAPESCA.  Organizations or cooperatives apply annually for a permit, and each permit comes with a specified quota.  With the help of fishermen, CRIP conducts stock assessments that include data on densities and size compositions.  Using this data, the maximum sustainable yield (MSY) and resulting quotas are calculated and permits are distributed.  The management reference point for harvest is 40% of the harvestable biomass each year and no more than 60% of the total harvestable biomass from legal-size clams (over 60 mm long).  INAPESCA then sets rules of operation, and inspectors enforce the quotas.  Permit holders are required to report their daily catch by weight to INAPESCA. SAGARPA considers the fishery for Mexican Bay scallops in Magdalena Bay to be at maximum sustainable yield , and recommends against increasing the current fishing effort for Mexican Bay scallops.  Permits are granted to organizations or fishing cooperatives and specify the number of boats and fishing days granted.  Permits generally limit catch to 100 kg of scallop live weight per boat per day.  Individual fishermen apply to work for permit-holding organizations or cooperatives.  The total quota varies annually based on the current stock abundance level assessed by CRIP.  The fishery may even be closed in certain years depending on the status of the stock, which occurred in 1994.  The total quota can vary from 130 kg of meat per boat day to the high of 1,815 kg of meat per boat day seen in past years.  In 2008, there were 55 individual permits and 97 fishing cooperative permits, totaling 152 permits.  In 2009, there were 162 total licenses covering 349 boats, and in 2010, INAPESCA authorized 379 boats to remove 688 tones of Mexican Bay scallops from Magdalena Bay. The only authorized equipment for harvesting this species consists of a small boat with an outboard motor and a compressor to supply air for one diver (also referred to as semi-autonomous or “hookah diving”).  Diving is the only approved method of extraction, and the harvest of scallops by walking out at low tide is prohibited.  Dredging has never been used in this scallop fishery, minimizing both general habitat destruction and by-catch. In most cases, each boat has enough equipment to send down one diver while two others remain on the boat; one driver and another to operate the compressor and assist the diver.  Open season is generally between May and June.  The duration of the open season depends on the annual abundance of the Mexican Bay scallop and ranges from just a few months up to eight months of the year (open all year except for the closed season).  Recommendations have been made to establish rotating banks, limit divers to one per boat, give permits to fishermen in communities closest to the resource, and develop a management plan for the species.  Some illegal fishing occurs, and it is recommended that inspection and monitoring activities be strengthened in order to reduce illegal fishing and guarantee the recovery of the scallop banks.  It is also recommended to establish mechanisms encouraging compulsory filing and the timely delivery of logbooks.