Chapter 29 - Scallop Fisheries and Aquaculture in Mexico

Abstract

This chapter describes the three most important Mexican scallop species (lion's paw: Nodipecten subnodosus; Pacific calico scallop: Argopecten ventricosus; Vogde's scallop: Euvola vogdesi), their ecology, fisheries and aquaculture. All commercially important scallops in Mexico occur in the Pacific Northwest and Gulf of California, especially in the lagoon systems along the coast in shallow waters to depths of about 100 m. The three scallop species are fast growing, reproduce early in life, and form large banks that have been commercially exploited over the past decades by hooka-diving from small fibreglass skiffs with outboard engines. As happened in many scallop fisheries around the world, exploitation is characterised by boom and bust phases. Commercial fisheries of Mexican bay scallop started in the early 1980s and represented the most important mollusc fishery in the country from 1985 to 2013, when the banks in Magdalena bay were diminished so much, that the fishery was closed. Vogde's scallop was only locally exploited for a short time, the lion's paw, however, has sustained a small commercial fishery in Ojo de liebre and Guerrero Negro lagoons from the early 1990s to 2010 with a maximum production of about 150 mt of meats. In 2010, the population crashed, probably due to a disease, the cause of which is still being investigated. This species was also fished at different sites in the Gulf of California (Loreto, Bahia de Kino), but on a much smaller scale. Today, all scallop fisheries in Mexico are in a serious crisis and are deemed unsustainable. Therefore, large efforts have been undertaken to develop commercial aquaculture of A. ventricosus and N. subnodosus. While hatchery techniques for the former are fully developed and commercial spat production has been accomplished routinely, hatchery production of the latter is still on a small scale, and no commercial spat supply is as yet available, despite a large number of scientific studies on the subject. Small-scale pilot and commercial cultures of both species have been conducted at >15 sites on the Baja California Peninsula and the coasts of Sonora and Sinaloa over the past two decades, with varying results. No active scallop cultures are in operation as of 2015, which shows that they have not been commercially viable for the most part. Lack of spat production, site selection, El Nino years, diseases, handling, market failures, competition with the capture fishery and mismanagement have been quoted as possible reasons, and the Mexican government does not have a comprehensive programme to promote scallop aquaculture. Unfortunately, the large body of scientific studies on scallop aquaculture in Mexico has not translated into an economic alternative for the aquaculture and fishing industry in the region. As fisheries in the region are clearly in decline, efforts should be strengthened to promote sustainable aquaculture of native species and thereby improve the livelihood of coastal communities.