Search

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The trajectory of the cannonball jellyfish (Stomolophus sp. 2) fishery in the central portion of Mexico's Gulf of California is an all too familiar one, consisting of exploration, rapid development, and, as of now, subsequent collapse. As all of the product is exported to markets overseas, buyers have little incentive to conserve local stocks, with jellyfish now exhibiting a global-scale sequential exploitation experienced by many other marine resources. While historical data gaps are often used as excuses for overexploitation after the fact, the emergence of this modern fishery was accompanied by relatively broad research interest; however, recommendations based on sound science were not followed. The resultant paucity of policy goals, regulation, cooperation, compliance, and enforcement has resulted in the mismanagement of a potentially lucrative fishery for future generations. There are always myriad challenges when attempting to manage a nascent fishery with high uncertainty, particularly in a developing country, and this case further highlights the importance of taking a precautionary approach to emerging resource extraction. Multiple prior experiences with similar outcomes should behoove regulators and managers to exhibit extra caution, and yet, sustainability and forethought still appear to be secondary to short-term profits and employment support. Nonetheless, it is perhaps not too late for cannonball jellyfish fisheries in the Gulf of California, and there are opportunities to implement management strategies that promote collaboration, research, and sustainability. This fishery requires a new management regime that embraces adaptive co-management in order to provide benefits to locals, both now and in the future. • Jellyfish are targeted for food exports in Mexico's Gulf of California. • Catches for one of the targeted species have declined, possibly due to overfishing. • Management challenges are complex due to natural and social factors. • Future strategies should include stakeholder collaboration and adaptive co-management. [ABSTRACT FROM AUTHOR]

Abstract: Constant harvest rate as a management strategy for the Pacific sardine (Sardinops caeruleus) fishery in the Gulf of California is supported by an analysis of variations in the catchability coefficient (q), stock abundance and commercial catch. Catchability was analyzed based on population length-structured data standard length (SL), expressed as CPUE, for 26 fishing seasons (1972–1973 to 1997–1998). We used a deterministic model of catchability to estimate the catchability-at-length assuming catchability depends on length and sardine behavior. Results demonstrated that catchability increases with sardine length, with low values for older sardines (sizes greater than 20.5cm SL), which are poorly represented in catches. Most changes in q-at-length values can be observed within the range of 12.5–15.0cm SL, which corresponded to first maturity and first capture lengths, respectively. Catchability-at-length pattern was represented for an exponential model with adjusted R 2 =0.94. Moreover, we observed an inverse power relationship between catchability and stock abundance with a slope value of β d =−0.58, which indicates the existence of hyperstability or density-dependent catchability. The strong fluctuations in biomass of the Pacific sardine, the pattern of hyperstability, and the current state of the sardine fishery defined to be harvested at the maximum allowable catch, are the rationale for recommending a constant harvest rate as management strategy, with a value of HR=0.29 and maintain the current minimum legal size of capture. [Copyright &y& Elsevier]