Assessment of recreational harvesting of the trigonal clam Tivela mactroides: Socioeconomic aspects and environmental perception

Author(s)

Turra, Alexander ^[1] ; Xavier, Luciana Yokoyama ^[1] ; Pombo, Maira ^[1] ; Paschoal, Camila de Carvalho ^[2] ; Denadai, Marcia Regina ^[2]

Affiliation

^[1] Univ Sao Paulo, Inst Oceanog, Dept Oceanog Biol, BR-05508120 Sao Paulo, SP - Brazil

^[2] Ctr Univ Modulo, BR-11660903 Caraguatatuba, SP - Brazil

• Document type: Journal article
• Source: Fisheries Research; v. 174, p. 58-67, FEB 2016.
• Web of Science Citations: 5

Abstract

Although it is one of the major threats to sandy beach ecosystems, the impact of harvesting on marine invertebrates is poorly understood, especially considering that recreational harvesting is practiced with little or no management on beaches worldwide. Current management strategies not only target economically valuable resources and focus on biological aspects of harvested populations, but they also tend to neglect socioeconomic information such as the profile, behavior, consumption characteristics of harvesters and their perception of threats to their activities, all of which are little studied. This study evaluated the social aspects of harvesting of the clam Tivela mactroides, based on semi-structured interviews carried out at Caraguatatuba Bay, Sao Paulo, Brazil, during two sampling periods between 2003 and 2008. This cultural activity has continued for decades, with the continual entry of new harvesters, and the harvesters' profile and methods varied little over time. Clammers do not depend economically on the resource, use clams mainly for family consumption, harvest them with low frequency, prefer free time periods (for subsistence) and invest little in developing more-efficient harvesting strategies, such as criteria for selecting the harvesting area and more-efficient tools. The clammers showed little awareness of the problems related to harvesting of T. mactroides and the risks associated with its consumption, despite local threats such as episodes of poor water quality and oil spills. Changes in stock abundance did not affect the socioeconomic profile or collecting behavior of clammers, and there was no evidence that harvesting pressure affects fluctuations in the clam stock. An alternate ecosystem-based management approach could include improvement of environmental quality, to guarantee food security for low-income families and food safety for all consumers, instead of traditionally employed resource-based restrictive practices, since clam collecting in Caraguatatuba Bay is a low-impact socio-cultural activity. These findings emphasize that managers of subsistence and recreational activities should not focus only on the potential environmental problems caused by exploitation, but may also benefit from understanding the harvesters, harvesting procedure and consumption estimates, as well as the sociocultural role of and threats to these activities. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/21804-3 - Integrating consistent individual differences theory into ecological and evolutionary studies related to global and local environmental change
• Grantee: Alexander Turra
• Support Opportunities: Research Grants - Visiting Researcher Grant - International