Can stable isotopes be applied to determine shrimp stocks origin in SE Brazil? An approach for utilization in fishery management

Abstract

Stable isotopes of carbon (13C) and nitrogen (15N) are chemical markers used to trace the geographic origin of species targeted by commercial fisheries, helping in fishery management strategies. Considering the extension of Brazilian coastline, approaches for shrimp stock discrimination may assist local fisheries. This study characterizes the isotopic composition in natural stocks of the penaeid shrimps Xiphopenaeus kroyeri, Artemesia longinaris e Litopenaeus schmitti, targets of small-scale coastal fisheries in SE Brazil. Shrimps were obtained from six fishing ports located on Rio de Janeiro and Espírito Santo coastline (from 18°S to 23°S). δ13C-δ15N distinguished stocks from fishing ports and δ13C had higher variability when compared to δ15N, explaining most of the differences between stocks for all species. This study presents a participatory planning for local fishery management with stakeholders (fishers, public managers and researchers) working together. The planning aims to minimize possible conflicts between near fishing communities through the identification of fishery boundaries, maintaining the fishing territories, and to promote the fishery production from a particular community, valuing the local economy. The proposed actions can establish an identity to local fisheries and improve small-scale fisheries governance in SE Brazil.