Dear colleagues,

We are pleased to announce the publication of a new paper in Deep Sea Research Part II that may be of your interest.
 
Foraging behavior of lactating South American sea lions (Otaria flavescens) and spatial-temporal resource overlap with the Uruguayan fisheries
Federico G. Riet-Sapriza, Daniel P. Costa, Valentina Franco-Trecu, Yamandú Marín, Julio Chocca, Bernardo González, Gastón Beathyate, B. Louise Chilvers, Luis A. Hückstadt
http://dx.doi.org/10.1016/j.dsr2.2012.09.005

ABSTRACT
The negative impacts of the resource competition between fisheries and marine mammal continue to raise concern worldwide. In order to measure the impact, data on spatial and dietary overlap of marine mammal and fisheries are needed. In Uruguay the South American sea lions population has been dramatically declining over the past decade. The reasons for this population decline are unknown but may include the following: (1) direct harvesting; (2) reduced prey availability and distribution as a consequence of environmental change; or (3) biological interaction with fisheries or with the sympatric South American fur seal. Understanding the extent of the impact of the fisheries overlap or competition for finite food resources on the sea lion population recovery is necessary for effective sea lion conservation efforts and fisheries management. This study aims to determine resource overlap and competition between South American sea lions (SASL, Otaria flavescens) and the artisanal fisheries (AF), and the coastal bottom trawl fisheries (CBTF). This is conducted by integrating sea lions diet (scat analysis), spatial and annual consumption estimates; and foraging behavior-satellite-tracking data from lactating SASL with data on fishing effort areas and fisheries landings. Lactating females (n =10) were fitted with satellite tags and Time-depth recorders. We used kernel (KR) and peeled minimum convex polygon (95% MCP) methods for estimating the foraging utilization distribution of lactating SASL. Lactating SASL are benthic divers and are restricted to forage in shallow waters within the continental shelf. SASL’s foraging areas overlapped with CBTF (15%) and AF (>1%) fisheries operational areas. In contrast, SASL dietary analysis indicated a high degree of overlap between the diet of SASL and the AF and CBTF fisheries catch. The results of this work show differing degrees of spatial resource overlap with AF and CBTF, highlighting a) differences in potential impact from each fishery; and b) that different management/conservation approaches may need to be taken to solve the fisheries-SASL conflict.