Evaluation of determinants of Xiphopenaeus kroyeri (Heller, 1862) catch abundance along a Southwest Atlantic subtropical shelf

Abstract

Generalized linear models were applied to identify factors affecting the capture rates (catch per unit effort, cpue) of Xiphopenaeus kroyeri and to estimate time-series data with standardized abundance indices. The adjusted models revealed that the most powerful vessels (with greater HP) were up to 3.5 times more efficient than vessels with less powerful engines. The seasonal variation of the resource changed from year to year, most likely due to variations in the recruitment season and the timing of temporary fishing bans. The variation of cpue was similar between the northern and southern sectors of the study area. In these, X. kroyeri abundances increased in the years 1996, 1997, 2001 and 2002, while in the central sector, the cpue fluctuated with a period duration of approximately two years. During the period, the relative abundance of the species displayed neither a decreasing nor an increasing trend, indicating that this has been harvested at stable levels. However, X. kroyeri stock was reduced by overfishing during the 1980s and exhibits variations in abundance that may occur in response to environmental fluctuations; thus, the harvesting of this species should be managed with extreme caution.

Spatial patterns of fishing fleets on the Southeastern Brazillian Bight

“…Fluctuations in population size of X. kroyeri are related to variations in water temperature and fluvial outflow that affect recruitment (Kolling, 2011;Kolling & Ávila-da-Silva, 2014).…”

“…Shrimp X. kroyeri, which supports a traditional and relevant trawling fisheries (Kolling & Ávila-da-Silva, 2014), and the sciaenid fish M. atricauda, which also figures among the main resources landed in São Paulo, were mostly caught at depths down to 20 m. X kroyeri inhabits sandy and muddy bottoms down to 30 m depth (Iwai, 1973). M. atricauda occurs down to 60 m, but it is concentrated along the 20 m isobath (Carneiro & Castro, 2005).…”

“…The determination of spatial patterns of fishing exploitation was addressed in the studies conducted by Carneiro et al (2000), Kolling et al (2008), Mourato et al (2011 and Kolling & Ávila-da-Silva (2014). However, unified assessments of marine space occupation for both artisanal and industrial fleets are not available yet.…”

The loss of fishing territories in coastal areas: the case of seabob-shrimp small-scale fisheries in São Paulo, Brazil

“…Despite all the problems, the seabob shrimp stock's CPUE has remained reasonably stable over the last decade, suggesting that overfishing is not in place at least for the target species (Mendonça et al 2013;Kolling and Avila-da-Silva 2014). A minimum revenue of R$3.00 per kilogram caught by the small-scale fleet was reported as an average in 2008 (Souza et al 2009a).…”