Abstract

GONZALEZ, Ángel; MENDOZA, Jeremy; AROCHA, Freddy  and  MARQUEZ, Arístide. Rate exploitation and sustainable harvest of Pseudoplatystoma fasciatum in the sector Orinoco Caicara-Cabruta. Zootecnia Trop. [online]. 2012, vol.30, n.2, pp.155-168. ISSN 0798-7269.

We evaluated the level of exploitation of Pseudoplatystoma fasciatum in the Caicara-Cabruta Orinoco sector using the analytical model of Thompson and Bell and the length of the fi sh landed by the main fi shing port in the region between January 2007 and December 2008. Total mortality Z was determined by different methods: catch curve, Beverton and Holt and Sssentongo and Larkin while natural mortality M was calculated using the empirical equations by Pauly, Rikhter and Efanov, Srinath and Alverson and Carney. The values of Z and M used to estimate the rate of exploitation and application of the Thompson and Bell model were selected by using the averages and confi dence intervals obtained from each method. Maximum sustainable yield (MSY) and fi shing mortality F was established from the yield per recruit curve, using the benchmark F_0.1. Biomass per recruit and spawning biomass per recruit was also determined using as reference points F_50% and F_40%, respectively. Z values were between 0.31 (0.29 to 0.34) according Beverton and Holt and 0.35 (0.34-0.37) according Ssentongo and Larkin while M ranged from 0.12 (0.11 to 0.14) according Srinath and 0.24 (0.22 to 0.26) according Pauly. According to the values of exploitation rate and F estimated in the different scenarios analyzed in the current conditions of capture of P. fasciatum in the Caicara-Cabruta Orinoco sector the species is between heavily exploited and overexploited, requiring the implementation of restrictive measures for proper management

Keywords : fisheries management; fi sheries rivers; Orinoco fi sheries; fi sh stock assessment; large catfi sh Pseudoplatystoma.

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