Selectivity of three artisanal fishing gears used for the capture of the white shrimp, Litopenaeus schmitti, in the Bay of El Tablazo, Zulia State, Venezuela

Authors: 

Andrade de Pasquier, G., S. Ramírez and J. Delgado

Year: 

2009

Journal/Publisher Name: 

II Foro Iberoamericano de los recursos marinos y la acuicultura

Publisher Address: 

Universidad de Oriente, Cumana, Venezuela

Volume (Issue #): 

2

Page #s: 

295-302

Contact information: 

gandrade@inia.gob.ve
Summary: 

The white shrimp, Litopenaeus schmitti, is one of the fishery resources of greater monetary value in Venezuela. This species represents about 90% of the catch of penaeid shrimp of Lake Maracaibo, where one of the largest populations of the species is found within the area of distribution of the species. The remaining catches are made up of three species of the genus Farfantepenaeus (F. subtilis, F. notialis and F. brasiliensis). The mesh opening of beach seine (BS) or Mandinga used to catch shrimp in Lake Maracaibo and Bay El Tablazo is not regulated and varies between 1 ", ¾" and ½ ". Since 2005 the bottom tangling net (BTN) with mesh opening of 2" started being used for shrimp capture of shrimp in the Bay of the Tablazo. In 2006 the Suripera net (SN) was introduced on an experimental basis in this area with 1" mesh opening. The objective of the present study was to evaluate the composition by length and weight of shrimp caught with these gears. From February to April 2007 the average size of shrimp obtained with the three gears in the Bay of El Tablazo were compared using ANOVA, and the  selectivity curve for each gear was obtained according to Sparre and Venema (1995). It was concluded that there were significant differences between the average sizes of shrimp for each gear. The BTN had a capture of individuals of greater length and weight, with an average size and weight of 14.25 cm and 18,04 g, respectively; followed by the SN with 12,86 cm and 12,80 g and finally the BS with 10,72 cm and 5.72 g. Many of the individuals caught in the BTN and the SN had already reached sexual maturity, and both nets had a low bycatch capture rate (0.26 kg of fish was captured for each kilogram of shrimp). The shrimp caught by these two gear types were mostly adults, which represents higher economic benefits for fishers since larger shrimp have a higher price in the national and international markets. A more sustainable use of resources in Lake Maracaibo would be obtained if the use of the BTN or the SN were implemented in the shrimp fisheries of the region.