Pesca de Peixes com linha e rede no Estado do Ceará

Abstract

Fishing has assumed a very important role in Ceará State’s economy as a source of income and food for a sizable share of its population, especially the one that lives on the coastal zone. and makes up its fishing communities. The fishery sector has always been known mainly because of the lobster resources, whereby far less information has been made available for fiifish exploitable stocks. This research work has a database which has been regularly controlled by the IBAMA office at Ceará State, comprising the surveillance of 267,458 landings and 289,739 reports on fishing effort statistics over the period from 1999 to 2008. Its primary objective is to provide a detailed investigation on the productivity of the fish fisheries with hook-and-line and gill nets, operated by small- and medium-scale motorboats and sail rafts and canoes. The main methodological tools entail the setting up of correlations between, on one hand, biological indicators of abundance, frequency and dominance of individual species within the biocenosis and catch rates of the outstanding ones, and on the other, main fishing grounds, county-based landings, seasonal changes, monthly periods and types of fishery, by means of a theoretical framework that comprises non parametric statistical methods, analysis of correspondence and hierarchic grouping analysis. Under the space dimension, the results point out to the western fishing area (51.10%) and Camocim county (42.94%) as the ones with the highest abundance indices. Under the time dimension, the rainy season (58.44%) and the first quarter stand out both in fish numbers and biomass. As to species, king mackerel (18.36%%), yellowtail snapper (18.26%) and Caribbean red snapper (8.21%) are the most abundant in biomass, and Atlantic thread-herring (32.36%), white grunt (18.94%) and yellowtail snapper (18.49%), in numbers. Lane snapper (33.22%), white grunt (25.14%) and king mackerel (21.17%) are the most frequent species in the landings. As concerns dominance, eight species were shown to conform to this condition, among which stand out yellowtail snapper (41.87%), Atlantic thread-herring (22.01%), white grunt (12.26%) and king mackerel (6.69%). The dominance indices have also been discussed as far as the time-space dimensions are concerned, on the basis of the results presented as to fishing ground and climate season. The outcome of the technological dimension analysis, fishery as the chosen attribute was broken down by the two types of fishing craft: sail boat units and motorboat units. In both cases, the analyses were carried out in respect to fishing ground, climate season and annual cycle. The results point out to the western fishing area and Camocim county as the ones with the highest abundance indices either by sail craft or motor craft types, and for each one of them hook-and-line fishing trips were shown to be more productive than the gill net ones. Individually, the big-sized motorboat and sailboat yielded the largest mean catch rates, namely 145.03 kg per day’s fishing and 34.72 kg per day’s fishing, respectively. In the overall analysis of each craft category a synoptic chart is presented with directions for the attainment of the highest catch rates as a function of the space and time dimensions. Among the main conclusions of this research work stand out the following: a) under the space dimension the western fishing area is the most important; b) under the time dimension the rainy season accounts for a higher abundance and the dry season, for a higher productivity; c) under the technological dimension the hook-and-line fisheries are more productive than the gill net fisheries.