Avaliação da sustentabilidade dos recursos pesqueiros explotados pela pesca de subsistência e comercial em lagos de Varzea

Abstract

The Amazon has a high diversity of fish and fishing is one of the main activities practiced by Amazonian populations, who consume large amounts of fish. The extent, complexity of this ecosystem and the diversity of fisheries make it difficult to assess the fish stock and the amount of fish consumption is not fully known. The objective of this research was to estimate the per capita fish consumption of the community on Ilha da Paciência (Iranduba, Amazonas) and to evaluate the relationship between fish biomass in lakes on the Island and commercial and subsistence fishermen. Ilha da Paciência is under a fishing agreement which regulates the use of lakes and pirarucu fishing. A total of 273 questionnaires were applied during the first two weeks of the month, between April 2021 and March 2022. One fisherman per household was interviewed. The questionnaire contained questions about the species captured and their quantities. Consumption was calculated by dividing the average monthly capture by the average number of residents per household interviewed that was multiplied by the number of questionnaires applied. We used a Rosenzweig-MacArthur predator-prey model and inserted commercial and subsistence fishermen as the predators and the total biomass of fish caught by riverines as the prey. We simulated scenarios by changing some model input values. Capture data were collected by commercial and subsistence fishermen who fish on the Island, as well as the total number of these individuals. The total catch was 3,479.85 kg and the highest monthly catch was 602.60 kg during the receding water in October. Daily per capita fish consumption averaged 70.88 ± 33.29 g/day, with a peak of 122.16 g/day during the low tide in August. The model showed that the fish population of the lakes was maintained with the exploitation of subsistence fishermen from Ilha da Paciência and commercial fishermen over 100 years. The scenarios showed that few fishermen exploring the lakes do not cause stock declines. In the scenario where the number of commercial fishermen was doubled, the prey and subsistence fishermen showed greater fluctuations and lower values compared to the original model and other scenarios. Fishing management carried out in the lakes is essential to guarantee food security for the community, offer alternative income and for the conservation of fish biomass in the lakes of Ilha da Paciência.