Local ecological knowledge indicates: There is another breeding period in the summer for the mullet Mugil liza in a Brazilian tropical bay

Abstract

Local Ecological Knowledge (LEK) is based on the knowledge that a community has about the organisms that occur in the place where people has lived for generations and can be useful to complement biological knowledge. The LEK of artisanal fishermen in the Sepetiba Bay (coast of the State of Rio de Janeiro) on the reproduction, migration and interactions (feeding and parasitism) of the mullet Mugil liza was analyzed. Semi-structured interviews were conducted with 40 informants (24–79 years old), from November 2017 to January 2019, considering the emic (fisherman's perception) and ethic (scientist's perception) aspects. Fishermen's information coincided with the literature for aspects of the species' biology, such as reproductive period, feeding patterns and parasitic relationships. However, new patterns have been described by the fishermen. These new patterns pointed to a probable reduction in the fish maximum body size and first maturation size. In addition, LEK also points to an additional period of reproduction in the summer, and the presence of north and east winds favoring the appearance of individuals in the bay. The summer spawning, already reported in other areas, was not foreseen in the biological literature for the Sepetiba Bay, and the LEK associated this spawning season to a possible resident population that stay most of the time under structures formed by wharfs of mega-enterprises in the area. Also, the mullet could be forming different metapopulations on the Southeast-South coast of Brazil with part of these populations entering into the Sepetiba Bay. These points raised by LEK need to be tested by biological studies, which could help to a rational management and conservation of this important fishery resource in the southeastern and southern Brazil.