Spawning patterns of commercially important reef fish (Lutjanidae and Serranidae) in the tropical western South Atlantic

Abstract

Although information on the spawning seasons of commercially important snappers (Lutjanidae) and groupers (Serranidae, subfamily Epinephelinae) is available for the north and central west Atlantic, there is little information for the tropical western South Atlantic (Brazil). As a consequence, there are few fishery regulations in this entire region that take into consideration such information. In this study, we characterized the reproductive cycles of three Epinephelinae serranids (Epinephelus morio, Mycteroperca bonaci and Cephalopholis fulva) and five lutjanids (Lutjanus synagris, L. jocu, L. analis, Ocyurus chrysurus and Rhomboplites aurorubens) that occur in the Abrolhos Bank, Brazil, the largest reef complex in the tropical western South Atlantic. A total of 3528 gonads were collected from May 2005 to October 2007. Temporal variability in spawning patterns was evaluated using the Gonadosomatic Index (GSI) and macroscopic analyses. The peak of reproductive activity for the three grouper species occurred between July and August. Snappers exhibited two peaks of reproductive activity, the more intense of which occurred between September and October. The other peak occurred between February and March, with the exception of the deep-dwelling species R. aurorubens, which only reproduced between February and March. Seasonal patterns were consistent over the two consecutive years that we studied, and these patterns are equivalent to those observed for the Northern Hemisphere, as are the sizes at maturity and at the time of sexual change (for the three protogynous hermaphrodite groupers). Fisheries management in this region could be significantly improved by a combination of catch and effort limitations being imposed during spawning seasons and by overall size limitations, particularly considering that most of the fish caught are generally below size at maturity. The proposed buffer zones for the marine areas that are presently protected in Abrolhos represent an opportunity for implementing both spatial (e.g. setting no-take zones that cover spawning sites) and temporal (e.g. seasonal closures during spawning peaks) management tools, using a participatory approach at the regional scale.

Keywords

• small-scale fisheries management
• reproduction
• reef fisheries
• abrolhos bank
• brazil