Seasonal rainfall influences reproduction and recruitment of tropical penaeid shrimps: Implications to fisheries management

Here, we present results from a study conducted in two major shrimp fishing grounds in the Northeastern Brazil Marine Ecoregion (NBME) that determined reproductive dynamics of the penaeid shrimps Xiphopenaeus kroyeri and Penaeus schmitti. We aimed to verify if the current closed season is appropriate and untangle the environmental drivers that control their dynamics. The periods of recruitment and reproduction of both species overlap significantly, with a major spawning peak taking place in the dry season and recruitment in the wet season. The recruitment process in both species seem to be indirectly controlled by the onset of the rainfall season, which triggers an increase in primary productivity. This indirect effect also appears to affect growth increments positively. Our results suggest that both species evolved to recruit in the wet and spawn at the dry season as mechanisms to maximize reproductive fitness. They also highlight the possible negative influence of climate change in tropical shrimp stocks and that the current local regulations must be adjusted to better protect them from overfishing. Therefore, we present multiple possibilities to the closed fishing season (CFS) addressed to local decision-makers and reinforce that environmental parameters and effects of environmental changes should be considered when planning management measures.

Automated summary

This study investigates the reproductive dynamics of two shrimp species in major fishing grounds in Northeastern Brazil. The results show that recruitment and reproduction periods overlap significantly, with recruitment occurring in the wet season and spawning in the dry season. The study suggests that both species have evolved to maximize reproductive fitness by recruiting in the wet season and spawning in the dry season. It also highlights the negative influence of climate change on tropical shrimp stocks and the need for adjusting local regulations to protect them from overfishing.