Are the Coastal Waters of French Guiana a Source or Sink Habitat for Atlantic Goliath Grouper Epinephelus itajara?

The coastal waters of French Guiana are amongst the most turbid and nutrient rich in the world, and as such, they favour the settlement and early development of several species of marine fish. Recent work has revealed a high abundance of Atlantic Goliath Grouper (Epinephelus itajara) in these waters, yet little is known about this species' reproductive biology, which this study aims to complement. During the period from 2010 to 2013, we surveyed Goliath Grouper at three rocky sites along the French Guiana coast and examined 602 individuals for evidence of maturation. Satellite tags were deployed on five individuals and an acoustic survey was conducted to identify potential spawning movements and activity. We found no evidence of sexually active individuals or local spawning aggregations. Most individuals showed high site fidelity, but one fish was located 1150 km away, near Trinidad and Tobago. We discuss these findings in the context of the wider literature and postulate that Goliath Grouper inhabiting French Guiana reefs originate from spawning sites in northern Brazil and disperse to westerly reefs with the onset of maturity. We propose that the Goliath Grouper populations of South America and Caribbean are linked, and that management of Brazilian source populations could have wide-reaching impacts on Goliath Grouper stocks.

Automated summary

The coastal waters of French Guiana are highly turbid and nutrient rich, making them favorable for the settlement and early development of various marine fish species. The study focused on understanding the reproductive biology of the Atlantic Goliath Grouper in these waters. Surveys were conducted from 2010 to 2013, which revealed a high abundance of Goliath Grouper, but no evidence of sexually active individuals or local spawning aggregations. The study suggests that the Goliath Grouper in French Guiana originates from spawning sites in northern Brazil and disperses to western reefs as they mature.