New research identifies key habitats to support triggerfish recovery in Brazil

Scientists at the National Oceanography Centre (NOC) have developed an innovative habitat mapping approach that could help restore threatened grey triggerfish (Balistes Capriscus) populations along the Brazilian coast. By combining machine learning, ecological modelling and satellite data, the team identified more than 8,000 km² of suitable habitat for adult fish and extensive nursery areas for juveniles, providing valuable guidance for future fisheries recovery efforts.

Researchers collaborated with Instituto Federal do Espírito Santo in Brazil on the study, focusing on the grey triggerfish - a species of major commercial and recreational importance in Brazil that has suffered significant population decline due to overfishing and habitat disturbance. Classified as Vulnerable globally, the species has become a growing conservation concern in Brazil because of its ecological and economic importance to coastal communities.

Using machine learning, ecological models, and long-term satellite data on floating sargassum, researchers identified where adult and juvenile triggerfish are most likely to be found along the Brazilian coastline. The study highlights key habitats that are important throughout the species’ life and identifies areas where conservation and stock enhancement efforts are most likely to be effective

The findings show that adult triggerfish are strongly associated with shallow rocky reefs and warm coastal waters, while juveniles depend heavily on pelagic habitats and floating sargassum, which provide both shelter and feeding opportunities during early life stages.

Importantly, the study identified areas of overlap between adult and juvenile habitats, including priority locations such as Espírito Santo, where conservation action and stock enhancement programmes could have the greatest impact.

Talicia Pillay, Applied Scientist at NOC and lead author of the study, said: “This research addresses a major challenge in marine conservation as many fisheries around the world lack the detailed data needed to guide restoration strategies. By combining advanced modelling with ecological insight, we were able to identify where threatened fish populations are most likely to recover, providing a practical roadmap for rebuilding fisheries, even where data are limited.”

This work was funded through BORA Blue Ocean Research Alliance®, an innovative alliance between NOC and Subsea7 that supports collaborative research to improve understanding of the world’s oceans. The Alliance is accredited by the United Nations Decade of Ocean Science for Sustainable Development, reflecting its international contribution to advancing ocean knowledge and supporting sustainable ocean management.

Liz James, Group Environmental Director at Subsea7, said: “The Essential Fish Habitat Mapping project is one of several important research initiatives currently being delivered through BORA Blue Ocean Research Alliance® and highlights the growing role that science-industry partnerships can play in addressing global marine challenges.”

The project also underlines the importance of collaboration between research institutions and industry in supporting food security. By improving understanding of fish habitat requirements and population rebuilding potential, the work contributes to NOC’s work applying ocean science to sustainable and resilient food systems, as well as to a wider sustainable marine economy.

Building on these findings, the next phase of the project will focus on turning habitat maps into practical decision-making tools for fisheries managers, helping to identify priority areas for conservation and support the recovery of grey triggerfish populations.