Protecting threatened Over-seas biodiversity

Encouraging results for the Nassau grouper

A new study by the Grouper Moon Project has demonstrated the recovery of Nassau grouper populations in the Cayman Islands in response to management actions that have been implemented by the government.

Nassau grouper © Dr Mary Gillham Archive Project

An alarming finding
The Nassau Grouper is a rather solitary species and difficult to approach. However, during the breeding season, individuals travel long distances and regroup in the tens of thousands, this is the time for “spawning”. However, these aggregations have led to their disappearance, thus facilitating their capture by fishermen targeting these breeding areas.
Due to this overfishing during the spawning seasons, most of the region’s breeding areas have disappeared and the only remaining ones did not contain more than 1000 individuals. In view of its state and threats to the species, the International Union for the Conservation of Nature has classified the species as “endangered” worldwide.

Conservation actions
In view of its observation at the regional level, the government of the Cayman Islands reacts and decides to prohibit fishing on the aggregation sites during the spawning season from 2003.
Meanwhile, the Reef Environmental Education Foundation (REEF), a non-profit marine conservation organization, is launching the “Grouper Moon Project” in partnership with the Cayman Islands Department of Environment (CIDOE), to develop a monitoring method of the remaining aggregations in the Cayman Islands based on the creation of markings and video transects, thus making it possible to more precisely estimate the annual number of fish in these aggregations.
After examining the data collected by the “Grouper Moon Project” in 2016, the government is launching an even more restrictive fishing policy, prohibiting all fishing for Nassau’s grouper during the winter spawning season and imposes quotas and sizes to be respected on individuals that can be kept.

In response to decisions blamed by the Cayman Islands government, the current Grouper Moon Project study shows that the population of Nassau Groupers has more than tripled in 10 years. In Little Cayman, the aggregate population increased from approximately 1,200 individuals in 2009 to more than 7,000 in 2018.
This study is the first to show a sustainable recovery of Nassau grouper populations after the collapse induced by fishing.

Find out more – original publication