Abstract

In the Cayman Islands, the oceans have been quiet for over a year due to the lockdown and closed borders resulting from the COVID-19 pandemic providing a unique opportunity to study how fish populations react when human activities are minimized and the oceans are relatively “quiet”. In July 2020, when lockdown restrictions were initially lifted, we conducted in situ fish population surveys to estimate fish density, biomass and diversity at 5 sites in and around George Town Harbour, which acts as the cruise ship base for Grand Cayman. Surveys were repeated every other month through August 2021 and compared to baseline fish population data from AGGRA surveys completed pre-COVID in 2018. Fish abundance and diversity increased significantly in July 2020 compared to 2018, but began to gradually decline across all survey sites over the course of the survey period as local activities increased. The density and biomass of herbivorous species were also found to significantly increase after COVID yet remained at high levels throughout the study. These results indicate that fish populations were able to rebound when disturbance was removed, but even minimal levels of human activity had a negative impact on fish abundance and diversity. Understanding how fish populations respond to human activity, and therefore how/if their natural role in the reef ecosystem is interrupted or changed, can help support conservation and management strategies that aim to minimize loss to biodiversity through implementation of strategic development plans.

PDF Preview