A behavioural assessment of Caribbean reef octopus in an isolated tropical marine lake

The use of insular systems as models for evolutionary-ecological feedbacks have been critical in furthering our understanding of both terrestrial and freshwater ecosystems. However, despite the unique attributes that make these systems so valuable for scientific scrutiny, there is a paucity of data concerning closed marine systems, their ecological significance, and ultimately their conservation value. A specific example of a closed marine ecosystem are anchialine lakes; characterised by their limited connectivity to the wider marine environment via subterranean aquifers.

Sweetings Pond is a unique and relatively unstudied ecosystem situated in north Eleuthera, Bahamas (25°21′40′′N, 76°30′40′′W). It is an anchialine lake of approximately 1600 x 800 m area of mean depth of 6 m, max depth at 14 m, with a complex benthic ecosystem distinguished due to its geographical isolation from the ocean and minimal tidal influence. It also hosts a substantial (sub) population of genetically important Hippocampus erectus (lined seahorse) and Octopus briareus (Caribbean reef octopus). The isolated nature of Sweetings Pond has led to hypotheses of ecological release in its mesopredators by Aronson, (1985), though literature on overall ecosystem functioning and its components are lacking. For any further unified work in an attempt to use Sweetings Pond as a model insular marine system, an understanding of its various components is required.

Here, we will conduct an octopus census (following Aronson’s method - systematic search during the day for occupied dens within a defined area) and general ecological survey, at two sites (time dependent) at the Sweetings Pond ecosystem.

This work is being led by University of Essex M.Sc. student Duncan O’Brien, in collaboration with CORE and the University of Tampa, and will form the basis for Duncan’s thesis. Updates on this project can be found here and on our Instagram Page. Please contact us through our website for further information - Research@coresciences.org