Gobies and hake in the hypoxic waters of the Benguela up-welling current
The aim of the project is to investigate how the goby (Sufflogobious bibarbatus) and the shallow water hake (Merluccius capensis) cope with the hypoxic waters of the Benguela current. Both are key species of the ecosystem. They show a remarkable tolerance to the hypoxic conditions found in this up-welling area, which is one of the five most productive marine ecosystems of the world. Due to a high sedimentation rate, large areas of the shelf are covered with hydrogen sulphide sediments, creating hypoxic conditions above the sea-floor and in the water column. As key species with a strong influence on the ecosystem functioning and productivity, these species ought to have evolved a very special physiology and behaviour that make them successful in this extreme marine environment.
The project will employ new acoustic methods (developed by Norwegian partners) to find individual hake and goby and to track their swimming patterns in the field. It also makes it possible to investigate how the two species respond to changes in oxygen, sulphide and predator-prey interactions. The field-generated hypotheses will be tested in laboratory experiments measuring the physiology and behaviour of the fish. Controlled experiments will make it possible to control water conditions (oxygen, sulphide levels) as well as being able to monitor individual fish’s swimming speed and activity levels.
The research questions are based on pure, curiosity-driven science but they have applications for fisheries management. An interdisciplinary approach will be used whereby marine ecologists, environmental biologists, physiologists, fisheries biologists and behavioural ecologists will meet and work together. The new acoustic information generated in the project may be a big step forward for South African fisheries management institutions, for use in their estimations of species abundance using acoustic techniques.
The project will provide common research opportunities for scientists and post graduate students in South Africa and Norway.
For the project webpage press this link.