Title: The bearded goby: a hypoxia-tolerant, jelly eating ecosystem savior on the Namibian Benguel
The oceans of the world are slowly losing oxygen, in part because of climate change and in part because of anthropogenic eutrophication. This deoxygenation affect marine organisms in species-specific ways. On the west coast of Southern Africa, I have together with colleagues from Africa and Norway, studied a little fish that cope well with hypoxic environments. This species, the bearded goby (Sufflogobius bibarbatus), is endemic to the Benguela upwelling ecosystem. It is abundant on the continental shelf and slope off Namibia, where 9 000 km2 of the shelf is hypoxic. Here, the species is considered now central to functioning of the ecosystem and in recent decades, it has sustained commercial fish populations. Unlike their predators, S. bibarbatus has strong anti-predator responses as they can remain alert and escape threats in anoxic and severely hypoxic waters, and it can cope with sulphide shocks. Populations display diel vertical migration and shuttle between suboxic seabed refugia during the day to more oxygenated waters higher up in the water column at night, and whilst they may share the water column with predators, they associate with jellyfish. The spatial distribution of gobies varies with changes in available oxygen, and populations expand and contract with climate-induced changes in the distribution of hypoxic waters. This species has an unusual diet and plays an important role in ecosystem functioning. It is a batch-spawner, with a protracted spawning season. Remarkably, males display alternative reproductive tactics and reproduction can take place at oxygen levels < 0.5 ml L-1 DO on the shelf break.
BIO: Professor in marine sciences at the University of Bergen since 2000. Supervise Research Master- and PhD-students on their projects. I am running a graduate field course in marine ecological field methods on-board ocean going research ships. I have published original articles in the peer-reviewed press in the field of marine ecology, biological oceanography, fish biology, animal behaviour and in the fisheries literature since 1991. Most recent: Has edited a text book “Marine Ecological Field methods – A handbook for marine biologists and fisheries scientists”, just published on Wiley, January 2018.