MAE: Ecophysiology

Coral reefs are facing multiple threats, from global warming to ocean acidification to impaired water quality. Marine Animal Ecology studies ecophysiological responses of organisms using state-of-the-art experimental set ups.

Multiple stressors on corals

Exposing adult corals and coral larvae to multiple stressors gives a more realistic view into what might happen in the future. Global stressors such as temperature increase and pH decrease are tested, but also their combined effect with local stressors such as water pollution. One of the pollutors looked at is oxybenzone, a UV-filter in most sunscreens. Corals are exposed to stress conditions and survival, photosynthetic yield and respiration are measured. A recent publication showed that the combined effect of both temperature increase and oxybenzone negatively impact corals. Results are relevant to adjust management protocols for sunscreen use. Furthermore, beyond the ecophysiological changes of the coral, studies are also on the way on the changes in the microbiome.

Aquarium setup for coral exposure to combined effects of temperature and oxybenzone. Photo: Dr. T. Wijgerde.
Aquarium setup for coral exposure to combined effects of temperature and oxybenzone. Photo: Dr. T. Wijgerde.

Sponges in a changing ocean

The most ancient animals on earth are sponges. Despite their abundance in benthic ecosystems, ecological functions of sponge-dominated areas (or sponge grounds) are yet unquantified. SponGES is a project focussing on deep sea sponge grounds. The goal is to develop an approach to preserve but also sustainably use deep sea ecosystems in the North Atlantic. Marine Animal Ecology has co-lead in the work package "Threats and Impacts" and its project focusses on the ecophysiological effects on sponges of anthropogenic induced environmental changes and disturbances. Underlying projects include:

The sponge loop and iron availability

Another effect increasingly observed on coral reefs is the shift from coral dominated states to macroalgae, cyanobacterial mats and/or sponges. Interestingly, this is far more readily observed in the Caribbean than in the Indo-Pacific. One hypotheses that is currently being investigated is that the higher influx of dust-associated iron in the Caribbean is the underlying mechanisms for supporting sponge proliferation. A current project is performing ecophysiological studies in the lab and in the field to test this hypothesis.

Incubation chamber to measure ecophysiological responses. Photo: M. Streekstra.
Incubation chamber to measure ecophysiological responses. Photo: M. Streekstra.

Techniques used & Implications

To study ecophysiological responses of various organisms, Marine Animal Ecology performs field, mesocosm and lab experiments. With a better understanding on how individuals respond to different stressors we are better able to conserve ecosystems to work towards climate resilience.