A minimal model of trophic and non-trophic interactions in cold-water coral communities

Do you want to understand cold-water coral ecosystems in the deep sea?
Are you up for the challenge of capturing this complex ecosystem in a mathematical model?

Background

Most people associate corals with warm tropical waters, but in the last decade it has become clear that also the deep sea harbors extensive coral reefs. Cold-water corals, like their tropical counterparts, form extensive 3-dimensional structures on the seafloor that provide a habitat for a very rich community of stony corals, soft corals, sponges, bivalves, polychaetes, shrimps and fish. Our understanding of these reefs and the interactions between the organisms in this community is still very rudimentary. In general, ecosystems in the dark deep sea are limited by the availability of food and cold-water corals are no exception. Trophic interactions, e.g. the competition for food, therefore play an important role in the cold-water coral community. However, recent experiments show that there are some intriguing interactions between a few components of the cold-water coral community that are non-trophic in nature. Cold-water corals create a carbonate skeleton that forms the basis of this deep-sea ecosystem, but a worm that lives between the living coral branches stimulates the formation of this skeleton. Sponges moreover, another key component of this community, appear to recycle an energy source, i.e. dissolved organic matter, that would otherwise get lost from the food web. These non-trophic interactions may be crucial in the functioning of a cold-water coral ecosystem, but so far they have not been considered in mathematical models.

In this project, the student is challenged to develop a mathematical model of trophic and non-trophic interactions between the key components of the cold-water coral reef ecosystem, i.e. cold-water corals, worms and sponges, and identify their importance for this unique deep-sea ecosystem.

Approach: Existing information on feeding by corals, sponges and worms will be used to setup a minimal model of trophic interactions in the cold-water coral community. The recently identified non-trophic interactions will be added to this minimal model to investigate the role and function of these interactions for the cold-water coral communities.