Community structure and functioning of worm-forest ecosystems at Arctic hydrothermal vents and cold seeps

Project title

Community structure and functioning of worm-forest ecosystems at Arctic hydrothermal vents and cold seeps

Supervisor

Mari Heggernes Eilertsen

Funding

WormFEST project, Research Council of Norway (Norges Forskningsråd, FRIPRO program)

Project description

The deep sea is generally a nutrient-poor environment, dependent on sinking organic matter produced at shallow depths. However, an exception to this can be found in chemosynthesis-based ecosystems (CBEs) such as organic falls, cold seeps, and hydrothermal vents. Here, microbes can fixate carbon through chemosynthesis, a process similar to photosynthesis, except it uses chemical energy instead of light energy. Some chemosynthetic microbes form symbiotic relationships with tube-worms, allowing them to form dense three-dimensional structures, much like how trees form the structure of a forest. These “worm-forests” may act as habitats, feeding-grounds, and nurseries for a wide range of animal groups. Therefore, CBEs are important sites where vibrant communities can flourish even in dark, deep waters.

While worm-forests at vents and seeps are well known from other ocean regions, those found in the Arctic remain largely uncharacterized. Therefore, my PhD project aims to address this knowledge gap through a baseline characterization of Arctic worm-forests in regard to their community-structure and functioning. This aim will be divided into sub-tasks of:

1. Identifying drivers behind the occurrence and structure of Arctic worm-forests.
2. Characterize the community composition and functional traits of worm forests across vents and seeps.
3. Reconstructing the food webs of these ecosystems.

Because of their specialized fauna, hydrothermal vent and cold seep communities are highly vulnerable to fragmentation from human disturbances and will therefore require informed conservation measures. By characterizing Arctic worm-forest communities this project will help in the identification of key environmental conditions and sensitive fauna, facilitating preservation of these unique ecosystems.