Cold water coral larval survivorship under environmental stressors: assessing anthropogenic impacts on vulnerable ecosystem engineers
MoRE2020 Fellow Rhian Waller, incoming mobility from the University of Maine, USA, to the University of Gothenburg
Cold-water corals provide critical habitat for thousands of associated species, including commercially important fish and shellfish. In particular, the hard coral Lophelia pertusa forms bioherms and even reef systems in the North Sea and North Atlantic, and forms critical habitat, allowing associated species to find protection from predators, areas for reproducing, and for finding food (i.e. other associated fauna). Even though these reefs reside in great depths (>100m), they are not buffered from anthropogenic impacts. Many local populations have been affected in the past from fisheries pressures, and predictions of climate change could see populations further affected. As such there are local areas currently classified as extinct, and those that have fortunately seen subsequent recruitment events in response to protections. For sessile organisms, like corals, larvae are the only means of exchanging individuals among habitats, hence successful larvae are essential to maintaining, and recruiting healthy populations. This project is designed to assess environmental stressors on that most vulnerable of life stages in critical habitat forming species within the Swedish-Norwegian fjord region. In collaboration with researchers at the University of Gothenburg marine research laboratory at Tjärnö, we will examine larval responses to ecological stressors such as temperature and salinity, as well as examine the reproductive ecology of other key coral species in the region that as yet remain unstudied. This project will produce information vital to effective marine management and conservation measures in the area, and add desperately needed data to larval dispersal models.
Collaborating end-user: Kosterhavet National Park
Summary of Project Results
This project was proposed to examine the early life history of the deep-sea coral Lophelia pertusa, which grows in the Skagerrak, as a partnership between the University of Maine, Gothenburg University and Kosterhavets National Park. Early in this fellowship we collected live corals and brought them back to the laboratory for their spawning period (Feb - March). As a major result of this study we documented the fertilization processes in this species, a first for any deep-sea coral worldwide. Through the use of a Laser induced Florescence experiment that Dr. Larsson had conducted, we were then able to model clouds of dispersal of sperm, which will provide a unique understanding of how the spatial arrangement of corals can affect whole population reproduction. This information is extremely valuable to the Kosterhavets National Park (and to other conservation organizations globally, as this species is found worldwide), who are currently participating in restoration efforts for this coral in their waters. This fellowship was extremely productive and is leading to a long-term collaboration between our institutions through the submittal of a research proposal to the National Science Foundation, USA. We are currently working on a manuscript together and our two Ph.D. students are also in close collaboration with their respective results.