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Unhappy Bedfellows? Interactions between the invasive species Sargassum muticum and Threatened seagrass beds (Zostera spp).

Successful invasive species often escape top-down pressure in the early stages of invasion. However, emerging evidence suggests that over time local animal consumers can adapt to control and moderate non-natives by incorporating invading species into their diets. These adaptations by local consumers are likely to be mediated by mutualistic intestinal microbes.

Seagrasses of the Zostera genus are important, but threatened benthic ecosystem engineers in UK coastal waters. Seagrass beds provide a unique and valuable habitat for a broad range of marine animals, including commercially important juvenile fish and vulnerable seabirds. As crucial refugia and sources of food, sea grass meadows are important for marine biodiversity, as well as being highly productive: Zostera beds sequester more carbon per unit area than terrestrial forests. Sargassum muticum is an invasive brown seaweed which negatively impacts seagrasses, both directly and indirectly by facilitating and exacerbating meadow fragmentation – reducing their value as habitats – and causing harmful shifts in animal communities.

This PhD will develop a deeper understanding of seagrass relations with invasive species, and the role of microbes in moderating the impacts of invaders, thereby identifying new avenues for controlling invasive species. The microbiome associated with seagrass and Sargassum, and with their herbivorous consumers, will be investigated for the first time, providing an overdue examination of microbial influence on a harmful species invasions.

The successful applicant will: undertake field surveys using sustainable non- and minimally-destructive sampling techniques; perform feeding trials in a laboratory setting, learning animal, plant, and algal husbandry techniques as well as a broad range of laboratory and aquarium-relevant skills, including logistical management and day-to-day maintenance of flow-through filtered aquaria; develop knowledge and skills in microbial techniques, including field sampling, laboratory analysis using contemporary next-gen equipment, and computational genomic analysis.


Applicants should hold a minimum of a UK Honours degree at 2:1 level or equivalent and ideally an MSc with distinction in an ecological subject. The applicant should be experienced with IT and statistical analyses. Excellent written and oral communication skills are essential, and the applicant must have initiative, self-motivation, and good inter-personal skills, as well as be able to manage their own time, work independently, and as part of a team. The student should be willing and able to undertake subaquatic and intertidal fieldwork throughout Wales; experience with diving or snorkelling is desirable, as is a full driving license and use of a car. Experience with relevant microbial techniques is desirable, as is animal and/or algal husbandry.


All interested applicants are invited to contact Dr Martyn Kurr in the first instance: