PhD student position: Impact of Expanding Top Predator and Definitive host Populations on Parasite Diversity and Transmission in the Baltic Sea We are seeking a highly motivated student holding a Master’s degree in Genetics, Biosciences, Molecular Biology, Ecology, Veterinary Medicine or a related field for a four-year, fully funded PhD position. The project investigates the hidden consequences of parasitism associated with expanding top predators and ecosystem engineers - cormorants and grey seals, in the Baltic Sea. By integrating molecular tools, experimental approaches, and field surveys, the study focuses on wide range of parasites with complex life cycle (trematodes, nematodes, cestodes and Acanthocephala). In this system, fish typically serve as second intermediate hosts, while birds (cormorants) and mammals (grey seals) function as definitive hosts. The central aim is to determine how recovering and expanding top predator populations reshape host–parasite interactions, enhance parasite transmission, and generate localized disease hotspots in coastal ecosystems. The admitted doctoral researcher will be employed as a full-time junior research fellow for four years. The research will be conducted at the Estonian University of Life Sciences (Institute of Veterinary Medicine and Animal Sciences, Chair of Aquaculture, Tartu, Estonia). The PhD project is supervised by Prof. Riho Gross, Prof. Anti Vasemägi and Dr. Alfonso Diaz Suarez. The Chair of Aquaculture hosts a multinational team of researchers, PhD/Master’s students, and technicians, offering the applicant extensive opportunities for collaboration. The PhD student will participate in the following research tasks: Investigate whether cormorant breeding colonies generate trematode and cestode transmission hotspots in adjacent coastal habitats, leading to elevated infection prevalence, parasite load, and diversity in first (snails and copepods) and second (fish) intermediate hosts. Investigate whether grey seal breeding and moulting colonies generate nematode, cestode, and acanthocephalan transmission hotspots, increasing infection levels in copepods (first intermediate host) and fish (second intermediate host). Requirements: Motivation: Highly motivated, intellectually curious and sociable. Technical Skills: At least basic experience in molecular methods, basic bioinformatics and statistical skills. Fieldwork: Willingness to participate in fieldwork. Collaboration: Ability to work both independently and as part of a team. Language: Fluency in English (both written and spoken). Proof of English language proficiency is required The following are considered as an advantage: Programming skills in R, UNIX, or other relevant languages. Experience in bioinformatics, metabarcoding, analyses of next generation sequencing data A university degree with a specific focus on genetics, molecular biology, ecology or fish biology. How to apply: Applications should be sent to supervisors, Prof. Riho Gross (riho.gross@emu.ee) and Prof. Anti Vasemägi (anti.vasemagi@slu.se) and include a motivation letter (with academic background, research experience, interests and goals), academic CV and contact details of two references and a copy of your master´s degree certificate (or expected date of obtaining the master's degree). Please use the code PhD2026 in the subject line. Submission deadline of applications to supervisors: May 10, 2026 We screen for potential doctoral candidates to whom we give a recommendation to submit their application documents in accordance with the procedures established by the university: Admission to PhD studies in Estonian University of Life Sciences: https://www.emu.ee/en/admission-to-phd-studies Description of Doctoral studies (PhD) in Estonian University of Life Sciences: https://www.emu.ee/en/doctoral-studies-phd Submission deadline of admission documents for non-Estonian residents: June 1, 2026. Starting date of PhD position: September 1, 2026. If you have any further questions, please contact Prof. Riho Gross (riho.gross@emu.ee). Magnus Lauringson (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)