Plastic pollution and ocean giants: Investigating the extent and impacts of plastic ingestion by marine megafauna (ref 4597)

The widespread and pervasive nature of plastic pollution has resulted in a growing body of evidence documenting the detrimental effects of anthropogenic waste on marine organisms. Over the last two decades, the number of marine species known to be impacted by debris, the majority of which is plastic, has more than trebled. Of particular concern are the marine megafauna, namely marine mammals (e.g. cetaceans and pinnipeds), elasmobranchs (sharks and rays), and marine turtles. These large marine vertebrates play key roles in the functioning and maintenance of marine habitats and are often considered indicators of marine ecosystem health. Many are also of conservation concern due to the plethora of anthropogenic pressures exerted on them. Plastic ingestion by marine megafauna can lead to a range of lethal and sub-lethal impacts, including intestinal blockage and internal injury, dietary dilution, malnutrition, exposure to chemical contaminants and increased vulnerability to disease. Our understanding of the fate of very small plastic particles, such as microplastics and nanoplastics, within mammalian gastrointestinal tracts, and the potential health implications, is extremely limited.

Project Aims and methods

In this PhD, the student will build on previous research undertaken by the supervisory team from the University of Exeter, Plymouth Marine Laboratory and the Cetacean Strandings Investigation Programme at the Institute of Zoology (IoZ)/Zoological Society of London (ZSL) to understand the extent and potential impacts of plastic ingestion by a range of marine megafauna species, including whales, dolphins, seals, turtles, and sharks, found in UK waters.

There is scope for the student to develop the specific objectives of the project but suggested aims include:


Work alongside strandings scientists and veterinary pathologists to develop a method of sampling large marine animals collected by the UK stranding networks for evidence of plastic consumption
Characterise any plastic debris (including microplastics) within the gastrointestinal tracts of the stranded animals, with a view to identifying potential sources and informing policy
Using data from strandings records and published research, investigate the differences in exposure to plastic pollution among species, life-stages, and feeding strategies/diet
Examine spatial patterns to assess species vulnerability by exploring the overlap between species distributions and habitat use with hotspots of plastic pollution
Work with the supervisory team and histopathologists at IoZ to co-develop methods for examining digestive tract samples for the presence and fate of nanoplastics
Investigate the link between plastic ingestion and exposure to chemicals, such as phthalates
Consider the adverse health impacts of plastic ingestion for individual animals as well as the potential population-level effects.