Sea-Changers

Seasonal monitoring of circadian temperatures in coastal habitats affected by plastic pollution

Lauren Smith (Project Manager TTPT) & David R. Green (Chair and Director of EGCP)

WHAT & WHY: As a coastal partnership we spend a lot of our time visiting the coast engaging with school groups as well as members of the public and local businesses. Unfortunately we see a lot of beach litter, primarily composed of plastics and as part of our work we organise clean-ups. Since late 2018, we have removed over 74 tonnes of litter from our stretch of the North East Scottish coastline.

However, we wanted to learn more about what impacts plastic pollution may be having on the environment and so our project focussed on investigating whether plastic pollution affected daily temperatures of beach sediments throughout the seasons. Our overall aim was to increase the understanding of the environmental impacts of these plastics and to investigate its effects in a wider ecological context.

Scientific research collected by environmental organisations usually focuses on documenting the presence, volume, or distribution of plastics in specific species & particular locations. Despite the fact that the presence of plastics in the marine environment have been documented for more than 50 years, little attention has been paid to the effects of plastic debris on the physical properties such as temperature, of the coastal environment. Temperature is a key factor that influences living things. While many species can tolerate a moderate increase in temperature, a recent assessment of > 530 aquatic and terrestrial species predicted that around 40% will experience local extinctions when maximum temperatures increase by more than 0.5°C. For species that occupy intertidal habitats, range shifts due to a warming environment have already been documented. And therefore, localised temperature changes, as a result of accumulated plastic debris in conjunction with climate change, could have critical implications for biodiversity and environmentally important coastal regions where wildlife and plastics frequently overlap.

The more we understand, the more we can direct our focus and create a greater impact during community outreach whilst adding to the existing area of research.

WHERE: Our study sites were Whinnyfold, Craigewan and Cairnbulg, three locations within Aberdeenshire, in North East Scotland. This study is the first of its kind to take place in the Northern Hemisphere and in fact only one other project which took place on some remote islands off Australia has looked at this.

HOW & WHEN: We monitored temperature profiles in the three locations at selected times, during spring, summer, autumn and winter, by burying temperature data loggers in the sediment in areas of zero, low, medium and high plastic densities. Temperature data and plastic pollution was then analysed to see if any correlations could be identified.

DATA ANALYSIS & FUTURE: We are currently completing the data analysis (so far the results indicate that at certain plastic densities the daily maximum and minimum temperatures are shown to be respectively higher and lower than the control areas with zero plastic). We hope to publish the findings in a peer reviewed journal, and will organise a community science workshop to engage members of the public and other interested parties e.g.: other coastal partnerships and community science groups with our study, there is also the longer term potential to run the same or similar studies at other locations around the coastline in the future.

We would like to thank Sea-Changers - the funders of this project - for enabling this study.