Chapter 4: Clean & Safe Seas

Introduction

The UK Government’s first report on marine stewardship, Safeguarding Our Seas, outlined a vision of clean, healthy, safe, productive and biologically diverse oceans and seas. In 2005, the first full assessment of the state of UK seas, Charting Progress, showed that recent regulations and recommendations had led to a marked fall in the amounts of measured contaminants reaching the sea. It also found that levels of contaminants in water, sediments and biota were generally low, apart from in a few estuaries that had been heavily contaminated by historical industrial and domestic discharges.

This chapter builds upon Charting Progress, showing what progress we have made towards the vision of clean and safe seas. Based on the Feeder Report produced by the Clean and Safe Seas Evidence Group, it assesses the impacts of six major components associated with the cleanliness of the sea (hazardous substances, radioactivity, eutrophication, oil and chemical spills, litter, and underwater noise). It also assesses the safety of seafood to consumers and bathing waters to swimmers through reporting on algal toxins and microbiological contamination.

Sampling off Stonehaven, North-East Scotland

© Colin Moffat, Marine Scotland Science

For this assessment, we used criteria developed in accordance with the OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic. We highlight where relevant assessment criteria are lacking.

Assessments of the potential impact of individual chemicals use an environmental quality standard (EQS), derived from the concentration at which laboratory data suggest that the chemical could be harmful. Most of these standards are for water. For sediments and biota, we have data on background assessment concentrations (BACs) and environmental assessment criteria (EACs), the latter based on toxicological information and which often also add a margin of safety to give a very conservative estimate of potential harm. Alternative approaches involve combining modelling, laboratory and field toxicity data to generate a range of concentrations within which potential effects may occur. For example Effects Range-Low (ERL) and Effects Range-Median (ERM) concentrations. This approach, first developed for the United States Environmental Protection Agency, is now widely used around the world.

We have outlined the specific approach taken within each section, and made individual assessments for each of the eight biogeographical areas see Figure 1.1. The chapter concludes with a table summarising the outcome of the assessments by topic and region. More detailed information is available in the Feeder Report prepared by the Clean and Safe Seas Evidence Group.