Martin M. Larsen, Zhanna Tairova, Cordula Göke, Jesper P.A. Christensen, Marie Maar & Vibe Schourup-Kristensen. 2022. Grundlag for overvågning af negative effekter af marine akutte forureningshændelser. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 96 s. - Teknisk rapport nr. 247. http://dce2.au.dk/pub/TR247.pdf
The purpose of this report is to set the basis for implementation of surveillance in Denmark in relation to the marine strategi directive descriptor 8, criterion 4 “The adverse effects of significant acute pollution events on the health of species and on the condition of habitats are minimized and, where possible, eliminated”.
The report contains: 1) identification of hazardous substances, which can cause acute toxic pollution in the marine environment; 2) an overview of land based industries, which potentially in case of accidents can cause acute pollution to the marine environment; 3) mapping of marine areas, that are particularly sensitive to acute pollution events; and 4) assessment of dispersion models, which can be used for acute spills and discharges.
A literature survey on ship accidents was performed, identifying the hazardous substances with the largest probability of causing acute pollution: benzene, styrene, vegetable oils, acids and bases, ammonia containing substances and nutrients, xylene, phenols, acetone, toluene, acetonitrile, vinyl acetate and paraffin waxes.
Risk assessment of the hazardous substances is based on IMO’s GESAMP (Joint Group og Experts on the Scientific Aspects of Marine Environmental Protection) system, which includes criteria on bioaccumulation and biodegradation potential of compounds, both acute and chronic aquatic toxicity and acute and chronic effects on marine mammals and limitations for other uses of the sea and coastal zone.
Companies that store environmentally hazardous substances were identified by the Danish environmental protection agency’s overview of “Listevirksomheder”, which include the largest and most polluting companies, that require special supervision from authorities. From this overview list, the companies for which the amount of hazardous substances stored/used was large enough were selected for this basis study. In total the list for this study amounted in 45 companies on the coast (<100 m from the coastline) and in all 226 companies within 3 km from the coastline. No central register was available with information on the hazardous substances which were actually stored for the individual companies, only the type of companies.
All habitat and protected areas are expected to be sensitive to acute pollution, but differ in sensitivity depending on pollution type and season. For example, the bubble reefs and biogene reefs are sensitive to acid spills, which can affect the reef structure itself, and bird sanctuaries for migratory birds are most sensitive in the migration periods in the spring and fall where the number of birds, which can be harmed by the pollution, is highest. As the largest focus until now have been on oil spills, the HELCOM Seatrack Web oil spills model are the most used model today. The model is built on the atmospheric and marine models from the Danish and Swedish metrological institutes (DMI, SMHI), with built in breakdown models for different types of oils. DMI is also developing an oil-spreading model, similar to HELCOM Seatrack Web, to be used for both the North Sea and in Greenland, which is also capable of calculating the different scenarios. For other hazardous substances, the models can be extended to include the physical-chemical properties and transformation of the chemical substances. These models, however, have no biological aspects, as they do not include bioaccumulation and other effects on species and habitats. Therefore a combination with ecological models, as e.g. in Flexsem, will be a possibility for selected areas.
