Method for classifying EUSeaMap according to the new version of EUNIS, HELCOM HUB and the Mediterranean habitat types

Abstract

The need for maps of the seabed has become increasingly urgent in recent years for a wide range of reasons and uses, including reporting on the state of the marine environment to implement EU policies such as the MSFD. In ten years, the EMODnet Seabed Habitats initiative has produced maps for all European marine regions, where input data allowed, the resultant seabed habitat maps are known collectively as ”EUSeaMap”. With products such as EUSeaMap, it is assumed that mapping the broad habitat types defined in seabed habitat classifications (e.g. EUNIS) provides appropriate proxies for the occurrence of the species or communities of species that occupy them. In addition to being released in EUNIS 2007-2011 and the MSFD Broad Benthic Habitat Types, the next version of EUSeaMap (expected in September 2021) will be released in three classifications, namely EUNIS 2019 (the new version of EUNIS), and the regional classifications HELCOM HUB and the Mediterranean habitat types. This report proposes crosswalks between EUSeaMap modelled broad habitat types and the three classifications, and briefly discusses the opportunities/challenges entailed by the crosswalks. Our conclusion is that no major issue is expected for the translation of EUSeaMap into these classifications. We also argue that in EUNIS 2019 there are gaps at biotope levels, particularly in the Black Sea and the Arctic, and that measures should be taken to address these gaps