Roger Coggan

Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs

The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europes seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification.

Rock Ridges in the Central English Channel

Publisher Summary The English Channel is a funnel-shaped, ENE–WSW-trending, shallow shelf sea between France and England. Hydrodynamically, it is a tide-dominated environment but is also influenced by long swell waves approaching from the open Atlantic Ocean. The Channel is situated at the boundary zone between Lusitanean and Boreal biogeographical provinces. The human impact on the benthic environment is assessed to be predominantly high to very high, including shipping, selective extraction (demersal fishing and aggregates), and obstruction (cables, wrecks), among others. Biological communities were compared across the three main geomorphic features, namely flat seabed, bedrock ridges and the palaeovalley, considering both the taxa recorded and the biotopes identified during the video analysis. Sixty-two taxa were identified to various levels of taxonomic precision and the analysis presented here is based on their relative frequency of occurrence. Geophysical and biological analysis revealed an extensive system of rock ridges located 30 km south of the Isle of Wight in water depths ranging between 40 and 80 m below Chart Datum. The feature extends 100 km in an east–west direction and 15 km in a north–south direction, covering ca. 1,100 km2 of seafloor. The rock habitat supports a substantial coverage of fauna including sponges, bryozoans, hydroids and anemones. Three major geomorphic feature types were identified, namely flats, rock ridges, and a palaeovalley. Surrogacy can be high for taxa that exploit niche habitats but is generally low when considering habitats and biotopes assigned according to the European Nature Information System (EUNIS) habitat classification scheme.

Open Shelf Valley System, Northern Palaeovalley, English Channel, UK

Publisher Summary The Northern Palaeovalley is an open shelf valley system in the English Channel. It is a distinctive erosional feature within the northern half of the eastern English Channel with a particularly well-defined margin on its northern side and an upper break of slope at a depth of 25–30 m with the valley floor generally at depths of 55–75 m. The valley is >100 km long and varies in width from 8 to 20 km. Its floor lies at depths of 45–90 m, with margins up to 30 m high. Net sediment transport is west to east, with rock and coarse sediment in the valley floor in the west and a gradual eastward increase in sand cover and volume, culminating in two large linear sandbanks up to 28 km long along the northeast margin of the valley. The Palaeovalley supports a rich diversity of infaunal and epifaunal communities. Considerable overlap exists in the infaunal communities associated with the different geomorphic features, while the epifaunal communities exhibit far greater variability in response to the environmental gradients. Interstitial polychaetes dominate the macrobenthic communities across the area reflecting the dominance of mobile sediment deposits. The Palaeovalley as a whole is characterized by comparatively rich macrofaunal communities comprising infaunal and epifaunal species in varying proportions. There is significant overlap between the infaunal communities associated with the five geomorphic features in this area, as all are dominated by interstitial polychaetes, many of which are tolerant of a wide range of sediment classes.