Fish in sand and gravel habitats in the North Sea and adjacent shelf seas: A systematic literature review

Mikael van Deurs, Matthew Baker, Petter Lundberg, Jane Windfeldt Behrens, Ole Henriksen, Tomas Brodin, Nicholas Patrick Moran 

Sedimentary habitats such as sand and gravel are among the most widespread seafloor environments in shelf ecosystems, yet fish–habitat relationships in these substrates remain poorly understood. Although these habitats support diverse and productive benthic communities, ecological information on how fish use them is fragmented, limiting the effectiveness of conservation frameworks such as EUNIS, the EU Habitats Directive, and ecosystem‑based fisheries management. To address this gap, we conducted a systematic review of peer‑reviewed studies reporting associations between fish species and sandy and gravelly substrate types across the Northeast Atlantic shelf. The review identified 104 studies covering 77 species associated with these substrate types, divided into littoral ecozones down to 200 m depth. Study frequency strongly influenced the number of habitat types in which species were recorded, complicating assessments of habitat specialisation based on available data. Across ecozones, sand consistently supported the highest species richness, and most nursery areas were linked to sand in the littoral and infralittoral zone. Species of conservation concern (IUCN) occurred across all substrate types; however, we highlight particular concern for gravel habitats as spawning grounds and as habitat for several red‑listed species, given their more limited distribution compared to sand. Commercially important species dominated reports of spawning and nursery functions. This synthesis provides a comprehensive overview to date of fish–habitat associations in sedimentary environments of the Northeast Atlantic shelf. The resulting literature list, database and habitat‑specific species lists offer a valuable foundation for marine spatial planning and area‑based conservation, including the identification of Essential Fish Habitat.