Abstract
Essential fish habitats (EFHs) are critical for fish life-history events, including spawning, breeding, feeding or growth. This study provides evidence of EFHs for the critically endangered flapper skate (Dipturus intermedius) in the waters around the Orkney Isles, Scotland, based on citizen-science observation data. The habitats of potential egg-laying sites were parametrised as >20 m depth, with boulders or exposed bedrock, in moderate current flow (0.3-2.8knots) with low sedimentation. This information provides a significant contribution to the understanding of EFHs for flapper skate.
Highlights
The authors examined a range of citizenscience evidence to assess the presence of potential flapper skate egg case nursery off the Orkney Isles, Scotland (Figure 1)
Sites with in situ egg cases recorded were characterised by boulder/rock substrates in high current flow (0.3–2.8 knots on spring tides, Admiralty Charts, 2021) (Figure 2, Supporting Information)
Further quantitative investigations are recommended to confirm the densities of egg cases and to determine whether these sites qualify as Essential fish habitats (EFHs)
Summary
The authors examined a range of citizenscience evidence (stranded egg case data, diver observations and towed camera surveys) to assess the presence of potential flapper skate egg case nursery off the Orkney Isles, Scotland (Figure 1). Diver surveys identified two sites where skate eggs were repeatedly recorded over a 15 year period: one at Galt and another at the Foot of Shapinsay (n = 40) (Figure 1a–c).
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