Developing essential fish habitat maps: report
The project helped define areas of the sea essential to fish for spawning, breeding, feeding, or growth to maturity. Twenty-nine species and multiple life-stages were reviewed covering marine fish and shellfish of commercial and ecological importance, relevant to offshore wind development areas.
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Footnotes
1. R088 - Spatial identification and categorisation of areas of particular importance to fish populations - GOV.UK (www.gov.uk)
2. The International Council for the Exploration of the Seas.
3. The boundary of Scottish (and UK) territorial waters (at the 12 nautical miles limit) is considered to be the inshore/offshore boundary for this study.
4. Additional habitat characterisation was available only in Phillips et al. (2021), but this was mostly from anectodal evidence and was not supported by other literature, hence it was not considered sufficient to inform habitat proxy assessment.
5. https://datras.ices.dk/Data_products/Download/Download_Data_public.aspx
6. https://eggsandlarvae.ices.dk/Download.aspx
7. SMALK data were also available for other species form IBTS and BTS surveys (e.g. herring), but the analysis of such data showed that mature individuals were almost exclusively in spent condition and therefore were not considered suitable for assessing spawning grounds.
8. Available data layers including Sabellaria reef features in Scottish and UK waters were used (see Table 4). It is acknowledged that recent work carried out by Marine Scotland Directorate indicates that Sabellaria reef is different in Scottish waters compared to English waters (Marine Scotland 2020).
9. An F1 score of 1 represents a model that perfectly classifies each observation into the correct class (hence identifying the perfect model) and a score of 0 represents a model that is unable to classify any observation into the correct class. Therefore, higher scores (closer to 1) are indicative of better model performance. See Annex 3 for details on how the F1 score is calculated.
10. Anita Franco, the project lead for this present study was also involved as an expert in that project.
11. The A1B (business-as-usual medium emission scenario) describes a world that has rapid economic growth, quick spreading of new and efficient technologies, and a global population that reaches 9 billion mid-century and then gradually declines. It also relies on a balance between different energy sources. In this scenario the global mean surface temperature is expected to rise by around 1.7-4.4 ºC during the 21st century as atmospheric carbon dioxide concentrations rise to around 700 ppm. The equivalent carbon dioxide concentration (with greenhouse gas forcing from other gases also included) is estimated to rise to in excess of 850 ppm by 2100.
12. https://marine.gov.scot/themes/climate-change
13. Depth was still considered in the analysis, albeit implicitly, by way of its correlate MLT. If MLT resulted as important model predictor (which it did not), this would have included the effect of Depth. The alternative approach of retaining Depth and excluding MLT from the analysis was explored, but it led to a model with lower predictive ability.
14. Classification of current and wave energy as low, moderate or high is based on criteria defined for the EMODnet substrate layer as follows: tidal current energy is Low if <130 N m2/s, High if >1160 N m2/s and Moderate in between; tidal current energy is Low if <210 N m2/s, High if >1200 N m2/s and Moderate in between.
15. Data were available from ICES International Herring Larvae Surveys, but a decision was made not to use these data for modelling as larval aggregations were deemed unsuitable to accurately identify spawning areas with the models used in this study, due to larval drifting away from spawning grounds during the time elapsed between hatching and being surveyed.
16. Herring Larval Modelling project, by Rory O'Hara Murray, Morven Carruthers, Alejandro Gallego and Ben James.
17. Survey data from additional inshore and offshore demersal surveys on the west coast of Scotland were not considered due to doubts raised during stakeholder consultation about the correct identification of common sole in the catches.
18. Data from scallop dredge surveys were indicated during stakeholder consultation as possibly better suited in sampling juvenile anglerfish. These data were not available at the time of the project.
19. Neuston layer is the pelagic (water column) habitat at the interface between air and sea waters.
20. The pelagic (water column) habitat at the interface between air and sea waters.
Contact
Email: ScotMER@gov.scot
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