Intertidal Habitats

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Intertidal
What is already happening?
  • Warm-favouring species of rocky intertidal habitats have continued to move north along the west coast and east along the south coast of the UK (e.g. the topshell Phorcus lineatus, limpet Patella depressa, and barnacle Chthamalus stellatus). 
     
  • Regional differences in abundance trends are observed in intertidal brown macroalgae around the UK coastline, with declines in the south, but no change or increases in central and northern areas.
     
CONFIDENCE LEVEL
MEDIUM

Medium evidence, high agreement

There is strong evidence and agreement for past and present change in intertidal species and community shifts. When considering hard and soft substrates, there is more information and agreement available for hard substrate systems.

What could happen in the future?
  • Warming marine temperatures are likely to result in the invasive Pacific oyster successfully being recruited annually in South-west England, Wales and Northern Ireland by 2040. 
     
  • Composition of intertidal communities around the UK is likely to alter as ocean acidification increases. 
     
  • Further declines in some cold-water species are expected as sea temperature increases.
     
CONFIDENCE LEVEL
MEDIUM

Medium evidence, high agreement

There is generally good agreement on the future direction of change. Again, when considering hard and soft substrates, there is more information and agreement available for hard substrate systems.

Key Challenges and Emerging Issues
  • Improving detection of climate driven changes to soft sediment benthic biodiversity by expanding monitoring sites. 
     
  • Sustaining time-series that are tracking climate-driven changes in intertidal biodiversity.
     
  • Providing more reliable information and scientific data to support implementation of marine biodiversity legislation.