C4: Diverse seas: condition of seafloor habitats

Interim Interim

Short description

This indicator of diverse seas evaluates the condition of seafloor habitats. Seafloor habitats assessed include soft sediment invertebrate communities and intertidal communities of seagrass, rocky shore macroalgae and saltmarshes. Once developed the indicator will assess the impact of human activities on seafloor habitats. Data for the seafloor habitat condition indicators comes from surveys undertaken on a 6-yearly cycle using methods developed for Water Framework Directive classifications, now transposed to the Water Framework Regulations (WFR). These include the intertidal rocky shore macroalgae tool, intertidal seagrass tool, Infaunal Quality Index, and intertidal saltmarsh tool.

This indicator is not available for reporting in 2021 in a finalised form. An interim indicator is presented here that shows target achievement for regional sea assessment, status of coastal water bodies and offshore unit assessments. The assessments used for this indicator have been reported under the updated UK Marine Strategy Part One (2019) to assess progress towards the UK Marine Strategy target of achieving and maintaining Good Environmental Status (GES) in UK seas. Data on benthic habitats, analytical methods and assessment are available. Further methodological development of this indicator is required and the indicator’s format will evolve.

Note

While the currently available data predate the 25 Year Environment Plan, they provide the most recently available assessment of the condition of benthic habitats. They enable a better understanding of a baseline from which to measure progress towards the goals of the 25 Year Environment Plan when the indicator is next updated.

Trend description

a) Seagrass

The UK Marine Strategy target for intertidal seagrass communities were met for all Regional Seas. Four Regional Seas were not assessed due to either an absence of intertidal habitat which is required by the indicator or an absence of existing WFD classification data. The natural conditions required for seagrass beds to exist limits their occurrence in coastal water bodies. However for those contributing, the quality threshold of ‘Good’ or ‘High’ Ecological Status was met for the majority of surveyed locations. The Irish Sea had the lowest extent of intertidal seagrass meeting the quality target, although the total remains markedly above the indicator quantity threshold of 85%.

b) Rocky shore macroalgae

The UK Marine Strategy target for the intertidal rocky shore macroalgae was met for all seven assessed Regional Seas. Two Regional Seas were not assessed due to either an absence of intertidal habitat which is required by the indicator or an absence of existing WFD classification data.

c) Saltmarsh

The UK Marine Strategy target for the saltmarsh communities was largely met for the Celtic Seas and Northern North Sea but was not met for considerable areas of the Southern North Sea and the Eastern English Channel Regional Seas. Five Regional Seas were not assessed due to either an absence of intertidal habitat which is required by the indicator or an absence of existing WFD classification data.

d) Soft sediment invertebrates

The UK Marine Strategy target for soft sediment (benthic) invertebrate communities was largely met for most Regional Seas including the Minches and Western Scotland, Scottish Continental Shelf, Shared Waters between Northern Ireland and Republic of Ireland, Northern North Sea and Eastern English Channel. The Western Channel and Celtic Sea did not reach the target largely due to the inshore WFD classification results, while the failure of the Southern North Sea to meet the target can be attributed to the offshore results. The Irish Sea did not meet the target due to both inshore and offshore results. The Atlantic North-West Approaches was not assessed due to an absence of data.

Sub-categories

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This table provides metadata for the interim or final indicator presented above.

Indicator name

Diverse seas: condition of seafloor habitats

Indicator reference

C4

Outcome Indicator Framework theme

Seas and Estuaries

Headline indicator status

Diversity of our seas

Relevant goal(s) in the 25 Year Environment Plan
  • Thriving plants and wildlife
Relevant target(s) in the 25 Year Environment Plan
  • Reversing the loss of marine biodiversity and, where practicable, restoring it
  • Ensuring seafloor habitats are productive and sufficiently extensive to support healthy, sustainable ecosystems
Position in the natural capital framework
  • Condition of assets - seas
Related reporting commitments
  • UK Marine Strategy (Marine Strategy Regulations 2010)
  • Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR)
  • Relevant to Sustainable Development Goal 14
  • Water Framework Regulations – The Water Environment (Water Framework Directive) (England and Wales) Regulations 2017, The Water Environment (Water Framework Directive) Regulations (Northern Ireland) 2017, Water Environment and Water Services (Scotland) Act 2003
Geographic scope

UK

Status of indicator development

Interim

Date last updated

11 June 2021