C5: Diverse seas: condition of pelagic habitats

Short Description

This indicator of marine biodiversity tracks changes in the Good Environmental Status (GES) of pelagic (water column) habitats. The assessment is based on (a) changes in lifeforms (groups of plankton species that perform the same function in the marine environment) that make up plankton communities, and (b) changes in the biomass of phytoplankton and the abundance of zooplankton. These assessments have been used to inform the assessment of GES for the updated UK Marine Strategy Part One (2019) and to fulfil reporting commitments under the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR). The changes experienced by plankton communities could have implications for the health, (functioning, dynamics and structure) of the whole marine ecosystem.

Readiness and links to data

This indicator is not available for reporting in 2023 in a finalised form as existing analytical methods are under ongoing development to gain a better understanding of the effects of the key anthropogenic pressures and climatic drivers. This indicator will be updated using elements of the pelagic habitat indicators and pelagic habitat thematic assessments reported via the OSPAR Quality Status Report 2023.

Additional background data on the abundance of plankton in UK waters are also available on the Plankton Lifeform Extraction Tool. The assessments of pelagic habitats used for this interim indicator have been reported under the updated UK Marine Strategy Part One (2019) and to fulfil reporting commitments under the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR).

Notes on indicator

Spatial representations and charts for the underlying data supporting this interim indicator can be accessed via the Marine Online Assessment Tool. While the currently available data predate the 25 Year Environment Plan, they provide the most recently available assessment of the condition of pelagic 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.

Indicator components

Trend description for C5a

The lifeforms (functional groups of species) that make up the plankton communities in the Celtic Seas and the Greater North Sea changed between the starting conditions period (2004 to 2008) and the current assessment period (2009 to 2014). Prevailing environmental conditions, in particular climate change, are likely to be driving these observed changes, but the potential role of direct human activities such as fishing and nutrient inputs contributing to these changes cannot be ruled out. It is currently uncertain whether GES has been achieved.

Assessment of change

No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.

Trend description for C5b

In most areas of the Celtic Seas and the Greater North Sea, phytoplankton biomass has increased between the starting conditions period (2004 to 2008) and the current assessment period (2009 to 2014). Changes in zooplankton abundance varied across the 2 sub-regions assessed, with increases in some areas, decreases in others, and no change in some. This assessment identified, with a medium to high level of confidence, changes in phytoplankton biomass and zooplankton abundance which may have consequences on the functioning, dynamics and structure of the whole marine ecosystem. It is not yet possible to say if GES has been achieved.

Assessment of change

No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.

Indicator Metadata