Distribution of marine species

Assessment versions

Published (reviewed and quality assured)

• Distribution of marine species (CLIM 015) - Assessment published Nov 2012

Justification for indicator selection

Changes in the distribution of organisms are one of the key indicators of marine climate change impacts. Distribution maps from the North-east Atlantic are used as one part of this indicator to demonstrate large-scale changes at the decadal scale. The second part of this indicator describes the ratio between a warm-water species (Calanus helgolandicus) and a cold-water species (Calanus finmarchicus) in the North Sea on an annual basis. In the eastern Mediterranean Sea, the introduction of warm and tropical alien species from the Red Sea has been exacerbated by observed warming, leading to a 150 % increase in the annual mean rate of species entry after 1998.

Changes in marine plankton can trigger further effects on marine and terrestrial ecosystems. For example, increases in the surface temperature of the North Sea in recent decades have triggered establishment of warm-water swimming crabs, which in turn allowed establishment of colonies of lesser black-backed gulls in Belgium and northern France, with expected follow-on impacts on terrestrial ecosystems through their fertilisation of terrestrial soils.

Scientific references:

• IPCC, 2007. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007; M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson (eds); Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Indicator definition

• Calanus ratio in the North Sea
• Annual mean number of Calanus per sample

Units

• Ratio [dimensionless]
• Number of Calanus [dimensionless]

Policy context and targets

Context description

Targets

No targets have been specified.

Related policy documents

• Climate-ADAPT: Mainstreaming adaptation in EU sector policies
  Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
• Climate-ADAPT: National adaptation strategies
  Overview of activities of EEA member countries in preparing, developing and implementing adaptation strategies
• DG Climate Action: What is the EU doing about climate change?
  Activities of the EU regarding climate change (both mitigation and adaptation)
• White paper - Adapting to climate change: towards a European framework for action
  EU framework for adaptation to climate change, leading to a comprehensive EU adaptation strategy by 2013

Methodology

Methodology for indicator calculation

Data from the Sir Alister Hardy Foundation for Ocean Science (SAHFOS) on Calanus abundance in the central North Sea 1958–2009 is used for the indicator. The Continuous Plankton Recorder (CPR) survey is the longest running, large-scale marine biological survey in the world. The CPR is a near-surface (10 m) plankton sampler voluntarily towed each month behind merchant ships on their normal routes of passage. Methods of analysis for, 400 phyto and zooplankton taxa have remained almost unchanged since 1958.

Methodology for gap filling

Not applicable

Methodology references

• Warner and Hays (1994): Sampling by the continuous plankton recorder survey Progress in Oceanography , Volume 34, Issues 2–3 , 1994, Pages 237–256

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• Continuous Plankton Recorder (CPR) survey

Data sources in latest figures

Uncertainties

Methodology uncertainty

Not applicable

Data sets uncertainty

In general, changes related to the physical and chemical marine environment are better documented than biological changes because links between cause and effect are better understood and often time series of observations are longer. The longest available records of plankton are from the Continuous Plankton Recorder (CPR) are some 60 years long. It is a sampler that is towed behind many different merchant vessels, along fixed shipping routes. Sampling was started in the North Sea in the 1950s and today a network covering the entire north Atlantic has been established. No other plankton time series of equivalent length and geographical coverage exist for the European regional seas, although many new initiatives investigating species distributions and their changes in Europe’s seas are now emerging.

Further information on uncertainties is provided in Section 1.7 of the EEA report on Climate change, impacts, and vulnerability in Europe 2012 (http://www.eea.europa.eu/publications/climate-impacts-and-vulnerability-2012/)

Rationale uncertainty

No uncertainty has been specified