Demersal Fish Community - spatial variation in size, species richness and diversity

What is it:

The three layers show the spatial variation of demersal fish (generally living on or near the seabed) in waters around Scotland (averaged over the period 1999 to 2008) for:

Size Composition (Large Fish Indicator) (defined as the proportion of fish (by weight) in the community that is greater than 40 cm in length). The higher the value (varying between 0 and 1), the greater the proportion of large fish in the community.
Species Richness (a count of the number of demersal fish species recorded in any survey sample).
Species Diversity (indices that also take account of the relative abundance of each species in the sample).

Date of Data: 1999-2008.

Links to Scotland's Marine Atlas:

Chapter 4: Demersal Fish Community

Data originators:

International Council for the Exploration of the Sea (ICES)

This information page is part of the theme:

Demersal Fish Community

More Information:

Scientific trawl surveys data have been used to assess change in the status of the fish communities. The data collected generate quantitative measures of particular characteristics of the fish community, and these can be used to monitor change in those characteristics over time and between different places. These measures are referred to as community indicators.

Over 240 species of fish inhabit the seas around Scotland. For Scotland’s Marine Atlas Marine Scotland undertook an investigation into the state of the demersal fish community in Scottish waters. The work employed a similar approach to comparable assessments for the UK's Charting Progress 2 and OSPAR's Quality Status Report. More information is available in the Demersal Fish Community Atlas link above.

All three aspects of the composition and structure of the demersal fish community, proportion of large fish, species richness and species diversity, vary markedly across Scottish waters. For example, fish greater than 40 cm in length constituted a much greater proportion of the biomass of demersal fish in western waters than in regions to the east of Scotland.

This page was last modified on :

Thursday, May 5, 2016 - 15:56

Map Type	Click title for metadata and licence information	Date of data	View Map
Map Layers (NMPi)	Demersal Fish - Spatial variation in Size Composition (Large Fish Indicator) of demersal fish in waters around Scotland, averaged over the period 1999 to 2008	1999-01-01 to 2008-12-31	Access this map on NMPi
Map Layers (NMPi)	Demersal Fish - Spatial variation in Species Diversity of demersal fish in waters around Scotland, averaged over the period 1999 to 2008	1999-01-01 to 2008-12-31	Access this map on NMPi
Map Layers (NMPi)	Demersal Fish - Spatial variation in Species Richness of demersal fish in waters around Scotland, averaged over the period 1999 to 2008	1999-01-01 to 2008-12-31	Access this map on NMPi

Type	Link Title	External Link
Data Portals	DATRAS - Trawl Surveys	www.ices.dk

Type	Title	External link
Web link	Fish and Shellfish Stocks: 2013	www.gov.scot
Marine Scotland Data Portal	Assessment of the "State" of the Demersal Fish Communities in OSPAR regions II, III, IV and V	data.marine.gov.scot
Marine Scotland Data Portal	Assessment of the “State” of the Demersal Fish Communities in UK waters	data.marine.gov.scot