The North-western North Sea is monitored for changes in the proportion, by weight, of large fish individuals (≥40cm) in fish populations. This indicator is based on standardised annual research survey trawls, with data up to 2014, and is published by the Joint Nature Conservation Committee on behalf of Defra. It tracks the impact of fishing on community structure, noting that species like cod, haddock, and saithe have formed a substantial part of large fish catches.
Use Cases
- Modeling the relationship between fishing pressure and fish community structure based on the proportion of large fish.
- Analyzing temporal trends in marine biodiversity indicators based on annual survey trawl data.
- Assessing the ecological impact of reduced predation from large fish on smaller prey species.
- Evaluating the effectiveness of fisheries management policies by tracking changes in the proportion of large fish over time.
Strengths
- Data is part of a formal suite of 24 UK biodiversity indicators published by an authoritative body (JNCC/Defra).
- Indicator methodology is detailed in a supporting technical document.
- Time series data likely spans from the 1980s to at least 2014.
Limitations
- Description metadata is limited; actual data quality requires manual inspection after download.
- Column-level documentation is absent; field semantics must be inferred after download.
- The latest data point is for 2014, which may limit analysis of recent trends.
Provenance
- Source
- Joint Nature Conservation Committee (JNCC) on behalf of Defra.
- Collection Method
- Standardised annual research survey trawls.
- Time Range
- 1980s to 2014
- Freshness
- Last updated 2026-07-08 13:32:31.628747; freshness should be verified
- Geography
- North-western part of the North Sea.