Demersal fish
Grey gurnard - eutrigla gernardus - grauwe poon.png
Layer Info
Category Fish
Editable No
Data source Ecosystem simulation
Extremely Low
Extra High


Small demersal fish

Example species: Grey gurnard

Habitat: Demersal
Main role: Predator
Trophic level: 4,5

Diet: Juveniles feed on a variety of crustaceans. The diet of older specimens consists mainly of juvenile fish.

Threats: Grey gurnards are of lesser commercial importance, and are mostly caught as bycatch for other flatfish.

Large demersal fish

Example species: Thornback ray

Habitat: Demersal
Main role: Predator
Trophic level: 3,8

Diet: This ray feeds on fish and invertebrates.

Threats: Of commercial interest and near threatened according to IUCN red list. The thornback ray is often caught as bycatch by trawl and gillnets.===MSP Challenge===

The small demersal fish group includes the following species: eelpout, shorthorn sculpin, Vahls’s eelpout, longspined bullhead, hooknose, common seasnail, greater weever, lesser weaver, snake blenny, striped red mullet, solenette, thickback sole, mediterranean scaldfish, argentine, dragonet, piper gurnard, red gurnard and grey gurnard.

The large demersal fish group includes the following species: rabbit fish, John Dory, sea trout, Norway red fish, Bluemouth, roundnose grenadier, starry ray, spotted ray , Common skate, cuckoo ray and thornback ray.

Demersal fish is a month-by-month, computer generated data layer following calculations made by the ecosystem simulation (EwE).

Different pressures generate by human activities (noise, bottom disturbance, surface disturbance, artificial substrate) have different, complex effects on marine species in terms of movement, survival and procreation.

Demersal fish are caught by all fishing fleets, but mostly by bottom trawl.

Food web2.png

In different languages

Grey gurnard

  • SN: eutrigla gurnardus
  • EN: grey gurnard
  • NL: grauwe poon
  • GE: Graue Knurrhahn
  • DK: grå knurhane
  • FR: grondin gris
  • NO: knurr
  • SE: knorrhane

The grey gurnard is an abundant demersal species. Gurnards are key predators in the North Sea and have become more important in recent years. In winter they form dense aggregations locally to the northwest of the Dogger Bank, whereas in summer they are more widespread. This fish produces sounds.

Thornback ray

  • SN: raja clavata
  • EN: thornback ray
  • NL: stekelrog
  • GE: Nagelrochen
  • DK: sømrokke
  • FR: raie bouclée
  • NO: piggskate
  • SE: knaggrocka

The thornback ray is usually found on shallow mud, sand, or gravel seabeds up to 60m depth. It is less abundant in the southern North Sea. Its population levels are presently too low for the ray to fulfill its ecological role.


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This page was last edited on 17 November 2020, at 20:09. Content is available under GPLv3 unless otherwise noted.