Baseline study Fish, fry and commercial fishery Nysted Offshore ...

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shoals in shallow waters. It lives near the bottom, except at night, when it moves up to
forage. Its main diet consists of crustacea, small shellfish and other creatures of suitable
size.
Its reproductive behaviour is very similar to that of the sand goby. It lives for a year,
and the adults die soon after spawning.
Butterfish (Pholis gunnellus)
The butterfish is found all over northern Europe, down to the French coast. They live in
tidal waters out to a depth of 30 metres. They are extremely tolerant of cold, and do not
therefore move out to deeper waters in the winter. They inhabit the seaweed on reefs
and slowly seek food in these areas. Sometimes they hide under shells to lie in wait for
food. Spawning takes place when they are 3 years old in January–July, and the female
releases 100–200 eggs. The eggs rest on the sea bed in the form of a cone. Both sexes
look after the eggs until they hatch. The fry are pelagic initially, until they are 3 cm
long. At this point they seek the bottom. Their diet consists of crustacea and other small
animals.
Eelpout (Zoarces viviparus)
Eelpout are widespread in Europe from the English Channel north. They live near the
bottom of eelgrass zones, and are distinctly stationary fish. They stay in shallow water
in the summer and move out to deeper waters in the winter. Their diet consists
principally of gammarus, shellfish, snails and small crustaceans. In brackish waters they
sometimes also take insect larvae. They move slowly around amongst the eelgrass,
examining one clump of macroalgae after another.
The eelpout is viviparous. The number of young varies, but is between 50 and 300. Like
their parents, the young are benthic, and they very quickly begin to forage for
themselves after birth. They grow very rapidly and are mature as early as their second
year.
They are treated as part of the by-catch in commercial fishery, and only occasionally
used as a table fish. Many anglers use them as bait.
Short-spined sea scorpion (Myoxocephalus scorpius)
The short-spined sea scorpion occurs throughout northern Europe. It lives amongst
stones and seaweed at depths from 1 to 200 metres. It tolerates low temperatures, which
means it can also be found in the arctic region. It is a distinctly stationary fish, which
means there are local varieties.
Breeding takes place in December–January. Fertilised eggs have been found in females,
indicating that fertilisation is internal. Once the female has spawned, the male looks
after the eggs until they hatch 5 weeks later. The fry are pelagic in habit, until they
achieve a length of approximately 15 mm, at which point they seek the bottom.
SEAS. Baseline study – Fish, fry and commercial fishery Dok. nr. 2148-03-001-rev3 2P.doc