Growth of juvenile halibut (Hippoglossus hippoglossus L.) in captivity

The growth and substrate preference of collected wild juvenile halibut under culture conditions were investigated. The size of the collected fish conformed well with year class data from earlier studies. Halibut growth in nature is slower than for i.e. cultured salmon up to the III-group. The present study showed, however, that halibut can grow much faster in culture than what is normal in nature. The substrate studies were contradictory in terms of growth and will have to be extended. The fish without substrate did, however, develope a dark coloration on the underside

An automatic feeding system for culturing rotifers with dry feed

An automatic feed distribution system for culturing rotifers is described and discussed. The system has been successfully used at the Austevoll Marine Aquaculture Station for 3 years

Dynamics of wintering Norwegian spring-spawning herring at the entrance to Tysfjorden, December 1996

The entrance region to Tysfjorden was acoustically surveyed a total of eleven times during the December 1996 abundance survey of the spawning stock of Norwegian spring-spawning herring (Clupea harengus). The observations are summarized through maps of the distribution, vertical sections, and statistical measures of acoustic density in each of two strata. Experimental variograms are modeled, yielding parameter values that summarize the major properties of aggregation. The collective measures of density and aggregation portray a highly dynamic situation with strong diel variation but a general persistence of the fish distribution over the eleven days of its repeated observation

The effect of shading in pen rearing of Atlantic salmon (Salmo salar)

A full scale pen rearing experiment with covers to reduce illumination was carried out. No significant effects were observed on growth, mortality, ectoparasite infection, maturation or net pen fouling

Day / night variation in fish directivity in the trawl opening

Still photographs of fish in the mouth area of a bottom trawl were taken by a downwards-oriented automated strobe camera mounted near the headrope. Fish angles relative to the towing direction were measured. Fish were significantly less polarized by night than by day, and in the daytime photographs less polarization was seen at low fish densities than at higher. The results are discussed with regard to fish herding patterns and potential escapement beneath the fishing line of a trawl

Seal investigations in the North Atlantic in 1974

Accounts are given of weather and ice conditions, the distribution of seals and of sampling of harp and hooded seals at Newfoundland-Labrador, in the West Ice (at Jan Mayen), in the East Ice (in the Eastern Barents Sea) and in the Denmark trait. A few provisional results of age analysis are given. Some observations from the coast of Norway suggest increasing numbers of local common and grey seals

Seal investigations in the North Atlantic in 1974

Accounts are given of weather and ice conditions, the distribution of seals and of sampling of harp and hooded seals at Newfoundland-Labrador, in the West Ice (at Jan Mayen), in the East Ice (in the Eastern Barents Sea) and in the Denmark Strait. A few provisional results of age analysis are given. Some observations from the coast of Norway suggest increasing numbers of local common and grey seals