Of eight main selected coastal fish species; Baltic sprat, herring, smelt, eelpout, four-horn sculpin, perch, flounder and turbot, five; herring, smelt, eelpout, four-horn sculpin, flounder, seem most suitable for heavy metal monitoring in coastal waters in the Norhern Baltic Sea. In general low concentrations of Hg and Cd were measured from the edible parts (muscle tissue) of the fishes. Preda...

The Atlantic herring (Clupea harengus), one of the most abundant marine fishes in the world, has historically been a critical food source in Northern Europe. It is one of the few marine species that can reproduce throughout the brackish salinity gradient of the Baltic Sea. Previous studies based on few genetic markers have revealed a conspicuous lack of genetic differentiation between geographi...

The aerobic intestinal microflora of 2-week-old herring (Clupea harengus) larvae was characterized by using conventional microbiological methods and electron microscopy. Larvae were hatched and kept in filtered seawater or in seawater with penicillin and streptomycin. The gastrointestinal tract of herring larvae is essentially a straight tube divided into two compartments. Light microscopy reve...

When prey and predator are seasonal migrants, encounters depend on migration phenologies and environmental constraints on predation. Here we investigate the relative contribution of seasonality in irradiance and prey abundance in shaping the rapid seasonal body condition increase of a migrating predator searching visually for its prey: the Norwegian spring-spawning herring, Clupea harengus, fee...

Norwegian killer whales debilitate prey by slapping their tails into herring schools. These underwater tail slaps produce a thud-like sound. It is unclear whether this sound is caused by cavitation and/or physical contact between herring and whale tail. Also the forces causing debilitation of the fish are not understood. Here we present an acoustic analysis of underwater tail slaps using a mult...

Throughout the 1980s, reproductive success of the top-predator cod declined and stock sizes of the main prey species herring and especially sprat, important planktivorous predators in the system, increased substantially. Although the hydrographic conditions conducive for survival of early life stages improved during the 1990s, recruitment success of cod remained far below average. As clupeids h...

Events of extensive gas bubble release in over-wintering Norwegian spring-spawning herring (Clupea harengus) were repeatedly observed acoustically and visually in Vestfjorden, northern Norway, during attacks from killer whales (Orcinus orca) and saithe (Pollachius virens). Gas bubbles were visually observed to come from the swimbladder of individual herring swimming very close to the surface an...

The Barents Sea system is often depicted as a simple food web in terms of number of dominant feeding links. The most conspicuous feeding link is between the Northeast Arctic cod Gadus morhua, the world's largest cod stock which is presently at a historical high level, and capelin Mallotus villosus. The system also holds diverse seabird and marine mammal communities. Previous diet studies may su...

Pacific herring, Clupea pallasi, were exposed both acutely (96 h) and chronically (9 wk) to the water-soluble fraction (WSF) of North Slope crude oil. Initial mean total PAH concentrations were approximately 10, 40 and 100 μg/L. Biological availability was suggested by a significant induction of hepatic cytochrome P450 content, ethoxyresorufin O-deethylase and glutathione S-transferase activiti...

Because of the high management relevance, commercial fish related aspects have often been central in marine ecosystem investigations. The iterative shiftogram method was applied to detect occurrence, type and timing of shifts in the single and multivariate time series linked to the spring spawning herring larvae in the Gulf of Riga (Baltic Sea). Altogether nineteen larval herring and related en...