We illustrate the theoretical plausibility that fishery removal of sharks can indirectly alter predation pressure on different fish species via the behavioural responses of mesoconsumers released from predator intimidation. Our dynamic state variable model of foraging decisions by harbour seals, a mesopredator, predicted indirect effects of the removal of Pacific sleeper sharks on two species c...

Behavior of killer whales feeding on herring schools was recorded with a high frequency (455 kHz) sonar and recorded on a SVHS tape. Synchronization of surfacing behavior of killer whales was analyzed from 8 mm videotapes recorded between 1990–92. Two different feeding techniques, carousel feeding, where killer whales cooperatively herd herring schools into a tight ball towards the surface and ...

Fish oil, made from the tissue of oily fish‐such as salmon, tuna, mackerel, herring, lake trout and sardines‐has many health benefits. Fish oil contains important Omega‐3 fatty acids , most notably eicosapentaenoic acid (EPA) and decosahexaenoic acid (DHA). These Omega‐3 fatty acids are believed to have health benefits ranging from reducing the risk of heart attack and coronary heart disease to...

Observers were placed on pelagic vessels in the Scottish fisheries for mackerel (Scomber scombrus), herring (Clupea harengus), “maatje” herring (herring caught just before their first spawning) and argentines (Argentina silus) to monitor by-catch composition and discarding practices. A total of 67 days was spent at sea, 11 on the argentine fleet, 28 on the herring fleet, 12 on the “maatje” herr...

Military antisubmarine sonars produce intense sounds within the hearing range of most clupeid fish. The behavioral reactions of overwintering herring (Clupea harengus) to sonar signals of two different frequency ranges (1-2 and 6-7 kHz), and to playback of killer whale feeding sounds, were tested in controlled exposure experiments in Vestfjorden, Norway, November 2006. The behavior of free rang...

Fish fat belongs to highly specific nutritious elements especially due to its high content of polyunsaturated fatty acids. The aim of the present study was to determine the content of 2-thiobarbituric acid reactive substances in over-the-counter cold and warm marinades in which the base fish material consists of the Atlantic herring (Clupea harengus). Fifty six marinated fish products stored at...

The construction of dams and tide gates on waterways has altered the physical structure many coastal, estuarine, freshwater systems. These changes have come at a cost to fish populations, most notably diadromous species, which rely connectivity between marine anthropogenic structures can direct effects migrating fish, such as blocking passage, or more subtle effects, changing movement patterns....

BACKGROUND In a "wasp-waist" ecosystem, an intermediate trophic level is expected to control the abundance of predators through a bottom-up interaction and the abundance of prey through a top-down interaction. Previous studies suggest that the North Sea is mainly governed by bottom-up interactions driven by climate perturbations. However, few studies have investigated the importance of the inte...

Nematodes from the superfamily Ascaridoidea (families Anisakidae and Raphidascarididae) are worldwide distributed parasites. Their live cycles include many species of water invertebrates and teleostean fish as intermediate hosts, and fish, sea mammals or fish-eating birds being definitive hosts. Humans can be infected with some of these parasites after consumption of raw or wrongly processed fi...

In this study, the identification of dominant fish species in East Sea was conducted using dB-difference method. The survey two frequencies 38 and 120 kHz transect 6 southern part Sea. Information on identified fishing gear e-DNA, target were selected analyzed as cod, anchovy, common squid, herring. range for each set to −0.86 dB < ∆MVBS 38–120 0.82 cod 2.66 2.84 anchovy. squid −0.36 1.25 0....