Data from: Feeding ecology of Northeast Atlantic mackerel, Norwegian spring-spawning herring and blue whiting in the Norwegian Sea

• Main Authors: Bachiller, Eneko, Skaret, Georg, Nøttestad, Leif, Slotte, Aril
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2017
• Subjects: Gastropoda cl; Limacina spp; Thysanoessa longicaudata; Crustacea subph; NEA mackerel; Clausocalanus spp; Oikopleura spp; Actinopterygii cl; Maurolicus muelleri; Calanus finmarchicus; Amphipoda ord; Calanus glacialis; Cladocera infraord; Calanus hyperboreus; Hyperiidae fam; Podon spp; Calanus spp; Thysanoessa spp; Hydrozoa cl; Chaetognatha ph; Themisto abyssorum; Euchaeta spp; Caridea infraord; Themisto spp; Munida spp; inter-annual variability; Sebastes spp; Metridia spp; Ostracoda cl; Limacina retroversa; diet composition; blue whiting; Gonatus fabricii; Meganyctiphanes norvegica; Evadne spp; Calanoida ord; Decapoda ord; Appendicularia cl; Thysanoessa inermis; Metridia longa; Myctophidae fam; Melanogrammus aeglefinus; NSS herring; Euphausiacea ord; Themisto libellula; Cephalopoda cl; Pandalus spp; Copepoda subcl; Northeast Atlantic; Norwegian Sea; Copepods
• Online Access: https://doi.org/10.5061/dryad.f5r7f

The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005-2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of regular monitoring of pelagic fish diets. CTD and fish ...