Pelagic Fish at the Barents Sea Polar Front in May 2022

## Methods

### Study area

This dataset is the result from sampling at 5 stations at the Polar Front in the western part of the Barents Sea.

### Time coverage

The samples were collected between 20 May 2022 and 25 May 2022.

### Sampling

5 pelagic trawl samples were collected with a Harstad pelagic trawl, which has an effective height of 9-11 m and width of 10-12 m when towed at ca. 3 knots. The mesh size of the inner liner of the cod end was 10 mm. The pelagic trawl was towed at ca. 3 knots for 20-30 min and abundances were standardized by converting to catch per unit effort (expressed in kilograms per cubic meter).

### Sample analysis

All organisms were identified to the nearest species or genus onboard. Throughout all stations, capelin had a large size distribution, so individuals similar in length were sorted into approximate size classes (small, medium, and large). The total number and weight of each species was recorded. For large catches, subsamples of 20-30 individuals were taken with representing length distributions of the catch. The standard length, height at the anus (up to the nearest 1 mm), and weight (up to the nearest 0.1 g) were measured for all specimens in the (sub)sample.

### Fish stomach content analysis

The stomachs were isolated and immediately preserved in 70% ethanol. For each individual stomach, the level of fullness (from 0: empty, to 4: full), prey composition (the count and % volume each prey item takes up in the stomach), and the level of digestion for each prey item (from 1: newly eaten, to 5: digested or non-identifiable) were estimated and recorded.