Norwegian jelly-cruise

27. 8. 2020

During the cruise that was held in the days of 26-27.8.2020, we trawled at 5 different locations in the inner part of Trondheimsfjorden and harvested in total 4 tons of Helmet jellyfish Periphylla periphylla and 150 kg of moon jellyfish Aurelia aurita. The catch was sorted after the trawls and the total jellyfish biomass estimated. Sub-samples from each location were taken to obtain weight and size measurements for individual specimen. In addition, tissue samples of the jellyfish were taken for population genetic analyses. The size distribution of Helmet jellyfish ranged from 0,5 cm to the largest specimen with 24 cm (individual weights ranging from 1g to 1,6 kg). Compared to previous years, larger numbers of small Helmet jellyfish were harvested in 2020. Moon jellyfish were harvested in lower numbers and the sizes ranged from 9-34 cm (35 g to 1,2 kg).