No future for Euro-Arctic ocean fishes?

• Published in: Marine ecology. Progress series (Halstenbek) 2017-07, Vol.575, p.217-227
• Main Author: Christiansen, Jørgen S.
• Format: Article
• Language: English
• Subjects: OPINION PIECE
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps12192

In this essay, I outline how vanishing sea ice may unveil costs and benefits for fishes native to the Euro-Arctic seas. Most arctic fishes are not directly associated with the sea ice, but constitute an integral part of the seafloor biota. Arctic seafloor fishes may temporarily benefit from improved feeding conditions but may also lose to novel predators such as invading southern fishes and emerging industrial enterprises on the Arctic shelves. Polar cod Boreogadus saida, on the other hand, an abundant and prominent member of the ice-associated biota, uses sea ice as spawning substrate, shelter and feeding ground. Thus loss of sea ice likely has severe and explicit costs for this focal species with profound ecological consequences. Time series and biological baselines for arctic fishes are fragmentary at best. As I see it, we need to diagnose our ignorance and put the precautionary principle into full effect while awaiting for knowledge gaps to be filled. Here I offer a sneak peek into the future of ocean fishes in the Nordic Seas, primarily in the Arctic sector, with my opinion based on recent studies in Arctic marine ecology and climatology.