The fundamental role of mesopelagic fishes for the structure and change of Northeast Atlantic marine ecosystems
Informations
- Funding country
Norway- Acronym
- -
- URL
- -
- Start date
- 1/1/2019
- End date
- 12/31/2024
- Budget
- 1,253,370 EUR
Fundings
| Name | Role | Start | End | Amount |
|---|---|---|---|---|
| Marine Resources and the Environment (MARINFORSK) - call 2016 | Grant | - | - | 1,253,370 EUR |
Abstract
As you move from the coast and towards the open ocean, there is no bottom or kelp forests to hide in. The small fishes and other prey organisms that occupy the pelagic live a game of hide and seek, where their only safe option is to swim down to the darker waters to hide. The darkness, however, also makes it difficult to find food, which has resulted in the world?s largest animal migrations as fish swim down to hide during day and swim up again in the evening to forage at night. The largest stocks in terms of biomass are the mesopelagic fishes, which are a couple centimeters long and thrive in the ocean?s twilight zone, down to about 1000 meters in clear water on a sunny day. North of the Arctic Circle, primary production and grazing zooplankton thrive 24/7 during the midnight sun, but the mesopelagic fish are trapped deep below, in the dark waters they prefer. During a typical summer day, there is no safe period for them to swim towards the surface to forage, with the result that they starve in the deep. Few mesopelagic fish are therefore found at northern latitudes, which reduces the grazing pressure on copepod zooplankton. This has opened a niche for migrating fish species that visit northern oceans during summer, such as herring and mackerel. And among zooplankton, the absence of mesopelagic fishes in in the north may allow for multi-year life cycles because zooplankton can expect to live longer before they are eventually eaten. This project will use computer modelling to put together what we know about these species and their ecosystem to identify the niches and adaptations of key players. The project will also focus on effects of climate change. In particular, periods of starvation can become harder if temperatures rise. Mesopelagic fishes may thus run into trouble during summer and herring during winter, with the like consequence that climate warming may push the distribution of these fishes southwards southwards, not northwards as is generally expected.