Data from: Rapid climate change increases diversity and homogenizes composition of coastal fish at high latitudes
Cite this dataset
Siwertsson, Anna et al. (2024). Data from: Rapid climate change increases diversity and homogenizes composition of coastal fish at high latitudes [Dataset]. Dryad. https://doi.org/10.5061/dryad.zs7h44jhf
Abstract
Rapid warming at high latitudes triggers poleward shifts of species’ distributions that impact marine biodiversity. In the open sea, the documented redistributions of fish lead to a borealization of Arctic fauna. A climate driven borealization and increased species diversity at high latitudes is also expected in coastal fish communities, but it has not been previously documented on a large, biogeographic scale. Here, we investigate the impact of temperature change over the last 25 years on fish communities along the coast of Norway. The study area, spanning different ecoclimatic zones between 62° and 71° N, harbors over 200 species of boreal and Arctic fish. Several of these fish species are harvested by coastal and indigenous communities, influencing settlements geography and livelihood. The long-term data on coastal water temperatures and fish species were obtained from monitoring stations and scientific surveys. Water temperature measured at three fixed sampling stations distributed along the coast show increased temperatures during the study period. The fish species distribution and abundance data were obtained from the annually standardized scientific bottom trawl survey program. Fish species richness, which was highest in the south, increased with warming first in the south and then, gradually, further north, eventually affecting biodiversity in the whole study area. Fish community composition showed a distinct latitudinal pattern early in the study, with Arctic fish species confined north and boreal species dominating south. The poleward shifts eventually eroded this zoogeographic pattern, resulting in more boreal fish species in the north and an increased homogenization of species composition along the Norwegian coast. The climate-driven reorganization of fish communities affects coastal ecosystems that are exposed to fisheries, aquaculture and other rapidly expanding human activities, stressing the urgent need for a climate adaptation of integrated coastal management.
README: Rapid climate change increases diversity and homogenizes composition of coastal fish at high latitudes
https://doi.org/10.5061/dryad.zs7h44jhf
The dataset contains summary statistics of fish diversity and composition from demersal trawls along the Norwegian coast. Raw data comes from an annual scientific survey and was collected by the Norwegian Institute of Marine Research (IMR). The results are based on a selection of 59 fish taxa, and presented per year (1995-2019) and sub-section along the coast. The coast was divided into 10 equally long intervals of c. 167 km each. Please read the paper or contact the author for more details.
Description of the data and file structure
| Column | Explanation |
|---|---|
| year | Year of sampling |
| coastint | Coastal interval, 167 km long segments along the coast, numbered from 1 (south) to 10 (north) |
| S | Mean species richness, number of species per trawl haul |
| J | Mean Pielou`s eveness index per trawl haul |
| H | Mean Shannon`s diversity index per trawl haul |
| totcount_nm | Mean fish abundance per trawl haul, standardised to counts per nautical mile trawled |
| ntrawls | Number of trawl hauls per year and coastal interval |
| north_perc | Percent of trawls assigned to the northern fish assemblage type |
Methods
Refer to the associated paper for a description of methods.
Funding
The FRAM Centre, ESCE, AVEC, CLEAN