Marine scientists are seeing an increase in temperature throughout the water column along the entire Norwegian coast.
Photo: Anders Jakobsen / Institute of Marine Research
Scientists at Norway's Institute of Marine Research have released data from a "unique" collection of ocean temperature measurements, taken by volunteers at regular intervals along the Norwegian coastline since 1935.
The data, from eight fixed hydrographic stations spanning the entire coast from north to south, shows that the average temperature has risen by one to two degrees celsius at all stations throughout the period in which samples have been taken - a clear indication of the impact of climate change on ocean environments, say marine scientists.
“This is unique data because it is so long and consistent. Since it is measured at the same place, it is comparable over a long period of time, and that makes it unique in a global context,” Mari Myksvoll explained, in a news release.
"We see that there has been an increase in temperature throughout the water column. At the top of the water column is the coastal water, and below that is the Atlantic water. And both are getting warmer,"
"It may not sound like a big change, but one to two degrees is a lot. The average temperature is often very stable. So when it changes, this is a significant change compared to how it usually is," she added.
The changing temperature directly impacts fish species native to these waters, the scientists point out.
“Some species have absolute temperature limits. Cod, for example, cannot spawn if it gets warmer than 10 degrees," Myksvoll explained.
Colour bars showing how temperatures deviate from the average since 1935. The top graphic shows the measurements from the hydrographic station at Eggum, on the Lofoten Islands of Norway, while the lower one shows the total for all eight observation stations.
Image: Norwegian Institute of Marine Research.
Norwegian marine researchers have previously warned that warming seas could have significant impacts on marine ecosystems as well as the fishing industry.
In a study published last year, researchers from the Norwegian Institute of Marine Research and the Arctic University of Norway demonstrated that fish populations along the Norwegian coast had shifted over a period of 25 years as a result of climate change, drawing on data from annual coastal expeditions.
"There is no doubt that the species richness in the north has increased considerably. It is a consequence of a warmer climate, which is causing fish that prefer colder waters to move north. Among the fish species that have arrived in the north, we find sprat and silver cod, among others," said researcher Ulf Lindstrøm, in a separate news release last August.
“When fish have to move, it will change the composition of species along the coast. If there are major changes in the ecosystem, it could also have consequences for the fishing industry,” he added.
“If local fish stocks are challenged, such as coastal cod, it could affect fisheries along the coast. With ever-increasing sea temperatures and increased human activity along the coast, the effects of climate change on biodiversity must be taken into account in future management of species and areas,” Lindstrøm said.
