By Magdalena A K Muir
Figure 1: Predicted number of high-latitude fish species in each approximately 50 × 50 km pixel of the Arctic region according to the EC-Earth model, RCP 8.5 scenario.
Figure 2: Sensitivity analysis of the interchange potential of the NE and NW passages between 2015 and 2100.
Figure 3: The prediction of suitable environmental conditions for three commercial species over time.
New research shows that species from the Atlantic and the Pacific oceans soon will start to mix, which could have serious consequences for commercial fisheries and local biodiversity and ecosystems.
For thousands of years, ice and harsh conditions have served as a natural barrier between species from the Atlantic and the Pacific oceans in the northern hemisphere. New research,shows that marine mammals and large fish populations will soon be able to make the journey northward, eliminating the barrier between the Atlantic and the Pacific Oceans.
Some species that have already crossed over. For example, the Alaska Pollock, an extremely important fish in the northern Pacifich has been observed off the coast of Northern Norway. It was originally believed that the fish observed belonged to another species as did not consider the possibility of movement between oceans. The Greenland whale is another species observed in the passages between the two major oceans.
“We predict that the exchange of species will start accelerating in 2050,” says the study’s lead author Mary Wisz from the Danish research instiution DHI. According to the researchers, 3 million years have passed since Arctic permitted extensive exchange of species between the northern Pacific and the Atlantic, and and since then only limited exchanges of species have taken place. The cold barrier between oceans has led to species developing in different directions in the two oceans. Life in the two oceans has developed in isolation from each other, so species are very different from each other.
The consequences could be huge if they suddenly start mixing. Commercial fishermen in the northern Atlantic and Pacific may be affected — positively as well as negatively — by a mixing of the species from the two oceans, as the North Atlantic and North Pacific contribute some 40 percent of all fish caught globally. Other impacts on biodiversity and ecosystems will also occur.
Nature Climate Change Letter: M.S. Wisz et al, Arctic warming will promote Atlantic–Pacific fish interchange, Nature Climate Change (2015), doi:10.1038/nclimate2500 . Figures in blog from this article.
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