Acid concentration in the Alaskan sea increased

What makes Alaska's seas one of the most productive regions in the world can also make them vulnerable to sea acidification. According to new findings by Alaska Fairbanks University dentists, Alaska's oceanic acid levels are rising and adversely affecting the crab and salmon fishery.

This spring, oceanographer Jeremy Mathis returned from a sea patrol with samples of seawater collected from the deep water of the Gulf of Alaska. When he tested the acidity of the samples in the laboratory, the results were higher than the initial predictions. This suggests that the sea acidification process in Alaska is more severe and occurs faster than tropical waters. This result is also consistent with his findings at the Chukchi and Bering beaches.

Mathis said: 'It seems that any area in Alaska waters we see signs of increasing acidity in the sea'.

Marine acidification is a phrase that describes increasing ocean acidity. The sea absorbs carbon dioxide from the air. The higher the amount of absorbed carbon dioxide, the higher the acid concentration. Scientists calculate that the sea today has 25% more acidity than 300 years ago.

Mathis said: 'Increased acidity levels can have a strong impact on the fishing industry. This is the problem we must consider in the next decade, not the next century. '

The sea contains minerals that organisms like oysters and crabs use to form their shells. Sea acidification makes this work more difficult, and in some cases the acidity of the sea becomes too high to make shells. Recent research by Mathis in Alaska Bay has shown that many sites have very low shell concentrations of minerals, making shellfish and other organisms in the area unable to create a strong shell.

Mathis explains: 'We are not saying that crab shells will gradually dissolve, but these organisms transform the physiology of itself to adapt to certain acid levels. Early results show that when some crabs and fish come into contact with seawater with higher acidity, some stress hormones increase and metabolism slows down. If they use energy to respond to changes in acidity levels, they will lack energy to grow, feed and reproduce. '

The winged animal (known as a sea butterfly or swimming sea snail) may be the first marine creature to be affected by sea acidification.Pteropods account for half of the diet of pink salmon.This pteropod is Limacina helicina helicina.(Photo: Russ Hopcroft, UAF Marine Science School)

Another creature that could also be affected by sea acidification are tiny winged animals, known as sea butterflies, or swimming sea snails . The foot-wing animal is the foundation of the food chain and accounts for half of the diet of pink salmon. The amount of winged animals only decreases about 10%, the body weight of an adult salmon will decrease by 20%.

Mathis said: 'This is the situation where we see that sea acidification has indirect effects on species with commercial potential through reducing their food sources.'

The cold waters and the wide and shallow rocks around the Alaska coast can push the sea acidification process in the north. Cold water can hold more gas than warmer water, which also means that cold waters off Alaska's coast can absorb more carbon dioxide. The shallow waters of Alaska's reefs may contain more carbon dioxide because there is less mixing between seawater and deeper water.

Ask any Alaska resident and they will tell you that Alaska's waters are rich in biological life, from tiny plankton to humpback whales. All of these animals use oxygen and release carbon dioxide. Mathis and other scientists call this 'biological pump'.

Mathis said: 'We are endowed with a high-productivity coastal area that can support large-scale commercial fishing, but this productivity acts as a pump, absorbing more and more carbon. Dioxide from the atmosphere. Because of this, the acidity of the seas in Alaska will continue to increase in the next decade. '

It is still unclear about the full impact of sea acidification, but it is clear that it is a threat to Alaska's fishing community.

Mathis concludes: 'We need to provide policy makers and managers and predict the acidification in Alaska to make appropriate decisions. The ecosystem in Alaska will suffer from sea acidification. And now, we still don't know what the reaction of these systems will be. '