Arctic ice and sea ice begin to melt as spring approaches and form melting ponds on the icy surface, which are becoming larger with global warming and provide more light and heat, which can have a direct influence And potentially important on life in the waters of that area of the planet.
This is ensured by five researchers from institutions in Denmark, Canada, China and the United Kingdom in a study published in the journal Polar biology , where they point out that algae and bacteria can evolve in melting ponds and provide food for marine creatures.
Fusion ponds can form their own small ecosystem . When all sea ice melts during the summer, algae and other organisms are released from the surrounding seawater. Some of that food is ingested immediately by organisms living in the shallowest part of the ocean.
Others sink to the bottom and are devoured by sea-bottom creatures, says Heidi Louise Sorensen of the University of Southern Denmark and lead author of the study.
At the top of the water column are mainly krill and copepods that benefit from algae and nutrient rich bacteria from the melting ponds. These creatures are devoured by larger animals , ranging from amphipods to fish, seals and whales. Further down, sea cucumbers and starfishes benefit from sinking algae.
Researchers have been aware for some time that simple biological organisms can evolve in melting ponds , but so far it was unclear why sometimes there are many organisms in ponds and at other times practically none.
Nutrients appear in various forms
According to the new study, nutrients is the key word, since when phosphorus and nitrogen find their way into a melting pond, whole communities of algae and microorganisms can flourish.
Nutrients can appear in a melting pond in several ways. Thus, they can be washed with waves of sea water , transported by dust storms of the mainland (for example, the Siberian tundra) or washed with coastal land when it rains . Finally, migratory birds or other larger animals resting on the ice may leave other sources of nutrients.
Researchers suggest that climate change may be accompanied by more storms and rainfall , so more nutrients are expected to be released around the melting ponds. These conditions, in addition to the fact that the distribution of melting pond areas is increasing, may contribute to increased productivity in plant and animal life in the Arctic seas, according to Ronnie Glud of the Department of Biology at the University of South of Denmark.
In addition, there are other factors that can potentially contribute to increased productivity in Arctic seas, as light can penetrate water when sea ice disappears and the more the continent heats up, the more melt water it can flow To the sea carrying nutrients in its wake.
Scientists selected six melting ponds in Young Sound (northeast of Greenland) for their study, two of them natural and four artificial. Phosphorus and nitrogen (nutrients that are also known from common garden fertilizer) were added in several combinations to four ponds, while two served as control ponds.
Over a period of up to 13 days, Sorensen measured many different parameters in the melting water, including the content of chlorophyll A, a pigment that allows algae to absorb light energy and which was two to 10 times greater than in The ponds enriched with phosphorus and nitrogen than in the control ones, which generated a higher content of algae.