http://www.digitaljournal.com/tech-and-science/science/melting-ice-may-lead-to-more-sea-life/article/489560

Sea life changes as a result of melting ice caps

Posted Apr 4, 2017 by Tim Sandle
The ecological changes that go with the increasing amount of sea ice melting in the Arctic is disturbing — but it's not the only side to the story. The melting leads to increased production of algae and more food for creatures in the sea.
Sheldon Glacier  Antarctica with Mount Barre in background  from Ryder Bay near Rothera Research Sta...
Sheldon Glacier, Antarctica with Mount Barre in background, from Ryder Bay near Rothera Research Station, Adelaide Island. A new study examines why Antarctic sea ice cover has increased under the effects of climate change over the past two decades.
NASA/JPL
More food for sea creatures means, in turn, a rise in the numbers of sea creatures and the impact of this is uncertain. This provides a new dimension to the effects of global warming impacting upon the Arctic.
When large amounts of ice melt they form ‘melt ponds’; new research reveals that within these pools large quantities of algae and bacteria evolve and this provides increased food sources for marine creatures. The existence of melt ponds makes the ice darker. This means the ice absorbs more light (rather than reflecting light) which cause heating. The rise in temperature accelerates the melting process. In addition, seawater entering the pond increases the melt rate because the salty water of the ocean is warmer than the fresh water of the pond. The effect is shown with satellite images.
The microorganisms increase in numbers due to higher levels of phosphorus and nitrogen being released into the melt water. These nutrients become compacted into ice after being transported by dust storms from the mainland or washed with earth from the coast due to rain. Seabirds also contribute to the buildup of nutrients.
With this altering complexity and diversity, melt ponds can be seen a mini-ecosystems, which develop during the winter months. As summer comes, the water inside the melt ponds, along with the microbial life forms, is released into the seawater.
The microbial life is either dissipated, or it is consumed by sea creatures living higher up the water column or else the organisms sink to the bottom providing food to seabed dwellers. This pattern is likely to increase as the rate of melting rises, according to lead researcher Dr. Heidi Louise Sørensen who works at the University of Southern Denmark. New research into the rate of melting relates to ice located in the territorial waters off North-Eastern Greenland.
In terms of the types of sea life that will increase in population, those in the upper part of the water column are krill and copepods. These creatures will digest the nutrient-rich algae and bacteria from melt ponds. In turn these creatures will be eaten by larger animals including amphipods, fish, seals and whales. At the seabed, the types of creatures that will benefit include sea cucumbers and brittle stars.
The new findings are published in the journal Polar Biology, under the title “Nutrient availability limits biological production in Arctic sea ice melt ponds.”