Why it’s a big deal that half of the Great Lakes are still covered in ice

http://grist.org/climate-energy/why-its-a-big-deal-that-half-of-the-great-lakes-are-still-covered-in-ice-2/

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Like the shipping troubles, some of the more unexpected things the lakes and their ecosystems could face in the next few months are the direct result of the lingering ice and cold:

Throughout the winter, huge numbers of ducks that feed by diving below the water for fish ended up starving to death. Connie Adams, a biologist in New York’s Department of Environmental Conservation, told the AP that the die-off was “unprecedented.”

Next in line for concern are a huge number of the Lakes’ fish species. Warming water temperature often biologically triggers migration to traditional spawning grounds, and experts expect that northern pike, lake sturgeon, steelhead, and rainbow trout could make moves far later this year. As Shedd Aquarium research scientist Solomon David told Michigan Radio, later egg laying could mean younger and far weaker fish come next winter, leading to an even longer impact.

Other changes will come about long after the ice melts, as water levels are predicted to rebound to levels not seen in the last few years. Seasonal shifts in water levels, with winter lows and summer highs, are normal. “If things stayed in sort of a balance, we would see all the Lakes’ water levels going up and then going down. Every year: up, down; up, down,” says Drew Gronewold, a scientist with NOAA’s Great Lakes Environmental Research Laboratory. But, “when water levels change a lot over time, something is happening in one of those two parts of the season.”