The annual temperature in Indiana has risen 1.2 degrees in the last century, and the annual rainfall has increased 5.6 inches.
Some effects from climate change come less documented but matter practically.
‘‘Beach season is now May into October,’’ said Paul Labovitz, the superintendent of the Indiana Dunes National Lakeshore. ‘‘How do I put lifeguards on when kids are going back to school?’’
The increased severity of storms affects a place made of dunes and the people who use it.
‘‘I had 20 people surfing [Sept. 8],’’ Labovitz said.
The tricky part about climate change is what comes next, especially in a system as sprawling as Lake Michigan. Climate change doesn’t happen in isolation.
‘‘Invasive species come in, and everything could be flip-flopped around,’’ Tomas Höök said Wednesday after the release of the report ‘‘Aquatic Ecosystems in a Shifting Indiana Climate.’’
On a broad level, Jeff Dukes, the director of the Purdue Climate Change Research Center, said Indiana should have a longer growing season, with temperatures rising by five or six degrees by midcentury, more extreme hot days and less extreme cold days and a continuing trend of being wetter. The models largely agree that winter and spring will be wetter. There’s less certainty about how dry summer and fall will be.
Höök, the director of the Illinois-Indiana Sea Grant, was the lead author of the report, the latest in a series of updated studies from the Indiana Climate Change Impacts Assessment team assembled and managed by Purdue University.
Two key findings most interested me.
† ‘‘Warming water temperatures will generally maintain or increase habitat range for Indiana’s warm-water fishes, while significantly reducing habitat for Indiana’s cool-water and cold-water fishes.’’
† ‘‘Near-surface summer water temperatures throughout Lake Michigan have warmed by over three degrees Fahrenheit since 1980, and this warming trend is projected to continue in the coming decades. However, the impact of warming temperatures on aquatic habitats in southern Lake Michigan is uncertain. Future conditions for Indiana’s shallow and highly variable near-shore water will depend on future water levels, wind patterns and lakewide warming.’’
Höök said the warming likely will increase thermal habitat, but it will be farther off-shore and in deeper water. He expects fish might spend less time in the shallower waters of Indiana’s Lake Michigan.
‘‘A lot of aquatic life can grow faster with warmer temperatures, but they have to have food,’’ he said.
Anyone who has followed Lake Michigan the last couple of decades knows the food chain is in near-crisis.
Höök said much is unknown about what will happen with wind direction and speed. That’s something fishermen understand affects upwellings on Lake Michigan and fish.
‘‘Species more flexible will be more likely to adapt [to the changes],’’ Höök said.
On Lake Michigan, fishermen have seen brown trout, lake trout and smallmouth bass adapt to the arrival of round gobies. Chinook and coho have not adapted as well.
Höök also cautioned it is hard to make precise predictions about effects on any one species because interaction is intense and ‘‘climate change is not the only stressor.’’ Invasive species, pollution and nutrient-loading also affect aquatic ecosystems.
Höök hopes one thing that will come out the report is that resource managers will start including long-term threats into natural-resources planning.
There’s much to do as changes keep coming.
Click here for the Aquatics report. Earlier reports and upcoming ones from the Indiana Climate Change Impacts Assessment team are or will be posted at IndianaClimate.org.
