EVANSVILLE — Indiana's aquatic ecosystems will experience wide-ranging changes as climate change affects the state's many lakes, rivers, streams and wetlands, a new report says.
The report is the latest in a series from the Purdue Climate Change Research Center breaking down the affects of climate change on the state.
More: Indiana already feeling climate change effects
Jeffrey Dukes, director of the center at Purdue University, said the animals and plants in those aquatic ecosystems will undergo a variety of changes depending on species and location.
While those changes might be difficult to predict, scientists know they will occur as animals and plants adapt.
"The issue is that these systems are just so complex. We know we are loading the dice in a way that is going to make it difficult for the plants and animals that live in them," Dukes said.
Changes in water quantity and temperature, ice cover, water clarity and oxygen content will occur with Indiana's shifting temperature and rainfall patterns, according to the report. Nine researchers from Purdue, Indiana, Ball State and Notre Dame universities worked on the report, which includes research from 14 studies and projections from 10 different climate models.
What it says
- As air temperatures warm 5-to-6 degrees by mid-century, water temperatures will increase too, duration and extent of ice cover will decline, and shifting thermal characteristics will affect growth, survival and reproduction patterns of aquatic organisms.
- There will be a significant reduction of habitat for Indiana's fish species that thrive in cold waters.
- There will be more variation and seasonal changes in the timing and amount of stream flows, threatening habitat, breeding and survival of sensitive species such as Indiana's endangered freshwater mussels.
- More frequent and intense rains, especially in spring, will wash into waterways more farm fertilizers, such as phosphorus. Combined with warmer waters this will cause more algae blooms, reduced water clarity and depleted oxygen levels.
- Indiana’s changing climate will lead to shifts in the types and number of aquatic and semiaquatic species throughout the state. Invasive animals and plants, along with new parasites, may expand their ranges into Indiana. Increased precipitation and flooding raises the risk of invasive freshwater species spreading to new habitats.
One potential effect could be changes in key biological events for some fish and as well as amphibian species, such as frogs and salamanders, according to the report. Changes in the timing of high and low flows in rivers and streams can disrupt cues fish use for spawning, egg hatching and migration.
Earlier warming in spring could cause some amphibian species such as frogs and salamanders to emerge before spring rains can fill the seasonal pools they need for breeding, the report said. This will increase the chance that more will die while waiting for a suitable breeding habitat.
One effect, the potential for increased algae blooms, could have impacts beyond Indiana. The report notes that most of the state's waterways ultimately drain into the Gulf of Mexico, via the Ohio and Mississippi rivers, or into Lake Erie.
Increased levels of agricultural nutrients such as nitrogen and phosphorus could increase already sizeable areas of low oxygen levels, called hypoxic zones, in those water bodies, making it difficult for aquatic life to live there.