Does protecting land help freshwater species?
A recently published Michigan State University study in the journal Landscape Ecology looked at connectivity among Michigan lakes from the perspective of both aquatic and semi-aquatic wildlife.
A recently published Michigan State University study in the journal Landscape Ecology looked at connectivity among Michigan lakes from the perspective of both aquatic and semi-aquatic wildlife.
Each lake was assessed to see if it was connected to many streams or wetlands, which would allow aquatic wildlife such as fish to access the lake relatively easily. In addition, a lake was assessed to see if it was surrounded by forest, wetlands and small ponds. These features help semi-aquatic wildlife such as amphibians and reptiles access the lake more easily.
As a society, we set aside land as national or state parks to help protect wildlife and their habitats. This land protection has been shown to benefit wildlife that lives on land, but does land protection also benefit wildlife that lives in water? This question is important to answer for both aquatic wildlife that spends their entire lives in the water (e.g., fish) and for semi-aquatic wildlife that spends part of their lives in the water and part of their lives on land (e.g., reptiles).
The authors found that most lakes have low levels of aquatic or semi-aquatic connectivity. Fewer than 3% of lakes were rated as highly connected for either type of connectivity. Connectivity was generally greater for lakes in the Upper Peninsula and northern Lower Peninsula where there is less human development.
Although the authors found few highly connected lakes, these lakes often occur in protected areas, suggesting that land protection may benefit freshwater wildlife.
“Protected lands are more likely than other lands to benefit freshwater wildlife,” said lead author Ian McCullough, a postdoctoral researcher in the MSU Department of Fisheries and Wildlife. “At the same time, it’s important to recognize that protected lands are mostly designated with land features in mind — things like forests and mountains. Keeping out development helps keep stream networks and wetlands intact, even if this wasn’t necessarily the original goal.”
Although the study provides some optimism for freshwater wildlife in Michigan and elsewhere, it is also important to recognize that land protection cannot be the only solution for protecting freshwater wildlife.
In fact, co-author Kendra Cheruvelil, a professor in the MSU Department of Fisheries and Wildlife, notes: “In addition to land disturbances affecting connectivity, both aquatic and semi-aquatic wildlife are threatened by the spread of non-native species, disease outbreaks and climate change.”
Therefore, conservation managers need to consider these additional threats to freshwater wildlife when considering land for protection.