Push to map Great Lakes bottom gains momentum amid promises effort will help fishing and shipping

What lies beneath the Great Lakes' waves is largely unknown, but there's a new push to learn more about thousands of shipwrecks, underwater infrastructure and the impacts of climate change on the bottom of the world's largest freshwater system. Only 15% of the lakes' bottom has been mapped, according to the Great Lakes Observing System. The organization has been pushing since 2018 to secure funding to map the entire lakebed in high-resolution. Advocates argue the effort would paint a detailed picture of shipwrecks, infrastructure such as pipelines and topography that would inform storm surge models as the climate warms. Two Congress members from Michigan introduced a bill that would allocate $200 million for the initiative.