Lake bottoms, visible from space, may hint at trout comeback

Capital News Service
LANSING — It might seem counterintuitive, but when trying to examine the bottom of Lake Huron, researchers discovered it is helpful to take a look from space. Satellite imagery offers a new tool for identifying nearshore habitats where lake trout spawn across broad areas of the Great Lakes, according to a recent study in the Journal of Great Lakes Research. Researchers have been using satellite imagery to look at how the distribution of lake-floor algae in the Great Lakes is changing, said Amanda Grimm, lead author of the study and an assistant research scientist at the Michigan Tech Research Institute in Ann Arbor. While studying lake trout rehabilitation in the Drummond Island Refuge in northern Lake Huron, U.S. Geological Survey researchers noticed that the stony reefs, where they found lake trout laying eggs, were cleaner of algae than surrounding areas, Grimm said. They realized the difference might be seen from satellite, which would help find good lake trout spawning grounds.

Artificial Reefs

Capital News Service
LANSING — Artificial reefs in all five Great Lakes and some of their tributaries are intended to improve sport-fishing, enhance fish habitats and reduce the impact of current and waves. But it’s uncertain whether they’ve been as successful as hoped in achieving those goals, according to a new study by scientists at the U.S. Geological Service’s Great Lakes Science Center in Ann Arbor. The problem is a shortage of long-term monitoring data on the region’s expanding number of artificial reefs. “Artificial reefs have been proven to attract fish and increase catch rates in recreational fisheries, but the ability of reefs to increase fish abundance is not well documented in freshwater and marine systems,” according to the study in the “Journal of Great Lakes Research.”
Among the reefs cited in the study are those near the Cook Nuclear Plant in Bridgman, J.H. Campbell Power Plant in Ludington, Hamilton Reef in Muskegon and ones in Thunder Bay and Port Huron. Some research shows increased spawning and fish feeding success, the study said, and sometimes the deposition of fish eggs has been greater on artificial than natural reefs.