USGS sediment sampling vessel on the Rainy River, Minnesota

USGS scientists aboard a sediment sampling vessel on the Rainy River, Minnesota, preparing for a day of sampling.

Scientists are collecting mud along the Rainy River and at its mouth in Four-Mile Bay, Lake of the Woods, Minnesota, to study how phosphorus stored in sediment may be interacting with river water and potentially contributing to problematic algal blooms in Lake of the Woods.