Freshwater Ecosystems

For over a century, cataloging the biodiversity of freshwater ecosystems required intensive, destructive, and physically demanding field surveys: dragging heavy bottom-trawls across lake beds, setting gill nets that kill fish, shocking mountain streams with backpack electrofishers, and spending weeks peering through stereomicroscopes trying to identify mutilated insect larvae. Yet despite exhaustive effort, cryptic, rare, endangered, … Read more

The littoral zone of freshwater lakes and slow-moving rivers is not an empty water column; it is a structural underwater forest engineered by Submerged Aquatic Vegetation (SAV, or true aquatic macrophytes). Unlike microscopic phytoplankton drifting freely in the pelagic sun, submerged macrophytes are complex, multicellular vascular plants (alongside macroscopic charophyte green algae) rooted directly into … Read more

For decades, aquatic ecology operated under the assumption that the biological productivity and water clarity of lakes were governed strictly from the bottom up—dictated solely by the availability of solar energy and dissolved nutrients (the Bottom-Up Resource Regulation Model). However, in 1985, Dr. Stephen R. Carpenter and his colleagues at the University of Notre Dame … Read more

When an environmental technician collects a grab water sample from a river on a Monday morning and sends it to a chemistry laboratory, the resulting data represents only a single, instantaneous snapshot in time. If an industrial plant dumped a slug of toxic chemicals at midnight on Sunday, Monday’s water chemistry test will frequently read … Read more