Displaying items by tag: sediment

Georgia’s Ocmulgee River is a case study in the decline of Southern river fisheries, and their revival

Ethan Hatchett is a writer for the Georgia Department of Natural Resources.

MACON — The Ocmulgee River has changed. The cloudy water once ran clear. The sandy bottom was once rocky. Fish swam upriver to breed from places as distant as the Altamaha River, which the Ocmulgee and Oconee rivers join to form near Lumber City and the Atlantic Ocean.

European settlement changed the river. Centuries of agriculture and development stripped away much of the land’s vegetation that filtered the flow, causing the Ocmulgee to fill with sediment. The soil particles gradually moved through the waterway, covering gravel that fish spawned in, smothering fishes’ eggs, mucking up the water and even building up on the banks, saturating the ground with sediment.

It is impossible to know how many freshwater fish the Ocmulgee lost since the first Europeans arrived. Many species disappeared without being discovered. Yet on a clear afternoon in May, DNR aquatics biologist Paula Marcinek led a team on the upper Ocmulgee in search of robust redhorse, a “lost” fish found in 1991.

Read DNR’s blog post about efforts to restore the robust redhorse, plus news of a new grant that will expand the work and rare video of these fish spawning.

Marie Kurz is seen at a pond on the campus of Oak Ridge National Laboratory.  Carlos Jones/ORNL

From California canyons to German creeks: Science is personal and practical for ORNL scientist Marie Kurz

Kristen Coyne is a writer for Oak Ridge National Laboratory.

OAK RIDGE — Spanning no less than three disciplines, Marie Kurz’s title — hydrogeochemist — already gives you a sense of the collaborative, interdisciplinary nature of her research at the Department of Energy’s Oak Ridge National Laboratory. Still, those six syllables only hint at the vast web of relationships encompassed in her work.  

Kurz studies how rivers flow through landscapes; what kinds of nutrients, contaminants and other material sail through them; and how they transform along the way. As an experimentalist, her favorite part of the job is getting into the field. Depending on the season, Kurz can be found clad in tights, gloves reaching her shoulders, a neon vest and a ponytail-taming cap as she sloshes in olive hip waders through the particular stream under her scrutiny. The getup, she said, always makes her feel a bit like the Michelin Man.