Brent Hess, a biologist with Georgia’s Fisheries Management Section, holds an 11-pound common carp. The carp and several other fish species were retrieved from the Chattahoochee River after they were temporarily stunned by an electric probe in the water. (They quickly recover.) CONTRIBUTED BY CHARLES SEABROOK

Getting a glimpse of fish diversity in the Chattahoochee River

Like in all rivers, the fish of the Chattahoochee River are mostly invisible unless we seek them out with a fishing rod or a net. Fish, though, play vital roles in the health and integrity of rivers and streams.

For one thing, they are important in recycling nutrients such as nitrogen and phosphorus. They also help maintain the integrity of river bottoms, and they are food for an array of creatures, including otters, eagles, humans and other fish. The presence or absence of a variety of fish in a river may indicate good or poor water quality.

The segment of the Chattahoochee flowing through metro Atlanta and some 60 miles downstream is home to trout, bass, catfish and more than 20 other fish species. To get a glimpse of some of the fish that might be swimming about in a short stretch of the river on a morning last weekend, we visited the McIntosh Reserve Park in Carroll County.

At the park, located along a graceful bend of the Chattahoochee, we met up with Brent Hess and Paul Jones of the Fisheries Management Section of the Georgia Wildlife Resources Division. They were there to demonstrate to the Friends of McIntosh Reserve the electric fishing rig and techniques they use to monitor fish in rivers and streams.

From their boat, they used “probes” to send electric pulses through the river’s water to temporarily stun the fish within a small area. They quickly scooped up the dazed fish and put them into a holding tank. They then showed us how the fish are weighed and measured before they are returned to the river, where they quickly recover.

Within 15 minutes, Hess and Jones retrieved eight fish species, the largest of which was an 11-pound common carp. Other species included channel catfish, flathead catfish, gizzard shad, spottail shiner, red-eared sunfish, spotted bass and bluegill.

IN THE SKY: From David Dundee, Tellus Science Museum astronomer: The South Delta Aquarid meteor shower will be visible Saturday night through all next week, reaching a peak of 15 meteors per hour this weekend. Best viewing: In the southeast from midnight until dawn.

The moon will be new on Tuesday. Mars is very low in the west at dusk. Jupiter is in the east at dusk. Saturn rises in the east at about midnight.

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