Fish going upstream on Cape Fear River to get a lift at Lock & Dam No. 1

EAST ARCADIA - For nearly 100 years, a dam has
blocked fish from swimming up the Cape Fear River to spawn, but a new,
man-made set of river rapids should make it easier for the fish to get
upstream.

The rapids are part of a $13 million repair and upgrade to Lock and
Dam No. 1 on the river near East Arcadia in Bladen County. The project,
which began in June, is about halfway finished, and the part that is
done is available to the fish, said biologist Frank Yelverton of the
U.S. Army Corps of Engineers office in Wilmington.

Scientists are studying the fish migration and expect to learn later
this spring whether the new fish passage is working, Yelverton said.

The lock and dam is one of three dams and navigation locks along the
140 miles of river between Fayetteville and the Atlantic Ocean. The dams
keep the river deep enough for boats and for the drinking-water intakes
of cities and towns along the river, including those for Fayetteville
and Wilmington. The locks, next to the dams, raise and lower boats so
they can continue past the dams.

Once used for commercial shipping, now the locks are primarily used by recreational boaters.

Without the dams, Yelverton said, the upper reaches of the Cape Fear
River could become shallow enough for people to walk across.

The renovation of Lock and Dam No. 1 is being paid for by the 2009 federal economic stimulus program.

The project first stabilized the lock wall and filled a 45-foot hole
in the riverbed that rushing water has carved over the years below the
base of the dam. The hole put the dam at a long-term risk of collapse,
Yelverton said, though it wasn't an imminent threat.

Now a large, sloping set of rapids and pools is being built from the
top of the dam down to the riverbed. About halfway complete, this
ramp-like rock structure will span the width of the dam. It's intended
to stave off formation of another scour hole and provide the fish a
means to swim over the dam.

By car, the lock and dam is about an hour and 20 minutes southeast of
Fayetteville. By water, it's about 80 miles downstream. Built in 1915,
it is the farthest downstream of the three lock-and-dam structures
between Fayetteville and Wilmington.

All three block fish from swimming upstream.

This affects anadromous fish such as sturgeon, shad, striped bass and
alewife that spend most of their lives in the ocean but breed many
miles inland in freshwater rivers.

The only way these fish can get past the dams is to travel through the navigation locks.

Three times a day during spawning season, said federal Park Ranger
Tom Charles of Lock and Dam No. 1, the locks are cycled in hopes that
fish trying to get upstream are swimming into them and being lifted past
the dam like a boat traveling upstream through the locks.

Some fish make it, but many don't, Charles said.

"When we're locking them in the locks, only half of them are making
it up to lock No. 1 or past No. 1," he said. Then they have to pass
Locks 2 and 3. "It cuts it in half each time, so by the time the fish
reach Fayetteville, they're really cut in half a lot."

Success rates
A four-year study of fish migration prior to the construction found
that 50 percent to 65 percent of the American shad get through Lock and
Dam No. 1 and 50 to 77 percent of the striped bass make it.

The study said 35 percent of American shad and 25 percent of striped bass had made it past all three of the dams.

There were no indications that sturgeon use the locks, and too few to
count for the study, according to the report Yelverton prepared.
Short-nose sturgeon are an endangered species.

The fish will still have to use the locks to get past the two dams
upstream, at Elizabethtown and the Bladen-Cumberland county line.

"Generally, if the fish can't make it upstream past the locks and
dams, they eventually spawn where they are," Yelverton said. "They may
or may not be successful. Some American shad and striped bass do spawn
successfully between the locks and dams, but the traditional spawning
grounds are upstream of Lock and Dam No. 3 at the natural rapids near
Lillington and Erwin."

Thanks for the great info!

Thanks for the article. Good read!