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Monday
Oct272014

Artificial Reef Projects Expand to Shallow Water

We’ve been using artificial reefs to improve habitat for fish and other aquatic life in deepwater ocean habitat for awhile now. But we’ve just begun to tap their potential in shallow water.

For example, artificial reefs finally are going to be deployed in Florida’s St. Johns River, following years of research and discussion.

“While the artificial reefs will not replace the natural system, they will help. The nooks and crannies will offer small spaces for small fish to hide and live. The concrete will provide a surface for marine growth to occur. Barnacles and oysters are expected to become established on the rocks,” says the Times-Union.

“Not only do they become potential food for fish, they also filter sediment and other particles out of the water, thereby improving water quality. The small fish become food for the larger fish, and so grows the food chain.”

Up in the Great Lakes, meanwhile, a spawning reef of four acres is being built in the St. Clair River, to benefit walleye, sturgeon, and whitefish.

The project at Harts light is the sixth spawning habitat built by the Michigan Sea Grant in the St. Clair and Detroit rivers

During the late 1800s and early 1900s, those systems were dredged to create deep shipping channels. In the process, 800 to 1,000 acres of prime spawning habit were destroyed.

And out in California, scientists have discovered that offshore oil rigs provide some of the most productive fish habitat in the world. They determined that the structures are home to 27 times as many fish as natural rocky reefs in the area.

Friday
Oct242014

Learning About the Birds and Bees . . .

Even several shots around the wound to numb the flesh didn’t detract from the relief that I felt. And as we waited for the anesthetic to kick in, I decided to impress the doctor with my innate knowledge of human anatomy.

“Is that the inner ear canal?” I asked, pointing to an illustration on the wall.

“No,” he said. “That’s the female reproductive system.”

Perhaps realizing that one day in the not too distant future I might develop an unwarranted reputation for sexual perversion if I didn’t know what goes where, my mother decided that my father should talk to me.

(Excerpt from a Fish, Frogs, and Fireflies essay about how I learned about the birds and bees from the birds and bees --- and turtles.)

Friday
Oct242014

Finding Ways to Tame Lionfish

Years ago, Missouri wildlife managers decided to reduce an exploding deer population in a St. Louis suburb. But instead of culling the herd humanely, they bowed to pressure from animal lovers, and, at great expense, trapped and moved deer to a more rural area.

Follow-up research revealed that those deer died of starvation. They had grown so accustomed to eating tulips, roses, and other domesticated plants that they did not recognize wild forage.

Besides showing the folly of trying to manage wildlife by emotion instead of science, this example reveals one of the reasons that exotic species can become so prolific and troublesome in their new habitats. Native species do not see them as food, and, consequently, their populations are free to grow unchecked by predation.

Down in the Caribbean, divers are trying to do something about that by teaching sharks to eat invasive lionfish. The latter are gobbling up native species, especially reef fish.

“From a scientific point of view, we don't know how successful the project is. But, apparently, recent videos show native top predators are starting to eat lionfish without them being previously speared by divers,” says a marine biologist. (Go here to see some great photos of sharks eating lionfish.)

Meanwhile, lionfish populations have declined around Jamaica because another species is eating the invaders --- man.

Dayne Buddo, a Jamaican marine ecologist who focuses on marine invaders at the Caribbean island's University of the West Indies, attributes much of the local decrease in sightings to a growing appetite for their fillets. He says that Jamaican fishermen are now selling lionfish briskly at markets. In contrast, a few years ago island fishermen "didn't want to mess" with the exotic fish with spines that can deliver a very painful sting.

The same strategy eventually may help us control Asian carp in the nation’s rivers and impoundments. Go here to check out my post about that.

Thursday
Oct232014

Unlike Some Environmentalists, Fish Love Oil and Gas Rigs

Life is rife beneath Platform Gilda, off the California coast (Image: Scott Gietler)

California environmentalists and others who hate the petroleum industry don't want you to know this:

A recent submarine study reveals that fish are far more adundant under oil and gas rigs off the coast of California than on reefs in the same waters.

"We find that fish production rates around individual oil rigs – scaled per unit of seafloor – tend to be around 10 times higher than comparable estimates in other highly productive marine habitats such as reefs and estuaries," says Jeremy Claisse of Occidental College in Los Angeles, who led the study.

The team surveyed 16 oil or gas platforms and 7 rocky reefs each year for 5 to 15 years, from 1995 to 2011. They counted how many fish, and of what size, were associated with each habitat. From this they worked out the weight of fish supported each year per square metre of sea floor in each area. To avoid overestimates, they included only fish within 2 metres of each structure that were clearly resident there, excluding fish just passing through.

Read more here.

Thursday
Oct232014

Pikeminnow Bounty Program Helps Anglers Find Smallmouth Bass

While many anglers fish for pikeminnows in the lower Columbia and Snake rivers in hopes of collecting bounties, they also catch plenty of other fishing, including smallmouth bass.

“I always thought it (catch statistics) could be of some use to anglers fishing the Columbia and Snake who are not obsessed with only salmon and steelhead,” said Eric Winther, pikeminnow manager for the Washington Department of Fish and Wildlife.

Typically, fishermen catch the greatest number of warmwater species at the Columbia Point station in the Tri-Cities (Kennewick, Pasco, and Richland). During the week of July 7-14, they boated 949 pikeminnows and 601 smallmouths, with Greenbelt and Lyon’s Ferry yielding more than 1/3 of the bass.

In 2013, pikeminnow anglers landed nearly 9,000 smallmouth bass, along with more than 4,000 sturgeon and nearly 1,500 channel catfish.

Operating from May 1 to Sept. 30, the program pays $4 to $8 for each pikeminnow caught that measures 9 inches or longer.

Formerly called northern squawfish, the pikeminnow is a native species that resembles a walleye. Impoundments on the rivers have enabled it to become a much more effective predator of young salmon and steelhead.

Since 1990, more than 4.2 million pikeminnows have been removed through the bounty program.