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Entries in invasive species (191)

Monday
Nov182013

Safe Launch Saves Boaters Coming and Going

Photo from www.boattest.com

If you haven’t forgotten to put in the drain plug before you launch, chances are that you know someone who has.

Consequences can range from aggravating--- fishing is delayed--- to catastrophic--- the boat sinks.

But did you know that pulling that plug when you exit the water also is important? That’s because of the threat posed to our fisheries by exotic mussels and other invasive aquatic species, which can hitchhike in water left in the boat. Once established in a new water body, they crowd out native species, smother fish habitat, and block intakes, endangering public water supplies.

As zebra and quagga mussels have spread into Minnesota, across Texas, and over the Rocky Mountains, the danger has become even more acute, and resource managers are taking action. For example, the Texas Parks and Wildlife Commission recently approved a rule requiring anyone leaving or approaching public waters in 17 north Texas counties to drain their boats and is proposing that 28 additional north and central counties be added to the mandate.

In some places, forgetting to take out that plug is going to hit anglers and other boat owners in the pocketbook, as they are fined for violating the law. That’s how seriously resource managers are taking this threat.

But for a few bucks you can be pro-active to protect yourself, your boat, and the resource, courtesy of the Safe Launch Drain Plug Reminder System developed by Steve Colsher and Ray Haber.

It’s ingenious, but simple and easy to install. You just place a metal flex hook into the drain hole.  The hook is attached to a lanyard with a split ring carabineer that easily attaches to one of the transom/trailer tie-down straps. When you disconnect the tie-downs, you can’t help but be reminded to remove the hook and insert the plug.

Conversely, when leaving the water, you will see the Safe Launch lanyard, which will remind you to remove the plug and insert the hook, which does not impede water drainage.

Colsher told Activist Angler that he originally came up with the idea as a way to remind himself to put in the plug on his own boat. “But as time went on, and we were looking into things, we began to see this as a safety product that could save people $500 or $600 if they forget to plug out the plug.”

It also can help prevent the spread of invasive species, which is why the Lake Havasu Marine Association is partnering with Safe Launch. It promotes Safe Launch as part of its “clean, drain and dry” program for boats, while the company donates a percentage of sales to the association.

“This is a model that I think will work well with other associations,” Colsher said. “It’s a win-win for both.”

Tuesday
Nov122013

Round Goby Expansion Continues

 

U.S. Fish and Wildlife Service photo of round goby.Since first discovered in 1990, the round goby has prospered in the Great Lakes, but that doesn’t mean the bottom-dwelling fish is content to stay there.

More and more in recent years, it has expanded its range. For example, it’s now established in about 170 miles of Wisconsin rivers and streams that feed Lake Michigan. The native of Eastern Europe also has moved into Ontario’s Trent River, Rice Lake, and Simcoe Lake, one of the province’s most famous smallmouth fisheries.

Most recently, it has been found in Cayuga Lake, the longest of New York’s Finger Lakes, and it also is suspected in Oneida. That expansion likely will be a mixed blessing, as it has been in the Great Lakes.

In Cayuga and Oneida, gobies may prey on eggs of lake trout, sculpin, and darters, according to the Cornell Cooperative Extension Invasive Species Program. Additionally, they make crowd out native species, including bass, from prime, nearshore spawning areas.

“The biggest concern for anglers is that when gobies get to high density, the prey fish will have plenty of food to eat, and it might be harder to catch fish,” said Cornell biologist Randy Jackson.

For smallmouth bass anglers, however, that hasn’t been the case in waters where gobies have long been established.

“They’ve been a huge plus in Lake Ontario and the St. Lawrence River, where (zebra) mussels came in first and then gobies came in to eat the mussels,” said guide Dean Meckes, who fishes those waters, as well as Cayuga and Oneida.

“Smallmouths are getting way bigger now,” he added, pointing out that 11 pounds often won a one-day tournament in the 1990s.

“Now you need 20 to 24 pounds (five fish) to win,” he continued. “In a tournament last weekend, I had 21-4 on the first day and was in fourth place. First place had 26 pounds.”

Research on Lake Erie, meanwhile, shows that young smallmouths are growing faster. Ohio biologist Kevin Kayle theorizes that is because gobies spawn late into the summer, allowing young-of-the-year bass to move more quickly to a fish diet.

On the negative side, Kayle said, “We’ve seen a decline in sculpins and darters because of gobies.”

Another concern is that toxins bio-accumulate in gobies as they feed on zebra mussels. The exotic fish then are eaten by birds and larger fish. Researchers believe that loons and other fish-eating birds have died of botulism because of this. The invaders, which grow to 6 or 8 inches, also are considered a nuisance by some anglers because they are such proficient bait stealers.

And This Just in . . .

After I wrote the above article for B.A.S.S. Times, I received this additional information from Randy Jackson, a fisheries scientist at Cornell University Biological Field Station on the shores of Lake Oneida:

“In general, we hate to see any new invasives enter our inland lakes because impacts are never predictable.”

The major threat that the goby poses is to bass reproduction, he said.

“Most people focus on impacts on bass nests where guarding males have been removed. While no doubt individual nests would be at risk if males were removed, we certainly haven't seen any reduction in bass production in Lake Erie with the combination of spring fishing and gobies.

“I suspect it is the classic question of individual nest threats and lakewide production risk. I'm inclined to think that except under circumstances of extreme spring fishing pressure that we would not likely see any system wide reductions in bass production with gobies.

“Many of the other likely goby activities would very likely be positive to sport fish. Where they occur, both walleye and bass seem to make great use of them, so they would likely represent an additional prey resource that could result in faster growth rates.

“They spawn throughout the summer so there will potentially be a steady supply of small fish prey for young bass and walleye. We know in Oneida that young walleye have had some difficulty remaining piscivorous through the summer due to poor yellow perch production, so gobies might be a benefit to them.

“Double-crested cormorants also like gobies, so gobies could represent an additional buffer for sport fish to cormorant predation. And gobies eat zebra and quagga mussels, which we have plenty of.

“I suppose my primary concern is how gobies might impact angler catch rates. While we don't have great data for bass, we have seen that in Oneida, walleye catch rates are very tightly linked to the abundance of forage for adult walleye, not the numbers of adult walleye. In years when yellow perch produce large year classes, small perch are readily available to walleye and angler catch rates go down.

“In years when perch are rare, walleye catch rates are high. Gizzard shad play a similar role. When they are abundant, walleye can be hard to catch.

“If gobies establish at high densities, they could negatively impact angler catches. So adult game fish may grow faster but anglers won't have as much luck catching them. There is some irony in that gobies could potentially benefit many dynamics of our sport fish but at the same time create conditions where it is more difficult for anglers to benefit from that.”

Monday
Oct212013

As Mussel Threat Moves West, Feds Sit Back and Watch

The federal government is doing a pitiful job of protecting our waters from invasions by exotic species. And I’m not talking about its reluctance to remove the manmade connection between the Mississippi River basin and Lake Michigan. Yeah, that’s a problem, but its failure is more all-encompassing.

During the 1980s, Asian carp escaped aquaculture facilities in the South, riding into the Mississippi and other rivers on flood waters. Within a decade, we knew that bighead and silver carp were crowding out native species, with the latter also a serious threat to recreational boaters because of its tendency to go airborne when frightened.

Yet, incredibly, the silver carp was not listed as an injurious species under the federal Lacey Act until 2007 and the bighead carp until 2011.

With the zebra mussel, the feds were a little more prompt. After it was discovered in Lake St. Clair in 1988, it was listed in 1991.

But the quagga, identified as a separate species about that same time, still is not.

What’s the big deal?  Well, invasive species don’t respect boundaries, and, under the Lacey Act, those who transport injurious species across state lines can be both fined and jailed for misdemeanors or felonies. Felony trafficking violations are punishable by a maximum of fine of $20,000, five years in prison, or both, and property used to aid the offense may be subject to forfeiture.

Had the weight of that law been hanging over his head, whoever carried quagga mussels across the Rockies in 2007 might have been a little more conscientious about cleaning his boat and trailer before beginning the journey to Lake Mead.

And if listing of both species had been combined with a more aggressive publicity and enforcement campaign by the feds, the two invaders might not now be threatening waters all over the West.

Already in the East, they’ve crowded out native species, disrupted food webs, fouled recreational beaches, and cost taxpayers billions of dollars in maintenance costs because of their tendency to clog water intake and delivery pipes and infest hydropower infrastructures.

“The little critters are a serious threat to the United States,” said Larry Dalton, recently retired invasive species coordinator for Utah, where mussels already have forced $15 million in repairs to water-delivery systems.

In a 2010 report, the Western Regional Panel on Aquatic Nuisance Species (WRP) estimated that zebra mussels already had been responsible for $94,474,000 in direct and indirect costs for Idaho.

And the Pew Charitable Trusts warned, “Their rapid spread threatens water supplies and energy systems in the West, a region heavily dependent upon hydropower and often gripped by drought. In response, state officials have stepped up boat inspections and cleaning efforts . . .”

Right now, western states are trying to protect their waters from quaggas with a patchwork of rules and regulations. But anecdotal evidence suggests the piecemeal strategy isn’t effective, especially as a deterrent.

For example, a trucker was stopped last fall as he entered Washington State, towing a boat that with about 100 zebra mussels attached. The offender had been caught doing the same thing in 2010. And during questioning, he said that he also had been detained in another state with a contaminated boat.

So why isn’t the quagga mussel listed under the Lacey Act? You’ll have to ask the bureaucrats at the U.S.  Fish and Wildlife Service (FWS) about that and why Pew estimates the agency could take as long as 10 years to take action.

“It basically takes an act of God to put something on the injurious wildlife list,” said Leah Elwell, WRP coordinator.

Or an act of Congress. That’s why Rep. Joe Heck of Nevada is sponsoring H.R. 1823, the Protecting Lakes from Quaggas Act of 2013.

And that’s why the Western Governors’ Association is supporting it.

“This (the act) would invest federal and state authorities with an important tool for containing and eradicating quagga mussels by providing for increased inspections of boats cross state lines,” they said.

The act makes sense, of course, and thus should pass with bipartisan support. But that doesn’t mean it will.

Nor would its passage ensure that federal officials would vigorously prosecute offenders.

If past performance is an indication of future actions, the feds will continue to sit back and watch as quagga and zebra mussels spread throughout the West, as they have in the East. 

Friday
Sep202013

Asian Carp Just One Big Leap From Lake Michigan

After being introduced into the Mississippi River, Asian carp will be kept out of the Great Lakes in the same way that snakeheads were kept out of the Delaware River system after they were introduced into the Potomac, and in the same way that zebra mussels were kept out of the rest of the country after they were introduced into the Great Lakes.

In other words, Asian carp won’t be kept out of the Great Lakes, and a billion-dollar sport fishery could be devastated as a result of that invasion.

Here’s the latest chapter in this saga that has only one ending but a multitude of plot twists on the way to the climax:

A 53-inch, 82-pound carp (probably a bighead) has been found in an Illinois lake less than 1,000 feet from the Calumet River, which flows into Lake Michigan.

Read the rest of the story here.

Don’t expect Burmese pythons to stay in the Everglades either. Oh, and, by the way, there’s another big snake on the block, courtesy of an unregulated and irresponsible pet industry.

Tuesday
Sep172013

Duke Energy Develops Effective Strategy for Hydrilla Control

For years, resource managers have struggled to find a cost-effective and efficient way to control hydrilla. Mass application of herbicide can be cost prohibitive, as well as unpopular with anglers, environmentalists, and lakefront property owners. Grass carp, meanwhile, need years to bring the fast-growing exotic plant under control, unless they are stocked at exceptionally high rates, which also can be unpopular and expensive.

But Duke Energy Corporation has developed an effective management strategy for five of its Piedmont reservoirs that incorporates moderate use of both herbicides and carp. This reduces cost, as well as minimizes the likelihood of the adverse effects on fisheries that often accompany heavy stocking of grass carp.

This one-two punch, however, is not the sole reason for success, according to Ken Manuel, Duke’s reservoir aquatic plant manager.

“Early detection and rapid response is critical,” he said. “The plants grow so fast that you’re quickly past just a small infestation.

“Hydrilla grows faster than you think,” Manuel added. “It’s not just an inch a day. A plan can grow multiple feet per day from all of its growth tips.”

And too often, it’s spreading undetected. “Especially in the East, the states, which manage the fisheries and the water quality, rely on interested individuals to tell them about invasive plants,” the scientist said.

By contrast, Duke Energy’s mosquito control teams aren’t just controlling blood-sucking insects while they are on the water full-time for six months annually. “They are constantly looking for hydrilla and other invasive plants so that we can act quickly,” Manuel said.

Once hydrilla is confirmed, it is treated with herbicide. Sometimes, that is enough. More often it is not. That being the case, stocking of triploid grass carp follows, at a rate of 20 per acre of surface infestation.

The herbicide reduces the plant’s biomass, while carp graze on what sprouts from the surviving tubers. “If you have 1,000 acres of hydrilla, you have 1,000 acres until the tuber bank is exhausted,” said the scientist.

Additional “maintenance” stockings at a rate of 1 per 8 acres of the reservoir might follow for 8 to 10 years. 

(This article appeared orginally in B.A.S.S. Times.)