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Entries in invasive species (207)

Friday
May222015

Monster Silver Carp Suggests Nightmarish Future Awaits Anglers, Native Species

What will happen to fisheries nationwide and even to outdoor recreation in general as Asian carp continue to spread, reproduce, and outcompete native species? We’ve just received a glimpse of a nightmarish possibility from Kentucky Lake, where angler Bill Schroeder foul-hooked and landed a 106-pound silver carp.

Although I’ve been unable to confirm it, I suspect that’s the largest silver carp taken in the United States, and possibly even the world. Experts say maximum weight for the exotic fish is about 60 pounds. And even now, the Tennessee state record for the silver carp, caught in 2013 on Kentucky Lake, was just 14 pounds, 13 ounces.

What’s going on? Silver carp like it here. So do bighead carp. Typically a larger fish, its maximum weigh is about 90 pounds. But in 2011, an angler targeting paddlefish hooked and landed a 106-pound specimen at Lake of the Ozarks.

And the exotic lionfish likes it here too. As it spreads all across the Gulf of Mexico and up the Atlantic coast, anglers are catching larger and larger specimens of this voracious predator. In its native range, it grows to 12 to 15 inches. Just a few days ago, one was caught off in the Florida Keys that measured nearly 19 inches.

Why are these exotics growing to horror-movie size proportions in our waters? Because they are exotic species, they have no “natural” predators, as they do in their native ranges. And they’re feasting on an abundance of food in our relatively fertile and healthy waters. By contrast, Asian carp struggle to survive in their native range because of pollution and overfishing.

Will the same happen with the Burmese python in the Everglades? Introduced to the wild by an irresponsible and little-regulated pet industry, it is now gobbling up native mammals and reptiles, and likely will expand its range into more developed areas. Will it grow to unprecedented size as well?

Now consider this: Asian carp are schooling fish. Frightened by disturbances on the surface, silver carp often go airborne, striking and injuring anglers and other boaters.

But the fish we see in videos of these airborne attacks usually weigh no more than 10 or 15 pounds. Imagine dozens of 100-pound silver carp taking flight all around you as you motor to your favorite fishing hole.

Of course, no one thought about such possibilities when the carp were imported by aquaculture facilities during the 1970s. And it wasn’t until the 1990s that we really started worrying about them crowding out native species in our rivers.

And then there’s the snakehead . . . 

Tuesday
May192015

Public Outcry Forces Minnesota to Delay Invasive Species Training Program

Following public outcry from resort owners, anglers and boaters, the Minnesota Department of Natural Resources (DNR) will postpone an invasive species training and trailer decal program that was set to go into effect July 1.

In the state legislature, a House committee voted to cancel the law, while a Senate panel has proposed a compromise that would delay implementation and remove charges for the class and decals. As the law was originally enacted, “lake service providers” are required to pay $50 for a three-year permit.

Passed in 2012, the law also requires boaters and others who tow boats and water-related equipment to take classes about how to avoid transporting aquatic invasive species, such as zebra mussels and milfoil, form one water body to another and then buy decals for their trailers to confirm that they have taken the class (usually online).

The DNR supports the education that would be provided under this law, but recognizes there are some concerns with the way the law is currently written,” the agency said. “For example, people transporting boats on trailers through Minnesota to another destination are required to take the course and display a decal even if they don’t put their boat in Minnesota waters.”

DNR Assistant Commissioner Bob Meier added, “With the legislative interest in this educational program and ongoing discussions about possible changes, we are postponing the launch until we see if the legislature acts this session to modify the program.”

State Sen. Tom Saxhaug said, “Education is critical to this whole aquatic invasive species idea. We are not trying to stop tourism in the state in any way, shape or form, but what we are trying to do is to make sure everyone in the state knows how to clean their boats.”

For funding its Invasive Species Program, Minnesota includes a $5 surcharge on watercraft registered in the state and a $2 surcharge on nonresident fishing licenses. Resort owners say current fees and decal requirements already have cost them business. 

Monday
May042015

Lionfish Threat Continues to Spread

As harmful invasive fish species, Asian carp seem to garner most of the headlines, mostly because of the threat that they pose to the Great Lakes.  But the lionfish, a marine invader from the Pacific Ocean, is decimating native species through much of the Caribbean, as well as spreading up the Atlantic coast and across the Gulf of Mexico. (See previous post.)

And now it’s been discovered off the coast of Brazil, which suggests the entire  coast of South America likely will be invaded.

“When the researchers analysed the fish’s DNA, they found that it matched the genetic signature of the Caribbean lionfish population, and not that of specimens from their native Indo-Pacific region. This suggests that the fish may have reached Brazil through natural larval dispersal from the Caribbean, the study’s authors say,” reports Nature.

“But Mark Hixon, a marine ecologist at the University of Hawaii at Manoa, says that ocean currents typically flow in the wrong direction for larval dispersal from the Caribbean to the southeastern Brazilian coast. He says that it is just as likely that the lionfish was brought to Brazil by humans. ‘Lionfish are easy to capture and make beautiful pets,’ says Hixon. ‘It’s easy to imagine boaters carrying lionfish as short-term pets in bait tanks or other containers on their vessels.’”

The Invasive Species Action Network adds this:

“Lionfish are vicious predators that eat any fish or invertebrate they can fit in their mouth. They reproduce easily and the rate at which they have expanded their range shows that they are thriving in this environment. With no predators in our waters they are rapidly impacting many habitats.

“Humans can have an impact. Fortunately, lionfish are very tasty and many restaurants have added them to the menu. In many areas concentrated spearfishing is keeping local populations in check but this is not a practical method of control across their range. In the USA, NOAA is the lead agency on this problem and they are the best source for lionfish information and research.

“NOAA has recently released the draft National Invasive Lionfish Prevention and Management Plan While the plan is still in draft form, it is scheduled to be approved at the next meeting of the Aquatic Nuisance Species Task Force meeting scheduled for the first full week in May.”

Thursday
Apr302015

Florida Plans Lionfish Removal and Awareness Day

The Florida Fish and Wildlife Conservation Commission (FWC) will celebrate its first Lionfish Removal and Awareness Day wtih a weekend of events across the state, starting Saturday, May 16, including a festival in Pensacola.

Lionfish Removal and Awareness Day (established to be the first Saturday after Mother’s Day each year) was created by FWC Commissioners to help draw attention to the lionfish issue. Lionfish are a nonnative, invasive species that have a potential negative impact on native species and habitat.

“We are thankful to all the groups that helped organize the Lionfish Removal and Awareness Day Festival and Tournament in Pensacola as well as all those who are hosting their own events across the state,” said FWC Commissioner Bo Rivard. “These efforts will help ensure we keep the lionfish issue on the forefront of everyone’s thoughts and minds.”

The FWC encourages all divers to remove as many lionfish on the weekend of May 16-17, no matter where they are in Florida.

The FWC also will unveil its Reef Ranger program this same weekend.

 Lionfish Removal and Awareness Day Festival and Tournament, Pensacola at Plaza de Luna, 900 S. Palafox St., Pensacola, on May 16-17.

This event will include celebrity chef demonstrations, lionfish tastings, fillet demos, a visit from world famous artist and marine conservationist Guy Harvey, family-friendly activities such as games and a fountain to play in, and more than 40 art, diving and conservation vendors; there will also be music, food and tons of helpful lionfish information.

The festival starts at 10 a.m. and runs until 5 p.m. each day. Updates will be provided from various other events across the state.

Want to participate in the tournament? Visit the Gulf Coast Lionfish Coalition (GCLC) webpage at Gulfcoastlionfish.com/lionfish_events to learn more or visit its Facebook page at Facebook.com/gulfcoastlionfishcoalition. GCLC is offering prize money for a number of categories, as well as chances to win great prizes with raffle tickets. Come by to check out the researchers counting and filleting fish. 

Meanwhile . . . 


The exotic lionfish is spreading up the Atlantic coast and along the Gulf coast, as well as throughout the Caribbean. A potential world record recently was caught off the coast of Mississippi.

Wednesday
Apr292015

Survey Reveals Carp DNA Throughout Chicago Waterway System

If Asian carp aren’t in the Great Lakes, they can’t get much closer. Sampling of the Chicago Area Waterway System (CAWS) last fall revealed carp eDNA throughout the system, including near a lock in downtown Chicago, just one block from Lake Michigan.

“Prevention needs to happen now and the U.S. Army Corps of Engineers and other key decision-makers should take swift action,” said the non-profit Alliance for the Great Lakes (AGL), which charges that the Corps lacks direction, as revealed in its Great Lakes-Mississippi River Interbasin Study.

“DNA evidence is an early detection tool to understand the potential movement of carp, and testing results have consistently found DNA hits on a path closer and closer to the Great Lakes over the past several years of testing,” the group added.

The Corps report outlined eight possible ways to stop migration of Asian carp into the Great Lakes, with the most expensive being an $18.3 billion separation of the CAWS from Lake Michigan. Meanwhile, the Alliance supports measures to temporarily reduce risk, including construction of a new channel and control technologies in the approach to Brandon Road lock and research on reconfiguration of locks in general.

But long-term issues with Chicago’s water system infrastructure must be addressed to keep the carp out, emphasized Jennifer Caddick, AGL spokesperson.

“It’s complicated. You can’t just build one dam and solve the whole problem,” she said. “There’s a lot of work to be done, but we need intensive focus.”

If/when Asian carp become established in the Great Lakes, consequences could be catastrophic for the multi-billion-dollar sport fishery. That’s because the exotic fish are fast-growing, prolific, plankton eaters. They likely would outcompete the many young and adult native fishes that rely on phytoplankton and zooplankton for their primary forage.

Additionally, the U.S. Geological Survey has identified 22 rivers in the U.S. portion of the Great Lakes that would provide suitable spawning habitat for Asian carp.