Read more: http://www.foxnews.com/science/2013/06/04/oklahoma-wildlife-officials-hope-fish-like-tornado-debris/#ixzz2W0JRnrJw

Lake on the Brink:

The unexpected consequences of fighting Eurasian Watermilfoil

By Eric Engbretson

In 2012, Greg Matzke, a fisheries biologist for the Wisconsin Department of Natural Resources, made a startling discovery on Florence County’s Lake Ellwood. During a comprehensive fish survey which included spring, summer and fall netting and electrofishing surveys, Matzke discovered that all of the lake’s largemouth bass were older than 5 years of age, with approximately 91% of the largemouth bass population being at least seven years old.  The absence of younger fish indicated a recruitment failure for a number of years.  Such failures in largemouth bass recruitment over multiple years are unprecedented in the state of Wisconsin.

“The current largemouth bass population is in serious trouble,” Matzke reported. “It appears that natural reproduction of largemouth bass has not occurred since 2007. As these older/larger fish move through the population, a significant reduction in largemouth bass abundance will take place, with the potential for the complete loss of this species of fish unless the current situation changes.”

Matzke next began looking at the lake’s panfish population.  What he found was stunning. Overall, the lake’s panfish abundance had fallen an estimated 75% in just the last 10 years, with bluegill and rock bass abundance down an estimated 65% and 89% respectively, showing that these populations also appear to be collapsing. Intense sampling throughout 2012 found only a single black crappie under six years of age, showing another alarming recruitment failure in several consecutive years. When Matzke analyzed the ages of Lake Ellwood’s northern pike population, the results were even more disappointing: There were no pike under the age of eight!

Matzke stared at the data he had collected. His department had never seen a mystery like the absolute and complete recruitment failures of native northern pike, black crappie, and largemouth bass (along with significant reductions in recruitment of other panfish populations). He shared his findings with other fisheries professionals across the state and they all said the same thing.  They had never seen a collapse like this in their careers. Matzke and his team scrambled to collect more data and tried to find a cause that could have brought the fish to the brink of extirpation in Lake Ellwood. Surveys from 2002 had shown normal abundance, size structure, growth, and recruitment in all of these species. What had happened in the last ten years that was preventing fish from successfully reproducing?

The only thriving species of game fish in the lake were smallmouth bass. Their abundance and size structure had grown in the last decade and recruitment was high.  This suggested that the problem was targeting specific species of fish. Because Lake Ellwood’s smallmouth bass were doing so well while the other species were collapsing, the focus turned to the lake’s historically sparse but important aquatic plant community. All the species showing recruitment failures are highly dependent on aquatic vegetation for spawning as well as cover and food for their young. Matzke observed that smallmouth bass seem to be different. “The fact that this species was not affected by the reduction in plant life,” he said, “is not a major surprise since as a species smallmouth bass are less dependent on aquatic vegetation.”

The Smoking Gun

Eurasian Water Milfoil was discovered in Lake Ellwood in 2002. Herbicide treatments began in 2003 and increased every year. By 2007 recruitment of northern pike, largemouth bass and black crappie had come to an end. “When I started to analyze the data it was strikingly obvious to me that there are some problems associated with the herbicide”, said Matzke. When he graphed the fish abundance (by year class) over the last decade and overlaid it with a graph showing yearly herbicide treatments, he found what he believed was a critical connection.  Fish numbers fell as the amount of herbicide increased.  Interestingly, in the year following a relatively low application of herbicide, young bluegill (and black crappie to a much smaller degree) began to appear again, but their numbers are still very low and they will likely disappear before they reach age 2.

Year class strength, indexed using age estimation to determine number of individuals of each year class captured during a 2012 comprehensive survey, for northern pike, black crappie, largemouth bass and bluegill plotted against the number of pounds of 2,4-D (not acid equivalent) used to treat aquatic plants in Lake Ellwood, Florence County, 2003-2012.

“We still wonder which stage of reproduction has failed in these species”, says Matzke. “Aquatic vegetation plays a major role in spawning site selection and in the survival of eggs and fry. Plants are also the source of primary production providing food and habitat for young fish and prey items, including invertebrates and minnows. It seems likely that one or all of these important phases of reproduction are dwindling in Lake Ellwood.”

On April 17, 2013 Matzke met with the Lake Ellwood Association to reveal his data and conclusions. He told the group, “The main cause for failed northern pike, largemouth bass and black crappie recruitment (along with the massive reduction in panfish abundance) appears to be the loss of aquatic vegetation.” The 2-4-D herbicide used on Eurasian watermilfoil had been successful in reducing the abundance of this invasive species significantly. Conversely, other native plants were also harmed by years of chemical treatment. Matzke said he has no reason to believe the chemicals have directly caused a failure in reproduction of any species of fish in Lake Ellwood. However, Matzke does believe that the chemicals have indirectly caused recruitment failure by eliminating too many of the aquatic plants young fish need in order to survive.  Matzke has called for a change in the way the Lake Ellwood Association has been managing the lakes aquatic plants.  He recommended that further chemical treatments for milfoil be stopped.

“First and foremost,” says Matzke, “we need to promote and strengthen aquatic vegetation in Lake Ellwood.” He stresses the role of aquatic vegetation in spawning and concludes that the loss of vegetation (including the invasive milfoil) has almost certainly wiped out a great deal of forage for young fish.

It seems that milfoil treatments controlled the invasive plant but also jeopardized the health of the lakes fishery. Today the lake contains a dwindling and rapidly aging population of largemouth bass, black crappie, northern pike, and bluegill. Matzke hopes the plants will come back in time for the remaining old fish to produce at least one year class before they die. If that doesn’t happen, many fish populations will likely be extirpated from Lake Ellwood. New fish can be stocked, of course, but the lake would lose the unique genetic lineage of the fish that have lived there for thousands of years.

The Future

Could chemical herbicide treatments for Eurasian watermilfoil be reducing fish recruitment in other lakes? None of the other lakes that have been receiving chemical treatments have had their fish populations surveyed this intensely. Large scale recruitment problems due to loss of important plant cover could be taking place throughout the region where the invasive plant is now being fought. There is no way to know if this is happening, and frankly, up until now, there has been no reason to find out.  Fisheries experts around the state are only now learning of Matzke’s findings on Lake Ellwood. In the future, they will likely start paying more attention to fish recruitment on lakes treated for Eurasian watermilfoil which would allow the Department of Natural Resources to determine whether this crisis is an isolated instance or a more widespread problem.

In the meantime, it’s a race against time for Lake Ellwood’s native fish. The question remains: Will the plants come back in time to save these fish populations?

Non-Profit Group Creating Fish Habiat for the Cape Fear River

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Trade practices around the port city of Wilmington over the past century have caused a significant decline in the number of fish in the Cape Fear River.  But thanks to the efforts of a local non-profit, their populations are staging a comeback.  Cape Fear River Watch Riverkeeper Kemp Burdette says there are several reasons why the fish numbers have dropped, but main reason is the construction of three dams on Cape Fear River in the early 1900’s.  The dams were originally built to facilitate trade and commerce along Cape Fear River between Wilmington to Fayetteville.

“Barges would approach the dam and would move into a lock chamber adjacent to the dam and that lock chamber would be flooded or drained depending on which way they were going and those boats would continue upstream.”

While the dams were beneficial for navigating barges and vessels, they prevented migrating fish species like striped bass, American shad, as well as the endangered Atlantic sturgeon and short nose sturgeon from swimming upstream to spawn during the spring.

“The American shad for instance, we are basically at 10 percent of what historic levels were. Nine out of every ten fish that used to be in the Cape Fear River are not there now. But none of these fish, none of these migratory species are even approaching the population numbers that would be considered healthy.  So, they all need help.”

To help restore the natural migration of fish in the Cape Fear River, the Army Corps of Engineers constructed of a fish ladder at Lock and Dam one in Reigelwood last year. It’s the first one of its kind on the east coast of the United States.  Fish climb the stair-step like structure made from carefully placed rocks by leaping out of the water, level by level, until they’re over the twelve foot high dam.  It’s the first migrating season since the fish ladder has been in place, and Burdette says it’s being used.

“The Division of Marine Fisheries has tagged fish with sonic tags then they’ve gone out and collected this data and these studies show these fish are using these fish passages, striped bass and shad are both using these fish passages, they’re both moving upstream unassisted for basically the first time in one hundred years so it’s really a significant breakthrough for the Cape Fear River and the migratory fish in the Cape Fear River.”

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Now two more Cape Fear fish ladders are in the planning phase. Two grant applications were recently submitted to the National and Oceanic and Atmospheric Administration to fund the design, construct, and monitor rock ramp fish ladders at the other dams on the Cape Fear River.

While one project focuses on helping migrating fish travel upstream, another project in the works will help restore breeding habitat.  Coastal Scientist Dawn York explains the project.

“Basically, the premise is to design a site where we can place about 1,000 tons of rocks down in an area that will help enhance spawning habitat for American shad.”

York is with Dial Cordy and Associates, an independent environmental consulting firm working with the Cape Fear River Watch as well as state and federal agencies on creating the fish habitat. She says the rocks will be placed at a half-acre area downstream of lock and dam 2.  An exact location for the habitat hasn’t been decided.  Crushed granite, ranging in size from 2 to 10 inches, will be set at the bottom of the Cape Fear River providing a safe place for striped bass, herring, and sturgeon to lay their eggs.  York says a dredging company in Wilmington will help facilitate the construction.

“They’ll travel up river it’ll take about 4-5 days to mobilize to lock and dam 2. They’ll use their excavator and smaller equipment to get the material onto a barge and they can handle about 90 tons per day. So we’re anticipating the construction of the restoration of habitat will take about 4 to 6 weeks.”

York says they want the first and last ton of granite material to be hand tossed into the water by volunteers.

“The rest of it would then be handled by the barge and mechanical means, basically an arm that will come down and grab large handfuls of material and place it into the river.  It’s going to be sort of spaced out over a half acre, so it’s sort of a flat area.”

Construction should take place between December of this year and February 2014. The project can’t begin sooner because of a moratorium banning the placement of material in the water due to fish migration.  Cape Fear River Watch Riverkeeper Kemp Burdette says the next several months will be spent finding the best location for the new fish habitat.

“It’s not nearly as simple as taking rock out there and dumping it off.  What we’re really going to do is side scan assessments of the riverbed and what we’re trying to do there is understand what the riverbed looks like and what the substrate looks like and identify the best places to put the granite.”

Even with the project wrapping up in early 2014, Burdette says their work repopulating the waters of Cape Fear River with migrating fish species is far from over.

“The project at lock and dam number one was a huge first step, but it’s not the last step.  We still have two more dams we need to have fish passage around because we really need these fish to get up into the fall line, that’s the area where they want to spawn, that’s the area where spawning would be most successful and so that’s where we need to go.”

Even though the construction isn’t underway, the project is already receiving national attention.  The National Fish Habitat Partnership has listed the Cape Fear River as one of the “10 Waters to Watch,” for its locally driven conservation areas and ongoing efforts.

Fishing is permitted at all three lock and dam sites, however, there is a moratorium on keeping striped bass.  It is illegal to keep sturgeon because they are an endangered species.  A dock was recently installed at lock and dam number one downstream from the dam structure and Burdette says it’s a popular fishing site for shad.   If you’d like to see a picture of the fish ladder in place at lock and dam one in Reigelwood, go to publicradioeast.org.

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For more on Cape Fear River Watches fishery restoration efforts, click here: http://www.capefearriverwatch.org/advocacy/fish-restorationBy JARED BRUMBAUGH

NEWS RELEASE — St. Paul, MN – Dirk Peterson won’t tell anglers where to catch a big fish, but he can tell them what’s needed to make sure there are big fish to catch when they get there.

More and more these days, he’s boiling it down to three words: good fish habitat. More habitat articles at fishiding.com

Peterson is in charge of the Minnesota Department of Natural Resources’ (DNR) fisheries section, which has just launched a new fisheries habitat plan. It outlines a strategic road map for making sure the state’s 10,000 lakes and hundreds of rivers and streams continue to provide the healthy aquatic habitat underpinning great fishing.

Pete Jacobson, a DNR fisheries research supervisor and one of the plan’s authors, makes it sound pretty simple. “The reason we have good fishing in Minnesota is because we have many lakes and streams with good water quality and habitat,” he said. “Healthy fish habitat is critical.”

But assuring the future of healthy aquatic habitat is anything but simple, because clean water depends on all that happens across a watershed, the hundreds or thousands of acres that drain into any particular lake or stream.

“When you lift a fish out of the water, that fish is a reflection of all that happens on the land,” Peterson said. “If we want to maintain great fishing, we need to focus more effort at the landscape and watershed scale.”

Peterson compares fisheries management to a three-legged stool: one leg is stocking fish, one leg is regulations that help control harvest, and one leg is habitat. Historically, the first two legs have been a little longer and more robust than the last one. The new plan aims to rectify that imbalance by directing staff and other resources to habitat protection and restoration.

While past fisheries habitat projects focused more on near-shore efforts such as protecting aquatic vegetation and stream channel improvements, the new approach seeks to move away from the water’s edge to encompass entire watersheds.

Because the DNR has little authority over land use – a chief determinant of water quality – working at the watershed level will rely more extensively on collaboration and coordination with other DNR divisions, local government, landowners, and other state and federal agencies.

Now there’s collaboration with DNR’s Forestry Division and local soil and water conservation districts to protect the watersheds of lakes with healthy populations of tullibee, a coldwater species sensitive to water quality, which provides important forage for game fish.

In the metro region, watershed scale collaborations with local government and other agencies have helped protect several trout streams, including Dakota County’s Vermillion River, a trophy brown trout stream just a half hour from downtown St. Paul.

While DNR fisheries has undertaken a few larger scale habitat projects before, they tended to be few and far between because there was little funding for big-picture, long-term approaches. The passage in 2008 of a state constitutional amendment dedicating a portion of a sales tax hike to the outdoors and to clean water has changed that. Much of the new habitat plan, available on the DNR website athttp://www.files.dnr.state.mn.us/fish_wildlife/fisheries/habitat/2013_fishhabitatplan.pdf, is aimed at better coordination and focus of funding sources to achieve the most bang for the buck.

An increase in fishing license fees – approved by the Minnesota Legislature last year – also is helping to put more focus on fisheries habitat work.

“We’ve always talked about habitat, but there rarely was adequate funding to really attack it at the appropriate scale,” said Jacobson, the fisheries researcher. “The constitutional amendment changes that, and we need to take advantage of it. The amendment is a mandate from the people for us to take fish habitat conservation seriously. This plan helps us do that.”By Site Editor

Yellow perch study finds correlation between reduced reproduction and increase in impervious surfaces. 

(Dave Harp)

A recent study suggests that land development in some watersheds around the Bay is literally paving over yellow perch habitat.

The study of five watersheds found that yellow perch were less likely to produce viable eggs in those with more roads, roofs, parking lots and other impervious surfaces than in those that retain more undeveloped land.

In places like Maryland’s Severn River, which was once a hot spot for yellow perch reproduction, the fish produce almost no viable eggs. Scientists say the culprit is likely increased development that has altered habitats, as well as toxic contaminants entering waterways from stormwater discharges.

“We can’t really explain it except for some combination of development and toxics, which may be two words for the same thing,” said Fred Pinkney, a toxicologist with the U.S. Fish and Wildlife Service’s Chesapeake Bay Field Office in Annapolis, and a co-author of the study.

“This study clearly documents the biology of the yellow perch reproduction problems, but we would need a new study to figure out what chemicals may be the cause,” Pinkney said.

While most Bay cleanup efforts have focused on nutrient reduction, the study highlights the increasing concern of some biologists and fishery managers around the Chesapeake that ongoing development and other pollutants — such as chemical contaminants — are continuing to degrade important fish habitats. Unless those issues are dealt with, they say, the Bay’s fish and shellfish populations could continue to suffer even as nutrient pollution is reduced.

The yellow perch study comes on the heels of a federal report released in January that found widespread evidence that chemical contaminants were affecting fish in the Bay and throughout much of its watershed. “We do have biological effects,” said Vicki Blazer, a fish pathologist with the U.S. Geological Survey, and a co-author of both the toxics report and the yellow perch study. “We have poor reproduction in some tributaries, we have fish kills, we have intersex, we have tumors. So obviously there are issues.”

Meanwhile, the Bay Program’s Sustainable Fisheries Goal Implementation Team, which helps to coordinate Baywide efforts to restore and manage fish populations and is made up of representatives from federal agencies and senior state fishery officials, has increasingly identified development and other land management actions as a major threat to fish populations.

Peyton Robertson, director of the National Oceanic and Atmospheric Administration Chesapeake Bay Office and chair of the Fisheries Goal Team, said it was important to make people aware of the issues, and to address them. “Those issues are difficult and deal with complex interactions between people and the places they live,” he added. “That is one of the challenges we face.”

Presentations at recent meetings of the fisheries team have highlighted how everything from hardened shorelines, to the loss of coastal marshes to increased pavement in upstream areas can impact fish health and productivity.

Those findings recently spurred the fisheries team to take the unusual step of writing to the Charles County Board of Commissioners, expressing concern that new development allowed in the county’s proposed new comprehensive plan could harm Mattawoman Creek and threaten its largemouth bass fishery, shellfish communities and anadromous fish spawning habitats. Because Mattawoman Creek serves as a spawning area and nursery for anadromous fish such as striped bass, alewife and blueback herring, the letter warned that further development in its watershed could have regional implications for some fish populations which are reared in the Bay but spend most of their lives migrating along the coast.

The letter said the draft plan “sets a precedent for unsustainable growth and development over conserving healthy habitats and economically important fisheries.”

Robertson said that it is not the team’s intent to interject itself in regional planning decisions throughout the watershed. But, he said, it is trying to identify other high-quality tidal rivers which, like the Mattawoman, may be particularly important for maintaining regional fish and shellfish populations, and to encourage greater protection for them.

“Fishermen have been basically subsidizing development,” said Jim Uphoff, a fisheries biologist with the Maryland Department of Natural Resources. Development can cause reduced fish production, as has happened with yellow perch in some areas, which results in reduced catch limits to help protect the population, said Uphoff, also a co-author of the new yellow perch study

He was part of a DNR research team that investigated sharply reduced fish production on the Severn River a decade ago. Those studies found that only 10 percent of the eggs produced by yellow perch on the Severn were viable, compared with 90 percent on the Choptank, Nanticoke and Patuxent rivers. It was also significantly less than had been produced in the Severn decades earlier, when it was less developed.

Yellow perch reproduction in the river is so low, Uphoff said, it likely couldn’t produce a sustainable population, even if fishing in the Severn was closed altogether. The DNR allows fishing, but the fish caught are generally those produced in other rivers that have ventured into the Severn.

“When you talk about the type of changes in egg viability that we’ve seen, fisheries harvest management doesn’t have enough leverage to offset the contaminant damage,” Uphoff said. “Essentially, you can’t turn that around by eliminating harvest. So why punish the fishermen for that?”

The new study provides new biological evidence of why the Severn River eggs were not viable by showing that the eggs themselves are deformed — something that strongly suggests chemical contaminants may be contributing to the problem.

The new yellow perch study, conducted from 2007 through 2009, looked at the Severn, the South, the Upper Choptank and the Mattawoman, as well as Allen’s Fresh, a small tributary of the Wicomico River. All had various rates of development: 24.6 percent of the South River watershed was covered by impervious surfaces, compared with 20.7 percent in the Severn; 10.2 percent in the Mattawoman, 4.8 percent in Allen’s Fresh; and 1.7 percent in the Upper Choptank.

In the study, the percentage of egg yolk deformities was significantly higher in the South and the Severn than in the less-developed rivers. The percentage with abnormalities of the zona pellucida, or the envelope that surrounds the eggs, was also highest in those rivers. None of the eggs from Severn females were fully developed at the time of collection in any of the years.

But it is exceedingly difficult to identify what triggered the problem in an area where water flow patterns fluctuate widely and where a witch’s brew of nutrients, pesticides, pharmaceuticals, PCBs, metals and other contaminants enter the water from runoff.

“It probably is not one thing,” Blazer said. “We can’t look at things one chemical at a time anymore, because that is not what organisms are being exposed to. They are being exposed to the whole suite of chemicals. Unfortunately, right now, we have very little information about how they all interact.”

Besides carrying toxic runoff, development has many other impacts, some of which may seem subtle but may be important to aquatic systems. They range from changes in salinity to changes in oxygen concentrations in the water to changes in flow regimes that affect whether food is available to fish larvae when they need it.

And while impacts are seen in fish like yellow perch, scientists say other less heralded species — but ones important to the food web — may be suffering even more. “We aren’t looking at those species because they aren’t commercially or economically important,” Blazer said.

Further, there’s little evidence that stormwater controls — even new practices that promote water infiltration rather than surface runoff — can fully offset the spectrum of impacts from new development on healthy streams. Stormwater projects, Uphoff said, don’t “dissolve all your developmental sins.”

As a rule of thumb, biologists say that aquatic life starts to suffer irreparable harm when more than 10 percent of a watershed is covered by impervious surfaces. Sensitive species can disappear at lower thresholds — in Maryland, brook trout typically disappear when imperviousness hits the 2 percent mark.

Uphoff said the DNR has increasingly been encouraging commercial and recreational fishermen and others to become more engaged in land use issues — particularly in areas that retain particularly valuable habitats — before they get developed. “We tend to think that the best strategy, at least for fisheries, is to work on conserving the places that are still functioning,” Uphoff said.

That is what triggered the fisheries goal team letter concerning the Mattawoman. Its watershed is at the 10 percent impervious mark, which means it could be near a tipping point where more development could impact a variety of fish habitats, including areas used by striped bass, shad and river herring — all of which are Bay Program target species for restoration.

While concerns about habitat degradation caused by development and toxics has worried biologists and fisheries managers, it remains unclear whether those issues will return in a significant way to the Bay Program’s agenda.

Toxics and land use were once key areas of focus for the state-federal Bay Program partnership. But issues related to toxics became overshadowed by nutrient pollution, and efforts to control sprawl development were even less successful — a goal in the Chesapeake 2000 agreement to reduce the rate of harmful sprawl faltered when, after years of debate, the partnership failed to agree on a definition of harmful sprawl.

A 2010 federal Chesapeake Bay restoration strategy called for setting new goals to control toxic pollution this year, but that idea has drawn little enthusiasm from many state officials who are already challenged to meet nutrient reduction goals stemming from the Bay Total Maximum Daily Load.

Nick DiPasquale, director of the EPA’s Bay Program Office, acknowledged that many partners were reluctant to add new commitments. “Dealing with the TMDL is a heavy lift itself,” he said. But he added that it was premature to judge whether the Bay Program could reach agreement on new toxics goals this year. He also noted that even without specific action by the Bay Program, other state and federal programs exist to deal with toxics. More habitat articles at fishiding.com

A summary of the yellow perch study is available on the U.S. Fish and Wildlife Service Chesapeake Bay Field Office website: www.fws.gov/chesapeakebay/.

By Karl Blankenship