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Invasive bullfrogs spreading quickly in Yellowstone River

Native ecoystems at risk

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Bullfrogs, native to eastern North America, have gained a firm foothold in the Yellowstone River, where they could put native species at risk. Photo courtesy USGS.

Staff Report

FRISCO — Big and pushy, invasive bullfrogs are expanding their range in the Yellowstone River floodplain in Montana at the expense of other native animals, biologists reported in  a new study released in “Aquatic Invasions.

“The impacts of bullfrogs on native amphibians in the Yellowstone River are not yet known, but native Northern leopard frogs are likely to be most vulnerable to bullfrog invasion and spread because their habitats overlap,” said Adam Sepulveda, USGS scientist and lead author of the study.

Bullfrogs are thought to be a cause in the declines of multiple amphibian and reptile species around the globe. They are big, mobile, omnivores with a voracious appetite, ability to reproduce rapidly, and carriers of amphibian diseases. This makes them an extremely successful invader and a threat to biodiversity. The study is the first of its kind to describe the rapid extent of bullfrog spread, as well as their preferred habitat along the Yellowstone River near Billings, Montana. Continue reading

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Global warming aids spread of invasive fish in Mediterranean Sea

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A juvenile rabbitfish, an invasive species blamed for wiping out huge areas of ocean habitat. Photo courtesy Zafer Kizilkaya.

Ocean ecosystems at risk from fish that kills algal forests

Staff Report

FRISCO — The spread of invasive tropical fish into previously temperate waters is also affecting the Mediterranean Sea, according to Australian scientist monitoring the spread of rabbitfish which have already devastated algal forests in the eastern Mediterranean Sea.

Global warming may help the fish spread into the entire Mediterranean Basin, researcher warned in a new paper published in the Journal of Ecology (Authors: Dr. Adriana Vergés, of the University of New South Wales, Australia, and Dr. Fiona Tomas of the Mediterranean Institute for Advanced Studies in Spain). Continue reading

Global warming driving invasive lionfish northward

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The lionfish are coming, for better or worse.

New study takes detailed look at changing ocean temperatures

Staff Report

FRISCO — Careful study of ocean temperatures shows how tropical fish are likely to expand northward along the Atlantic coast into the temperate ocean zone off the Carolinas. Invaders could include the poisonous lionfish, which is already causing problems on coral reefs in the Caribbean.

Researchers with NOAA and the University of North Carolina-Wilmington combined year-round bottom water temperature data with 2006-2010 fish community surveys in water depths from 15 to 150 feet off the coast of North Carolina. The study revealed that the fish community was primarily tropical in the deeper areas surveyed, from 122 to 150 feet, with a winter mean temperature of 21 degrees Celsius (69.8 degrees Fahrenheit).

Many of the native tropical fishes, usually abundant in shallow, somewhat cooler reefs, tended to remain in the deeper, warmer water, suggesting that temperature is a main factor in controlling their distribution. The findings were published in the September issue of Marine Ecology Progress Series. Continue reading

Scientists face endangered species conundrum

Bay Area marsh bird at nexus of endangered and invasive species

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A clapper rain along the shore of San Francisco Bay. Photo via USFWS.

Staff Report

FRISCO — Conservation biologists in the San Francisco bay area say they’re facing a conundrum, as they try to remove an invasive salt marsh grass while recovering an endangered bird that has come to rely on the non-native plant.

In a study published last month in the journal Science, researchers at the University of California, Davis said that an all-out push to eradicate the marsh cordgrass could hamper efforts to recover the clapper rail, a bird on the brink because of urban development and loss of wetlands.

Their results showed that, rather than moving as fast as possible with eradication and restoration, the best approach is to slow down the eradication of the invasive species until restoration or natural recovery of the system provides appropriate habitat for the endangered species.

Scientists in the southwestern U.S. have faced similar issues as they try to remove invasive tamarisk, which has come to provide habitat for rare southwestern willow flycatchers. Continue reading

Global warming making things tough for native trout in the northern Rockies

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Cutthroat trout. Photo courtesy National Park Service.

30-year study shows how warmer stream temperatures are linked with hybridization

Staff Report

FRISCO — Scientists studying trout in the northern Rockies say warmer stream temperatures and lower spring flows in mountain streams is increasing the pace at which introduced rainbow trout and native cutthroats interbreed. Hybridization has already contributed to the decline and extinction of many native fishes worldwide, including all subspecies of cutthroat trout in western North America.

The long-term research shows that, while hybridization used to be limited to lower stream reaches, during the past 30 years, it has quickly spread upstream as temperatures warm. According to the scientists, the process is irreversibly reducing the genetic integrity of native westslope cutthroat trout populations. Genetically pure populations of westslope cutthroat trout are known to occupy less than 10 percent of their historical range. Continue reading

Environment: Study says overpopulation of deer at root of invasive plant problem in Pennsylvania forests

Ecosystem breakdown more complex than just invasive species

Colorado mule deer.

Colorado mule deer. bberwyn photo.

By Summit Voice

FRISCO — Valiant weed warriors, who have made it their mission to try and eradicate non-native plants, may want to think about the bigger ecological picture as they plan their weekend weed pulls.

A new study led by the University of Pittsburgh’s Susan Kalisz suggests that, in some cases, invasive plants overwhelm native ecosystems because of an overpopulation of deer. The density of deer in the United States is about four to 10 times what it was prior to European settlement of North America. That density, Kalisz posits, is the main reason garlic mustard is crowding out native plants, such as trillium, which are preferred food for wild deer. Continue reading

More quagga mussels found in Lake Powell; Is the Lower Colorado River ecosystem at risk?

Quagga mussels coating a flip-flop in Lake Mead. PHOTO COURTESY NATIONAL PARK SERVICE.

Quagga mussels coating a flip-flop in Lake Mead. PHOTO COURTESY NATIONAL PARK SERVICE.

National Park Service seeking input on mussel management plan

By Summit Voice

FRISCO — The battle to keep Lake Powell free of non-native mussels is tilting toward the aquatic invaders and federal resource managers are concerned the invaders may spread into Glen Canyon.

As of January, the National Park Service reported finding — and removing — about 1,300 hundred adult quagga mussels, and managers at the reservoir said they’re finding more as the season progresses.

In response, the park service is developing a quagga-zebra mussel management plan to help the the agency decide what tools are appropriate to support the ongoing management of invasive mussels in Glen Canyon now that quagga mussels are present in Lake Powell. Continue reading

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