Post by Deleted on Mar 8, 2020 15:55:40 GMT -5
New invasive species found in Oneida Lake, described as ‘one of the more disruptive’ pests
Updated Mar 08, 2020; Posted Mar 05, 2020
A picture of a spiny water flea on Oneida Lake
Oneida Lake has a new invasive species to contend with – the spiny water flea.
Spiny water fleas (scientific name: Bythotrephes longimanus) were first discovered in the lake back in September in samples collected by Cornell researcher Kristen Holeck, who was holding a Cornell Field Biology class on the waterway. Their widespread presence in the lake was subsequently confirmed a few days later by additional sampling by biologists from the Cornell Biological Field Station in Bridgeport on the lake’s south shore.
“It is one of the more disruptive invasive species,” said Lars Rudstam, director of Cornell’s field station. He added it ranks among the top four with the most negative impact in the Great Lakes system along with zebra mussels, quagga mussels and fish-hook water fleas.
Zebra and quagga mussels are currently found in Oneida Lake. Fish-hook water fleas are not.
Spiny water fleas are an aquatic zooplankton (small animals) from Europe and Asia that have invaded the Great Lakes ecosystem. In New York, they are found in more than 10 counties. Lake Ontario, Lake Erie, Lake George, Sacandaga Reservoir, Saratoga Lake and a number of smaller water bodies are infested.
“Adults range from ¼ to ⅝ inch long and they have a single long tail with 1-3 sets of small spines along its length. Infestations of spiny water fleas negatively impact native fish populations, aquatic habitats, and sports fishing,” according to the state Department of Environmental Conservation.
There is no successful method of control.
“There’s nothing you can do. Once they are here, they are here,” Rudstam said.
Although they have been in Lake Ontario since 2005, he said, it is suspected that spiny water fleas finally got into Oneida Lake from the east through the Erie Canal – and that they will continue to spread throughout the Finger Lakes.
Rudstam said sampling by Field Station biologists detected spiny water fleas in Oneida last fall in densities of 20 to 140 per cubic meter, which is comparable to densities found in Lakes Erie and Ontario.
Spiny waterfleas are known as a “food web disruptor” in the Great Lakes because of their ability to decrease the abundance of other zooplankton, particularly daphnia. Daphnia are an important food source for fish such as alewive, and the young of other species, including perch and walleye.
There are no alewive in Oneida Lake.
However, Rudstam said a marked decrease in daphnia in Oneida Lake could possibly result in a decreased grown rate of perch and walleye during the very early part of their lives, affecting their survival rate. He noted one Minnesota study tied a decline in the walleye fishery to the presence of spiny water fleas, but Rudstam said he has strong doubts about that happening on Oneida.
A decline in daphnia, “an important grazer of phytoplankton,” has caused declines in water clarity in other waterways where they are found. However, the presence of zebra mussels and quagga mussels in Oneida Lake, which are filter feeders, most likely will counteract that effect, Rudstam said.
Rustam said anglers this coming year should begin seeing spiny water fleas on their fishing lines, particularly during the summer and fall, when they are the most plentiful. They will not, though, form large clumps on lines and clog up the eyelets on fishing rods like the related fish-hook water fleas do.
On the positive side, fish do feed on spiny water fleas, although small ones may have problems dealing with their spines. Cornell staff at the field station on Oneida Lake found lots of spiny water fleas in the stomachs of yellow and white perch and emerald shiners that were sampled last fall.
The DEC cautions that invasive species can travel from waterway to waterway on boats and fishing gear. Boaters should drain all water-holding compartments before leaving a water body. Methods to clean and disinfect fishing gear can be found on the DEC website.
www.syracuse.com/outdoors/2020/03/new-invasive-species-found-in-oneida-lake-described-as-one-of-the-more-disruptive.html
www.dec.ny.gov/animals/50121.html
Invasive aquatic plant species hanging off a trailered boat
Updated Mar 08, 2020; Posted Mar 05, 2020
A picture of a spiny water flea on Oneida Lake
Oneida Lake has a new invasive species to contend with – the spiny water flea.
Spiny water fleas (scientific name: Bythotrephes longimanus) were first discovered in the lake back in September in samples collected by Cornell researcher Kristen Holeck, who was holding a Cornell Field Biology class on the waterway. Their widespread presence in the lake was subsequently confirmed a few days later by additional sampling by biologists from the Cornell Biological Field Station in Bridgeport on the lake’s south shore.
“It is one of the more disruptive invasive species,” said Lars Rudstam, director of Cornell’s field station. He added it ranks among the top four with the most negative impact in the Great Lakes system along with zebra mussels, quagga mussels and fish-hook water fleas.
Zebra and quagga mussels are currently found in Oneida Lake. Fish-hook water fleas are not.
Spiny water fleas are an aquatic zooplankton (small animals) from Europe and Asia that have invaded the Great Lakes ecosystem. In New York, they are found in more than 10 counties. Lake Ontario, Lake Erie, Lake George, Sacandaga Reservoir, Saratoga Lake and a number of smaller water bodies are infested.
“Adults range from ¼ to ⅝ inch long and they have a single long tail with 1-3 sets of small spines along its length. Infestations of spiny water fleas negatively impact native fish populations, aquatic habitats, and sports fishing,” according to the state Department of Environmental Conservation.
There is no successful method of control.
“There’s nothing you can do. Once they are here, they are here,” Rudstam said.
Although they have been in Lake Ontario since 2005, he said, it is suspected that spiny water fleas finally got into Oneida Lake from the east through the Erie Canal – and that they will continue to spread throughout the Finger Lakes.
Rudstam said sampling by Field Station biologists detected spiny water fleas in Oneida last fall in densities of 20 to 140 per cubic meter, which is comparable to densities found in Lakes Erie and Ontario.
Spiny waterfleas are known as a “food web disruptor” in the Great Lakes because of their ability to decrease the abundance of other zooplankton, particularly daphnia. Daphnia are an important food source for fish such as alewive, and the young of other species, including perch and walleye.
There are no alewive in Oneida Lake.
However, Rudstam said a marked decrease in daphnia in Oneida Lake could possibly result in a decreased grown rate of perch and walleye during the very early part of their lives, affecting their survival rate. He noted one Minnesota study tied a decline in the walleye fishery to the presence of spiny water fleas, but Rudstam said he has strong doubts about that happening on Oneida.
A decline in daphnia, “an important grazer of phytoplankton,” has caused declines in water clarity in other waterways where they are found. However, the presence of zebra mussels and quagga mussels in Oneida Lake, which are filter feeders, most likely will counteract that effect, Rudstam said.
Rustam said anglers this coming year should begin seeing spiny water fleas on their fishing lines, particularly during the summer and fall, when they are the most plentiful. They will not, though, form large clumps on lines and clog up the eyelets on fishing rods like the related fish-hook water fleas do.
On the positive side, fish do feed on spiny water fleas, although small ones may have problems dealing with their spines. Cornell staff at the field station on Oneida Lake found lots of spiny water fleas in the stomachs of yellow and white perch and emerald shiners that were sampled last fall.
The DEC cautions that invasive species can travel from waterway to waterway on boats and fishing gear. Boaters should drain all water-holding compartments before leaving a water body. Methods to clean and disinfect fishing gear can be found on the DEC website.
www.syracuse.com/outdoors/2020/03/new-invasive-species-found-in-oneida-lake-described-as-one-of-the-more-disruptive.html
www.dec.ny.gov/animals/50121.html
Invasive aquatic plant species hanging off a trailered boat