Low oxygen and high temperatures appear to have caused the deaths of hundreds of eels and trout in Dunedin’s Silverstream.
Mosgiel angler Bevan Campbell, who alerted Fish & Game Otago and the Otago Regional Council, said he had never seen anything like it.
Both agencies were on site last night.
Trout used the lower Silverstream as a refuge when the Taieri River was in flood and dirty, Campbell said.
Otago Fish & Game chief executive Ian Hadland said the likely cause of death was warm, low-oxygen inflows of ponded floodwater from surrounding farmland.
‘We have taken oxygen levels in the lower Silverstream today and they are still very low – borderline lethal for fish – and it’s down to near zero in one of the drains leading into the stream.
Courtesy of nzherald.co.nz
Thousands of dead fish, crabs, eels and other marine life wash up, ‘never seen before’, on the shores of South Florida’s Biscayne Bay, USA #Fish #Crabs #eels #Octopus#Shrimp #Florida #BiscayneBay #USA
Thousands of dead fish and other sea life washed up this week on the shores of South Florida’s Biscayne Bay.
The fish kill was first reported on Monday. Members of Miami Waterkeeper, an advocacy group, saw about a dozen dead fish when they went out to conduct weekly water sampling. Then reports of dead fish, shrimp, crab, eels, octopus and other animals came in from North Miami to Virginia Key.
“I’ve never seen anything like this,” local resident Kathryn Mikesell told New Times. She has swam in the bay at least three mornings a week for five years.
Researchers and government agencies are still investigating the cause, but indicators point to very warm water temperatures and low levels of dissolved oxygen in the water, according to a news release from Miami Waterkeeper.
“It’s an emergency. The bay is not in a good place right now,” Piero Gardinali, an associate professor at Florida International University who is helping investigate the fish kill, told New Times. “It’s a warning sign.”
In addition to the dead fish, a large group of rays, believed to be struggling to breathe, huddled along the shoreline near the Pelican Harbor Seabird Station, a bird rescue and rehabilitation facility on Biscayne Bay. Personnel from a nearby science aquarium used soaker hoses and air pumps to aerate the corner of the bay where the rays had taken refuge to save them.
Fish and other underwater marine life rely on dissolved oxygen in the water to survive. Warm waters bring those levels down. The Waterkeeper noted very high water temperatures of about 90 degrees in the area where the fish kill was first discovered.
Algae blooms can also cause low oxygen levels, but the Waterkeeper said in an update Thursday that there was no evidence of a toxic bloom. They think an ongoing die-off of sea grass, which produces oxygen, could be a main factor that led to the fish kill.
More than 20 square miles of seagrass has disappeared from the bay in recent years, according to the Waterkeeper. A study last year from NOAA warned that the bay’s ecosystem was on the verge of a “regime shift”. The study found increasing levels of nutrients in the water, which causes numerous impacts that are detrimental to marine habitats.
“We are passing a tipping point for the bay not being able to support any life – literally overnight, the bay became a dead zone,” Miami Waterkeeper said of this week’s fish kill.
“This event is not a ‘normal occurrence,’ but rather a sign that something is seriously out of balance in our bay.”
Courtesy of weather.com
3,500 dead birds and hundreds of dead eels found in the waterways of Coromandel Peninsula, New Zealand #Birds #eels #NewZealand
More than 3500 birds and hundreds of eels have been found dead in waterways on the Hauraki Plains in the Coromandel.
Scientists and conservationists say the crisis is the worst they’ve seen in decades, and it’s putting two areas at risk that are regarded as internationally significant.
Courtesy of newshub.co.nz
Jeff Medor was fishing for bowfin with his sons on Lake Champlain in eastern Alburgh when one of his kids caught something unusual: an American eel.
While that eel looked healthy, that same week they spotted another one on shore, dead.
“And then another one and another one,” he said. “I think we’re up to six here.”
Bernie Pientka, a fisheries biologist with the Vermont Department of Fish and Wildlife, said the state has received reports of 16 dead eels washed up on northern Lake Champlain so far this year — up from one last year.
“It’s not necessarily huge,” he said. “But it’s not a common occurrence.”
The dead eels being reported are larger fish, probably 8 to 10 years old, that seem to be prepping for migration, he said.
Courtesy of vtdigger.org
Hundreds of fish and eels were found dead in one of London’s busiest canals after the heatwave.
Environment Agency teams were called at the weekend after the marine life was spotted on the surface of the Grand Union Canal. About 400 fish were removed from a basin of water near to Kensal Green that included pike, tench, perch and roach.
Tests are being carried out by the Canal & River Trust to find the cause. An Environment Agency spokesman said: “We currently believe the causes were natural following the hot weather, however, at the moment we can’t rule out pollution in the canal.”
Extra oxygen was pumped into the water after the removal operation. Waterways can heat up in summer causing a reduction in oxygen levels.
The canal is also experiencing high levels of duckweed, that can also threaten marine life by depleting sunlight hitting the water and further reducing oxygen levels.
Duckweeds are ladybird-sized flowering aquatic plants that float on the surface of slow-moving water, blanketing it in a green crust. Nearly 800 tons of the suffocating weed have been scooped from London’s waterways by the trust since April as temperatures have risen. Joe Coggins, spokesman for the trust, said: “Our teams working out on the water will continue to monitor for any signs of fish distress and will continue to remove duckweed.
Courtesy of standard.co.uk
Hundreds of dead fish, manatees, sea turtles, eels and other marine life wash up in Boca Grande, Florida, USA
Charter boat captain Chris Oneill videotaped those dead manatees, Tuesday, and posted the video to his Facebook page. The video has since been viewed more than a million times and drawn attention to the area’s fish kills.
“I haven’t been able to fish for a week, since mid-last week, because fish started dying and we’re not going to take people out here and subject them to these conditions because there are potential health concerns as well,” Oneill said.
Hundreds of dead fish were crowding Boca Grande’s coastline. Maggots were seen eating the rotting fish, which were emitting a strong odor.
Oneill counted more than 40 endangered Goliath Groupers washed up on the beach this week, ranging from 10 pounds to 400 pounds.
“Black grouper, gag grouper, red grouper, trout, eel, puffer fish, everything you could imagine is right here in this weed line that’s washed up the last couple days,” he said as he pointed out the rotting fish.
Guests were also frustrated by the fish kills. The beach was mostly empty, Wednesday, with the exception of a couple of visitors who were checking out the dead fish for themselves.
“We’ve been hanging out at the pool because… look, there’s no one hanging out at the beach. It’s terrible,” said one visitor. “We have another family vacation planned without kids in August and we’re not sure we’re going to come. If there’s red ride, we’re definitely not coming.”
The fish kills come as the National Weather Service issued beach hazards statements for red tide for coastal northern Lee County and coastal Sarasota County.
Captain Oneill is not sure what is causing the red tide, but notes after Lake Okeechobee water releases, Southwest Florida’s coasts regularly have fish kills.
“I can’t put my finger on what exactly the problem is, but I can certainly tell you any time they dump that lake, and the discharge comes out of the mouth of the Caloosahatchee River, within a week we start seeing significant kills along our shorelines here in Southwest Florida,” he said. “It’s sad to see that so much death is happening. I’ve only been here 15 years, and year after year I see things like this. This is the worst I’ve seen, and I’ve yet to see anyone out here assessing the problem or trying to figure it out.”
Courtesy of abcactionnews.com