Latest news with #mayflies
Yahoo
a day ago
- Science
- Yahoo
Low Danube waters bring huge mayfly swarms in Budapest
STORY: :: Mayflies swarm the river Danube earlier than usual and in greater numbers :: Budapest, Hungary :: July 23, 2025 :: Gyorgy Kriska, Associate Professor, Eotvos Lorand University 'Since 2012 we have seen huge swarming in those years when the water levels are quite low. We think it is because the sun lights the riverbed more and the algae can breed more and that way the larvae find more food.' :: Researchers put up special blue lights to guide the mayflies, which get confused by city lights :: July 26, 2025 'What our lights are doing is that they keep them here, they don't let them fly above so they keep swarming around the lights, and often a swirl of insects form around the lights, which reaches the surface of the water and they splash into the water. Where the mayflies reach the water they place their eggs there. What we can achieve is that they stay in place over the water and the next generation is saved. They cannot go further up but at least their offspring survive.' :: Mayflies, a protected species in Hungary, live for less than a day after they hatch Hundreds of thousands, sometimes millions, of mayflies engage in a frantic rush to mate and reproduce before they perish within just a few hours. Mayflies live for less than a day after they hatch, and their abundance is closely connected to the health of the Danube. Danube mayflies usually start swarming in August, but this year it began in mid-July, and is expected to last for weeks. Danube mayflies, a protected species, did not swarm for about four decades as the river was too polluted. They returned in 2012 when the Danube became cleaner due to the construction of wastewater treating plants, he added. As mayflies swarm upriver after mating, they can be confused by city lights or the shadows of bridges, causing them to crash on the riverbank instead of laying their eggs in the water. To help them as much as possible, Hungarian researchers installed special blue lights on two bridges. Solve the daily Crossword
Reuters
2 days ago
- Science
- Reuters
Low Danube waters bring huge mayfly swarms in Budapest
BUDAPEST, July 28 (Reuters) - Mayflies on the river Danube in Budapest are swarming earlier and in greater numbers than usual this year due to low water levels and an unusually hot summer, filling the air along the riverbanks as they are drawn to the city lights. Hundreds of thousands, sometimes millions, of mayflies engage in a frantic rush to mate and reproduce before they perish within just a few hours. Mayflies live for less than a day after they hatch, and their abundance is closely connected to the health of the Danube. Danube mayflies usually start swarming in August, but this year it began in mid-July, and is expected to last for weeks. Researchers say their early appearance in huge swarms could be linked to higher temperatures. "We have observed that massive mayfly swarms occur in years when the water levels are particularly low," said Gyorgy Kriska, associate professor at Eotvos Lorand University in Budapest. Earlier this month unusually low water levels disrupted shipping, opens new tab along the Danube, Europe's second-longest river. Low water means more sunlight reaches the riverbed, helping algae grow, which provide food for the mayfly larvae, Kriska said. Danube mayflies did not swarm for about four decades as the river was too polluted. They returned in 2012 when the Danube became cleaner due to the construction of wastewater treating plants, he added. The mayfly is a protected species, with the notional value of a single specimen being 10,000 forints ($30). As mayflies swarm upriver after mating, they can be confused by city lights or the shadows of bridges, causing them to crash on the riverbank instead of laying their eggs in the water. To help them as much as possible, Hungarian researchers invented and installed special blue lights on two bridges. "Our lights simply keep them here, ... they continue to fly in front of the lamp ... and crash into the water," Kriska said. "This way, we can ensure they stay above the water, and the next generation survives."
CTV News
16-07-2025
- Science
- CTV News
What the pesky swarm of mayflies say about the health of our lakes
They appear in massive, pesky, swarms striking an unusual reaction from anyone living near the water. But before swatting them away or complaining about their creepy appearance and substantial presence it's worth asking: What are these insects good for? Despite their name, mayflies or shadflies, these critters typically appear in late spring and summer especially around freshwater lakes and rivers. They gather in large numbers near cottages, hanging in clusters from street lights and swarming around boardwalks. Though short-lived, their lives often begin underwater where they play an essential role in our local ecosystems. According to the National Wildlife Federation, Mayfly larvae, spend up to a year beneath the water's surface, feeding on yummy plants and organic debris. They serve as food for fish, amphibians, and birds alike. Mayflies Pesky mayflies swarm Lake Simcoe. (Lake Simcoe Region Conservation Authority - LSRCA) But surprisingly enough their value doesn't stop there. 'Mayflies are a natural bioindicator,' says the Lake Simcoe Region Conservation Authority in Newmarket. 'They thrive only in clean, oxygen-rich water. When we see them emerge in large numbers, we know the water is healthy.' Lake Simcoe, specifically, sees massive mayfly emergences each year. Believe it or not, this swarm is actually an encouraging sign according to conservationists out of Newmarket. These large-winged insects even inspired the name of the authority's research vessel. 'Their scientific name is the namesake of our research boat and reflects our ultimate goal of a healthy Lake Simcoe,' shared the local conservation authority. While they may seem like a nuisance to some, mayflies tell an important story about the water we swim in. These oddly large bugs aren't just a summertime spectacle, they're a reminder that the ecosystem is functioning properly. So the next time you are at the cottage or enjoying a day on the lake and you stumble across this odd critter that may cloud your headlights or cover your dock, just remember... their presence is actually a positive sign.
CBS News
08-07-2025
- Science
- CBS News
Impending mayfly hatch causes southeastern Minnesota bridge to go dark
The lights will go out on a bridge over the Mississippi River in Winona, Minnesota, for the next few weeks to squelch the impact of a mayfly hatch. The Minnesota Department of Transportation said the overhead lights on the Highway 43 bridges will be off until mayflies fully hatch, "to reduce the number of mayflies on the bridge." Having mayflies on the bridge can "cause dangerous driving conditions because it becomes slippery," MnDOT said. MnDOT While the insects are harmless, their sometimes overwhelming numbers can make them a nuisance. Still, the Minnesota Department of Natural Resources said they are extremely important in the aquatic food web, and are fed upon by other invertebrates, amphibians, reptiles, fish, birds, and mammals. Mayflies spend 99% of their lives as larvae living in the sediment of freshwater systems like the Mississippi River, the DNR said. The hatching phenomenon in the Mississippi River occurs as the burrowing mayflies emerge all at once to mate, lay eggs and then die. In 2021, a massive hatch in downtown St. Paul blanketed the city's roads and sidewalks. A year later, a hatch near La Crosse, Wisconsin, was so large it showed up on radar.
CTV News
25-06-2025
- Climate
- CTV News
Swarm of fish flies returns to Leamington, signalling a healthy lake — and a seasonal headache
Residents of Leamington are once again swatting, sweeping and sighing as fish flies make their annual appearance along the Lake Erie shoreline. The delicate, short-lived insects — also known as mayflies — emerge in large numbers every June, coating cars, sidewalks, and windows across the southern Ontario town. 'If it's good for the environment, I'm happy to see them, but they are kind of a pain in the neck,' said Daphne Steer, a Canada Post letter carrier. 'You just use the mail and swat around you as you're walking.' Fish flies in Leamington, Ont. 2025 Fish flies swarm Leamington, Ont., seen on June 25, 2025. (Chris Campbell/CTV News Windsor) While their presence can be overwhelming, scientists and local officials say the arrival of fish flies is actually a positive sign. 'When mayflies are thriving and hatching, that's telling you that you have a lot of oxygen in the water,' said Ken Drouillard, director of the School of the Environment at the University of Windsor. 'And it basically suggests that things are getting pretty good.' Leamington Mayor Hilda MacDonald agrees. 'This is just what happens. It's a sign the lakes are healthy, and we just get used to it,' she said. 'We turn off the outside lights at night. We hose off our cars. They're not particularly creepy. They're just kind of annoying. And they're on your windows and all of that. It's a regular season, I can't say there's more. The one big thing is they smell bad when they're dead. They smell like fish.' Fish flies in Leamington, Ont. 2025 Fish flies swarm Leamington, Ont., seen on June 25, 2025. (Chris Campbell/CTV News Windsor) The smell, the mess, and the sheer volume are what many residents are dealing with this week. 'We get thousands of them,' said Connie Nelson, who has lived in Leamington for five years. 'The good thing is they're only here for a couple of weeks, and we know they're going to come every June. So, we just deal with it and know that July's coming soon.' Alan Antoniuk, who lives near Seacliff Park, said the latest wave hit hard overnight. He placed a 'Free fish flies' sign on his front yard. 'The fish flies hit hard last night again. About four to six inches in spots,' he said. 'The town's been fabulous cleaning it up. We haven't had any accidents. Some years, it makes such a grease slick that the cars go to stop, and they go right into the fence down here at Seacliff Park. But for the most part, it's been okay.' He added that they're feeding the environment, and they're needed, but they cause a big mess. 'Free fish flies. Bring your own buckets. Bring your own truck. Truckloads at a time. I'll give you the shovels if you want, you can clean them up on your own first thing in the morning,' Antoniuk said. Drivers are among those most frustrated, with cars and windshields often coated by the insects, especially if they sat under a light overnight. 'There's a lot of them,' exclaimed Tim Hergott as he washed his car. 'I don't know why they use my car as a target, but they do.' Hergott said he's been washing his vehicle more often since the insects arrived. Fish flies in Leamington, Ont. 2025 Fish flies swarm Leamington, Ont., seen on June 25, 2025. (Chris Campbell/CTV News Windsor) 'I'd rather they move on, but they're only here for, like, two or three weeks, and then they're gone,' he explained. 'You'd never know they were here.' Others are simply avoiding cleanup until the bugs are gone. 'I don't like it. They smell and there's no sense in trying to clean it off until they're all done coming here,' said Susan Bondy. 'It's crazy.' While short-lived, the mayflies serve a vital role in the ecosystem. 'It's remarkable how many other things in the environment are just waiting for that mayfly emergence to happen,' Drouillard said. 'So, first of all, even when those mayflies are sitting in sediments, they're a prominent component of fish food. Our walleye and yellow perch are consuming these at various stages of their life stages. And then when they emerge and they come out into the air, all kinds of birds and frogs and snakes, you name it. I've even seen skunks having a feeding frenzy on these mayflies.' As Leamington residents brace for another week or two of buzzing, crunching and sweeping, many are trying to keep their cool — and their sense of humour. 'Free fish flies,' Antoniuk said. 'Truckloads.'
