Latest news with #GregoryDick
Yahoo
14 hours ago
- Health
- Yahoo
Toxic algae blooms are lasting longer in Lake Erie − why that's a worry for people and pets
Lake Erie algal blooms, August 2011, along the southeast Lake Erie shore of Pelee Island, Ontario, Canada, 5 miles north of the international line. | Michigan Sea Grant Gregory J. Dick, University of Michigan Federal scientists released their annual forecast for Lake Erie's harmful algal blooms on June 26, 2025, and they expect a mild to moderate season. However, anyone who comes in contact with the blooms can face health risks, and it's worth remembering that 2014, when toxins from algae blooms contaminated the water supply in Toledo, Ohio, was considered a moderate year, too. The Conversation asked Gregory J. Dick, who leads the Cooperative Institute for Great Lakes Research, a federally funded center at the University of Michigan that studies harmful algal blooms among other Great Lakes issues, why they're such a concern. bulletin_current 1. What causes harmful algal blooms? Harmful algal blooms are dense patches of excessive algae growth that can occur in any type of water body, including ponds, reservoirs, rivers, lakes and oceans. When you see them in freshwater, you're typically seeing cyanobacteria, also known as blue-green algae. These photosynthetic bacteria have inhabited our planet for billions of years. In fact, they were responsible for oxygenating Earth's atmosphere, which enabled plant and animal life as we know it. Algae are natural components of ecosystems, but they cause trouble when they proliferate to high densities, creating what we call blooms. Harmful algal blooms form scums at the water surface and produce toxins that can harm ecosystems, water quality and human health. They have been reported in all 50 U.S. states, all five Great Lakes and nearly every country around the world. Blue-green algae blooms are becoming more common in inland waters. The main sources of harmful algal blooms are excess nutrients in the water, typically phosphorus and nitrogen. Historically, these excess nutrients mainly came from sewage and phosphorus-based detergents used in laundry machines and dishwashers that ended up in waterways. U.S. environmental laws in the early 1970s addressed this by requiring sewage treatment and banning phosphorus detergents, with spectacular success. Today, agriculture is the main source of excess nutrients from chemical fertilizer or manure applied to farm fields to grow crops. Rainstorms wash these nutrients into streams and rivers that deliver them to lakes and coastal areas, where they fertilize algal blooms. In the U.S., most of these nutrients come from industrial-scale corn production, which is largely used as animal feed or to produce ethanol for gasoline. Climate change also exacerbates the problem in two ways. First, cyanobacteria grow faster at higher temperatures. Second, climate-driven increases in precipitation, especially large storms, cause more nutrient runoff that has led to record-setting blooms. 2. What does your team's DNA testing tell us about Lake Erie's harmful algal blooms? Harmful algal blooms contain a mixture of cyanobacterial species that can produce an array of different toxins, many of which are still being discovered. When my colleagues and I recently sequenced DNA from Lake Erie water, we found new types of microcystins, the notorious toxins that were responsible for contaminating Toledo's drinking water supply in 2014. These novel molecules cannot be detected with traditional methods and show some signs of causing toxicity, though further studies are needed to confirm their human health effects. We also found organisms responsible for producing saxitoxin, a potent neurotoxin that is well known for causing paralytic shellfish poisoning on the Pacific Coast of North America and elsewhere. Saxitoxins have been detected at low concentrations in the Great Lakes for some time, but the recent discovery of hot spots of genes that make the toxin makes them an emerging concern. Our research suggests warmer water temperatures could boost its production, which raises concerns that saxitoxin will become more prevalent with climate change. However, the controls on toxin production are complex, and more research is needed to test this hypothesis. Federal monitoring programs are essential for tracking and understanding emerging threats. 3. Should people worry about these blooms? Harmful algal blooms are unsightly and smelly, making them a concern for recreation, property values and businesses. They can disrupt food webs and harm aquatic life, though a recent study suggested that their effects on the Lake Erie food web so far are not substantial. But the biggest impact is from the toxins these algae produce that are harmful to humans and lethal to pets. The toxins can cause acute health problems such as gastrointestinal symptoms, headache, fever and skin irritation. Dogs can die from ingesting lake water with harmful algal blooms. Emerging science suggests that long-term exposure to harmful algal blooms, for example over months or years, can cause or exacerbate chronic respiratory, cardiovascular and gastrointestinal problems and may be linked to liver cancers, kidney disease and neurological issues. In addition to exposure through direct ingestion or skin contact, recent research also indicates that inhaling toxins that get into the air may harm health, raising concerns for coastal residents and boaters, but more research is needed to understand the risks. The Toledo drinking water crisis of 2014 illustrated the vast potential for algal blooms to cause harm in the Great Lakes. Toxins infiltrated the drinking water system and were detected in processed municipal water, resulting in a three-day 'do not drink' advisory. The episode affected residents, hospitals and businesses, and it ultimately cost the city an estimated US$65 million. 4. Blooms seem to be starting earlier in the year and lasting longer – why is that happening? Warmer waters are extending the duration of the blooms. In 2025, NOAA detected these toxins in Lake Erie on April 28, earlier than ever before. The 2022 bloom in Lake Erie persisted into November, which is rare if not unprecedented. Scientific studies of western Lake Erie show that the potential cyanobacterial growth rate has increased by up to 30% and the length of the bloom season has expanded by up to a month from 1995 to 2022, especially in warmer, shallow waters. These results are consistent with our understanding of cyanobacterial physiology: Blooms like it hot – cyanobacteria grow faster at higher temperatures. 5. What can be done to reduce the likelihood of algal blooms in the future? The best and perhaps only hope of reducing the size and occurrence of harmful algal blooms is to reduce the amount of nutrients reaching the Great Lakes. In Lake Erie, where nutrients come primarily from agriculture, that means improving agricultural practices and restoring wetlands to reduce the amount of nutrients flowing off of farm fields and into the lake. Early indications suggest that Ohio's H2Ohio program, which works with farmers to reduce runoff, is making some gains in this regard, but future funding for H2Ohio is uncertain. In places like Lake Superior, where harmful algal blooms appear to be driven by climate change, the solution likely requires halting and reversing the rapid human-driven increase in greenhouse gases in the atmosphere. Gregory J. Dick, Professor of Biology, University of Michigan This article is republished from The Conversation under a Creative Commons license. Read the original article.
Yahoo
23-05-2025
- Science
- Yahoo
Earth's Rotation Is Slowing Down, And It Might Explain Why We Have Oxygen
Ever since its formation around 4.5 billion years ago, Earth's rotation has been gradually slowing down, and its days have gotten progressively longer as a result. While Earth's slowdown is not noticeable on human timescales, it's enough to work significant changes over eons. One of those changes is perhaps the most significant of all, at least to us: lengthening days are linked to the oxygenation of Earth's atmosphere, according to a study from 2021. Specifically, the blue-green algae (or cyanobacteria) that emerged and proliferated about 2.4 billion years ago would have been able to produce more oxygen as a metabolic by-product because Earth's days grew longer. Check out the video below for a summary on the research. "An enduring question in Earth sciences has been how did Earth's atmosphere get its oxygen, and what factors controlled when this oxygenation took place," microbiologist Gregory Dick of the University of Michigan explained in 2021. "Our research suggests that the rate at which Earth is spinning – in other words, its day length – may have had an important effect on the pattern and timing of Earth's oxygenation." There are two major components to this story that, at first glance, don't seem to have a lot to do with each other. The first is that Earth's spin is slowing down. The reason Earth's spin is slowing down is because the Moon exerts a gravitational pull on the planet, which causes a rotational deceleration since the Moon is gradually pulling away. We know, based on the fossil record, that days were just 18 hours long 1.4 billion years ago, and half an hour shorter than they are today 70 million years ago. Evidence suggests that we're gaining 1.8 milliseconds a century. The second component is something known as the Great Oxidation Event – when cyanobacteria emerged in such great quantities that Earth's atmosphere experienced a sharp, significant rise in oxygen. Without this oxidation, scientists think life as we know it could not have emerged; so, although cyanobacteria may cop a bit of side-eye today, we probably wouldn't be here without them. There's still a lot we don't know about this event, including such burning questions as why it happened when it did and not sometime earlier in Earth's history. It took scientists working with cyanobacterial microbes to connect the dots. In the Middle Island Sinkhole in Lake Huron, microbial mats can be found that are thought to be an analog of the cyanobacteria responsible for the Great Oxidation Event. Purple cyanobacteria that produce oxygen via photosynthesis and white microbes that metabolize sulfur, compete in a microbial mat on the lakebed. At night, the white microbes rise to the top of the microbial mat and do their sulfur-munching thing. When day breaks, and the Sun rises high enough in the sky, the white microbes retreat and the purple cyanobacteria rise to the top. "Now they can start to photosynthesize and produce oxygen," said geomicrobiologist Judith Klatt of the Max Planck Institute for Marine Microbiology in Germany. "However, it takes a few hours before they really get going, there is a long lag in the morning. The cyanobacteria are rather late risers than morning persons, it seems." This means the window of daytime in which the cyanobacteria can pump out oxygen is very limited – and it was this fact that caught the attention of oceanographer Brian Arbic of the University of Michigan. He wondered if changing day length over Earth's history had had an impact on photosynthesis. "It's possible that a similar type of competition between microbes contributed to the delay in oxygen production on the early Earth," Klatt explained. To demonstrate this hypothesis, the team performed experiments and measurements on the microbes, both in their natural environment and a laboratory setting. They also performed detailed modelling studies based on their results to link sunlight to microbial oxygen production, and microbial oxygen production to Earth's history. "Intuition suggests that two 12-hour days should be similar to one 24-hour day. The sunlight rises and falls twice as fast, and the oxygen production follows in lockstep," explained marine scientist Arjun Chennu of the Leibniz Centre for Tropical Marine Research in Germany. "But the release of oxygen from bacterial mats does not, because it is limited by the speed of molecular diffusion. This subtle uncoupling of oxygen release from sunlight is at the heart of the mechanism." These results were incorporated into global models of oxygen levels, and the team found that lengthening days were linked to the increase in Earth's oxygen - not just the Great Oxidation Event, but another, second atmospheric oxygenation called the Neoproterozoic Oxygenation Event around 550 to 800 million years ago. "We tie together laws of physics operating at vastly different scales, from molecular diffusion to planetary mechanics. We show that there is a fundamental link between day length and how much oxygen can be released by ground-dwelling microbes," Chennu said. "It's pretty exciting. This way we link the dance of the molecules in the microbial mat to the dance of our planet and its Moon." The research has been published in Nature Geoscience. An earlier version of this article was published in August 2021. New Jersey Hawk Develops Clever Hunting Strategy Using Traffic Signals Your Sensitive Teeth May Exist So Ancient Fish Could Avoid Danger Expert Explains Why We Need to Stop Giving Milk to Cats
E&E News
16-05-2025
- Science
- E&E News
NOAA staff cuts could threaten monitoring of Great Lakes toxic algae
Deep staff reductions and potential funding cuts to NOAA's primary science center on the Great Lakes could increase the risk of human exposure to toxic algae, a perennial threat in the world's largest freshwater ecosystem, officials say. Since February, NOAA has lost 16 staffers at the Great Lakes Environmental Research Laboratory in Ann Arbor, Michigan. Those employees — who were either fired probationary workers or longtime staffers who took retirement — included key members of a team responsible for collecting, analyzing and communicating risks from 'harmful algal blooms,' or HABs. That's more than a third of the 48-employee lab best known by its acronym, GLERL. Advertisement 'This is a critical time,' said Gregory Dick, director of the Cooperative Institute for Great Lakes Research, or CIGLR, a formal partnership between NOAA and 15 academic institutions and private-sector partners that is housed within GLERL. 'I would definitely say our HABs monitoring program is very much in jeopardy for this summer.'
Yahoo
26-04-2025
- Science
- Yahoo
Earth's Rotation Is Slowing Down, And It Could Explain Why We Have Oxygen
Ever since its formation around 4.5 billion years ago, Earth's rotation has been gradually slowing down, and its days have gotten progressively longer as a result. While Earth's slowdown is not noticeable on human timescales, it's enough to work significant changes over eons. One of those changes is perhaps the most significant of all, at least to us: lengthening days are linked to the oxygenation of Earth's atmosphere, according to a study from 2021. Specifically, the blue-green algae (or cyanobacteria) that emerged and proliferated about 2.4 billion years ago would have been able to produce more oxygen as a metabolic by-product because Earth's days grew longer. "An enduring question in Earth sciences has been how did Earth's atmosphere get its oxygen, and what factors controlled when this oxygenation took place," microbiologist Gregory Dick of the University of Michigan explained in 2021. "Our research suggests that the rate at which Earth is spinning – in other words, its day length – may have had an important effect on the pattern and timing of Earth's oxygenation." There are two major components to this story that, at first glance, don't seem to have a lot to do with each other. The first is that Earth's spin is slowing down. The reason Earth's spin is slowing down is because the Moon exerts a gravitational pull on the planet, which causes a rotational deceleration since the Moon is gradually pulling away. We know, based on the fossil record, that days were just 18 hours long 1.4 billion years ago, and half an hour shorter than they are today 70 million years ago. Evidence suggests that we're gaining 1.8 milliseconds a century. The second component is something known as the Great Oxidation Event – when cyanobacteria emerged in such great quantities that Earth's atmosphere experienced a sharp, significant rise in oxygen. Without this oxidation, scientists think life as we know it could not have emerged; so, although cyanobacteria may cop a bit of side-eye today, we probably wouldn't be here without them. There's still a lot we don't know about this event, including such burning questions as why it happened when it did and not sometime earlier in Earth's history. It took scientists working with cyanobacterial microbes to connect the dots. In the Middle Island Sinkhole in Lake Huron, microbial mats can be found that are thought to be an analog of the cyanobacteria responsible for the Great Oxidation Event. Purple cyanobacteria that produce oxygen via photosynthesis and white microbes that metabolize sulfur, compete in a microbial mat on the lakebed. At night, the white microbes rise to the top of the microbial mat and do their sulfur-munching thing. When day breaks, and the Sun rises high enough in the sky, the white microbes retreat and the purple cyanobacteria rise to the top. "Now they can start to photosynthesize and produce oxygen," said geomicrobiologist Judith Klatt of the Max Planck Institute for Marine Microbiology in Germany. "However, it takes a few hours before they really get going, there is a long lag in the morning. The cyanobacteria are rather late risers than morning persons, it seems." This means the window of daytime in which the cyanobacteria can pump out oxygen is very limited – and it was this fact that caught the attention of oceanographer Brian Arbic of the University of Michigan. He wondered if changing day length over Earth's history had had an impact on photosynthesis. "It's possible that a similar type of competition between microbes contributed to the delay in oxygen production on the early Earth," Klatt explained. To demonstrate this hypothesis, the team performed experiments and measurements on the microbes, both in their natural environment and a laboratory setting. They also performed detailed modelling studies based on their results to link sunlight to microbial oxygen production, and microbial oxygen production to Earth's history. "Intuition suggests that two 12-hour days should be similar to one 24-hour day. The sunlight rises and falls twice as fast, and the oxygen production follows in lockstep," explained marine scientist Arjun Chennu of the Leibniz Centre for Tropical Marine Research in Germany. "But the release of oxygen from bacterial mats does not, because it is limited by the speed of molecular diffusion. This subtle uncoupling of oxygen release from sunlight is at the heart of the mechanism." These results were incorporated into global models of oxygen levels, and the team found that lengthening days were linked to the increase in Earth's oxygen - not just the Great Oxidation Event, but another, second atmospheric oxygenation called the Neoproterozoic Oxygenation Event around 550 to 800 million years ago. "We tie together laws of physics operating at vastly different scales, from molecular diffusion to planetary mechanics. We show that there is a fundamental link between day length and how much oxygen can be released by ground-dwelling microbes," Chennu said. "It's pretty exciting. This way we link the dance of the molecules in the microbial mat to the dance of our planet and its Moon." The research has been published in Nature Geoscience. An earlier version of this article was published in August 2021. This Single-Celled Microbe Can Transform Into a Multicellular Creature Scientists Spotted Signs of a Hidden Structure Inside Earth's Core 'Bone Collector' Caterpillar Wears Dead Bugs to Steal Prey From Spiders
