Toxic algae flowers last longer in Lake Erie – why this worry for people and pets

Federal scientists have published their annual forecast of harmful algats of Lake Erie on June 26, 2025 and expect from a gentle to moderate season. However, anyone who has encountered flowers can face health threats, and it is worth remembering that 2014, when toxins from algae bloom bloom He stopped water supply At Toldo, Ohio was also considered a moderate year.

We asked Gregory J. Dickwhich leads Cooperative Institute for Great Lakes ResearchThe center financed by the Federal at University of Michigan, which examines harmful algae blooms among other problems with huge lakes, why they are such a problem.

1. What causes harmful algae flowers?

Harmful algae flowers are dense patches with excessive algae growth, which can occur in any type of water reservoir, including joints, tanks, rivers, lakes and oceans. When you see them in fresh water, you usually see CyanobacteriaAlso known as blue-green algae.

These photosynthetic bacteria have lived in our planet for billions of years. In fact, they were responsible for the oxygenating atmosphere of the earth that enabled the life of plants and animals as we know.

Algae are natural elements of ecosystems, but they cause trouble when high densities spread, creating what we call flowering.

Harmful algae flowers create scum on the water surface And produce toxins that can harm ecosystems, water quality and human health. Were Reported in all 50 US statesIN All five great lakes AND almost every country around the world. Flowers with blue-green algae become more common in inland waters.

The main sources of harmful algae flowers are excess nutrients in water, usually phosphorus and nitrogen.

Historically, these excess nutrients came mainly from detergents based on sewage and phosphorus used in washing machines and dishwasher that hit waterways. The Act on the US environment in the early seventies concerned this, requiring sewage treatment and prohibiting phosphorus detergents, with spectacular success.

https://www.youtube.com/watch?v=drdpqtj3dje

Today, agriculture is the main source of excess nutrients from chemical fertilizer or manure used for farm fields for cultivation. Bulborms wash these nutrients in streams and rivers, which provide them to lakes and coastal areas, where algae flowers will fertilize. In the United States, most of these nutrients come from corn production on an industrial scale, which is largely used as animal feed or for the production of ethanol for gasoline.

Climate change also worsens A problem in two ways. First of all, cyanobacteria grow faster at higher temperatures. Second, Increase in climate rainfallespecially huge storms, they cause more rafting of nutrients led to record flowers.

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Harmful algae flowers contain a mixture of cyanobacterial species that can produce a number of different toxins, many of which are still discovered.

When my colleagues and I recently seized DNA from Lake Erie Water, we I found new types of Mikrocystinknown toxins for which they were responsible Detaining of toledo drinking water supply in 2014.

These up-to-date molecules cannot be detected by time-honored methods and show some signs of toxicity, although further research is needed to confirm their health activities.

We also found Organisms responsible for the production of saxytoxinMighty neurotoxin, which is well known for causing paralytic poisoning of crustaceans on the Pacific coast in North America and other countries.

Saxytoxins have been detected in low concentrations in huge lakes for some time, but The last discovery of hot gene points that produce toxin It makes them an emerging problem.

Our research suggests Warmer water temperatures It can escalate production, which raises concerns that saxytoxin will become more common along with climate change. However, toxin production controls are intricate and further tests are needed to test this hypothesis. Federal monitoring programs They are necessary to track and understand emerging threats.

3. Should people worry about these flowers?

Harmful algae flowers are unsightly and smelly, which makes them concern for recreation, real estate values ​​and companies. May disturb the nutritional networks and damage to water lifeAlthough the last study suggested this Their impact on the era’s food network They are not significant so far.

But the greatest impact is toxins that produce these algae harmful to people and fatal to animals.

Toxins can cause acute health problems such as gastrointestinal symptoms, headache, fever and skin irritation. Dogs can die because of water consumption from the lake with harmful algae flowers. Emerging science It suggests that long-term exposure to harmful algae blooms, for example for months or years, can cause or tighten problems with the respiratory, cardiovascular and digestive tract and can be associated with liver cancer, kidney disease and neurological problems.

In addition to exposure by direct consumption or contact of the skin, recent studies also indicate that inhaling toxins that go into the air It can harm health, increasing the fears of coastal residents and sailors, but further research is needed to understand the risk.

The crisis in drinking water from 2014 illustrates the huge potential of algae blocks to cause damage in huge lakes. The toxins infiltrated the drinking water system and were detected in processed urban water, which caused three -day advice “not drink”. The episode influenced residents, hospitals and companies, and ultimately City cost estimated $ 65 million.

4. Flowers seem to start earlier this year and lasts longer – why is this happening?

Warmer waters extend the duration of the flowers.

In 2025, Noaa detected these toxins in Lake Erie on April 28 Earlier than ever before. . 2022 Bloom in Lake Erie lasted until NovemberWhich is sporadic, if not unprecedented.

Scientific research on the Western Lake Erie shows that a potential cyanobacterial growth rate increased by up to 30% And the length of the flowering season increased by up to a month in 1995–2022, especially in warmer, shallow waters. These results comply with our understanding of cyanobacteria: It blooms as it is hot – Cyanobacteria grow faster at higher temperatures.

5. What can you do to reduce the likelihood of algae blocks in the future?

The best and perhaps the only hope of reducing the size and occurrence of harmful algae flowers is to reduce the amount of nutrients reaching huge lakes.

In Lake Erie, where nutrients come primarily from agriculture, this means an improvement in agricultural practices and restoring wetlands to reduce the amount of nutrients flowing from agricultural fields and to the lake. Early indications suggest that Ohio’s H2Ohio programwho cooperates with farmers to reduce rafting, brings some profits in this area, but future funds on H2Ohio are uncertain.

In places such as the Superior Lake, where harmful algae flourishes It looks like it is powered by climate changeThe solution probably requires retaining and reversing the rapid growth of greenhouse gases in the atmosphere.