Summer Days Are Waning But Algal Blooms Are Growing
The evidence is all around us: Bigger and more deadly storms; once-in-a-1,000 years heat waves; much of Western North America in flames; and unprecedented flooding across the world. There is no doubt that global warming is real.
The combination of hotter summers and strong storms is not only damaging; it also can cause serious health problems.
One example is the growing presence of toxic algal blooms in lake water. Harmful algal blooms are more frequent and occurring earlier across New York and the nation. They can pose a threat to recreation and can taint drinking water supplies.
Harmful algal blooms aren’t your typical green surface ooze that you may see on the top of lake waters. While ugly to look at when at the surface, a bloom can also be dangerous, so much so that the state has a blanket policy to stay out of the water should there be evidence of one.
While every algal bloom isn't toxic -- some algal species can produce both toxic and nontoxic blooms -- toxic blooms can cause problems for swimmers and other recreational users in the form of rashes or allergic reactions. People who swim in a bloom may experience health effects including nausea, vomiting, headaches, respiratory problems, skin rash and other reactions. There have also been reports nationwide of dogs and livestock dying shortly after swimming or wading in a bloom.
The blooms are a blue-green slimy substance. They often crop up in late summer and early fall, (although they have already started to show up in New York’s surface waters) when waters are warm and calm. They also need nutrients to bloom, so they’ll often be observed after heavy storms.
The nutrients they primarily rely on are phosphorus and nitrogen. The algal blooms have increased due to a rise in nutrient runoff from sources such as soil erosion from fertilized agricultural areas and lawns, erosion from river banks, river beds, land clearing (deforestation), and sewage effluent. All of these are the major sources of phosphorus and nitrogen entering water ways. These nutrients coupled with warm, calm water is the recipe for an algal bloom.
The heating planet also drives algal blooms. Warmer temperatures prevent water from mixing, allowing algae to grow thicker and faster. Algal blooms absorb sunlight, making water even warmer and promoting more blooms.
Climate change will lead to more droughts, which make freshwater saltier. This can cause marine algae to invade freshwater ecosystems. In the southwestern and south central United States, toxic marine algae have been killing fish in freshwater lakes since 2000.
Algae need carbon dioxide to survive. Higher levels of carbon dioxide from the burning of fossil fuels can lead to rapid growth of algae, especially toxic blue-green algae that can float to the surface of the water.
Unfortunately, the recent heat waves helped trigger some algal blooms that showed up in lakes and reservoirs across New York State.
As of today, there are 47 lakes confirmed to have algal blooms, including the drinking water supplies for some towns in upstate. When the blooms are found in drinking water supplies, it can result in that system being unusable for human consumption. For the past three years, for example, Onondaga County’s Skaneateles Lake had multiple toxic blooms during the summer months. The toxins threatened the drinking water of not only local town and village residents, but also those in the city of Syracuse and surrounding areas.
Another example, according to the state Department of Environmental Conservation, is the 23 confirmed blooms of toxic algae on Cayuga Lake in July. At that time, there was no threat to drinking water supplies, but swimming was limited. Cayuga Lake, however, continues to be plagued by algal blooms.
In other areas, surface waters have seen algal blooms, but public drinking water supplies were not under threat. In Rensselaer County, for example, Glass Lake has had a confirmed algal bloom. In New York City, Prospect Park Lake and Central Park Lake have both reported algal blooms.
To check out the New York lakes for which algal blooms are a concern, you can go to the DEC website, which has a harmful algal bloom notifications webpage that it updates regularly. If you identify an algal bloom and want to report it, send a photo to the DEC.
While we all must do everything possible to reduce the world’s reliance on fossil fuels and aggressively embrace energy efficiency programs and alternative energy sources, due to the amount of CO2 in the atmosphere, the planet will continue to heat up. There is not much that New York can do to reduce the damage that has already been done and that is fueling the current rising heat of the planet. But when it comes to protecting surface waters and drinking water supplies, the state has to do a lot more to reduce the runoff from agriculture, landscaping and wastewater sources. New York must be proactive about protecting drinking water supplies and recreational waters.
Failing to do so will drastically compound the looming catastrophe of what global warming is doing to the atmosphere. Water is a precious resource and we must act to safeguard it.
Blair Horner is executive director of the New York Public Interest Research Group.
The views expressed by commentators are solely those of the authors.They do not necessarily reflect the views of this station or its management.