Health & Safety

The Cullen Park and Grassy Island wetlands create multiple risks to health and human safety. At the present time, the risks caused by Harmful Algal Blooms (HABs) containing Microcystin, which causes cause gastrointestinal illness and liver damage, are the most concerning. These wetlands will worsen the problem, not make it better.

Wetlands are known as “nature’s kidneys” and are valued for that reason. However, not all kidneys work in all bodies. This is why a donor is tested to make sure the donated kidney will be a match before a transplant is done. These wetlands are not a match for the selected locations.


The Cullen Park and Grassy Island wetland sites are in water already inundated with HABs that blow in from Lake Erie and that flow down the Maumee River.

“Don’t Touch The Water”: Toxic Algae Bloom Covers Maumee River (

Constructing wetlands to slow the flow of water in the Cullen Park wetland also will slow the flow of water moving outside the wetland along its perimeter and the surrounding area. This is the water where the kayak and the boat launches are: areas where the primary activities require physical contact with the water.

The Cullen Park wetland design constricts the opening between Cullen Park and the Maumee River. Once HABs flow into Cullen Park, this constriction will make it more difficult for HABs to flow back out.

The aquatic wetland plants intended to absorb the excess wetlands will be maintained only within the wetland. They will not be available to any of the excess nutrients that don’t go through the wetland before flowing into Cullen Park. When the HABs flow into the areas around the boat and kayak launch, they will be in an area abundant with sunshine, warm shallow water, and excess nutrients. The microcystin will flourish, becoming more and more toxic as it does so.

Nice sunny days, warm water, and increased nutrients are the perfect recipe for algae to grow. 

One Health and Disease: Harmful Algal Blooms National park service  One Health and Disease: Harmful Algal Blooms (U.S. National Park Service) (

To say it simply, these wetlands are being constructed in the wrong place. A simple analogy between wetlands and a dam illustrates this point very well:

When a town has a flooding problem, a dam can be built in the river upstream of the town to prevent excess water from reaching the town and causing floods. When a lake has an HAB problem, wetlands can be built in the river upstream of the lake to prevent excess nutrients from reaching the lake and causing HABs. If the dam is built in the middle the area prone to flooding it will only make the flooding in that area worse. If a wetland is built in the middle of an area prone to HABs it will only make the HABs in that area worse.


Like kidneys, wetlands can fail.

Wetlands do not have an unlimited ability to remove nutrients from the water supply. Too many nutrients will overload, overwhelm, or destroy a wetland, causing it to send more phosphorous back into the water supply.

The nice thing about wetlands is that they can CLEANSE and FILTER water as it MOVES through. But too much can OVERWHELM this natural filtering system and DESTROY it.

Thomas Miller, Working Wetlands, A collaborative study about wetland’s capacity for removing nutrients.  National Estuarine Research Reserve Science Collaborative, January 16, 2020

The maximum amount of phosphorus a wetland can retain before it becomes overloaded or overwhelmed is called the threshold. If the threshold is exceeded, the result can be harmful algal blooms in the water around the wetland.

Working Wetlands Infographic

Excess nutrients in contaminated waters can spur microbial growth and cause harmful algal blooms.

Wetlands, Mosquitos, and West Nile Virus by the USDA Natural Resources Conservation Service. 

There are two ways a wetland can reach its threshold and emit the excess nutrients that cause HABs. One is short term overload. This is when too many nutrients enter the wetland at one time. An example is after a rain when more nutrients get washed off the land and into the water supply.

Despite the capacity of wetlands to purify water, they do have their limits (Verhoeven et al. 2006). They can only process and assimilate a certain amount of agricultural runoff, and only so much inflow from domestic and industrial wastes”.  

Ramsar Technical Report No. 6

The other is by the wetland itself being saturated with nutrients to the point it no longer has the ability to absorb any more. Once this threshold is met, the sediment must be removed or the wetland cannot continue to function. For diked wetlands like the Cullen Park and Grassy Island wetlands with multiple bi-directional entrance points, wetland science has not yet progressed to the point where this threshold can be accurately measured. Click Here for more information.


Microcystin exposure can come from airborne droplets of water, such as from the whitecap of a wave or the wake of a boat. Science is also discovering that cyanotoxins, like Microcystin, that are contained sediments can be carried on the wind.


For more information about mosquito born diseases, click Here. Current research is being done on the issue of antibiotic resistent bacteria in wetlands:

The agricultural use of antibiotics in animal feed can result in the selection and transmission of antibiotic-resistant bacteria which move through the environment by different routes. . . . A significant one is via surface water, suggesting an obvious role for wetland managers in ensuring that waste does not enter surface waters untreated.”

Ramsar Technical Report No. 6

Much wetland research being done, and more will be required as wetland science progresses. There are newly discovered wetland related health risks, such as those created by dried up sediment and antibiotics, that are being studied to determine what their potential and severity could be. It is certain that as time goes by there will be more health risks relating to wetlands will be discovered.


  • When the number of CAFO’s in the Maumee watershed started exploding, the public didn’t expect the excess nutrients emitted by the CAFOs would cause water borne toxins in Lake Erie. When Lake Erie had a record setting HAB in 2011, the public didn’t expect that within 3 years Toledo would have its water shut off because of an HAB. Nevertheless, these things happened.

  • When the use of presription medication started, and when unused medications began being flushed down toilets, the public didn’t expect it would have any impact on the health of fish, animals, or humans. Nevertheless, this happened.

  • When antibiotics became widely presribed for human illnesses and CAFO’s started using prophylactic antibiotics, the public didn’t expect it would cause antibiotic resistent bacteria. Nevertheless, this happened.

  • In 1995 the public didn’t expect that mosquitos would transmit the West Nile virus in the United States. Nevertheless, they do.

  • We don’t know what wetland related future human health risks will happen. Nevertheless, we know that they will happen. We to take all reasonable precautions to make sure that when they do humans are protected as much as possible.

Constructing permanent diked wetlands in a densley populated, urban, residential environment and in waters whose primary prupose is recreation with full body contact does not protect humans from these future health risks. It brings those risks to where we are the most exposed and have the least protection.

This fact alone should make it clear that the Cullen Park and Grassy Island wetlands projects should be abandoned and the money allocated to other H2Ohio projects.