Announcement

How lawn clippings can be harmful to our canals

Wednesday, June 30, 2021

A message from the Environment and Natural Assets Committee:

The committee was recently alerted by a conscientious property owner of her concern about people on her canal blowing lawn clippings and yard waste into the water.

While a few leaves will naturally fall into the water, as homeowners we should be mindful not to upset nature’s balance. Leaves, grass clippings, and pet waste should never be blown into or dumped into our canals. Yard waste, grass clippings, leaves, pet droppings, etc., when put in the canals, begin to decompose and use up the critical, life-giving oxygen in the water. In addition, the water can become unsightly and release a foul odor.

Yard waste can also “super-fertilize” and can lead to algae blooms and fish kills. Over time, that part of water may become a hypoxic zone (a place where no other organisms can survive because of extremely low dissolved oxygen levels).

Yard waste should be mulched (clear of the water), composted, or set out with the trash. Pet waste should always be bagged and placed in the trash. If you are using a lawn service, please make sure they adhere to these commonsense guidelines.

Please keep the water that surrounds us clean.

*More on this subject

What is cyanobacteria, more commonly known as blue-green algae, and why is it important to evaluate it?

When cyanobacteria degrade, they may release algal toxins that can be harmful to aquatic and human life. One such algal toxin (also known as a cyanotoxin) is microcystin. Although there are relatively few documented cases of severe human health effects, exposure to cyanobacteria or their toxins may produce allergic reactions such as skin rashes, eye irritations, respiratory symptoms, and in some cases gastroenteritis, liver and kidney failure, or death. The most likely pathway to exposure for humans is through accidental ingestion or inhalation during recreational activities in the waterbody.

What can cyanobacteria tell us about the condition of water?

Cyanobacteria can tell us about how safe a waterbody is for recreational use. When high levels of cyanobacteria are present in a waterbody, the biological condition of the water resource may also be degraded, as the condition that allows for cyanobacterial growth is typically high in nutrients and low in dissolved oxygen. Large cyanobacteria blooms may also affect benthic macroinvertebrates and submerged aquatic plants due to decreased light penetration.

How human activities increase the occurrence of cyanobacterial blooms

There is widespread agreement within the scientific community that the incidence of Cyanobacterial Harmful Algal Blooms (HABs) is increasing both in the U.S. and worldwide. This recent increase in the occurrence of HABs has been attributed to increasing anthropogenic activities and their interaction with factors known to contribute to the growth of cyanobacterial blooms. Point sources (which may include discharges from municipal and industrial wastewater treatment plants, concentrated animal feeding operations [CAFOs], Municipal Separate Storm Sewer Systems [MS4s], stormwater associated with industrial activity, and other) and nonpoint sources (which may include diffuse runoff from agricultural fields, roads and stormwater)s may be high in nitrogen and phosphorus and can promote or cause excessive fertilization (eutrophication) of both flowing and nonflowing waters.

Causes of cyanobacterial blooms

Both physical and chemical factors contribute to the formation and persistence of cyanobacterial blooms in freshwater systems, including:

1. Light availability

2. Water temperature

3. Alteration of water flow

4. Vertical mixing

5. pH changes

6. Nutrient loading (both nitrogen and phosphorus)

7. Trace metals

Because of the interplay of these factors, there may be large temporal fluctuations in the levels of cyanobacteria and their toxins in predominating species that occur largely on seasonal time scales. Specifically, the ratio of nitrogen to phosphorus, organic matter availability, temperature and light attenuation, likely play an interactive role in determining corresponding HAB composition and toxin production.

In order to resolve these occurrences, we need to determine the “green scums” identity so we can resolve this issue to the best of our ability. It will require obtaining the services of the State of Maryland to determine the necessary information to resolve this issue.