How can you help get rid of green algal slime choking our shores and smearing our beaches?
Nitrogen is the worst pollutant in the world affecting the oceans because it causes harmful algal blooms, eutrophication and ocean dead zones (hypoxia), makes marine life more vulnerable to disease, reduces biodiversity in shallow estuarine waters, degrades ocean ecosystems and contributes to global warming. Algal blooms deplete dissolved oxygen, causing marine wildlife to suffer and become more vulnerable to toxins and disease. Nitrogen in the blooms also produces nitrous oxide (N20), a greenhouse gas far more potent than carbon dioxide. This contributes to global warming, which further degrades oceans by increasing acidity in the water as the oceans absorb more and more carbon.
The Ocean River Institute is educating and mobilizing individuals across the country for responsible land practices for stewardship of the ocean.
In Florida’s Indian River Lagoon, the most bio-diverse estuary in North America, nitrogen runoff from lawn fertilizers, septic tanks, and outflows from Lake Okeechobee has caused massive algal blooms. These blooms have become toxic at times and contributed to dolphin die-offs in 2001, 2008, 2009, 2010 and 2013. Last year 80 dolphins died and over 100 manatees died. There is hope now. After four years of working in concert with locals taking action, all five Lagoon counties have passed strong lawn fertilizer ordinances. They ban the application of fertilizers during the rainy summer months, require the use of at least 50% slow release nitrogen, and that people observe setbacks from waterways. In 2014, we saw fewer dolphin deaths and fishkills, along with the return of 5,000 acres of sea grass. Click here to learn more about our work in Florida.
That nitrogen is the worst ocean pollutant in the world was evident on a hot summer day in 2018. In Boston Harbor thousands of menhaden, a midsized bait fish, were chased by predatory striped bass in the Mystic River. Just before the Amelia Earhart Dam fish entered an ocean dead zone where blooming algae had consumed all of the dissolved oxygen. The fast swimming, dark-muscled fish died quickly.
There are three major sources of nitrogen polluting our waters. Septic and sewage is often the biggest source. However, Boston Harbor and the Mystic River watershed communities have their sewage treated by the Massachusetts Water Resources Authority (MWRA). We cleaned up Boston Harbor by building a state of the art treatment facility complete with methane digesters, windmills and solar panel arrays.
Agriculture is the second source of nitrogen pollution. Here in greater Boston there is not a lot of agriculture and we have very active Conservation Commissions making sure that fertilizer and waste does not leave the farm.
For the Mystic River watershed, lawn fertilizer is a significant source of nitrogen. With lawns, unlike for sewage and agriculture, homeowners are paying to pollute. Feeding grass fertilizer from above discourages the sinking of roots, opening the soil, and developing symbiotic relationships with fungi and bacteria to build vast underground networks. Fertilized grass greens up quick and is wimpy, easy munching for pests. The dirt spaces between plants, called “sunspills,” dries and hardens. The ground is then only penetrable by weeds. Lawn care commercials have a solution to “your lawn problems” called “overseeding.” They’ll spread seed on the bare spots with a liberal amount of pesticides and herbicides.
People blame lawns for polluting and needing lots of water. It’s not the fault of the grass. We deserve the blame for mismanaging and interrupting natural processes. Leave the grass cuttings and that’s equivalent to one application of fertilizer. Lawn flowers such as clover in urban lawns cut every three weeks instead of more frequently where found to be pollinated by 93 species of bees.
Next time they offer to look under your turf measure how your lawn is prepared for the growing season, say no thanks. Unlike an automobile with oil that must be checked regularly, power your lawn with nature and let it be.
Be a player in the Natural Lawn Care for Healthy Soils and Less Sea Level Rise Competition. Join a team or form your own team. Teams with greatest number of persons and households pledging not to spread quick-release fertilizer, pledging not to use harsh chemicals like Roundup, win. You will also be scored by town and watershed where highest recognition goes to communities with the highest percentage of households volunteering not pollute with nitrogen our lawns and our waterways.