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Green Yards and a Blue Casco Bay
Friends of Casco BaySouth Portland, Maine
Our lawn care practices are changing the ocean
in our lifetime
Since 2001, Friends of Casco Bay has been testing for pesticides and fertilizers in stormwater runoff in
coastal communities
Are pesticides getting into Casco Bay?
Friends of Casco Bay has found pesticides in stormwater runoff at 13 sites.
Some pesticide levels exceeded what EPA Some pesticide levels exceeded what EPA has determined as “safe for aquatic life.”has determined as “safe for aquatic life.”
Synthetic pyrethroids – used for lawn insect, tick, and mosquito control, have been found in sediments along the Bay. These chemicals have been shown to affect shell formation in small aquatic animals.
Are fertilizers getting into Casco Bay?
Friends of Casco Bay has tested for nitrogen at 60 sites around the Bay.
Nitrogen and phosphorus were found everywhere we sampled
with the highest concentrations where stormwater runs off and at river mouths
Just not too much…
The ocean is overdosing on nitrogen.
Nitrogen pollution leads to
Here in Maine we are experiencing…Low dissolved oxygen Loss of eelgrassGreen slimeFish killsRed tidesMarine mammal deathsMore jellyfishOcean acidification
What is ocean acidification?
Offshore: Excess carbon dioxide from burning
fossil fuels dissolves in ocean
Nearshore: Excess nitrogen promotes algae blooms and die-offs
Why is this happening?
When carbon dioxide mixes with water, it forms carbonic acid.
This makes sea water more acidic.
More acidic conditions make it harder for marine life to build their shells.
“Death by Dissolution”As a result,
Shells of baby clams dissolve or are pitted
Clam spat won’t burrow into mud -- get eaten
Stunted growth in adults
Similar effects in mussels, oysters, scallops
Ocean acidification makes it harder for shellfish to survive!
Excess nitrogen in Casco Bay mud is affecting shell production in juvenile clams.
Where does nitrogen pollution
come from?
Excess nitrogen comes from runoff from streets and yards
That ends up in the ocean
How is Friends of Casco Bay approaching the problem?
Monitoring nitrogen levels in Casco Bay since 2001
Developed a model to track nitrogen levels in the Bay over time
Established protocols for other researchers to sample elsewhere in coastal Maine
Lobbied State to require DEP to set a limit on nitrogen discharges into coastal waters
Work to increase awareness of Nitrogen pollution
BayScaping was started to create a cultural shift
among homeowners
In collaboration with Maine Board of Pesticides Control
“Weed’n’Feed isn’t fish food”
What is BayScaping?
Landscaping that recognizes the connection between your backyard and Casco Bay
A six-step lawn care plan to minimize reliance on pesticides and fertilizers
The Elements of BayScapingThe Elements of BayScaping
Education promotes low-impact horticulture, especially lawn care
Water quality monitoring demonstrates that pesticides and fertilizers are entering Casco Bay
Recognition rewards residents, businesses, and municipalities that adopt BayScaping practices
BayScaping’s Six StepsBayScaping’s Six Steps
Lay the groundwork
Water deeply
Mow high
Control thatch & compaction
Fertilize frugally
Use common-sense pest control
1. Lay the groundwork
• Think about how you use the yard. How much lawn do you need?
• Plant shrubs and trees to buffer runoff
• Don’t try to grow grass where it won’t flourish. Plant a rain garden, bushes, patio instead
Lush lawnsLush lawns
• At least 3-6 inches of top soil• At least six hours of sun a day, best in AM• Good drainage• A good mix
– There are no native Maine grasses– Choose fescues & rye grass
• Add clover • Avoid grass in high traffic areas
2. Water deeply2. Water deeply
• Water infrequently
– Water 1 - 2 times a week
– Water early in the morning between 6 & 10 AM
• Apply 1 inch of water a week– Add enough water to soak into the ground 6 to 8 inches
– Use a rain gauge
• Allow grass to go dormant in the summer– Apply 1/4 - 1/2 inch water every 3 weeks
3. Mow high
• Mow lightly and often
• Remove no more than a third of the leaf blade at a time
• Mow grass to 3 to 3.5 inches high
• Vary your mowing pattern
• Keep mower blades sharp
Root length is a reflection of blade length
Cutting too low makes the grass put more energy into growing the leaf blade, and takes away from its roots
4. Loosen up!4. Loosen up!
• Rake, de-thatch, or aerate in spring or fall
• Keep thatch, that decaying layer of dead grass, under 1/2 inch thick
5. Fertilize frugally5. Fertilize frugally• Test the soil to see what—and IF—you need to add
amendments
• Best time to apply is August/September
• Maine soil rarely needs phosphorus
• Maine soil usually needs lime to reach 6.0 -7.0 pH
• Apply after a rain, not before
• Use slow-release organic fertilizers
• Sweep up fertilizer from driveways and sidewalks
6. C6. Common sense pest controlommon sense pest control
• Accept a few weeds or insects
• Identify the pest
• Pull it out or mow it off
• Encourage biological controls
How can you help?
at home
and around the Bay
You—and your neighbors—
ARE making a difference.
Never doubt that a small group of thoughtful,
committed citizens can change the world.
Indeed, it is the only thing that ever has. Margaret Mead
