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EcoLogic: Quality Control
Keeping tabs on water cleanliness for plants, critters—and crowds.
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Whether you’re diving, surfing, or sailing in the ocean or freshwater this summer, it’s good to know how the health of the ecosystem is measured—and understand its biggest threats. A few indicators:
BACTERIA: Enterococci strongly indicate untreated sewage and pathogens, and the Cooperative Coastal Monitoring Program closes Jersey beaches when concentrations exceed 104 enterococci per 100 milliliters in consecutive samples. (Readings and closing notifications are available at njbeaches.org.) Yearly numbers vary, but in 2007 the CCMP closed ocean and bay beaches 142 times for bacterial and other health concerns.
CHLOROPHYLL: It’s essential for photosynthesis, but high concentrations indicate nutrient pollution from fertilizer and other runoff. The possible result: algal blooms that deplete oxygen, killing aquatic life.
TEMPERATURE: It’s more than just human comfort. (To that end, Rutgers monitors coastal water temps at
thecoolroom.org.) If the water gets too warm in certain ecosystems, it means less oxygen, killing fish.
pH: Fish and aquatic plants favor a pH level of 6 to 9. (Chem review: 7 is neutral, below is acidic, above is alkaline.) Acid rain, mining runoff, and pollution can shift the pH level out of the healthy range.
CLARITY: Clear water means sunshine for plants and visible food for sea life. To measure it, a disc is submerged until it can’t be seen—a four-foot depth is the healthy minimum. Sediment and algae are top offenders.
DISSOLVED OXYGEN: It is created by photosynthesis, the surrounding air, and the aeration of water as it tumbles. At least 5 parts per million of oxygen are necessary for a healthy and diverse fish population.
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SUMMER SWEEPS:
You can’t see bacteria in the water, but trash is another story. Plastic, which marine life may ingest, made up 74 percent of the debris collected by Clean Ocean Action in 2008 Jersey beach sweeps. (The national range is 60 to 80 percent.) Based in Sandy Hook, COA cleans and protects the coast, hosting statewide sweeps every April and October. They also offer help to those who host such events: clean-oceanaction.org has a step-by-step guide to plan a clean-up; get permission and support; advertise; and—important to COA’s efforts—collect data.
“It turns a one-day event into a legacy of information,” says pollution-prevention coordinator Tavia Danch. “Not only is the data an educational tool, we think the experience is, too. Because volunteers see what’s washing up on our beaches.”
