ANNAPOLIS – From brown and mahogany tides to slick surface masses of blue-green scum, stretches of unnaturally abundant algae drift through the Chesapeake Bay.
Some of the more benign blooms merely produce foul odors. Others form sweeping masses that block sunlight from reaching the submerged seagrass that provides a habitat for young fish and crabs.
Although it is an integral part of the watershed, too much algae can suffocate marine life, endangering the state’s seafood industry, tourism economy and bay culture.
“We need algae. Fish feed on algae. But when you have too much algae, that’s when you have a problem,” said Bruce Michael, director of Resource Assessment Services at the Department of Natural Resources.
“When these algae grow and bloom into large concentrations, they eventually die off and sink to the bottom. The decomposition of these [blooms] robs the water of the oxygen that is needed for shellfish and finfish” to survive, Michael said.
Some algae blooms can, in high concentrations, produce toxic chemicals that can harm marine life, pets, livestock and humans.
After the “pfiesteria hysteria” of 1997, in which a toxic pfiesteria bloom incited public panic about water quality, the Department of Natural Resources’ bay monitoring program was expanded. It now aims to asses every river in the watershed and the main stem of the bay, monitoring harmful algae blooms and coming up with plans to ease the problem.
Biologist Debbie Howard spends some workdays touring the watershed in a state van, armed with the tools that are needed for monitoring water quality — empty water jugs, glass flasks, a black and white secchi disk that measures underwater light penetration and a device that filters water through small, circular pads.
Decomposed organic matter turns the once white pads an army green before Howard wraps them in silver foil to send to the Chesapeake Biological Laboratory in Solomons.
There, the pads are tested for nutrients, an excess of which is the principal cause of most algae blooms. This information is then used to locate problem areas in the bay and to determine the efficacy of the state’s current management strategies, Howard said.
Howard took her monitoring tools out of the van and into the water this month, touring Cecil County’s Elk River with fellow biologist Jamie Strong.
Their boat zigzagged from monitoring station to monitoring station, getting a full perspective of the waterway, tracking the growth of submerged aquatic vegetation. Bobbing atop of an algae bloom, the boat’s chlorophyll readings were off the charts.
In October, the Department of Natural Resources has reported microcystis aeruginosa blooms in the Transquaking River and mahogany tides in Old Road Bay and the Potomac.
Limiting the frequency of these blooms means limiting the nutrients that enter the bay through urban and agricultural runoff.
“That means upgrading wastewater treatment plants, looking at developing best management practices to put on our farm fields, planting cover crops [and] reducing air pollution,” Michael said.
“As long as we can get the resources to help reduce nutrient pollution … that will probably make the biggest difference for reducing the amount of algae blooms that we actually see,” Michael said.
After decades of declining water quality, the government has accelerated its bay cleanup efforts. In May, President Obama issued an executive order requiring federal agencies to develop a solid plan for bay cleanup.
A second draft of the plan is expected to be released in November.
In September, Sen. Benjamin L. Cardin, D-Md., introduced legislation that would provide incentives for watershed states to improve water quality and give the Environmental Protection Agency the power to punish those states that fail to meet federal water quality standards.
Watershed states like Maryland have pledged to restore the bay through the protection and restoration of water quality, living resources and habitat.
“We have been making progress. It’s just not as much progress as we would like to see. On a large scale, it’s going to take time,” Michael said.