concentrated the nutrients are in local waters, the more they help microscopic plants, such as algae, in the estuary to grow and cloud the water. When microscopic plants ultimately die, they break down in a process that consumes the dissolved oxygen. Dissolved oxygen is the amount of oxygen
available to sustain marine life, such as the crabs, anchovies and bass. High nutrients tend to be associated with cloudier water and lower dissolved oxygen.
According to the report card, nitrogen and phosphorus levels increased. Chloraphyll a, an indicator of algae in the water, also increased.
Conversely, improvements in water quality contributed to the resurgence of aquatic grasses,
considered one of the most important habitats in the Chesapeake Bay. However, the Patuxent region, where Calvert County falls west of the bay, had the lowest aquatic grass score.
Testa said the grasses that grow on the bottom of the bay are one of the organisms scientists are trying to restore because they create a habitat for a number of different organisms and provide protection for smaller, vulnerable species. There
are many factors that determine whether the grasses come back.
“They need light more than anything. If the water is too cloudy, there is not going to be grasses coming back,” said Testa. “Part of Patuxent’s low relative grade is because the water is still kind of cloudy.”
Progress has been made to correct the water quality.
“Marylanders are helping to protect the land, water, air and natural resources and
that’s leading to a healthier Bay for all,” Maryland Department of the Environment Secretary Ben Grumbles said in the release.
Grumbles said even more progress can be made with the continuation of innovation and partnership with all sectors within the watershed, from agriculture to energy and transportation, across all the streams, wetlands and aquifers that feed into the bed.
Some local efforts to restore and preserve the bay underway in Calvert County have contributed to its improved health.
“It’s fair to say that the major improvements that have happened in the Patuxent watershed, the upgrades to the sewage treatment facilities, that’s part of an overall effort baywide, is a contributor to some of the improvements,” Testa said. “The tributaries are really impacted by their own watersheds.”
The Patuxent River received a status of “poor” ecosystem health. The Patuxent’s score over the past five years has been relatively steady, with some indicators improving while others declined.
Testa noted the relatively low grade for the Patuxent is a sign there is still work to be done locally to clean up the river.