(Sept. 27, 2019) Like a student who missed too many chemistry classes because of a cold, Maryland’s coastal bays received an “Incomplete” on this year’s Bay Report Card, because bad weather prevented sufficient data collection.
“Last summer … two bad things happened,” said Dr. William Dennison, vice-president for Science Application at UMCES. “One, we had record rainfall, lot of runoff, not good water quality. Secondly, partly because of the bad weather, we weren’t able to collect and accumulate the data that we normally use.”
This does not mean, however, that members of the Maryland Coastal Bays Program were clueless on the current state of coastal bays.
Dennison said the data the group was able to gather indicated that the coastal bays would receive a poor grade.
“We know anecdotally … and we know from scientific observations that we had very high tepidity, and our water clarity was compromised. So we suspect our aquatic grasses … did not fare well, because the water was too cloudy, and they need light to survive,” Dennison said.
Coastal bays health is defined as the progress of water quality indicators — nitrogen, phosphorus, chlorophyll A (the primary pigment of photosynthesis) dissolved oxygen, hard clams and seagrass — make toward ecological thresholds or goals.
Researchers had problems collecting data on seagrass and clams because of the aforementioned bad weather, which Dennison attributed to climate change.
“We are, number one, changing the sea level, so … marshes are eroding, and when we lose the marsh, we lose a natural filter, we’re losing the kidneys,” Dennison said.
In addition, abnormally hot summers and falls “cooked” the seagrass, causing the once abundant population to plateau in 2000, and crash within the following decade, he said.
“We measured over time increased sea levels, increased temperature and … increased rainfall,” Dennison said. “These aren’t climate projections — these are real data on what’s already happened. That’s why I can be so confident.”
Dennison’s assertions are supported by a recent United Nations study that found Earth’s waters were under extreme strain from climate change, with rising average temperatures and declining oxygen levels.
Dennison clarified that the increased rainfall by itself wasn’t the problem, but that its runoff, which carries manure, sediment, other matter, is the real culprit.
“It ends up in the coastal bays, and that’s a problem,” he said.
The runoff and higher-than-average temperatures also led to an unusual algal bloom around December that continues to persist.
According to the Environmental Protection Agency, algal blooms sometimes produce toxins that harm fish and other animals.
Even if it does not produce toxins, it can block out sunlight and clog fish gills.
More importantly, algal blooms create dead zones — areas in water with little to no oxygen — and decimate fish and aquatic populations.
So what can be done to improve water quality in coastal bays?
On a macro-scale, Dennison said communities along the bay need to upgrade their septic systems to remove nitrogen from wastewater, because excess nitrogen can cause algal blooms.
Agricultural industries need to increase usage of cover crops, which help mitigate erosion, and prevent over-fertilization, he said.
Dennison also recommended upgrading the 90th Street sewage treatment plant in Ocean City, as a crew of scientists had found the effluent has been causing phytoplankton populations, micro-algae, to flourish.
Preventing further coastal bay damage on a micro-level involved largely the same ideas: prevent nutrient runoff by using less fertilizer, and picking up after pets.
The Maryland Coastal Bays Program plans to continue monitoring coastal bays and protecting water quality, but it needs help.
“We’re actively trying to secure funding to maintain our … environmental intelligence program,” Dennison said. “We’re providing really important feedback on our large investments in water treatment, in rain guards — all of the best management practices that we’re implementing, which are hundreds of millions of dollars.”
For more information on this years Bay Report Card, go to https://mdcoastalbays.org