(The Center Square) — After decades of conservation work and multiple pieces of state and federal legislation passed on its behalf, 2023 proved a banner year for the Chesapeake Bay, according to data gathered by the Maryland Department of Natural Resources and Virginia’s Old Dominion University.
For years, conservationists have expressed concern over the amount of nutrient pollution entering the bay and disrupting its ecosystem. This year’s data showed that the bay had the “lowest average hypoxic volume since monitoring began 39 years ago,” according to a statement released by the Maryland DNR.
Tens of billions of federal and state dollars have been spent on bay conservation efforts — including reducing hypoxia, or dangerously low oxygen levels that inhibit marine life — since 1985, a couple of years after the first piece of federal legislation to restore the bay was passed. Federal and state governments have invested over $15 billion in the bay since 2015 alone. And those involved in such efforts are attributing 2023’s good news, at least partly, to the many initiatives that both government and non-governmental organizations have championed for so long.
When released, the Maryland DNR’s Program Chief of Water Quality Informatics commented on the results.
“This year’s Chesapeake Bay dissolved oxygen conditions are the best on record,” said Mark Trice in a statement. “These results illustrate that nutrient input reductions can produce a significant improvement for fish, crab and oyster habitats, and that we need to continue to advance our management efforts throughout the watershed.”
Trice referred to the management efforts, including agricultural and urban strategies to reduce polluted runoff implemented in parts of Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia.
“We can say these efforts are working — in the last reporting year (2021), we found that 77% of nitrogen reductions came from the agricultural sector,” said Rachel Felver, Program Communications Director for the Chesapeake Bay Program, in an email to The Center Square.
However, Felver also told The Center Square that during the most recent reporting period from 2019-21, the Program found that nitrogen and phosphorus, which are abundant in agricultural fertilizers and can contribute to hypoxia, still entered the bay in numbers that are difficult to comprehend — 286 million pounds of nitrogen and 19.9 million pounds of phosphorus. Nearly 18 billion pounds of sediment entered the bay during that time.
“These figures are lower than the long-term average (1985-2021) but are increases from the previous year,” Felver said.
It will take time to know what those numbers were for 2023.
This year’s low hypoxic volume happened despite imperfect conditions. Freshwater inflows (which carry runoff) to the bay were close to historical lows, but air temperatures were among historical highs, contributing to lower oxygen levels in the water.
Hypoxic volume can also fluctuate significantly with the seasons.
“Dissolved oxygen was better than average in May through August, with early August having the lowest volume of hypoxia ever measured during that time period,” Maryland’s DNR reported. “Hypoxia remained into September with worse than average conditions of 0.84 cubic miles observed versus a September historical average of 0.45. No hypoxia was observed in October.”