Record rainfall degrades Chesapeake Bay’s waters, but not as much as scientists thought
"The Chesapeake Bay, the nation’s largest estuary, is a little less healthy than it used to be.
Record rainfall upset the salinity balance and caused more pollutants to run off into the water, but newly-released results aren’t as bad as scientists expected.
More than one-third of the bay and its tidal tributaries met clean water standards for clarity, oxygen and algae growth between 2016 and 2018, according to the Chesapeake Bay Program. The goal is to reach 100% dissolved oxygen in the water.
Newly-released measurements taken during the three-year period indicate 38% of the bay has sufficient oxygenation. That rating is down from 42% at last count.
“When we say 38% … when you look at the bay as a whole, 38% of the bay has enough oxygen for the fish now. Thankfully, most of that oxygen is in the upper part of the bay waters. There, we are doing OK. It’s the lower part of the waters, the deeper waters, where we don’t have enough oxygen,” said Scott Phillips, Chesapeake Bay program coordinator for the U.S. Geological Survey.
While the score is lower than the record-high 42% from the previous reporting period, it is the fifth-highest estimate of water quality standards attainment since 1985, the Chesapeake Bay Program said. The Chesapeake Bay Program said for Chesapeake Bay and its tidal tributaries to function as a healthy ecosystem, water quality must improved in 62% of the bay. . ."