Chesapeake Bay's
dead zone shrinks
The Virginian-Pilot (TNS)
The dead zone of the Chesapeake Bay -- sometimes covered in red and brown algae and deadly to fish -- is shrinking, according to a recent study by the Maryland Department of Natural Resources and Old Dominion University.
The oxygen-depleted zone stretches from the middle of the bay near Baltimore to around Mobjack Bay near Gloucester County.
The progress means the bay is getting healthier for aquatic life and safer for humans. Dead zones, which occur when too many algae bloom, can make people sick if they swim in the water. The shrinking dead zone leaves more room for fishing and outdoor recreation.
Dead zones occur when pollution, such as fertilizers and dog waste, gets into the bay. Its high levels of nitrogen and phosphorus can cause algae to bloom.
When the algae die, they sink and decompose, sucking oxygen from the water faster than plants can replenish it. The vegetation dies and fish and other animals that rely on it will suffocate or have to migrate to an area with more oxygen.
Dead zones expand and contract throughout the year and are linked to spring rainfalls that wash pollutants into waterways. Warmer temperatures can help dead zones grow and make them last longer.
Virginia and the other states along the bay are working under the Chesapeake Clean Water Blueprint to decrease the pollution. The dead zone has been shrinking as cities have improved the facilities that filter wastewater into the bay.
While the commonwealth is on track to reduce pollution from wastewater, it is behind in reducing agricultural and stormwater runoff, according to the foundation.
The blueprint calls for about 90% of the remaining pollution reductions to come from agriculture.
The Inflation Reduction Act and the U.S. Department of Agriculture also provided funding this year for farmers to put in forested buffers and wetlands at little to no cost. The buffers trap much of the runoff before it can enter the bay.
Under the reduction act, farmers can get help in using conservation practices such as reducing fertilizers and using no-till or limited-till farming through organizations such as the Environmental Quality Incentives Program.
Paper: 94% in U.S.
have had covid-19
The Associated Press
An estimated 94% of people in the U.S. have been infected with the covid-19 virus at least once, according to according to a new paper from researchers at Harvard's School of Public Health.
As of early November, the percentage of people with some protection from new infections and severe disease is "substantially higher than in December 2021," according to the authors.
"Moving forward we are in probably the best shape that we've been," said Dr. Peter Chin-Hong, a professor of medicine at the University of California San Francisco who did not participate in the study. But that does not mean covid is less prevalent than before or that you're less likely to catch it.
A preprint of the paper, which has not yet been peer-reviewed, was published last week on MedRxiv. The findings are based on a statistical analysis of Centers for Disease Control and Prevention-reported diagnoses, hospitalizations and vaccinations, rather than antibody testing of a representative sample of Americans.
The team estimated that 29.1% of Americans have been vaccinated and infected, 55.7% are vaccinated and reinfected, 2.4% are unvaccinated and infected, 7% are unvaccinated and reinfected. Of those who have never been infected, 3.5% are vaccinated and 2.1% are unvaccinated.
The researchers from Harvard, Yale and Stanford set out to understand how immunity to the virus had changed since December 2021.
They compared the situation as of November to 11 months before and took into account the fluctuating prevalence of covid over time and geography, how much and how fast immunity fades, reinfections, vaccination status and the efficacy of those shots.
In December 2021, 59.2% of people had been infected with the covid-19 virus, they estimated.
"Between Dec. 1, 2021, and Nov. 9, 2022, protection against a new omicron infection rose from 22% to 63% nationally, and protection against an omicron infection leading to severe disease increased from 61% to 89%," the analysis found.
The authors caution that the introduction of "a more transmissible or immune-evading [sub]variant, changes in [human] behavior or ongoing waning of immunity" could change the calculations.
The study estimated that in less than a year there were 116 million first infections in the U.S. and 209 million reinfections, nearly all from omicron subvariants.