DISSOLVED OXYGEN IN
THE HARBOR REMAINS AT HEALTHY LEVELS
of the early perceptions about the effects of pollution in Boston
Harbor was that dissolved oxygen (DO) in the water was too low.
We now know that, except for a few isolated locations, DO levels
in the harbor were high enough to support healthy marine life
even before the Boston Harbor Project began. This change in perspective
is not only based on more monitoring data, but also on by the
U.S. Environmental Protection Agency showing that DO requirements
for marine life are actually lower than previously thought.
levels in Boston Harbor have benefited from the harbor being so
well-mixed and well-flushed. MWRAs monitoring has revealed
little change in DO concentrations in the harbors waters
since the early '90s.
of Dissolved Oxygen in Boston Harbor
This map shows the average pattern of
DO in the bottom waters of the harbor during the summer.
|A moored instrument near the
New England Aquarium shows DO in the water decreases at
night, and increases through the day. Note that even in
the early morning when DO is lowest, concentrations are
greater than EPA's new recommended standard for marine waters
(an average of 4.8 mg/l).
More on the State of Boston Harbor