Monday, May 25, 2020

Health of the Chesapeake Bay Looks Worse


from UMCES
Last week the University of Maryland Center for Environmental Science released their 13th annual report card on the health of the Chesapeake Bay for 2019. Overall, Chesapeake Bay scored 44% in 2019. This is the lowest score and first C- since 2011 and pretty discouraging considering all the effort and money that has gone into the Watershed Implementation Plans to meet the goals of the Chesapeake Clean Water Blueprint. will ensure pollution reductions in the Chesapeake Bay by 2025 that was supposed to lead to the "fishable, swimmable" waters.

Although several indicators of bay health improved in 2019, they did not offset those that declined. Bay-wide, dissolved oxygen scored 83% in 2019, a decrease from 2018. Water clarity scored 10%, a slight decrease from last year’s 7%. The benthic community score sharply decreased from a 59% to a 38%. Total nitrogen scored 39%, a decline from last year’s 44%. Total phosphorus scored 76%, a slight increase from 2018. Chlorophyll a scored 26%, an increase from 22% in 2018. Aquatic grasses scored 35%, a decline from last year’s 39%.

from UMCES
Overall Chesapeake Bay Health Scores have been variable in the past and bounced around a bit. From 2015-2017 the, Chesapeake Bay Health Scores were in the high C range (53, 54, 54). At that time the consecutive scores contributed to an overall positive trajectory and it appeared that we were making progress. More time only served to show that the Health Index broke out of its historical range to the down side. This year they explain that the moderate and poor scores in 2019 were mainly due to above-average temperatures almost every month of the year. Warmer air temperatures means warmer waters, and the intense heat hurt aquatic grasses and benthic macroinvertebrates, and caused lower dissolved oxygen levels. The year before it was excessive rain and heavy storm events that caused the disappointing results. A changing climate seem to be impacting the performance of the Clean Water Blueprint. The next phase of the plan is supposed to account for changing climate.

This is the first year that they have scored the watershed, using five indicators of ecological and socioeconomic health. The University of Maryland Center for Environmental Science has incorporated new indicators for Chesapeake Bay health including some indicators of watershed health. Watershed health includes traditional ecosystem indicators, but also social, economic, and cultural indicators.
from UMCES
Overall, the Chesapeake Watershed scored 60%, a B-. There were four aquatic indicators and one societal indicator. Watershed-wide, total nitrogen scored 79%. Total phosphorus scored 61% and turbidity scored 68%. Stream benthic community scored 46%. One social indicator was included, the Social Index, which scored 60%. I have no idea why these scores were given.

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