Laserfiche WebLink
Environmental Oversight Committee Meeting - September 13, 2012 <br /> Rick York <br /> Santuit Pond Water Qualitv <br /> Water Quality in Santuit Pond improved this summer as a result of the SolarBee <br /> water circulators. The water is much clearer with no pea-soup green color algae bloom <br /> and no floating algae film that was seen in past years. Fishermen are reporting that the <br /> fish look healthier and are fatter. Secchi disk visibility measured weekly by myself and <br /> Friends of Santuit Pond volunteers taken at various locations throughout the pond <br /> including the Town Landing averaged 103 centimeters (40") with a range of 70 to 150 <br /> cm (28-59"). The readings were about the same throughout the pond on a given day <br /> indicating that it is well mixed. The Massachusetts Department of Health has been <br /> monitoring the pond weekly during the summer at the Town Landing since 2009. Last <br /> year (without SolarBees) MDPH Secchi disk visibility averaged 51 cm (20") with a range <br /> of 30 to 86 cm (12-34"). We do not have their Secchi disk data from this year yet accept <br /> one reading that was 94 cm (37"). The doubling of visibility means that the algae bloom <br /> was cut in half as predicted by the AECOM report. (AECOM estimated the average <br /> total phosphorous concentration would be reduced from the pre-circulator average of 80 <br /> micrograms/liter to 38 with the circulators operating. Since phosphorous is the nutrient <br /> limiting growth of the algae, the bloom should be cut in half.) The average of the MDPH <br /> microscopic counts of algae at the landing was not much different from last year <br /> resulting in health advisories at times this year when the counts exceeded 70,000 cell/ <br /> milliliter. Their highest count (on July 24, 2012)was 130,000 cells/ml which was less <br /> than half of the highest count in previous years (278,000 cells/ml on August 25, 2009). <br /> Their water samples are collected from a depth of about 6" where the water was <br /> probably about the same average clarity in past years with the algae bloom <br /> concentrated above it. I split a sample with them on July 31, 2012 and got the same <br /> count that they did. The Secchi disks measure the bloom more accurately than a <br /> sample at a given depth by including water from the surface down into the water <br /> column. Counts in the surface water at the landing in past years were in the millions of <br /> cells/ml. No toxin has been detected. We thank the Friends of Santuit Pond for their <br /> efforts in the restoration of water quality in Santuit Pond. <br /> Water Quality Monitoring <br /> Water quality in the ponds in Mashpee is good. I am working with the Mashpee <br /> Environmental Coalition to sample the ponds for the Pond and Lake Sampling (PALS) <br /> program. We measure water temperature, dissolved oxygen and Secchi disk visibility, <br /> and send samples to the tlMass Dartmouth SMAST for lab analysis including nutrients <br /> and chlorophyll. We monitor Ashumet, John's, Mashpee/Wakeby, Moody's and Santuit <br /> Ponds 3 times during the summer. <br /> Water quality in the estuaries does not appear to be any worse this summer <br /> considering the nitrogen load and resulting algae blooms. The concentrations and <br /> species of algae were better for shellfish growth than in the past few years. There were <br /> no fish kills. One new development is the detection of a species of phytoplankton <br /> (Cochlodinium polykrikoides) that can kill fish, but does not affect people. It is the first <br /> harmful algal species detected in Mashpee estuaries in the 20 years that I have been <br />