Many thanks to Mike Spall who tests the salinity pond nearly every month from his kayak. Mike, a member of the OPET Board and a scientist at WHOI, had been tracking the pond’s salinity and temperature levels every month using a CTD ( conductivity, temperature, and pressure) instrument borrowed from WHOI. Unfortunately, due to the COVID-19 virus, WHOI is closed and results from that instrument can’t be accessed. Mike switched to using OPET ‘s YSI instrument that only captures levels at specific depths and not a continuous read out as with the WHOI CTD device. He could only measure salinity accurately in the upper 4 meters of the pond. The results indicate that spring storms have raised the salinity.
The February 2020 deep dredging of Trunk River and the Lagoon continues to increase the pond’s salinity. The salinity was a very low 0.9 ppt during the peak of the algal bloom in summer of 2016. It is now at 5.5 ppt, outside the 2 ppt to 4 ppt range that is best for the pond. Now we have to limit the amount of salt water entering the pond, therefore we asked the Town to put in additional planks at the weir to block the flow of salt water into the pond.
