"Before" July 14, 2004
Mats of Cladophora glomerata overrun the surface of the Trunk River Lagoon.
Here are two pictures worth at least a thousand words.
These are "before" and "after pictures of Trunk River Lagoon, the body of water just south of Oyster Pond that empties into the Trunk River. The "before" shows the horrendous algae bloom that spread over the lagoon this past summer. The "after" shows a pristine pond at the end of September. How was this problem solved? We can thank many Town officials who recognized the need for immediate action.
Unfortunately, it can be traced to a problem seen before in this area. Winter storms deposited clumps of eelgrass far up into the lagoon entrance, piling up to depths of 4 to 6 feet! As a result, neihter the pond nor the lagoon could drain properly. The pond was 10 inches above normal and far above the weir boards, meaning that the weir was not functioning as designed.
This backed-up lagoon becamse a stewpot for growing algae. As the weather warmed up, the eelgrass began to decay and mix with the nutrient rich waters creating perfect conditions for algae growth. First noticed in May, by mid-July it was 21" think and covered most of the surface of the lagoon. Aimlee Laderman, PhD of the Swamp Research Center, identified the mats as mainly tangled filaments of Cladophora glomerata, an algae often associated with emerging sewage plumes in freshwater bodies.
Not only was the algal mat unattractive, it was a threat to Oyster Pond's resident herring population. Young spring spawned herring and some adults, were blocked from migrating out to sea. By mid-July, thousands of young herring were schooling near the weir as they were unable to pass throught the laggoon. It was too dangerous for them. They risked suffocation from the anoxic conditions and hydrogen sulfide. And adult herring straying off the shallow main channel to Trunk River quickly perished. Fearing a repeat of the herring deaths from 2002, a meeting with Town Hall officials was organized. In 2002, several dead herring were found washed ashore after moving throught low oxygen waters and hydrogen sulfide in Trunk River. The OPET board knew that Trunk River had to be dredged to release the blockage and allow the Lagoon and the Pond to drain properly.
On July 22 a meeting was held at Town Hall to address the problem of the algae growth in the lagoon. It was a remarkable meeting in that all the people involved ...
Below is a sketch of Trunk River from 1996 showing how a high profile at the lagoon exit
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Contact WebmasterA Problem for Oyster Pond's Herring
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and Trunk River
can constrict the outflow from Oyster Pond.
