The narrow channel extending from Oyster Pond to the culvert near the juncture of Surf Dnve and Oyster Pond Road is a cauldron of life and death. In the late summer and fall, it teems with thousands if not tens of thousands of young alewives trying to navigate the channel and culvert on their journey from Oyster Pond to Vineyard Sound. The 3 to 5" long juvenile fish face many dangers here: eels hiding among the rocks that line the channel, white perch awaiting them patiently in the culvert, cormorants and mergansers diving through the culvert in pursuit of them, and occasionally children (or OPET's Bob Livingstone) standing atop the weir with dip nets at the ready for an easy catch. Not an enviable journey for the small fry that so far already have had to escape, since they were spawned in Oyster Pond, predation by insect larvae, tadpoles, minnows, turtles, eels, other fish and birds. This year, the alewives' journey through the channel was further complicated, and ours enriched, by the presence of a Green-backed Heron there. This solitary creature could be seen daily in the vicinity of the weir, perched on the rocks near the water's edge, gulping down alewives, and apparently oblivious to the traffic only 15 feet away. On the day I shot the photos, the bird seemed to swallow more fish than could possibly be accounted for by its own volume. Since the black and white renditions cannot do justice to the ornate mixture of green, brown, and blue feathers and yellow beak and legs, I hope the bird will return next year for all to see in person. You can view it in full colors, though, here on the Watershed edition posted on our website, www.opet.org. A prize to the first person who can tell from the photo whether the bird is a male or a female.
--by Larry Pratt (better known as Mindy Hall's husband)The Green Heron of the Weir, Photo by Larry Pratt
The Army Corps of Engineers has given its stamp of approval for the repair work of the Trunk River jetties and the Trunk River channel itself. They also approved digging of the channel down to the level recommended by the designers of the weir that is to allow adequate but controlled salt water inflow into Oyster Pond. The proposal for this repair project had been initiated by OPET to at last put the weir to the test. Sand and eelgrass brought into the Trunk River system by even minor storm tides had built up to the point that the pond water level was up to 6" higher than the top of the weir, ever since its construction! The high pond level brought complaints from residents about water in their basements and about shore erosion on their properties. Salinity of the pond continued to fall to near-fresh water level (even salinity-sensitive frogs started to thrive in the pond), and the danger of pondweed infestation became a real one. The Department of Public Works submitted an article at Town Meeting and was granted the financing for the Trunk River Repair. Work was to begin in November, and the tension is mounting: Will the repaired jetties keep the Trunk River free-flowing (except after major storms, of course)? Will the weir fulfill our expectations and hold pond salinity as 2-4 ppt?
Trunk River Channel in Disrepair and Clogged. Photo by B. Rose
Email OPET
Contact Webmaster