President: Thomas Wallace VP Science and Education: Dr. Burton Fleming Treasurer and Secretary: David Luening Vice President: Robert Hughes
Directors: Mark Patinkin, Joseph Loughrey, William Darman, Brendan O’Neill, John MacKenty, Sally Steenland Administrator: Diane Abbot Director of Science and Education: Robert Woodruff Director, Special Projects: John Coskie
2008 Summer Pond Report
From the Board of Directors, Edgartown Great Pond Foundation
The state of the pond has been troubling this summer, with the worst spread of algae in years. Although rains and a cooler, higher pond by early August made the algae less visible, it is still a problem, covering the bottom of much of the pond. The Great Pond Foundation remains alarmed, and we are moving on many fronts.
As far as the cause of the algae, the authoritative Massachusetts Estuaries Report, (which picked our pond as an early focus because the Foundation offered ample baseline data) has found the pond is overloaded with nitrogen from household septic tanks, fertilizers, other watershed runoff, and possibly the plume from the old sewage treatment plant. Birds may also be a factor.
In addition, this year, we had a bad-luck stretch of dry, hot weather after the last cut in spring, keeping the pond unusually low. The "filamentous" algae (forming surface mats) are triggered more readily in shallow waters where heat and sunlight stimulate growth. Our pond is susceptible since its average depth is four feet compared to Tisbury Great Pond's average of 8 feet.
Finally, openings to the ocean have been inadequate for several years. This is because sand build-up inside "the cut" has formed a huge, blocking delta that impedes ocean exchange and long openings. It has been almost five years since the town dredge was in the pond to clear out that delta. This brings us to the Foundation's biggest initiative.
A key recommendation of the Mass. Estuaries report is to achieve better, more frequent openings to the sea. In accordance with this recommendation, there was an attempted opening this past weekend, the third this year. Unfortunately, it closed quickly.
As most of you know, to improve openings, the Foundation has been working for a year to buy its own dredge - a $500,000 piece of equipment named "Nessie" made by Keene Engineering in California, the only shallow-water dredge that can be trailored to our shore and self-launched. All others would need to be put in by crane at a cost of $2,000 to $12,000 each move.
We had a model of the Nessie shipped here for a one-month test in March. Weather forced our crew to bring it to a sheltered cove several times. It was easily moved in an hour or so, demonstrating that it is much more nimble than any other dredge.
Given the limited time, we were able to cut only a single channel through the multi-acre delta. That led to some success with two openings in spring, the first lasting 4 or 5 days, the second a week. Our hope, however, is that once the delta is dredged out, pond openings will be longer with a more dynamic water exchange. It will be necessary to continue dredging the delta in future years to keep it from growing again (as it does with each opening) and to do more dredging of problem points around the pond.
During the March test, our operating team, led by Edgartown's Steve Ewing, felt the dredge moved as much sand as the bigger town dredge. The team suggested a few mechanical changes, which were negotiated with the manufacturer, and a down-payment has been sent to finalize our order for late January delivery. But the manufacturer has been frustratingly slow because of its other orders. If delivery is late, we face a shortened time for use since the commonwealth bans dredging between the end of March and the end of summer. We are pushing Keene as hard as we can to solidify the schedule.
The Foundation is moving on other fronts, as well:
Our interns, working with the MV Shellfish Group, have managed to seed the pond with 2 million oysters in the past month.
Our hydro geologist is doing bi-weekly water testing at six pond stations to track nitrogen, salinity, temperature and other factors.
We are seeking permission to neutralize goose eggs to reduce population of this excess nitrogen source.
Samples of the algae have been sent to experts to fully understand its origins and ways to deal with it.
We are experimenting with techniques for harvesting the algae and are testing its potential as an agricultural fertilizer. The Nessie has several add-ons for cutting and gathering algae.
Two additional test wells will be installed to better to track the plume.
After conferring with pond-front owners, we will seek permits to dredge other problem points around the pond.
We are backing the Estuary Report recommendation of connecting high density developments in the pond's huge watershed to the wastewater treatment plant, which removes 90 percent of nitrogen, and are pushing for lower density future development.
Property owners are being urged to reduce or even eliminate the use of fertilizers.
Homeowners are being urged to do regular maintenance and pump-outs of septic systems.
Advisors expect it will take at least a year of successful openings for the pond to begin to get back in balance. Pond management is a complex business.
Therefore:
The Foundation is working with the Edgartown Ponds Advisory Committee to bring together all interested parties - shell fishermen, the town, pond owners, experts - to come up with a Comprehensive, integrated plan for managing the pond in general, and openings in particular.
Our key initiative remains the dredge. The total cost is almost $1 million, including purchase of the dredge, the recent $80,000+ dredge rental and evaluation, and the first two years of operating expenses. We currently have $700,000 in pledges. Other island pond groups have inquired about renting the dredge, which would help recover future operating expenses, but the Edgartown Great Pond will always be our first priority.
Clearly, the town and state should be more involved with pond improvement, and we are pushing for their increased participation. Meanwhile, the Foundation will do all it can as a citizen-action group to rescue this priceless but challenged natural resource.
We are grateful to all those who are providing financial support to this effort as well as to on-going operation of the Foundation. Now is the time to send your pledge payment or additional pledge to:
Great Pond Foundation, PO Box 2005, Edgartown, MA 02539
The state of the pond has been troubling this summer, with the worst spread of algae in years. Although rains and a cooler, higher pond by early August made the algae less visible, it is still a problem, covering the bottom of much of the pond. The Great Pond Foundation remains alarmed, and we are moving on many fronts.
We had a model of the Nessie shipped here for a one-month test in March. Weather forced our crew to bring it to a sheltered cove several times. It was easily moved in an hour or so, demonstrating that it is much more nimble than any other dredge.
Our interns, working with the MV Shellfish Group, have managed to seed the pond with 2 million oysters in the past month.
