September 30, 2004
To: International Missisquoi Bay Task Force
From: Ron Haskell, Alburg Springs, VT
This letter supports the removal of the Alburg-Swanton causeway. The views expressed here are mine alone and in no way reflect organizations or companies with which I am affiliated.
My involvement with the bridge replacement and causeway removal project has been extensive. I am a member of the bridge steering committee and currently involved with the ongoing spiny softshell turtle monitoring effort as a field researcher. Since 2002, I have spent over 500 hours on the causeway from April through October, observing turtles as well as water quality.
While I could offer comment on the causeway's potential contribution to the increasing severity of algae blooms, I believe you have probably received sufficient community input on this factor, and I would not be able to offer scientifically grounded insights. However, I am compelled to observe that the Vermont Agency of Natural Resources policy (unstated but very clear to those of us living on Missisquoi Bay) to retain the causeway in order to contain the Bay's phosphorous loads is a miserable failure, as evidenced by the southern reach of this summer's toxic bloom.
I do, however, have insights regarding the relationship between softshell turtles and the causeway. Some people will argue that the spiny softshell turtle may not be entitled to protected status. Regardless of that argument, I believe the turtle population will not benefit by retaining the causeway and may, in fact, be at risk of degrading.
Biologists note that the spiny softshell is an opportunistic creature. Indeed what makes our population unique is that this riverine species has adapted to the lake environment. In 1934, according to LH Babbitt, a naturalist of the day, spiny softshells were rarely sighted except when they happened to be caught by fishermen, who simply beheaded them. His reports on the extent of the population must be considered unreliable, however, since, at certain times of the year, softshells are quite invisible. I mention this here since some may argue that the population has grown as a result of the causeway. This may or may not be so but is, in any case, irrelevant.
Turtles interact with the causeway in two significant ways. First, one of five hibernacula exists near the causeway. Second, turtles bask on the rocks from spring to fall.
Two reasons for the popularity of this particular hibernaculum have been advanced: the presence of bubblers near the trestle and a cut channel resulting from flow through the causeway opening. However, no one really knows why some turtles congregate in this area. One thing we do know from the radio tagging efforts is that individual turtles may not have fidelity for one hibernaculum over another (at least one tagged turtle overwintered in two different hibernacula).
In early May as water temperatures reach 50 degrees, turtles move away from the hibernaculum and onto nearby rocks to bask in the sun. Typically these are large females who within a week or less move on to shallower water in swampy areas. They continue basking subsurface or on suitable habitat in preparation for egg laying. These large females return to the causeway area in late August or early September where they again bask to build up energy stores prior to entering torpor. Males and juvenile females can often be spotted along the causeway throughout the summer. Softshells and other turtles also bask on fallen trees, mid-lake rocks, lily pads, floating detritus, shorelines, and, well, pretty much anything.
Once the bridge receives a superstructure, most of the causeway will be in shadow and effectively destroyed as preferred basking habitat. However, the bridge design included an alternative basking habitat structure that will extend south of the bridge and, hopefully, meet all or most of the softshells' basking needs. After all, turtles are somewhat gregarious with their own and have no trouble piling atop one another.
The fact that softshells are opportunistic provides a sound reason for us as environmental caretakers to remove the causeway: doing so will encourage softshells to move to potentially quieter hibernacula, and even perhaps to Quebec. While turtles are strong, fast swimmers, they are no match for powerful bass boats and racing jet skis, whose presence around the causeway is also on the rise. Furthermore, the causeway hibernaculum is always at risk of being exposed to toxic materials that travel our roadways. Why would we ever want to encourage them to stay around the causeway?
I frequently observe turtles that bear scars on their shells or have had, literally, chunks removed. Earlier in September an injured softshell showed up on a beach near the causeway. Surgery reattached its nose, but nothing could be done to restore its severed jaw. The injuries may well have been caused by a propeller or by a collision with a boat. Though we cannot know for sure what happened to this turtle or to others that bear obvious signs of damage, we can protect them by removing the causeway, a structure that tends to bring humans and turtles into greater contact.
In closing, I wish to thank the IJC and the review committee for agreeing to hear our community comments. This is not an easy issue to sort out. Still, at this point removing the causeway will provide the community a collective sigh of relief without increasing harm to other parts of the lake or to the spiny softshell turtle.