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HomeMy WebLinkAboutA.M. Wilson response to shellfish reportpdfFrom: A.M.Wilson Associates <amwilsonassoc@amwilsonassociates.com> Sent: Saturday, December 31, 2022 12:30 PM To: Karle, Darcy Cc: Cavanaugh, Kimberly; Croteau, Amy; Stephen M. McParland; Brad Holmes Subject: Town Shellfish Report /20230103 NOI McParland 150 Carriage Rd Response to Town Shellfish Report Follow Up Flag: Follow up Flag Status: Flagged Darcy – I would appreciate it if you could provide copies of this response to the Town’s Shellfish report on the McParland pier project to the Commissioners in anticipation of Tuesday’s hearing. The line of the pier had been staked for some time. I suspect that the storm of Christmas week displaced them. I assume that Ms. Lewis’ sample plots run from the seaward edge of the salt marsh out. With the transects spaced only 2’ o-c, the samples do not extend beyond the actual footprint of the pier. We also assume that the transects run from north to south with the “A” line on the north edge of the pier. Ms. Lewis sampled 30 plots of 1 s.f. each for a total of 30 s.f. of sample area. ERC sampled 18 plots, 3’x3’ each, for a total of 162 s.f. over an area 20’ wide to get an idea of the resource not just in the line of the pier, but also in the vicinity of the structure. In terms of findings, the two studies are not significantly different. Neither found a softshell population in the intertidal area nor in the near subtidal shallows to a depth of 20”MLW. Ms. Lewis provides some presumptions about duck predation as the reason for the lack of softshell population. However, with no information on duck species in the area, and the ERC observation of significant but unprotected vegetative bottom cover, there is no way to discern if the ducks were eating flora or fauna. Both studies found a moderate band of quahogs from a depth of 20” MLW, out. There is a math error in the ERC table. The total for transect “C” should be 11, rather than 9 quahogs. That makes the overall total 31 rather than 29 and the average per square foot 0.19 rather than 0.17, an insignificant change. Both studies found ribbed mussels at the salt marsh edge. This is a condition which helps to bind the marsh edge, protecting it from erosional forces. Ms. Lewis suggests that only a pile supported structure permanently removes bottom habitat. Yet, her own findings show this not to be the case. The liquified sediments in the area of removed post supports of seasonal piers do not allow for spat settlement. Nor can they support the weight of adult shellfish. As we have noted previously, and has been confirmed by a member of your own Commission, those liquified sediments also do not provide adequate structural support for the seasonal pier support posts. The result is that the contractors tend to adjust the location of the posts from year to year to grab the firmer sediments at the edges of the holes. So, the holes get bigger and bigger over time and the area of unsuitable, altered habitat grows with the size of the post disturbances. Any animal settlement that might occur is blown away in the spring when the posts are reset by jetting. Thus, over the course of a few years, the habitat losses become quite similar. Ms. Lewis suggests that the platform and stair design for the pier end to facilitate kayak launching will act as a groin, slowing water circulation and trapping sediment. This might be the case if the stairs had solid risers. They do not. The stair treads, being in the same plane as the movement of the water, being only a few inches in height, and utilizing slotted or gridded material to allow for vertical as well as horizontal water movement do not cause such impacts. The Commission has authorized this design at least 3 other times that I am aware of without adverse comment from the Town Shellfish Officers. The most recent of these was for the Landry dinghy dock under SE3-5927 on 8/4//22. The others are; the Remondi pier at 150 East Bay Road under SE#-5591 in the summer of 2018, and the Tavilla pier on Long Beach under SE#-5394 in the summer of 2016. Although the Landry pier is still in permitting, the Remondi pier was built and received a CoC in 2020. Neither the Mass Division of Waterways not the US Army Corps of Engineers expressed concerns that the design would cause water circulation or sediment deposition issues. Finally, Ms. Lewis raises the potential for a boardwalk as an alternative. This is one of the few areas I have seen where the shalt marsh is actually expanding. The marsh is important as a wave attenuator and as a shellfish and finfish nursery habitat. Ensuring that any structure built over it allows for sufficient sunlight penetration is important to the continuing health of the marsh. A low boardwalk with a slotted surface through which the vegetation would grow, allowing foot traffic to repeatedly damage the grass blades and thus stress the plants would not be ideal. Further, it would encourage foot traffic and dragging small boats through the marsh that would cause damage to both the marsh and, by reducing the amount of marsh, to the shellfish/finfish habitat, which is contrary to the interests of the Act and Ordinance. Finally, I would note that both of the abutters have pile supported piers servicing motorized vessels. These structures and uses do not seem to have diminished the area habitat quality. I look forward to discussing these issues at the project hearing. - Arlene A.M. Wilson Associates, Inc. 20 Rascally Rabbit Road - Unit 3 Marstons Mills, MA 02648 508-420-9792 amwilsonassoc@amwilsonassociates.com www.amwilsonassociates.com CAUTION:This email originated from outside of the Town of Barnstable! 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