Penobscot Bay dredging/mercury resuspension could cost lobster industry millions

Friends of Penobscot Bay update for 7/16/13 

 

Maine' has issued a two lobsters/per week mercury consumption advisory.

Searsport dredge plan could cost Bay lobster industry millions in lost sales if state's 2-per-week mercury safety limit drops to 1/week for Penobscot Bay lobsters.

According to Pamela Wadman, an environmental toxicologist  at Maine Ctr for Disease Control and Prevention, Maine presently  has a coastwide two lobsters/week safety limit advisory for pregnant women & other sensitive people.  This is based on the "Maine Fish Tissue Action Level for Methylmercury"  which is 0.2 mg/kg  per week.

However, the  two-per-week coastwide lobster advisory is based on those two lobsters each having 0.1mg/kg  methylmercury or less in their meat.  If she can confirm information supplied us by a Belfast lobsterman that mercury levels in a significant percent of lobsters in that area are  double that, around the 0.2 mg/kg level or higher, she will have to issue a "Spot Advisory"  restricting safe lobster consumption of lobsters captured in that area to one lobster meal per week.  

Where is that area? Belfast lobsterman  gathered lobsters from an upper bay area for mercury testing under a special license from DMR for several years. See attached map (map also here) of the area.  Lobsters were collected inside the red triangle.

This triangle's corners are the II Buoy northeast of Marshall Point on Islesboro, the Gong 1 buoy south of Sears Island, and the DMP Buoy in the middle of the upper bay waters shared by Islesboro, Belfast and Searsport.

There is a " pretty heavy concentration of mercury" along the line between the II Buoy and the Gong 1 Buoy. This is the area beginning north of the old disposal site, then going northeast along the edge of the shipping channel  to the Gong 1 Buoy.  

But the very hottest  reach is the shoal edge above  the deeper water east of  the DMP buoy, (the shoal edge is the wiggly line inside the red triangle)

The lobsterman said that while he did not take sample lobsters from the exact bay floor the army Corps of engineers wants to dredge, which is  northeast of the DMP buoy, he is confident that the same elevated mercury would be found in that area if they do test for it. 

If so they've got a problem.  Having a "spot advisory"  for a small part of the upper bay would be economically disrupting enough for people that fish in that area. But if dredging and dumping tainted sediment resuspends a significant amount of methyl mercury in the waters from Searsport to Vinalhaven, the state might be required to issue a Penobscot Baywide lobster methylmercury advisory.   

If that happens, the drop in sales of live and processed lobsters sourced from Penobscot Bay could easily be in the million dollar-plus range. The heightened advisory would also throw a monkeywrench into the state's brand new Maine lobster sales global promotion strategy.  Eeek! No expansion dredging please!