2 MERCURY
We are requesting expansion of Maine's safe eating guidelines for fresh water and salt water species to include Recirculating Aquaculture System (RAS) salmon tankfarms raised in waters with known mercury restrictions based on those guidelines.
Specifically the new label would be for Atlantic Salmon and other fishes raised in Recirculating Aquaculture System facilities , when the incoming habitat water for the tank-farmed salmon is taken from rivers and/or lakes with fish or seafood consumption warnings imposed by the state for pregnant and nursing women, women who may get pregnant, and children under the age of 8.
Or where wild harvest is prohibited due to mercury concerns as in the case of Lower Penobscot River's lobster and crab fisheries.
We think that DEP has erred by declining to adopt an incremental precautionary approach to the health safety impacts from the introduction of the new Recirculating Aquaculture into Maine's top wild salmon waters: Penobscot River and Penobscot Bay.
Expressing an inadequate “best professional judgement” that the fish grown in a lower Penobscot river-dependent RAS operation proposed for Bucksport probably would not violate state mercury safety standards.
Importantly, even then, DEP is only referring to the discharge wastewater, not the content of the flesh of the fishes themselves.
Suspended mercury levels in these waters will vary as tanker ships, cruiseships tugboats and the annual snow melt stir up and re-elevate mercury-tainted lower river sediments . Whatever systems the company proposes for mercury removal from incoming river and lake water must be able to adapt as the area's water concentrations of methylmercury rise and fall.
Our concern is that, despite their best efforts, the mercury concentrations in the RAS salmon fish tissues will fluctuate. This would vary based on the location and seasonality of the salt wedge in the lower Penobscot River, where sediments can resuspend as currents collide at this fresh salt interface.
For that reason, we believe that mercury advisory guidelines be developed.specifically for fishes raised in tanks whose waters are sourced in lower Penobscot River and Hancock County lakes and ponds.
The state currently suggests that fish from waters of "Penobscot River below Lincoln" be limited to "1-2 fish meals per month"
Penobscot River below Lincoln: | |
While it may never need to be imposed, it is critical for the public health agencies have an advisory's language already drafted for this new class of salmon, that, unlike landlocked salmon and open ocean net pen salmon, must spend their entire lives bathing & breathing waters known to have elevated mercury levels. The potential for significant mercury uptake in RAS tank farmed salmon is real in our estimation.
It is prudent for the State of Maine to act NOW and preemptively develop a guideline mercury standard for the flesh of RAS fish raised entirely using state waters known to be contaminated by that metal. For RAS applicants the potential for label requirements will be a powerful incentive to those and future applicants to take this issue very seriously from the start.
The new advisory and label will be timely. This new system of fish farming in Maine is drawing many investors. Maine is touted by the seafood industry press and media as one of the most desirable states in which to operate these facilities. We have little doubt that Penobscot Bay and its tidal rivers will feature greatly in such initiatives,
It is imprudent to waiting until more of these facilities dot the shores of Maine rivers, bays and coasts, and the industry gets the clout to challenge creation of such standards.
Such an advisory label, clearly visible to potential buyers,would be used by: in three venues
* Wholesale distributors' invoices of product from a RAS facility with such water quality challenges.
* Retail and online outlets where said product is sold fresh, frozen or processed,
* Advertisements and commercials promoting said product from that facility
At Issue: Unlike landlocked salmon, RAS farmed salmon are raised in both freshwater and saltwater tanks during different stages of their lives. When the freshwater for an RAS facility is drawn from a lake sufficiently contaminated with mercury to have an advisory for its fishes, and then the saltwater for that facility's fishes' post-smolt phase of their lives is drawn from a section of a river closed to crustacean harvesting due to mercury contamination, the farmed fish will have at least double the exposure to mercury.
Our mercury advisory request presently concerns the proposed use of Penobscot River water pumped ashore in Bucksport Maine to raise Atlantic salmon in a land based recirculating aquaculture operation that would be joined by freshwater from a Bucksport Lake that also has a mercury advisory.
According to court ordered and peer reviewed studies, the high turbulence of river waters adjacent to the town of Bucksport resuspends more mercury into the water column there than anywhere else on the river.
Source: Penobscot River Mercury Study, Chapter 7 "Field Investigations of Hydrodynamics and Particle Transport in Penobscot River and Bay", See Figure 7A.
Significantly, the level of mercury in this reach of waters may be grossly underestimated, due to incomplete testing. After revealing very high levels of resuspended mercury, the sampling device used in the Penobscot River Mercury Study failed, preventing a fuller understanding of the mercury content of the Bucksport water column. ( (PMRS Ch7).
A RAS facility that uses river and lake waters that are under mercury advisories may assert that certain filtering processes will remove a large percentage of mercury from those waters before their seafood species are immersed in it.
This is only a partial removal at best, and is yet to be proven for waters pumped continually into and through the facility at a very high rate and in such large amounts, as RAS facilities require, with varying levels of mercury in them
At best the organisms raised in such waters their entire lives would have lower levels of mercury (but most certainly not mercury-free)
At worst would have MEHG levels above the state's food safety advisory trigger. That they are raised in a concentrated area with little of the variability of wild fishes.
Moreover the aforenoted incomplete records of mercury contamination off Bucksport may skew the decision making on how much mercury must be removed to let the RAS facility's fish avoid labeling.
Until such time as a reliable study clarifies the amounts of mercury actually in Bucksport waters, we request the department to be responsibly precautionary and require safe eating guidelines labeling of aquaculture products raised in waters that are under state and/or federal mercury advisories.
In closing, we must again emphasize that as interest in siting RAS aquaculture facilities in Maine grows ,it is imperative that the state of Maine protect health of consumers of RAS aquaculture products raised with such waters, by requiring the appropriate health advisory labels to be affixed to the products whether fresh, frozen or processed.
The advisory would warn pregnant and nursing women, women who may get pregnant, and children under age 8 not to consume fishes from RAS facilities raising fishes using significantly mercury contaminated waters, and for others to limit their consumption of salmon from such a facility to once per month.
SUGGESTION We would like to work with Maine CDC and this new industry to ensure that our concerns are reviewed and that, as needed, the products of land based recirculating aquaculture systems are listed appropriately in the state's Safe Fish Eating Guidelines.
