Comments Received from John Parks Re Thunder Bay North
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DAMSA INTEGRATED RESOURCES MANAGEMENT INC. 790 Highway 527 Phone 807 345-7774 Shuniah, Ontario email: [email protected] Canada P7A 0M9 www.damsa.ca December 2, 2014 EcoSuperior Environmental Programs 562 Red River Road Thunder Bay ON P7B 1H3 Attention Jamie Saunders, Program Coordinator Dear Mr. Saunders Re: Sediment Management Options Evaluation – Final Report Thunder Bay North Harbour Please accept these comments on the last Cole Engineering report (August, 2014) on the sediment management options evaluation for the Thunder Bay North Harbour as draft. While the key comments/concerns are identified, there is some follow up details that may be warranted. These concerns extend beyond the intent or expectations for the report provided and are grouped in the following categories. Identifying Resources at Risk The remedial measures proposed in the Cole report are based on the risks identified in the Franz report which presented an assessment of potential risk to human and ecological receptors from exposure to contaminants in the sediment of Thunder Bay North Harbour. The meaning of these risks as reported in the Cole report however are not always easily understood by the general public – and the very technical nature of the Franz report make it difficult for most citizens to understand what Ecological Risk Assessments can portend. Further, the synopsis provided within the Cole Report on the Franz material is not always consistent with the Franz Report itself. For example the Cole Report notes “The human health risk assessment indicated that the unacceptable risks related to consuming recreationally caught fish were present for recreational user/subsistence fishers (page 6). This statement is true not just for the North Harbour but probably for the rest of Thunder Bay Harbour and most inland lakes as well. These risks are outlined in the OMNR-OMOE Guide to Eating Ontario Fish. It is noteworthy that mercury concentrations in walleye (2006) standardized to 40 cm collected in Lake Superior (Current River area) nearest to the proposed remedial site of 0.25 µg/g are substantially lower than fish in most other lakes in Ontario (attached Figure, Damsa 2014). 1 Parks-Saunders Draft Comments on North Harbour Sediment Management Options Dec 2, 2014 And while walleye concentrations of mercury at the Lake Superior (Current River) Site are amongst the highest in the northwest part of Lake Superior (data not presented), the larger more mobile walleye collected here will be influenced from elevated mercury not only associated with the proposed remedial site (26 ha) but also with mercury associated with Current River inflows – which are also elevated in comparison to Greater Lake Superior waters (Stantec 2003) Given the mobility of fish taken for consumption, the Franz Report (p155) explicitly notes” it is expected that implementation of the proposed passive and active management area will result in the site having a negligible impact on humans consuming fish from the harbour”. The Franz Report also documents what was just previously noted above, that the MOE (2013) already has in place consumption advisories for fish caught from Thunder Bay Harbour (including the remedial Site) in the Sportfish Consumption Guide and this guide already provides a degree of management of risks from ingestion of recreationally caught fish at the Site It is also possible that the human health risk assessment overestimated risk for the group of recreational users/ subsistence fishers from exposure to mercury via ingestion of and dermal contact with sediment (P117) that include exposure from swimming, and wading in near shore waters . As documented in the Cole Report the elevated mercury in the sediments is associated with organic matter (fibre) from historic pulp and paper operations. We suspect that most of the public that have any experience/knowledge with this material would believe that such environments would be unlikely targeted for recreational activities. In fact, it is likely that the reverse is true. Mercury associated in sands and other recreationally desirable substrate are about order of magnitude lower than that used in the risk assessment process. Utilizing the Bald Eagle as potentially being at risk may be considered questionable at best without better documentation. And its designation as being at risk can carry a particularly important connotation with the public because it has been designated as “Special Concern” in the Ontario Endangered Species Act. As noted in the Franz Report, the wildlife at risk is assumed to have 100% exposure to the proposed remediated zone in question, yet the home range of the Bald Eagle far exceeds this area. The home ranges of Bald Eagles can vary widely depending on the area, season, availability of and distance to food resources and breeding status of the individual (Buehler 2000, cited in USEPA 2014) home ranges for bald eagles typically extend 10 to 100 times the 26 ha designated for remediation in the harbour (USEPA 2014). Further, the area in question is simply insufficient to provide forage for eagles given the low productivity of Lake Superior and that eagles require about half a kg of food per day. Mercury in fish, the source of the risk to eagles - in the rest of the harbour and Lake Superior are much lower than those in the proposed remediated zone (Fletcher 2007, Stantec 2003) and mercury concentrations in general in other harbour areas – as indicated by mercury concentrations in walleye - are near the lower quartile for mercury concentrations in walleye in other locations within the province. 2 Parks-Saunders Draft Comments on North Harbour Sediment Management Options Dec 2, 2014 The same considerations for the other wildlife identified as at risk – the mink, common loons and belted kingfishers are further outlined in the following section. Quantifying Resources at Risk That Would Benefit From Proposed Remedial Measures It is possible to gain a best case perspective of the benefits of remedial measures to fish and wildlife by modelling the community exposed to the aquatic environment containing the sediments that would be remediated (26 ha) and making some “worst case” assumptions. For human health effects through consumption of mercury enriched fish, assume for example that fish were hypothetically restricted to the proposed remedial zone of 25 ha through their life cycle. Also assume that all fish productivity for this 26 ha area was channelled into one of the most desirable fish consumed in Ontario – walleye. In this worst case simulation all the forage fish, suckers and less desirable species found in the area (Foster 2012) are turned into walleye equivalents. Also assume that walleye captured in Lake Superior at the Current river location derived none of their mercury body burden from the proposed remedial area and truly represent background mercury exposure. Under such conditions 40 cm walleye in the proposed remedial zone could have mercury concentrations of about 0.75-1.00 ppm based on the premise that the larger fish reflect the same relative bioaccumulation characteristics as exhibited in the small fish surveys where mercury body burdens are believed to reflect local exposure. In the small fish surveys, concentrations of mercury in the proposed remediated zone were typically 2-4 times background values. (Stantec 2003, Fletcher et al. 2007) Given that the total yield for all fish in Lake Superior is a little less than 1 kg/yr (SPOF 1982), it is possible to estimate the benefits of the remediation proposals for 26 ha would amount to 26 kg/yr. For mink, home range sizes are reported to range from 7.8-1626 ha and 1.86 to 5.9 km of stream/river. As was the case for eagles these foraging /home range areas substantially exceed the site boundaries of the study area and as noted by Grapentine and Milani (2002) if areas outside of the Hg-contaminated zones of Thunder Bay are not equally Hg-contaminated the actual predicted risk would be lower. And as previously noted organisms outside the study area typically have lower mercury concentrations. Likewise, belted kingfishers require 0.24-0.64 miles of linear shoreline as habitat requirement with double that for breeding pairs. Population densities have been reported as 1 pair per 1.8 sq. mi. in Minnesota. (USEPA 1993) Nesting common loons in Minnesota typically require lakes of >20 ha with multiple loon pairs found mostly on lakes greater > 80 ha. Thus the theoretical carrying capacity for the proposed remedial area could include 2-3 mink, 2-3 loons and perhaps half a dozen belted kingfishers based on home range characteristics, assuming no additional conflict from territorial behaviours (USEPA). 3 Parks-Saunders Draft Comments on North Harbour Sediment Management Options Dec 2, 2014 If this brief analysis is anywhere near correct in its assumptions, the remedial measures proposed could likely benefit a very few mink, loons and belted kingfishers, an improved benthic community and less risk to those having to work/exposed to mercury-enriched fibre sediments. Net Benefits (Cole Report) In our opinion the net environmental impact section in the Cole report (p 40) is speculative and provides little substance for support/justification of 40 million dollars or more for remedial measures. The Cole Report identifies that the project will also result in lower mercury concentrations in fish tissue, which reduces human health and ecological risks, yet as previously noted, the Franz Report notes that such reductions to human health would be negligible. Cole notes that the deepening of the SMU and placement of gravels and cobbles in appropriate locations may improve the near shore and littoral habitat as well as provide suitable spawning habitat for fish that spawn over a range of substrates in spring and fall seasons. These species may include Walleye, Northern Pike, Whitefish, Lake Trout and others. As far as I am aware northern pike are not gravel and cobble spawners.