TECHNICAL REPORT NO. 93 TECHNICAL REPORT NO. 77 Survey of mercury and cyanotoxin concentrations in fish tissues in Lake Champlain May 2018 Final Report Prepared by: Mark Swinton Sandra Nierzwicki-Bauer Darrin Fresh Water Institute For: The Lake Champlain Basin Program and New England Interstate Water Pollution Control Commission This report was funded and prepared under the authority of the Lake Champlain Special Designation Act of 1990, P.L. 101-596 and subsequent reauthorization in 2002 as the Daniel Patrick Moynihan Lake Champlain Basin Program Act, H. R. 1070, through the US EPA and the Great Lakes Fishery Commission. Publication of this report does not signify that the contents necessarily reflect the views of the states of New York and Vermont, the Lake Champlain Basin Program, the Great Lakes Fishery Commission, or the US EPA. The Lake Champlain Basin Program has funded more than 90 technical reports and research studies since 1991. For complete list of LCBP Reports please visit: http://www.lcbp.org/media-center/publications-library/publication-database/ NEIWPCC Job Code: 0100-310-029 Final Report NEIWPCC Job Code: 0100-310-029 Project Code: L-2016-058 Prepared by: Mark Swinton Sandra Nierzwicki-Bauer Darrin Fresh Water Institute Date Submitted: January 2018 Date Approved: May 2018 Survey of mercury and cyanotoxin concentrations in fish tissues in Lake Champlain Contact Information ────────────────────────────────────────────────────────────────── Sandra Nierzwicki-Bauer, Associate Director Darrin Fresh Water Institute 5060 Lake Shore Drive Bolton Landing, NY 12814 phone (518) 644-3541 FAX (518) 644-3640 [email protected] This is a Lake Champlain Basin Program funded project 54 West Shore Road Grand Isle, VT 05482 802.372.3213 www.lcbp.org Final Report Form v.1.2016 (Revised: 11/3/2016) Survery of mercury and cyanotoxin concentrations in fish tissues in Lake Champlain This project was selected for funding by the Lake Champlain Basin Program (LCBP) Steering Committee and it has been supported directly by an agreement or sub-award issued by the New England Interstate Water Pollution Control Commission (NEIWPCC). NEIWPCC manages LCBP’s personnel, contracts, grants, and budget tasks through a partnership with the LCBP Steering Committee. Although the information in this document may have been funded wholly or in part by the United States Environmental Protection Agency (under agreement CE982720010), the National Park Service, or by the International Great Lakes Fishery Commission, through their respective contracts to NEIWPCC, it has not undergone review by the Agency, Service, or Commission, and no official endorsement of the content of the document should be inferred. The viewpoints expressed here do not necessarily represent those of NEIWPCC, the LCBP, the USEPA, the NPS, or the GLFC, nor does mention of trade names, commercial products, or causes constitute endorsement or recommendation for use. Page 2 of 100 Survery of mercury and cyanotoxin concentrations in fish tissues in Lake Champlain Executive Summary Mercury and cyanotoxins in Lake Champlain pose health concerns to humans and the ecosystem. Mercury poisoning through the consumption of contaminated fish has been well documented for more than half a decade, typically with top predators posing the greatest threat. And while the most common route of cyanotoxin intoxication is exposure through drinking water and recreational contact, research has shown cyanotoxin levels in fish can reach concentrations that pose health risks, if consumed. The aim of this study was two-fold, 1) to reassess fish mercury throughout the lake to determine which species at what size pose a health concern, identify areas that are disproportionally impacted by mercury and assess long-term changes, along with 2) determining if cyanotoxins are present in fish, and if so, do concentrations in fish correlate with presence in water samples. More than 600 fish of five species (smallmouth bass, walleye, lake trout, yellow perch and white perch) from the seven segments of Lake Champlain (South Lake, South Main Lake, Main Lake, North Main Lake, Malletts Bay, Northeast Arm and Missisquoi Bay) were analyzed for total mercury. While all fish species had specimens exceed the US EPA mercury advisory limit of 300 ppb, walleye and smallmouth bass had 38% (28/74) and 17% (27/157) of their specimens, respectively, exceed the USFDA action limit of 1000 ppb. Fish length and location were significant factors explaining mercury variability for the five species tested, however, no consistent trend was observed for location among species. Because these species include cold, cool and warm-water fish feeding from benthic and pelagic food webs along with different growth rates and efficiencies, utilizing fish mercury concentrations to determine lake segments that are disproportionately affected by mercury was inconclusive. Assessing long-term mercury trends in fish shows a significant decrease in lake trout, walleye and yellow perch from their initial mercury surveys (1987-1990). Smallmouth bass and white perch did not show a significant decrease from their initial surveys in the mid-1990s. An unexpected finding was the increase in smallmouth bass and yellow perch mercury concentrations since the 2011 study. Similar findings have been documented in the Great Lakes region and Ontario with proposed explanations including enhanced deposition from Asia, invasive species and climate change. These along with impacts of Hurricane Irene in 2011 are plausible explanations for the increase in Lake Champlain fish mercury but require additional research. Cyanotoxins (microcystins, anatoxin-a and cylindrospermopsin) were measured in water samples collected throughout the summer and fish samples during low and high bloom periods from the Main Lake and Missisquoi Bay. Analysis utilized HPLC coupled with tandem mass spectrometry able to detect microcystin metabolites, a technical advancement over ELISA that can react with non-microcystin metabolites leading to spuriously high values. However, all water and fish measurements were below the detection level agreeing with VT DEC data showing no microcystin or anatoxin in water samples during this time period. Although correlations of cyanotoxin concentrations between water and fish could not be compared due to non-detectable levels, the study validated the method used for microcystin detection and demonstrated microcystin, anatoxin and cylindrospermopsin did not bioaccumulate in fish as cyanotoxins were present in 2015. Page 3 of 100 Survery of mercury and cyanotoxin concentrations in fish tissues in Lake Champlain Table of Contents Page Executive Summary ................................................................................. 3 1 Project Introduction .............................................................. 5 2 Tasks Completed ................................................................... 8 3 Methodology ......................................................................... 11 4 Quality Assurance Tasks Completed .......................... 155 5 Deliverables Completed .................................................... 16 6 Conclusions .......................................................................... 54 7 References ............................................................................ 62 8 Appendices ........................................................................... 65 Page 4 of 100 Survery of mercury and cyanotoxin concentrations in fish tissues in Lake Champlain Project Introduction This project focused on health risks associated with the consumption of fish contaminated by mercury and cyanotoxins. Mercury biomagnifies through the foodweb and top predatory fish can reach levels to warrant fish consumption advisories. The mercury portion of this study is part of a recurring study that began three decades ago that reassesses mercury in fish to help better inform the public of health risks. More specifically, this study was designed to answer how mercury burden in fish varies among species and location with special attention to the influence of body condition, measured as relative weight. Cyanotoxins have become more prevalent in the last decade, likely a result of warmer waters and eutrophication. Typical exposure to cyanotoxins occurs through ingestion or direct contact but research has shown fish can accumulate cyanotoxins (Paerl and Paul 2012, O'Neil et al. 2012). Therefore, this study was designed to determine the extent to which Lake Champlain fish accumulate cyanotoxins, and how do the concentrations in water samples correlate to those in fish tissue. MERCURY Mercury is a ubiquitous pollutant that despite knowing the neurological, developmental and sometime fatal effects since the Minamata Bay, Japan poisoning during the 1950s (Selin 2009), is the most frequent cause for fish consumption advisories worldwide with >35% of the US freshwaters having some fish consumption advisories due to elevated methylmercury (Ward et al. 2010). Mercury is incorporated into the atmosphere from anthropogenic and natural sources, primarily in elemental form which can stay in the atmosphere for more than a year allowing it to travel around the world (UNEP 2013). When it enters the aquatic environment through atmospheric deposition and runoff, it can become methylated by sulfur and iron-reducing bacteria in anoxic environments (UNEP 2013). The preferential binding of methylmercury (MeHg) to thiol groups (Gabriel & Williamson 2004) enables methylmercury