COMERN Project Description
15/02/16
PROJECT DESCRIPTION
1. Identification
Project Manager: Dr. Paul A. Arp
Forestry and Environmental management Faculty,
University of New Brunswick, Fredericton, NB.
Research Title: Case study: Coastal environment of the Bay of Fundy
Theme Leader: Dr. Paul Arp
Collaborators: Dr. Charles Bourque
Forestry and Environmental management Faculty,
University of New Brunswick, Fredericton, NB.
Neil Burgess M.Sc.
Canadian Wildlife Service, Environment Canada,
Sackville, NB.
Dr. Mick Burt
Huntsman Marine Science Center, St.Andrews, NB.
Dr. Laurie Chan
Department of Biological sciences, McGill University,
Montréal, Qc.
Dr. Gail Chmura
Department of Geography, McGill University, Montréal,
Qc
Dr. Roger Cox
Forestry and Environmental management Faculty,
University of New Brunswick, Fredericton, NB.
Dr. Rick Cunjak
Forestry and Environmental management Faculty,
University of New Brunswick, Fredericton, NB.Qc.
Dr. Anthony Diamond
Forestry and Environmental management Faculty,
University of New Brunswick, Fredericton, NB.
COMERN Head Office: Université du Québec à Montréal, President-Kennedy Bldg – Suite PK-7150 C.P.8888,
Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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COMERN Project Description
Dr. Frank Gobas
15/02/16
School of Resources and Environmental management,
Simon Fraser University, Vancouver, BC
Dr. Charles Gobeil
Maurice-Lamontagne Institute, Fisheries and Oceas
Canada, Mont-Joly, Qc
Dr. Rui Fan Meng
Forestry and Environmental management Faculty,
University of New Brunswick, Fredericton, NB.
Dr. Alphonso Mucci
Earth and Planetary Science department, McGill
University, Montréal, Qc.
Dr. Donna Mergler
Département des sciences biologiques, Université du
Québec à Montréal, Montréal, Qc.
Dr. Gerhard Pohle
Atlantic Reference Center, NB
Dr. Judy Snyder
Health Canada, Ottawa, Ont.
Dr. Lou Van Guelphen
Atlantic Reference Center, NB
2. Project summary
Atlantic Canada is a region where high mercury (Hg) deposition occurs, and this is - in part - due
to atmospheric pollution from the U.S, Central Canada, and local sources scattered within the
region. Although limited, our knowledge about the dynamics of Hg in marine environments
suggests that coastal areas may be most susceptible to increases in atmospheric deposition.
Elsewhere, a number of highly industrialized estuarine regions such as the Scheldt Estuary,
flowing into the North Sea, and Kastela Bay in the Central Adriatic are already experiencing Hg
contamination problems, even at low trophic levels. The location of the Bay of Fundy provides
an interesting case study of airborne pollution issues as the boundary between Canadian and
American waters is located at the coalescence point for several continental air masses from the
Eastern and Central United States. Whereas coastal fisheries and salmon and finfish aquaculture
are vital for the local economy, a number of undesirable changes have been noted in the region:
elevated levels of Hg in porpoises (Phocoena phocoena) and seals (Phoca vitula) and high levels
of Hg in the blood of common loons (Gavia immer) and seabirds (e.g. Phalacrocorax auritus).
Little is known at this time how Hg works itself through into the coastal areas. It is thought,
however, the frequent fog occurrences add considerably to coastal Hg inputs. Here, local
catchments, vegetation and soils may have strong influences on further channeling the incoming
Hg into coastal brooks and tidal marshes. In particular, catchments with low permeability and
essentially anaerobic substrates play a crucial but unwanted role in transforming some of the
COMERN Head Office: Université du Québec à Montréal, President-Kennedy Bldg – Suite PK-7150 C.P.8888,
Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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COMERN Project Description
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incoming Hg into highly toxic methylmercury (MeHg). Subsequent seepage from these
substrates into the coastal brooks and tidal marshes below, or into the Bay itself, may be one of
the most important pathway by which measurable amounts of MeHg enter the coastal food web.
This project deals with quantifying coastal mass balance inputs and outputs for total and organic
Hg, per select coastal catchments, and seeks to quantify subsequent estuarine and coastal impacts
on select sediments and biota, from phytoplankton, through feeders (mussels, clams), select fish
and bird species, to local communities that depend on some of these species as part of their daily
or seasonal food supplies.
3. Research objectives:
The overarching objective of this section is to identify the fate of Hg in coastal ecosystems of the
Bay of Fundy, and the susceptibility of this coastal region to local and long-range sources of
atmospheric Hg contamination. Doing so involves:
•
Identifying the principal inputs of Hg in coastal regions including a) atmospheric deposition
(precipitation, dry deposition, fog); b) riverine and subsurface flow; c) geologic sources and
natural background concentrations; d) historical records of deposition.
•
Characterizing the cycling of Hg in the abiotic environment of coastal subcatchments,
including a) mass transfer of Hg from the atmosphere to land and sea and back; b) role of
suspended particulate matter and sediment transport processes on methylation of Hg; c) role
of environmental variables such as redox fluctuations and tidal freshwater-saltwater mixing
on biotic productivity and on Hg methylation rates.
•
Determining the susceptibility of benthic organisms, fish and seabirds to enhanced
deposition of Hg from the atmosphere and local sources of contamination.
•
Integrating the results to develop whole-ecosystem model of Hg dynamics in coastal
regions to forecast Hg levels in predatory fish and seabirds from inputs of Hg to the system.
•
Installing a local resource link to the proposed COMERN study of Hg food chain effects on
human health. The results from the above biomonitoring will be linked to human exposure
and its impact on human health. Human exposure in these coastal communities to Hg and
other contaminants will be evaluated and dietary questionnaires will serve to establish the
population's use of the local resources. Assessment of health and well-being will be carried
out.
•
Synthesizing the results to analyze the management and policy implications of the study for
regulations of trans-boundary Hg contamination on the Maine-New Brunswick border and
managing ecosystem impacts of Hg in the Bay of Fundy.
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Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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COMERN Project Description
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Details
Coastal Subcatchment Study
Preliminary results for Canadian sites in the US National Atmospheric Deposition Program
showed that wet deposition Hg in the Atlantic region is approximately: 8.5 ug/m2/year. Eastern
Canada likely receives about 4.6 tons of wet Hg deposition per year, i.e., 2 to 3 times more since
the last century. Hg inputs into coastal subcatchments are regionally higher than elsewhere
because of combined wet and dry atmospheric deposition plus fog deposition. Run-off from the
many small coastal catchments (<1 to about 500 ha) adds Hg to the marine environment, and
may be intercepted in coastal marshes, mudflats, tidal plains and estuaries. These systems are
unique in the sense that they catch most of the coastal fog, especially if oriented towards the
prevailing direction of fog and sea-spray drift.
With this study, we intend to model total atmospheric Hg inputs/outputs and related pathways for
small forest catchments along the Fundy Coast. The model will be calibrated with Hg data from
small paired forest subcatchments on the Point Lepreau Peninsula. Subcatchments will be
selected so that both point southwest and southeast and will have to present tidal flats, with
defined water pathways and sufficient biotic activities. The landowner is NBPower, who will
also be a research partner.
The monitoring results will be used to calibrate an existing forest hydrology model (ForHyM2)
that simulates all major water flows and water storage compartments of forest watersheds at the
subcatchment level. Calculated water flows will be used to estimate Hg transfer rates through the
forest subcatchments. An Hg input/output model will be calibrated for the pre-disturbance
situation and will be formulated to predict outcome. The subcatchments will be treated after the
second year of monitoring, to test the model predictions.
Coastal Impacts: Sediments and Hg transfer to biota
Coastal and marine sediments may serve as potential sources and sinks of toxic substances in
aquatic systems. The investigation of diagenetic processes in marine and continental sedimentary
systems has become a vital component of pollution assessment studies but the key question
remains to what extent are these contaminants transferred to the biota.
To examine the ability of benthic invertebrates to extract Hg from sediments, we have made a
preliminary study of the marine polychaete worm Maldane Sarsia, common specie in the
sediments of the deep St. Lawrence Estuary. Although these sediments are not what one would
normally consider to be seriously contaminated (50-300 ng/g sediment or 0.05-0.3 ppm), we
found Hg concentrations in the worms as high as 100 ppm, corresponding to an average 250-fold
concentration factor between worms and sediment. We observed that MeHg is produced just
below the sediment-water interface under suboxic and anoxic conditions. Burrowing benthic
COMERN Head Office: Université du Québec à Montréal, President-Kennedy Bldg – Suite PK-7150 C.P.8888,
Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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COMERN Project Description
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organisms can accumulate MeHg directly from anoxic sediments and may serve as a vector of
this substance to their predators. It has been demonstrated that Hg is then transferred from
marine sediments to commercially exploited fish species. A study on the bottom feeding
snowcrab and shrimp in the Saguenay Fjord revealed Hg levels much higher than in the bottom
sediment, exceeding the norms established for the protection of human health. These studies and
others have shown conclusively that the abundance of a toxic metal in a sediment is not in itself a
good indicator of the potential flux of the metal into fish and from there further up the food chain
and, thus, even sediments with moderate to low levels of toxic metals can be a source of
contamination.
We will attempt to determine the proportion of Hg in marine sediments from anthropogenic
sources, the forms (species) in which the metals occur in sediments, and the mechanisms that
allow for mobilization and incorporation of Hg into benthic invertebrates. We will also seek
relationships between Hg in sediments, in benthic invertebrates, and in bottom feeding fish.
Distinguishing between natural and anthropogenic sources of metals in sediments is a classical
problem to which there are no simple solutions. The most direct and common approach has been
to compare the abundance of a metal in a sediment with its abundance in a pre-industrial
sediment. This works well as long as diagenetic mobilization does not significantly change the
historical distribution of the metal. Fortunately, Hg seems little affected by diagenesis, and we
propose to use high-resolution vertical profiles of Hg in sediment cores to estimate the
importance of anthropogenic Hg inputs.
A database will be gradually established on the Hg burden of benthic invertebrates, and the
results compared with analyses of the sediment in which the organism were found. In addition to
the generated data on anthropogenic Hg in sediments and benthic invertebrates, data from an
ongoing program by the DFO on Hg in bottom feeding fish in the Bay of Fundy and the StLawrence Estuary will be used. All the information on metal abundance will be combined with
information on the location of the feeding grounds of the fish (approximated as the location
where the fish was when it was caught) and multivariate analysis will be used to identify
correlations.
Coastal Impacts: Biomonitoring of Hg levels from freshwater to salt water, bottom-feeding
fresh water fish, clams, mussels, and seaducks
We will determine the levels of Hg present in specific organisms and verify if there is a constant
relationship of these levels with atmospheric and freshwater Hg levels within an ecosystem. We
propose to do this by collecting and analyzing Hg levels in 10 different watersheds in coastal
southwest NB. In each, water samples, freshwater clams, sediments, and piscivorous fishes
(pickerel/perch) will be collected. At the mouth of each river, saltwater mussels will also be
collected. Bottom-feeding fish will be monitored for Hg in coastal freshwater streams. Seaducks
(all-year resident birds such as Common Eider (Somateria mollissima), and migrant species such
as Leach’s Petrel (Oceanodrama leucorrhoa) will be monitored for Hg in feathers at time of
COMERN Head Office: Université du Québec à Montréal, President-Kennedy Bldg – Suite PK-7150 C.P.8888,
Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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COMERN Project Description
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molting, at select shore locations. The watersheds that will be sampled in-shore near the
estuaries, within the estuaries, and the tidal flats for clam, fish and mussel collections are: (1) St
Croix River, (2) Chamcook River, (3) Digdeguash River, (4) Magaguadavic River, (5) New
River, (6) Lepreau River, (7) Musquash River, (8) Saint John River, (9) Gardner Creek, (10) Big
Salmon River. Each watershed will be visited 3 times. The first visit will collect freshwater
clams and water samples; the second will collect fish; the third will collect saltwater mussels at
the mouth of these rivers. Results about Hg accumulation in select tissues will be compiled and
examined within the geographic context of each location, to provide parameters essential for
food chain modeling based on local abiotic Hg loading and locally relevant and species-specific
Hg transfer mechanisms.
The Big Salmon River catchment that feeds into the Bay of Fundy is particularly noteworthy
offering unique opportunities for studying the process and direction of Hg contamination in a
coastal inland-estuary ecosystem at a variety of scales - from headwaters to estuary, lacustrine
versus lotic, terrestrial to aquatic, and for a variety of trophic levels from primary consumers to
the top predators. Its forest is relatively pristine, and there has been little direct influence of
urbanization or industrialization along the watercourse. In addition, there is ready access to the
headwater streams, the river mouth/estuary, and a large lake with a unique population of relict
arctic char (a pelagic predator). From a species perspective, the Big Salmon River has
populations of diadromous species such as Atlantic salmon, brook trout and American eels, as
well as freshwater resident species such as brook trout and various minnow species. In addition
to the biomonitoring program, we plan to trace the transfer of groundwater Hg into the eggs of
salmonid fishes (trout, salmon) that incubate in the gravel of groundwater discharge zones.
Coastal Impacts Model
A whole-ecosystem model linking inputs of Hg to the coastal environment to tissue
concentrations of predatory fish and seabirds in the Bay of Fundy will be developed, based on the
best available knowledge on the fate of Hg in coastal regions. We intend to develop this model
for multimedia usage by managers who deal with Hg contamination issues in coastal ecosystems.
It will consists of three main sub-components:
1. A first sub-model describing the speciation of Hg into its more toxic organic forms, based on
available thermodynamic data that present the affinity of different Hg species for various
ligands and the chemical and physical characteristics of the medium of interest. In sediments,
e.g., this includes redox status, dissolved sulfide concentrations, organic carbon, temperature,
nutrient status and salinity.
2. A second “environmental fate” sub-model describing how Hg partitions between various
media, including air, water and sediments. This sub-model includes site-specific parameters
affecting the transport of various Hg species by way of (e.g.) tidal and freshwater inflows,
settling of suspended particulate matter, and molecular diffusion.
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Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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COMERN Project Description
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3. A third “bioaccumulation” sub-model simulating Hg dynamics in food webs. This submodel is based on biological, physical uptake and excretion parameters specific to the species
of interest. This sub-model will be based on similar freshwater ecosystem-scale Hg
models118, with special calibrations for the marine setting.
These sub-models will first be applied to Passamaquoddy Bay in the Bay of Fundy. This area is
of particular interest due to its proximity to the Canada-United States border and the
concentration of commercial and aquaculture fisheries in that region. The model is currently
being parameterized using physical and hydrological data from the Passamaquoddy Bay. An
independent data set on Hg concentrations in sediment, water and organisms from the region has
also been partially assembled and will be used to test the model forecasts. Data required to
complete the food-web bioaccumulation model will also be provided by a study currently
underway at the DFO in Dartmouth, NS. This study will provide data on total Hg and MeHg
concentrations and diet composition of marine species at 4 trophic levels the Bay of Fundy.
Observed empirical and model-predicted concentrations of Hg in sediment and biota will be
compared to test the mechanistic model and generate an estimate of model bias and related
uncertainties. Monte Carlo simulations will be used to investigate the effects of uncertainties in
key input parameters, and to forecast a plausible range of output results.
A copy of the modeling software will be available for managers concerned about Hg
contamination issues in other ecosystems. The dataset on Hg levels in marsh sediment cores,
aquatic sediments and organisms in the Passamaquoddy Bay region and New Brunswick
coastline of the Bay of Fundy will also be available for future use. Ultimately, successful
application of this model will help to identify the level of emissions to the environment that
maintains Hg concentrations in the tissues of fish and seabirds below regulatory guidelines. This
knowledge could then be combined with inventories of the sources of Hg contamination in the
region in order to identify the most appropriate regulatory framework that minimizes the risk to
both human and ecological health.
COMERN Head Office: Université du Québec à Montréal, President-Kennedy Bldg – Suite PK-7150 C.P.8888,
Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635
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