The Global Programme of Action for the Protection of the Marine Environment from Land-Based Activities, usually abbreviated to the GPA, was developed and adopted by the United Nations Environment Programme in 1995. The GPA calls for actions by each signatory nation to preserve and protect the marine environment on a national, regional and international basis in order to reach the goal of "sustainable seas."

In North America, the Commission for Environmental Cooperation (CEC) was created as a result of NAFTA (North American Free Trade Agreement) negotiations to facilitate cooperation and public participation to foster conservation, protection, and enhancement of the North American environment. In pursuing its mandate, the CEC decided to promote a series of pilot projects in North America to implement the GPA, and selected the Gulf of Maine as one project site. The CEC brought together a diverse group of individuals with an interest in the Gulf and the GPA to develop and implement a project of their own design, with some support from the CEC. The group, which has named itself the GPA Coalition for the Gulf of Maine (GPAC), has formulated an action plan to this end. A key component in the plan is a workshop in Saint John, New Brunswick on April 29 and 30, 1998, at which participants will focus on impacts due to contaminants in the GOM and develop a consensus list of prioritized issues related to contaminants, upon which an action plan to reduce or eliminate their impacts would be developed. The participants will represent industry, community groups, First Nation/Tribal groups, municipalities, scientific institutions, provincial and state governments, and federal governments. In order to focus that workshop on the priority contaminants, a scoping paper has been prepared by a consultant for consideration by the participants prior to the workshop.

A task group has been established through the GPAC to provide advice to the consultant and to review progress and final reports. The chair of the GPAC Contaminants Task Group is:

John D. Clarke, P.Eng.,

Environment Canada

45 Alderney Drive

Dartmouth, Nova Scotia, B2Y 2N6

CANADA

Tel: (902) 426-6135; Fax: (902) 426-3897; e-mail: john.clarke@ec.gc.ca

The Gulf of Maine watershed encompasses 69,115 square miles in three U.S. states and three Canadian provinces: Massachusetts, New Hampshire, Maine, Nova Scotia, New Brunswick, and a small portion of Quebec.

The overall watershed may be sub-divided into 25 major watersheds (13 in the United States and 12 in Canada) and 11 minor coastal drainage areas. Major river drainages in the watershed include the Merrimack, Saco, Androscoggin, Kennebec, Penobscot, St. Croix, and Saint John rivers.

The principal goal of this scoping paper is to provide a background of the state of knowledge regarding contaminants and their impacts in the Gulf of Maine as a basis for the Saint John workshop.

The GPA categorizes contaminants as the following (not listed in order of priority):

5. oils (hydrocarbons);

6. nutrients;

7. sediment mobilization; and

8. litter.

In the scoping paper, we have chosen a slightly different format. Because the categories of sewage and sediment mobilization do not refer to contaminants per se, but to sources or means of distribution of contaminants, we will not utilize them directly. Sewage and sediments as sources, sinks, or temporary repositories for contaminants will be incorporated into the discussions of virtually all of the contaminants. To the listing of contaminants, we have added pathogens; bacteria and viruses. The scoping paper does not include discussions of radioactive substances or litter. Consequently, the organization of this paper will be as follows:

c) dioxins/furans

3. heavy metals

As much as possible, we have organized the information around the following attributes of each contaminant:

The point source inventory provides data on 15 contaminants from direct dischargers in he years prior to 1991. The general types of point sources in the Gulf are summarized below.

A non-point source model for the Gulf of Maine is currently under development at the University of Texas, Austin but, as of this writing, the model is incomplete. An assessment of atmospheric deposition was conducted in 1995 by MacAdie for the International Joint Commission which identified several data gaps which must be resolved before an adequate evaluation can be made for many of the contaminants of concern. The assessment did provide estimates of atmospheric deposition for certain metals (e.g., atmospheric deposition accounts for 25% of the total lead and 15% of the total cadmium loadings to the Gulf).

The Gulfwatch Program provides a measure of biological uptake of contaminants within the Gulf, using only blue mussels. We have summarized the data from their 1996 report in the table and graphs below.

The USGS contaminated sediments database is still in development, but when completed will summarize data from a variety of sources collected over the past 25 years. Unfortunately, it only covers the U.S. portion of the Gulf. The current version of the database and related maps and tables may be viewed on the web at http://oracle.er.usgs.gov/sonsed/index.htm.

Approximately 300 billion gallons of effluent from at least 378 wastewater treatment plants are discharged annually into the Gulf of Maine or waterbodies which drain directly to the Gulf. This discharge contains a range of contaminants, depending on the level of treatment at the wastewater facility or pretreatment at industrial or commercial facilities connected to the sewer lines.

Depending on connections to industrial or commercial facilities, levels of pretreatment, or connections to stormdrains, wastewater treatment facilities may provide point sources for the discharge for a wide range of pathogens and toxic materials. Additionally, many treatment plants around the Gulf are underdesigned and discharge untreated sewage during major rainfall events.

Fecal coliform bacteria serve as indicators of fecal contamination. The amount of these bacteria measured in the environment is utilized by managers as a threshold to determine whether harvesting of shellfish or water-contact recreation should be prohibited in order to avoid public health concerns.

Gulf-wide, measurable fecal coliform levels are found in estuaries and nearshore waters. There seem to be seasonal variations in levels, but these appear to be more related to seasonality in runoff rather than to sewage discharge. Higher bacteria levels are generally associated with larger population centers. The top three pollution sources identified as affecting harvest limitation in estuarine and non-estuarine waters are wastewater treatment plants, direct discharges, and urban runoff.

The following table shows temporal trends in shellfish closures in the U.S. portion of the Gulf.

(in thousands of acres)

Many of the most productive shellfish harvesting areas in the Bay of Fundy are closed to harvesting because of sewage contamination or as a precaution against wastewater treatment facility failure. A number of communities in that region dump untreated, or minimally treated, sewage directly into the sea, or into the rivers and estuaries that flow to the Gulf. Reportedly, a significant volume of the sewage from Saint John, New Brunswick is dumped untreated into the harbour. Point source data from 1991 identified the South Essex (MA) WWTP as the largest contributor of fecal coliform bacteria in the Gulf of Maine. The second largest source was identified as the Moncton (NB) Sewerage Commission and the third was the Yarmouth (NS) sewage treatment plant.

The closure of shellfish beds to harvesting or beaches to water-contact activities appears to be a reasonably effective means of protecting public health; there have been only limited numbers of reports of human health-related problems from fecal bacteria.

A recent epidemiological study in Santa Monica Bay, California, provides a strong suggestion that runoff through storm drains (with suspected illegal connections to septic sources) can be linked to human health impacts. People who swam in front of flowing storm drains were 50% more likely to develop symptoms than those who remained 400 yards away from the drains. The "closer" group of swimmers experienced a broad range of adverse health effects including fever, nausea, and gastroenteritis, as well as cold and flu-like symptoms. Increased health risks were associated with high bacterial indicator counts.

Shellfish closures, while effective in protecting public health, have direct economic impacts to coastal communities and their citizens through the loss of shellfisheries and restrictions of recreational uses. For example, losses to the coastal economy in Massachusetts from bacterial contamination of shellfish and recreational waters exceed $75 million annually.

In addition to economic impacts, shellfish closures due to potential bacterial contamination, also have cultural impacts. Loss of full-time or part-time jobs disrupt traditional ways of life in smaller communities as well as First Nation/Tribal groups. In some First Nation/Tribal groups, hunting and gathering traditions are still strong from both a cultural and economic basis. The inability to harvest shellfish curtails a traditional activity and removes a traditional foodstuff from the community.

Currently there is a general lack of information regarding non-point source loading to the Gulf of Maine. The non-point source model presently under development does not have a fecal coliform component and it is unclear whether or not such an element can be incorporated. It is possible that pathogens, reflected by fecal coliform contamination, are affecting the Gulf of Maine on a broad scale basis, but there has been no comprehensive study to demonstrate this or ascertain the extent of the problem. Most reported impacts are human health-related, i.e., illness due to ingestion of shellfish exposed to sewage or swimming in waters contaminated by run-off or discharge.

The movement and impacts of viruses in coastal and marine waters is virtually unstudied. However, their ability to move through the system and survive for significant periods suggests that this is an area suitable for further investigation.

Viruses tend to be between one and two orders of magnitude smaller than bacteria and consequently are generally not filtered out as effluent from septic systems percolates through the soil, with the exception of movement through soils with high clay content. The most significant factor in determining viral survival (or inactivation) in groundwater is temperature. In coastal Maine, the groundwater temperature is approximately 7-8 degrees Celsius year-round. At this temperature, viruses can be expected to survive for periods of 800-1,000 days. If groundwater moves on the order of one foot per day, septic systems within a 1000 foot distance from the shore could be expected to contribute some level of viral contaminant load.

Persistent organic pollutants (POPs) include a wide array of chlorinated compounds including pesticides, polychlorinated dibenzodioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls (PCBs). These compounds do not readily degrade in the environment and tend to bioaccumulate in mammals. Pesticides have been widely used on agricultural and forested lands in Gulf of Maine watersheds and thus enter the marine system through non-point sources such as runoff and atmospheric deposition. The characteristics that made these synthetic chemicals useful, their toxicity to pest species, also makes them harmful to other, non-target organisms. Unfortunately, when some of these chemicals were being spread widely, little was known about their adverse affects and resistance to degradation.

Many animals show reproductive problems that have been linked to POPs, but marine mammals such as whales, dolphins, seals, and polar bears may face the greatest jeopardy, particularly over the long term. Persistent chemicals accumulate and concentrate in the marine food web, exposing the long-lived predators to the highest levels of contamination. These chemicals are passed to offspring through breast milk.

Recent research suggests that exposure to persistent organic pollutants may pose significant risk to a larger proportion of the general human and wildlife population than previously thought. Some POPs are now known to act as endocrine disrupters, mimicking the body’s hormones, turning off and on important developmental processes at critical times. Some scientists believe that fetal exposure to endocrine disrupters or estrogenic chemicals (including some organochlorines such as DDT, some PCBs, dioxins, and furans) may be responsible for declining sperm counts and the rising incidence of abnormalities in human male reproductive tracts.

The following graphs depict concentrations of organic contaminants found at Gulf Watch monitoring sites in 1996. Generally, they indicate lower concentration in the Bay of Fundy and higher concentrations as one moves southwest to the more developed areas.

Significant declines have been noted in both PCBs and DDT in Bay of Fundy Harbor porpoises, gray and harp seals since the 1970s. This appears to be directly related to the bans on those chemical in both the U.S. and Canada.

For some First Nation/Tribal groups, bio-accumulation in marine mammals is a human health issue. Conversations with the Passamaquoddy Tribe at Pleasant Point, Maine suggests that porpoise remains a traditional food source. Tribal members take approximately 50 porpoises a year for consumption. Of particular concern is that they consume virtually all of the animal, not merely the muscle tissue, with the liver being a particular delicacy. A similar situation occurs with the consumption of fish. Tribal members typically consume the entire fish, not only the fillets of muscle tissue. Most fish sampling done by government health or environmental officials, however, focuses on fillets, not the entire body burden of contaminants. This, combined with a strong tradition of use of marine species, suggests that Tribal/First Nation members may be consuming a greater load of contaminants than the general population.

Heavy, or trace metals, have been major environmental contaminants since the beginning of the industrial revolution. Several are highly hazardous to aquatic life and humans. Being basic elements, they do not biodegrade and remain in the environment. Many rivers and estuaries leading to the Gulf of Maine were heavily loaded with metals during the 19th century from industries located on rivers in the region.

The U.S. Food and Drug Administration (FDA) has published a series of "Guidance Documents" for cadmium, chromium, lead and nickel. These are alert levels and by themselves do not warrant the issuance of health advisories. For 1996, no metals sampled as part of the Musselwatch program in U.S. waters, approached the guideline levels. There are also screening values, established by the US EPA, for cadmium, mercury, and selenium; 11 organochlorine compounds; one chlorophenoxy herbicide; total PCBs; and dioxins/dibenzofurans. None of the contaminants sampled at 1996 Gulfwatch stations exceeded these screening values.

For the majority of the Bay of Fundy, heavy metals in the sediments are at or near natural levels for unpolluted coastal sediments. Off Saint John is a disposal site for dredged harbour sediments where concentrations of metals are higher than normal. Levels of some metals are also higher in sediments in Passamaquoddy Bay because fine contaminated sediments in the Saint John River plume are swept into the area by coastal currents and deposited there.

The following graphs depict the spatial distribution, clockwise around the Gulf starting at the southwest, of levels of heavy metals in blue mussel tissue as sampled in 1996. The straight line indicates the mean for 23 reference stations, or relative pristine sites, along the coast of Maine from a previous study. These concentrations represent the amount of metal taken up and sequestered in mussel tissue and thus are representative of metals in the water column that are bioavailable.

Larsen reported in 1992 that blue mussels from Boothbay Harbor, ME, had large kidney concretions resulting from the accumulation of heavy metals. The mean body burden of lead in Boothbay Harbor mussels was the highest of ten sites he sampled along the Maine coast.

Because urban activities are most apt to generate PAHs, it is not surprising to find the highest concentrations in adjacent harbors, generally as a mixture of combustion-sourced PAHs and petroleum-sourced PAHs, with the former being most often in predominance. This group of contaminants is relatively non-volatile and has a low solubility in water. Degradation is slow in sediments and therefore this medium is the major environmental sink. In the air, soil, and water, PAHs generally adsorb to particulate matter on which they are transported. PAHs from petroleum sources apparently are more bio-available than those from pyrogenic sources as Mussel Watch samples display more petroleum-based PAHs.

Shellfish have very little capacity for metabolism of hydrocarbons. Therefore, shellfish accumulate these compounds to levels higher than those appearing in fish from the same environment.

Sites in the Gulf of Maine with high concentrations of PAHs include Boston Harbor, Casco Bay, and Penobscot Bay. Loadings to Massachusetts Bay alone are estimated to be between 2.1 to 13.7 metric tons per year; the areas near combined sewer overflows in Boston Harbor are among the most contaminated locations. Larsen noted high concentrations of PAHs in Casco Bay with the highest in Portland Harbor. Johnson reported elevated levels in Penobscot Bay. Harbor sediments near the discharge of Marsh Creek at Courtenay Bay at the mouth of the Saint John River currently exceed 2.5 ppm. Larsen reported PAHs in the sediments of the depositional basins in the central Gulf of Maine.

Because PAHs are hydrophobic, they can be taken up by many marine organisms across gill surfaces and other surfaces and partition into the organisms. PAHs can also enter organisms by way of food.

It is thought that toxicity associated with PAHs is due not to the initial compound, but rather metabolized intermediates. The majority of enzymatic activity associated with the metabolization of PAH compounds takes place in the liver. The metabolic by-products go through a series of reactions, ultimately forming diol-epoxides and phenol oxides, which are believed to be the carcinogenic intermediates of PAHs.

PAHs are also potent immuno-toxic compounds, suppressing cell-mediated immune response. It appears that PAH compounds which are carcinogenic are also immuno-suppressive.

Different species have different capacities for the metabolism of PAHs. It also appears that the capacity for PAH metabolism can change within a single individual as a result of exposure to the PAH, or in different life stages. Invertebrates have lower rates of PAH metabolism than fish.

In general, PAHs show little tendency to biomagnify in food chains despite their high lipid solubility. This situation is thought to occur because most organisms rapidly metabolize and excrete PAH compounds. Where assimilation of ingested PAHs has been demonstrated, metabolism and excretion were rapid.

PAHs are considered to be possible or probable human carcinogens and hence their distribution in the environment and possible exposure to humans is the focus of much attention.

Nutrients commonly thought of as pollutants include nitrogen and phosphorus. In marine waters, nitrogen is generally of concern because it is the limiting nutrient controlling primary productivity. The critical concentration for marine waters can be as low as 0.2 mg/l, depending on the rate of tidal flushing. In marine waters, nitrate is the predominant inorganic form of nitrogen, although the majority of nitrogen occurs as dissolved organic nitrogen. Excessive nitrogen to marine ecosystems can result in algal blooms, decreased water clarity, and declines in eelgrass beds--important shellfish and finfish habitat. Chronic impacts can lead to changes in speciation and diversity.

In the eastern United States and western Europe, contemporary nutrient loading of rivers is probably 10-50 times greater than prehistoric loadings.

A mass balance approach to the inputs of nitrogen into the Gulf described by the U.S. National Oceanic and Atmospheric Administration suggests that sources from the open ocean are larger than anthropogenic inputs. Nitrogen inputs entering via the Northeast Channel and Scotian Shelf have been estimated at 2 million metric tonnes/year compared to terrestrial and atmospheric inputs (both natural and anthropogenic) of approximately 0.1 to 0.2 million MT/year. Schlitz and Cohen estimated the relative loadings to be 97.39% from offshore sources, 0.9% from river discharge, and 1.89% from rainfall.

A NOAA/US EPA Team focusing on Near Coastal Waters highlighted those estuarine systems bordering the U.S. portion of the Gulf of Maine that have medium or high nutrient potential concentration status:

Eutrophication has not been noted in the open waters of the Gulf of Maine nor have hypoxic conditions been noted in offshore bottom waters of the Gulf, primarily due to dilution, mixing, and flushing. Eutrophic conditions occur in nearshore waters, and particularly embayments, because focused inputs of nitrogen are coupled with warm waters, which speed chemical actions and biological activities, and poor flushing.

It has been speculated that the addition of nitrogen into the central portion of the Gulf may be altering the composition of the phytoplankton community, in some cases giving rise to blooms of noxious algal blooms. Of particular concern are:

Nutrients from land-based activities flow into the Gulf of Maine from both point and non-point sources. Most wastewater treatment plants discharging into the Gulf of Maine are not equipped for nutrient removal. Agricultural activities and suburban landscaping use of manure and fertilizers lead to discharge through groundwater or runoff from storm events or snow melt.

Atmospheric deposition of biologically available nitrogen has been estimated to represent a potentially significant (20-30%) contribution to estuarine and coastal nutrient budgets. This source to the world’s oceans has increased by 5-fold over pre-industrialized times, largely due to emissions from increased biomass burning and energy utilization.

Nitrogenous wastes from aquaculture operations are also a growing concern. Pen culture of finfish is of particular concern because of its potential for localized inputs of nutrients in the forms of fecal wastes and uneaten feed. While coastal water quality and habitats can be affected by aquaculture, a review of Maine waters suggests that it has not been shown to cause irreversible or unacceptable adverse impact to water quality or habitats there.

It has been estimated that the Massachusetts Water Resources Authority wastewater treatment plant, located in Massachusetts Bay, is contributing the largest anthropogenic load of nitrogen--26,707 million pounds (12.1 metric tonnes) of nitrogen annually into the Gulf.

Our knowledge of the health and environmental impacts of human perturbations in the Gulf of Maine is fair, at best. There is a general knowledge of the amounts of contaminants introduced through point-source discharges. Our understanding of non-point source discharge of contaminants is in its infancy, particularly in the area of atmospheric deposition. Except for a few well-studied sites and species, little is known about the locations, fates and effects of pollution on the ecosystem. What has been observed are the obvious signs of the effects of pollution, where we are seemingly lacking is in the understanding of the collective, cumulative, and synergistic effects of food chains, environmental variability, and contaminant effects all operating at the same time.

The highest concentrations of chemical contaminants are to be found in nearshore, industrialized/heavily urbanized, and waste disposal areas. Such areas can also be spawning and nursery habitats for many important commercial fishes. The early life stages of these fishes are most susceptible to toxicants.

Pathogens-Bacteria:

POPs

Metals

PAHs

Nutrients

1 Effectiveness of E. coli as indicator has been questioned