Estuarine Sediment Sampling of Tributyltin and Polynuclear

Aromatic Hydrocarbons in the St. Croix Estuary

Report on the 1998 Tributyltin & Polynuclear Aromatic

Hydrocarbons Sampling Program

St. Croix Estuary ProjectPO Box 1180

St. Andrews, NB, E0G 2X0

PO Box 394Calais, ME, 04619

September 23 , 1998

Supported by:

Environment CanadaThe U.S. Gulf of Maine Association

Copies of this report are available at cost from the St. Croix Estuary Project. To obtain a copy or copies, or for more information on SCEP, please contact:

The St. Croix Estuary Project PO Box 1180

St. Andrews, NB, E0G 2X0

PO Box 394Calais, ME, 04619

(506) 529-4868 (tel)(506) 529-4878 (fax)scepnet@nbnet.nb.ca

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TABLE OF CONTENTS

PAGE

Table of Contents.............................................................................................................................iAcknowledgments...........................................................................................................................ii

1.0 INTRODUCTION...............................................................................................................11.1 Purpose of the Study......................................................................................................21.2 Sampling

Locations......................................................................................................................................2

2.0 SAMPLING DESIGN..................................................................................................42.1

Protocols.......................................................................................................................................42.2 Sample Analysis...........................................................................................................5

3.0 RESULTS AND DISCUSSION....................................................................................53.1 Polynuclear (Polycyclic) Aromatic Hydrocarbons...............................................................63.2 Tributyltin...................................................................................................................8

4.0 CONCLUSIONS..........................................................................................................104.1 PAHs........................................................................................................................104.2 TBT..........................................................................................................................10

5.0 LITERATURE CITED.................................................................................................13

ABOUT THE ST. CROIX ESTUARY PROJECT...................................................................15

LIST OF MAPSMap 1: Sample locations within the St. Croix Estuary..............................................................iii

LIST OF TABLESTable 1: July 30, 1998. Sample times, Depth at Sample location, Tidal stage ,and Surface Salinity of

Sampling locations...............................................................................................4Table 2: July 30, 1998. Weather/tidal notes, local conditions during sampling...........................5Table 3: Result of PAH Analysis........................................................................................7Table 4: Result of Butyl Tins Analyses...............................................................................9

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ACKNOWLEDGMENTS

The 1998 Tributyltin and Polynuclear Aromatic Hydrocarbons Sampling Program, and preparation of this report, was conducted by Mark Bader, SCEP Program Director, and Phil Holmes, SCEP Environmental Technician. Sample analyses were completed by the Chemical and Biotechnical Services section of the Research and Productivity Council (RPC) laboratory in Fredericton, New Brunswick.

The study was made possible through funding provided by Environment Canada and The U.S. Gulf of Maine Association. The St. Croix Estuary Project is grateful to these organizations for their support.

SCEP would also like to thank the following individuals and organizations for additional in-kind support and professional assistance:

The St. Croix International Waterway Commission, St. StephenThe Atlantic Reference Centre, St. AndrewsDr. Vlado Zitko, Fisheries and Oceans Chemist, St. Andrews Research StationBill Hogans, Huntsman Marine Science Centre, St. Andrews

- iii -Map 1: Sample locations within the St. Croix Estuary.

1.0 INTRODUCTION

The St. Croix River Estuary, located in Passymaquoddy Bay, is part of the northern boundary of the Gulf

of Maine. With its rich diversity of fauna and flora, the estuary forms a vibrant environmental and

economic zone shared by Canada and the United States. Lobster, clam, and scallop fishing support

many families in Washington County, ME, and western Charlotte County, NB. Long lines of lobster

buoys are often spotted along the Maine side of the estuary between Devil’s Head and Robbinston. Six

to seven scallop draggers can regularly be seen at one time around Oak Bay and at the confluence of the

St. Croix and Waweig Rivers.

Oak Bay, a prominent feature of the estuary, represents the largest clamming flat in the area and

presently supports depuration clamming activity. Currently, Environment Canada and The Department

of Marine Resources, working in conjunction with local interest groups, have been conducting extensive

water quality monitoring in support of re-opening these clam flats. The flats are expected to re-open to

non-depuration clam diggers as soon as rigid assurances to human health can be declared.

St. Croix estuary is also rich in history. The name “St. Croix” was given by the explorer Samuel de

Champlain due to the estuary’s cross-like shape. The estuary provided a rich bounty of food and other

resources for aboriginal people for centuries prior to European settlement. The first attempt by France to

permanently settle the area occurred in 1604 on St. Croix (Dochet’s) Island (Map 1). The expedition,

led by Sieur de Monts, though ending in bitter failure, represents the first European settlement in North

America north of present day Florida.

To say that the estuary is important to the well being of those who reside on or near its shores would be a

grave understatement. Rather, the well being of the estuary is so intertwined with that of local

communities, the two may be considered inseparable. The future health of the estuary requires the

support of all citizens living on both sides of the border to maintain and improve the water quality of

this area. The St. Croix Estuary Project has conducted extensive water quality projects since 1993.

1.1 Purpose of the Study

On March 27, 1997 SCEP released a comprehensive environmental management plan (CEMP) entitled

Caring for our Coast: A Plan for Community Management of the St. Croix Estuary Area. The sampling

of TBT and PAHs in sediment addresses two of the 50 actions in the CEMP that have been deemed,

through research and public input, necessary to maintain and make improvements in the health of the St.

Croix Estuary. The two actions read as follows:

● Action 17: Assess PAH concentrations and potential ecological effects.

● Action 41: Assess TBT concentrations and potential ecological effects.

When the CEMP was published, sediment analysis data for TBT and PAHs in the St. Croix region were

(and continue to be) exceedingly limited. At the outset of this project, only one triplicate sample for

PAHs in sediment could be found (O’Neill and Kieley, 1992), and no Tributyltin data could be located

for the St. Croix River estuary. PAHs and TBT have been identified as toxic substances of concern to

human and environmental interests. This project was undertaken in order to determine the impact these

substances have had in the St. Croix Estuary.

1.2 Sampling Locations

While there are some naturally occurring PAHs in the environment, the great majority of them are of

anthropogenic origins. TBT is also a human creation. In addition to this, a large portion of previous

TBT and PAH sampling conducted in Atlantic Canada has occurred around areas of concentrated human

activity. In light of these facts, the locations for sampling (Map 1) were selected based on an

incremental scale of human activity. More specifically:

1. Oak Bay - This sample site was selected North of the Bayside Marine Terminal between Todd’s point

and Hill’s Point at about mid point. This part of the bay was chosen as there are no boat moorings or

wharfs nearby. As such, the level of toxic chemicals found here are considered as ambient or

background levels, there being no obvious concentration of human activity present. This site, believed

to represent a ‘less contaminated’ area, was included to allow comparison with other, more suspect

locations.

2. St. Croix Yacht Club - The St. Croix Yacht Club is located about 10 km down river of St. Stephen.

From May to October, there are approximately six to ten sail boats buoyed at this location. Most of these

are lifted out of the water at Bayside Port at the end of the summer season. These recreational vessels, as

with all marine vessels, are freshly painted with a (leaching) antifouling paint shortly before being

lowered into the water each spring. This being so, the site is considered to be an area of moderate

human activity and, in theory, a location of moderate input of toxic substances. The sampling for this

site was conducted from a club service raft that was about mid point amongst the moorings. Past studies

suggest that the current can flow up to two knots at this location.

3. Bayside Port - The Bayside Marine Terminal is located about 11 km North of St. Andrews on the east

shore just south of the junction of Oak Bay, Waweig and St. Croix River. The port is designed to

accommodate two freighters with the capacity to service a third, smaller ship on an inside sheltered area.

Gypsum, granite, potatoes, sand, and frozen foods are the major items of business. This location

experiences by far the greatest human activity in the estuary. Furthermore, large vessels like those found

at the port are still allowed to use anti-fouling paints with Tributyltin additive, a practice that has been

banned on boats under 25m in length (Environment Canada, no date). The sample was taken adjacent to

the pier on the shore side. The pier structure consist mostly of concrete. There are wooden pilings and,

although treated, are not of recent installation. The inside location was quite sheltered against the very

strong currents that are experienced adjacent to the west (outer) side of the pier.

Table 1: July 30, 1998. Sample times, Depth at Sample location, Tidal stage ,and Surface Salinity of Sampling locations.

Location Lat/Long Sample Time (2400

hr)

Depth (m) Tidal Stageat Time of Sampling

Surface Salinity(0/00)

Oak Bay (OB) N 450 10' 14"W 670 09' 10"

918 15 Mid Falling 30

Bayside (BS) N 450 09' 33"W 670 08' 26"

1125 9.1 Low Tide 25

Yacht Club (YC) N 450 10 '01"W 670 10' 11"

1300 12.2 High Falling 28

2.0 SAMPLING DESIGN

2.1 Protocols

In compliance with a Quality Assurance Project Plan (QAPP) that accompanies all US GoM Association

funding for sample testing, the Standard Operating Procedures (SOPs) for this program were those of the

US Environmental Protection Agency (EPA) - Sediment Sampling SOP# 2016, following all applicable

sections including sub-section 7.2.4: Sampling Surface Sediment with an Ekman or Ponar Dredge from

Beneath a Shallow or Deep Aqueous layer, and Sampling Equipment Decontamination SOP#: 2006

(Appendix B). An Ekman dredge was used for this study which was decontaminated between samples

at a shore station. This decontamination station was located on the service raft at the St. Croix Yacht

Club, with fresh water being supplied from shore via the clubhouse.

Basic sampling protocols followed those which are outlined in the US EPA Chain-of-Custody

Evaluations (CCE) circular (Appendix A). Particulars of the CCE with respect to sample collection are

summarized in Table 1 and Table 2. Compliance with the CCE after samples were signed over to RPC

laboratories may be confirmed with that organization.

Table 2: July 30, 1998. Weather/tidal notes, local conditions during samplingWind Tide Visibility

Direction EstimatedVelocity (km/hr)

Time High Time Low TidalHeight (m)

Calm Calm 523 1147 5.5 Sunny and Clear

2.2 Sample Analysis

Analysis of sediment samples was conducted by the Research and Productivity Council laboratory in

Fredericton, New Brunswick. RPC followed the standard Atlantic Region Monitoring and Evaluation

Branch (Canada) protocol for the analysis of Polynuclear Aromatic Hydrocarbons and Total Arochlors in

Sediments, which covers the qualitative and quantitative determination of PAHs and polychlorinated

biphenyls (PCBs) in a sediment matrix (Appendix C). As the analysis of Tributyltin is rather uncommon

for any lab in Canada, like documentation for analysis protocols of TBT was unavailable at the time of

this report.

The Limit of Detection (LOD) or detection threshold for PAHs was 0.01ppm (mg/g) and 5ppb (ng/g) in

the case of TBT. The limit for PAH sampling represents an industry standard for such analyses, while

the LOD for TBT is the lowest possible given readings below this level may be due to instrument error.

3.0 RESULTS AND DISCUSSION

Results of the analyses conducted by RPC were turned over to Dr. Vlado Zitko, a chemist with the

Department of Fisheries and Oceans Research Station in St. Andrews, New Brunswick. Dr. Zitko has

worked in this capacity for 15 years and is a recognized expert in the field of organic chemistry. Some

of the conclusions drawn from this study are based upon Dr. Zitko’s professional opinion, given that the

results of the analyses as reported by the lab are accurate.

3.1 Polynuclear (Polycyclic) Aromatic Hydrocarbons

PAHs comprise a group of over a hundred organic compounds with a base form of two or more benzene

rings (Kennish, 1992). PAHs are derived from the incomplete combustion of fossil fuels. Natural

sources such as forest fires, volcanoes, and decaying organic matter (Environment Canada, 1995)

account for a small percentage of PAHs, while the majority found in sediments are from anthropogenic

sources (O’Neill and Kieley, 1992). Human sources include oil spills and atmospheric deposition from

the combustion by-products of fossil fuels, primarily generated by automobiles. Human activity caused

an abrupt and measurable increase of PAHs in sediments at the beginning of the Industrial Revolution

(Kennish, 1992).

PAH compounds are readily adsorbed by particulate matter contaminating water, air, and land through

many means. Once in a river or estuarine water body, these particles with adsorbed hydrocarbons

accumulate in sediments near sources of entry. Harbors are especially noted to have high levels (Clarke

{ed}, 1998). PAHs are slow to degrade making sediments an environmental sink for these chemicals.

Shellfish have minimal capacity to metabolize hydrocarbons, and accumulate hydrocarbons at a higher

concentration than finfish that inhabit the same environment (Clarke {ed}, 1998). However, bottom

feeders such as flatfish have been

found to suffer from liver damage, tumors, and reproductive complications where PAHs are present

(Ernst, 1996). Although PAHs do not significantly biomagnify, some PAHs are among the most

carcinogenic, mutagenic and toxic compounds found in estuaries (Kennish, 1992).

Interestingly, PAH levels on average did not vary in the way one might expect, given the differences in

human activity at the sampling sites. It is reasonable to believe that the highest concentrations of PAH

would be found at the Bayside Port, and the lowest in Oak Bay. Upon cursory inspection of the data

(Table 3), it is obvious this hypothesis does not hold true in this case. In the case of Acenaphthene, for

example, the predicted outcome appears true: Acenaphthene is present at the Port, but not at the Yacht

Club or Oak Bay site. In the case of Chrysene/Triphenylene this is also true. However, in the case of

Anthracene, the opposite appears to be the case.

Table 3: Result of PAH Analysis*

Sample Locations

PAH Substance Bayside Marine Terminal Oak Bay St. Croix Yacht Club

BP 1P BP 2P BP 3P OB 1P OB 2P YC 1P YC 2P

Naphthalene 0.02 0.01 0.01 0.01 0.01 0.01 0.02

Acenaphthylene 0.01 n.d.. n.d.. n.d.. n.d.. n.d.. 0.01

Acenaphthene 0.01 0.01 n.d.. n.d.. n.d.. n.d. n.d.

Fluorene 0.02 0.01 0.01 0.01 0.01 0.01 0.01

Phenanthrene 0.09 0.06 0.08 0.07 0.07 0.09 0.08

Anthracene 0.04 0.03 0.03 0.07 0.02 0.03 0.03

Fluoranthene 0.21 0.17 0.18 0.1 0.16 0.21 0.2

Pyrene 0.17 0.13 0.14 0.1 0.14 0.18 0.16

Bz (a) anthracene 0.07 0.07 0.07 0.08 0.07 0.07 0.07

Chrysene/Triphenylene 0.13 0.1 0.11 0.08 0.1 0.11 0.11

Bz(b+k)fluoranthene 0.14 0.15 0.14 0.08 0.15 0.16 0.14

Bz(e)pyrene 0.06 0.06 0.05 0.03 0.06 0.07 0.06

Bz(a)pyrene 0.07 0.08 0.09 0.04 0.08 0.11 0.08

Indenopyrene 0.04 0.04 0.04 0.02 0.04 0.04 0.04

Bz(ghi)perylene 0.05 0.05 0.05 0.03 0.05 0.05 0.05

Debz(ah)anthracene 0.01 0.01 0.01 n.d.. 0.01 0.01 0.01

Average*Results expressed in ppm (ug/g) on a dry weight basis

Creosoted structures, like wharf pilings, have been linked to PAH presence in shellfish and sediments

(Eaton and Zitko, 1978) {Cited in O’Neill and Kieley, 1992}. Concentrations found in shellfish were

found to decrease with increased distance from a creosote treated structure, but this pattern was not as

clear in the case of sediments.

As stated in the description of the Bayside Port facility, the wooden pilings present contain PAHs in the

form of creosote wood preservative, and have been in situ for many years. It is possible that, even

though human activity is far greater at Bayside Port than at the St. Croix Yacht Club or Oak Bay, little of

the activity taking place at the port results in or includes the input of PAHs into the water way (and,

subsequently, estuarine sediments). If the PAH chemicals in the wooden piling have been leached out

and denatured over many years of tidal activity and heavy current, this could explain the lack of

distinction between the sample sites.

3.2 Tributyltin

During the 1950s and 1960s, Tributyltin compounds were used as a mollusicide to control species of

fresh water snails in Africa which were vectors of Schistosomiasis disease (Fairman, 1997). The

attractive pesticide characteristics of Tributyltin led to its use as an additive of anti-fouling paints for

boats in 1961. The slow release of TBT into the water surrounding the hull of a boat inhibits molluscs

from attaching themselves (PMEP, 1998) and results in reduced drag, thereby significantly increasing

speed and energy performance of a vessel (Hennigar and Garron, 1992).

Like PAHs, TBT is very insoluble in water and binds readily to suspended organic or inorganic

sediments. This results in TBT being localized near the source of its release. Vessels, storms and

dredging can stir up the sediments and re-release TBT compounds to the water column (Fairman, 1997).

In the 1980s, negative side effects of the use of TBT emerged with discoveries of growth abnormalities

in shell fish. Among other complications, it was discovered that male sex organs were forming on

female gastropods (dogwhelks, periwinkles, etc.); a disorder referred to as imposex (Prouse, 1997). This

phenomenon was directly related to the snails living in close proximity to yachting marinas and harbours

(ibid.).

These and other findings pressured countries to restrict usage of TBT paints. A ban in Canada, the US,

the United Kingdom and France has been placed on the use of TBT as an antifoulant on boats less than

25 m in length. The logic behind the cut off length of 25m was that larger commercial vessel spend a

much larger proportion of time out at sea and, when berthed, were in deeper water ports away from

potentially impacted areas (Hennigar and Garron, 1992). This did not account for hull maintenance at

harbours where paint is often striped off by use of abrasives (sandblasting). Antifouling paint

regulations seem to have less impact in areas where many vessels greater than 25m may congregate, and

significant hull maintenance/refinishing operations undertaken.

Only samples collected at the Bayside Marine Terminal were of levels detectable to analysis equipment

(Table 4). TBT at the port had an analysed mean value of 54 ppb (ng/g). These findings hold true to the

prediction that TBT, being banned for use on vessels of less than 25m long, would not be present in

great concentration in any location other than those where large ocean going ships are berthed.

Table 4: Result of Butyl Tins Analyses. Site Location Sample

NumberMonobutyl

Tin(ppb)

Dibutyl Tin(ppb)

Tributyl Tin(ppb)

Bayside MarineTerminal

BP1T n.d. n.d. 58

BP2T n.d. n.d. 50

Oak Bay OB1T n.d. n.d. n.d.

OB2T n.d. n.d. n.d.

St. CroixYacht Club

YC1T n.d. n.d. n.d.

YC2T n.d. n.d. n.d.

Limit of Detection (ppb) 5 5 5Note: LOD is a level below which readings by an analytical instrument can be due to error.

The measured levels of TBT are far below that which would be considered acute and chronically toxic to

most marine organisms. Cardwell & Meador (1989) {cited in Hennigar and Garron, 1992} determined

threshold levels to be acutely toxic at 1.593 ug/g (1593 ng/g) and

chronically toxic at 0.141 ug/g (141 ng/g). Breakdown products eventually result in the formation of Tin

ions, and all breakdown products are less toxic than TBT itself. Under aerobic conditions, TBT takes

one to three months to degrade. Under Anaerobic conditions, this process can take more than two years.

4.0 CONCLUSIONS

As discussed previously, it does not seem at this time that PAH and TBT levels in sediment should be of

significant concern to those living on and around the St. Croix Estuary. All tested levels for these toxins

were far below determined toxicity levels as found in existing literature.

4.1 PAHs

Even though resulting concentrations of PAH did not reflect expected changes in levels among sites

(given variation in human activity), levels were consistently low. These results may be viewed as such:

There appears to be a lack of PAH input at Bayside Port, so little that the test results from this location

do not differ significantly from that of Oak Bay where human activities are widely dispersed.

It can be concluded that there is some input of PAHs into the estuary, but Bayside Port cannot be

attributed as being a point of acute input. It is likely that PAH inputs into the estuary come from a great

many, less identifiable sources, or from another as yet unidentified large source. There are current

attempts to develop a Marine Environmental Quality Guideline in Canada (O’Neill and Kieley, 1992). It

stands for now that all PAH criteria tested were below the tentative threshold criteria for PAHS in

sediments (MacDonald et al, 1992).

It may be suggested that, though levels of PAH as tested were quite low, the number of samples taken

was also quite small (n=7) and may not accurately reflect the concentrations of PAHs in the entire

estuary. It is recommended that, when considering PAHs and human health, people use good rational

judgement when utilizing local resources. When collecting low mobility species for consumption

(things like clams and periwinkles), it is suggested to conduct these practices a reasonable distance away

(~100m) from obvious sources of PAH input (eg: wharf pilings, storm drains). The likelihood, when

acquiring pelagic (ocean going) species such as mackerel, of catching a specimen of acute PAH toxicity

is quite low.

4.2 TBT

The analysis of TBT indicates that this chemical is not of great concern in the St. Croix Estuary either.

Other means of investigation such as the testing and examination of marine indicator species (such as

Dogwhelks), would form a definitive response regarding the bioacummulative effects of TBT.

The bioavailability of TBT in sediment, measured as No Observable Effect Concentration (NOEC), is

considered to be 1000x lower than in the surrounding water (Cardwell and Meador, 1989). This is

interesting given that Grovhoug et al (1989) {cited in Hennigar and Garron, 1992} have determined that

TBT occurring in sediment is on average at a concentration which is 1000x that which is found in the

water column. As concentrations of TBT at Bayside Port were in the same order of magnitude as the

LOD, it would seem unlikely that TBT would be of a detectable level if shellfish meat sampling were to

occur. TBT bonds readily with other organic and non-organic particulate matter and, bound with these

other particles, becomes less toxic (but more persistent) in sediments (Hennigar and Garron, 1992).

The World Health Organization determined that an exposure to TBT of 3.2 ug/Kg is a maximum,

provisional acceptable daily intake (PADI) level for humans (Heard, Walker and Hawkins, 1989).

Granted, the levels determined in this study were taken from sediment and not food stuffs. However,

levels are such that, given the opportunity to bioaccumulate, the detected levels of TBT would still not

represent a significant risk to human health (Zitko, 1998 pers. comm.).

Once again, the small sample size of this study should be pointed out. It is possible that the seven

samples collected do not give a fair and accurate representation of TBT concentrations in the whole

estuary. It is, however, more likely the case of TBT in the estuary compared to the situation with PAHs.

As TBT is a banned substance, the Bayside Port should be the only area where TBT has the opportunity

to accumulate. For this reason alone, it is suggested that human activity, particularly food gathering and

angling, be conducted at a rational and reasonable distance away from hull overhaul activities.

5.0 LITERATURE CITED

Cardwell, R.D., and J.P. Meador (1989). Tributyltin in the Environment: An Overview and KeyIssues. In: Proceedings, Oceans 89 Symposium, Seattle, WA. 18-21 Sept., 1989.Marine Technology Society. 2: 537-544. Cited in Hennigar &Garron (1992).

Clarke J. D. {ed.} (1998). Impacts of Contaminants on the Resources of the Gulf of Maine.Executive Summary for the Global Programme of Action Coalition for the Gulf of Mainethrough the Commission for Environmental Cooperation. Horsley & Witten, Inc.

Eaton, P., and Zitko, V. (1978). Polycyclic Aromatic Hydrocarbons in Marine Sediments andShellfish Near Creosoted Wharf Structures in Eastern Canada. International Council forthe Exploration of the Sea. C.M. 1978/E:25. Cited in O’Neill and Keiley, 1992.

Environment Canada {anonymous} (1995). Enviro Facts: Toxic Chemicals in Atlantic Canada- Polynuclear Aromatic Hydrocarbons (PAHs). Environment Canadahttp://www.ns.ec.gc.ca/epb/envfacts/pah.html

Environment Canada {anonymous} (No Date). Pamphlet: Tributyltin (TBT) Facts. Publishedby EC Environmental Protection Branch, Dartmouth, NS, (902) 426-6141.

Ernst, B. (1996). The Effects Monitor. Environmental Effects Monitoring Newsletter for theAtlantic Region. Vol. 3, No. 1.

Fairman, R., Mead, C. D. & W. P. Williams (1997). Environmental Risk Assessment -Approaches, experiences and information sources. Summary. EEA publication

http://www.eea.dk/Projects/EnvMaST/RiskAss/Chap6EX1H.HTML

Hennigar, A. P. and C. A. Garron (1992). Tributyltin (TBT) Levels in Marine Sediments in theAtlantic Region. Environment Canada Surveillance Report EPS-5-AR-92-3.

Kennish, M. J. (1992). Ecology of Estuaries: Anthropogenic Effects. CRC Press, Boca Raton,FL, 494 p.

O’Neill, H. J. and K. M. Keiley (1992). Polynuclear Aromatic Hydrocarbons: Atlantic RegionData Summary and Review. Conservation and Protection Atlantic Region TechnicalReport Series, No. 92-01.

MacDonald, D.D., Smith, S.L., Wong, M.P. and P. Murdroch (1992). The Development ofCanadian Marine Environmental Quality Guidelines. Ecosystem Sciences andEvaluation Directorate. Eco-Health Branch, Ottawa, ON. Minister of Supplies andServices, Canada.

Maguire, R. J., Chau, Y.K., and J. A. J. Thompson (1996). Summary of Proceedings. TheWorkshop on Organotin Compounds in the Canadian Aquatic Environment. NationalWater Research Institute. Http://www.cciw.ca/nwri-e/publications/reports/organotin/part3.htm

Pesticide Management Education Program (PMEP) (1998). Pesticide Information ProfileTributyltin. Extoxnet Extension Toxicology Network.Http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ext.html

Prouse, N. (1997). Survey of Eastern Canada for Imposex, a Bioindicator of Tributyltin (TBT)Contamination, in the Dogwhelk Nucella Lapillus. Abstract. National Water ResearchInstitute. Http://www.cciw.ca/nwri-e/publications/reports/organotin/prousen.htm

ABOUT THE ST. CROIX ESTUARY PROJECT

The St. Croix Estuary Project (SCEP) is a not-for-profit and non-government organization dedicated to promoting the wise management of the St. Croix Estuary Area and its resources. Founded in 1992, SCEP is fostering a community-based response to primarily local environmental challenges, towards maintaining or restoring ecosystem health and, therefore, community sustainability.

An 18-member Board of Directors, consisting of citizens elected from SCEP’s membership, provides general guidance. Staff and volunteers carry out program work in four main areas: comprehensive environmental planning; environmental monitoring; land use, water use and resource mapping; and awareness and education projects. Accomplishments since 1992 include the following:

✔ Formulated a Vision for the Future for the coastal waters and lands of the Estuary Area (1994).✔ Implemented a field program involving water testing at local wastewater treatment plants, stream and estuarine sites, sediment sites in the upper St. Croix Estuary, clam flats in Oak Bay, and measuring water movement as a way to track wastewater effluent. An extensive water quality database has been developed as a result of this work, and results have been published in five reports (1993-1995).✔ Wrote a report on the potential use of economic instruments to address on-site systems management in the Estuary Area (1994).✔ Published a poster entitled Beauty Shared — The St. Croix Estuary, which has been widely circulated and very well received in the community (1994).✔ Completed a residential, industrial, commercial and institutional water audit in St. Stephen to identify opportunities for water conservation (1995).✔ Produced a 73-map coastal resources atlas for Charlotte County, New Brunswick and a portion of Washington County, Maine, as well as digital map files. This was a major joint project involving two other non-government organizations and Fisheries & Oceans Canada (1994-1996).✔ Provided physical, biological, historical and socio-economic information in St. Croix Estuary Area: A Profile (1997).✔ Completed Caring for Our Coast: A Plan for Community Management of the St. Croix Estuary Area; this document contains 50 recommendations to address approximately 30 environment-development issues (1997). Since publication, work has been started on 35 of the 50 recommendations in this plan, primarily on the instigation of SCEP.

In March 1996, SCEP was given a Visionary Award by the Gulf of Maine Council on the Marine Environment.

In April 1998, SCEP was entered in the St. Croix Heritage Honour Roll for developing an environmental management plan for the St. Croix Estuary, by the SC International Waterway Commission.