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Rendez-vous St. Lawrence 2006
An encouraging interim assessment
The St. Lawrence River continues to show signs of recovery. Following on an initial report card indicating in 2003 that the river was healthier then than it had been during the second half of the 20th century, more recent results point to further improvement on several fronts. There have been some setbacks, however, and an important caveat is in order in light of the emergence of novel contaminants about which little is known at present.
That
summarizes the findings of the Rendez-vous St. Lawrence 2006, a
forum held under the auspices of the State of the St. Lawrence Monitoring
Program last summer in Nicolet. At this second Rendez-vous, attended
by some 200 experts and stakeholders from a variety of backgrounds,
the latest results were provided for 9 of the 21 environmental indicators
established to evaluate the general health of the St. Lawrence River.
This information has been used to update the corresponding fact
sheets, published in 2003. The Rendez-vous event also provided the
opportunity to explore avenues for enhancing the monitoring program
by addressing the most topical environmental issues and increasing
community involvement.
Relatively clean water
Water quality in the river has improved overall since the 1970s, although some parameters have shown a negative trend.
From a bacteriological standpoint, 160 sampling sessions carried out at 16 potential swimming sites between Montreal and Ile d’Orléans in 2005 revealed that fecal coliform (E.coli) counts were below the exceedance criteria at 56% of the sites, compared with only 25% in 2003.
“While this indicates an improvement in bacteriological quality,
the difference between the 2005 results and the earlier results
is attributable primarily to meteorological conditions, since in
2005 more of the sampling was carried out during dry weather. This
does not necessarily mean that sewer overflows associated with heavy
rainfall (one of the main bacterial contamination problems) are
controlled more effectively,” said Linda Tapin, co-chair of
Rendez-vous St. Lawrence 2006 and representative of the Quebec Department
of Sustainable Development, Environment and Parks.
Ms. Tapin said that if municipalities undertake to build retention
basins, as the City of Quebec did two years ago, the situation should
improve even more. According to Isabelle Saulnier, who heads up
the State of the St. Lawrence Monitoring Program at Environment
Canada, the real improvement will come when wastewater treatment
plants, particularly those in Montreal, Longueuil and Repentigny,
start to disinfect their wastewater. They do not do this at present
because of a lack of suitable technical resources. Bacterial contamination
caused by discharges from treatment plants and by sewer overflows
during heavy downpours can be detected as far away as Bécancour.
Farther downstream in the St. Lawrence, specifically in the estuary and Gulf, bacteriological tests are performed to assess water quality for shellfish harvesting rather than swimming. Sixteen new shellfish areas have been added to the 238 areas already included in the testing program in 2003. Although the percentage of sites that are closed to harvesting because of persistent bacterial contamination problems (51%) has not changed, two harvesting areas have been reopened, one in the Magdalen Islands and one on the North Shore, and two areas in the Gaspé may be reopened in the near future.
Turbidity and phosphorus on the rise
The 2004–2005 results for the other physico-chemical parameters assessed in the river corridor show that water quality is good between the Beauharnois canal and the outlet of Lake Saint-Louis, but that degradation has occurred farther downstream. Of the eight parameters studied, turbidity and phosphorus (both of which increased over the 2000 and 2001 levels, especially downstream from Lake Saint-Pierre) are the ones that have the greatest negative influence on the overall physico-chemical picture. The increased turbidity, which frequently coincides with a rise in phosphorus concentrations, may be linked to riverbank erosion and to the increase in river flows and levels that has been observed since 2000.
Levels of toxic substances (PAHs, pesticides, metals, etc.), which are now sampled at the outlet of Lake Ontario and at the mouth of the Ottawa River, as well as at the Quebec City station, still fall within the applicable standards. Mercury is the only toxic substance for which an increase has been recorded. Airborne pollution is likely to blame, given that this volatile metal can be transported over long distances in the atmosphere.
The waters of the St. Lawrence exhibit much lower levels of contamination by toxic substances than most of the major European and North American rivers. This is one of the findings highlighted by the specialists at the forum. Even St. Lawrence River sediments, which are more adversely affected than the water itself, show an appreciable improvement. Some areas where sediment accumulation is more pronounced and ongoing, such as the islands in Lake Saint-Pierre, remain vulnerable.
New substances that are of concern
What researchers are now looking into are the novel substances that are being used by a wide range of industrial plants, particularly pharmaceutical manufacturers. Isabelle Saulnier cautioned that “These emerging contaminants definitely deserve our attention since they could create problems for the river’s biodiversity.”
Perfumes, hormones, antibiotics, Teflon chemicals and other such substances that end up in effluent discharges to the St. Lawrence may have benign effects individually, over the short term. Over the longer term, however, the substances could have an enormous impact as a result of synergistic effects and bioaccumulation in the food chain. Although research on this topic began only a few decades ago, it has been shown that some of these substances are endocrine disruptors and have induced a sex change in molluscs.
In view of the significance of this issue, the State of the St. Lawrence Monitoring Program has initiated studies on certain classes of substances (nonylphenol ethoxylates–NPEs, and polybrominated diphenyl ethers–PBDEs), which will come under greater scrutiny over the next few years. Linda Tapin said that PBDEs might soon join the ranks of the substances already evaluated under the program, since an analytical method was developed for them in 2005.
Wetland losses in check
The latest map survey conducted under the Monitoring Program confirmed that wetland losses along the St. Lawrence have been contained over the past decade. From the standpoint of surface area, the overall picture is no longer negative. While new losses have been posted for some sections of the river, such as the Montreal–Longueuil stretch and Lake Saint-Pierre, substantial gains have been recorded for other sections, especially those in the estuary.
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Common reed |
Wetland area does not tell the whole story, however. According to Isabelle Saulnier, the composition of these dynamic environments is another aspect that needs to be monitored, because their structure can change. For example, most of the stretches of river studied have exhibited changes in their dominant wetland species. Two highly invasive exotic plant species that have a major impact on plant diversity—reed canary-grass and common reed—have continued to gain ground. Although these plants do not grow in many areas, wherever they do become established, they quickly become dominant.
Total wetland area and invasive plants are important indicators of the health of the St. Lawrence. It is believed that a more realistic picture could be obtained if the ecological structure of wetlands were also taken into consideration (marsh, swamp, aquatic grass beds, etc.), given the major influence that wetland structure has on the functioning of these ecosystems. “There are some elements that we still need to define over the coming years in order to refine the indicators,” said Ms. Saulnier.
Fish and bird species: highs and lows
Invasive exotic species are not confined to the plant world. Among fish species, the appearance of the round goby in the 2006 surveys sounded alarm bells for biologists. Accidentally introduced to the Great Lakes in the early 1990s, this bottom fish species, which is native to Europe, could pose a threat to indigenous aquatic fauna. However, as with many other exotic species, the potential effects, both negative and positive, are not fully known. The Chinese mitten crab is another worrisome invader; some of these Asian crustaceans were caught recently in Lake Saint-Pierre, in the Quebec City area and in the estuary.
Since 2003, Monitoring Program teams have not observed a decrease in the number of fish species in the St. Lawrence. It is nonetheless difficult to ascertain whether the total biomass (population density) has declined or not. Linda Tapin said that the experts with the Quebec Department of Natural Resources and Wildlife who handle this part of the Monitoring Program in the estuary are currently refining their methodology and will be able to submit more comprehensive analyses this year.
With respect to avifauna, the Bonaventure Island population of Northern Gannets—a sentinel species for the Gulf—is still doing well and has shown continued growth. However, the situation varies for the other marine birds that are being monitored: the Caspian Tern made a timid comeback after the 2003 surveys failed to find any of these birds; the Razorbill posted a rapid increase in numbers, the Atlantic Puffin a slight decrease, and the Common Murre (whose population was considered stable in 2003) a drop of 50%!
New indicators and community involvement
Rendez-vous 2006 provided the opportunity for Monitoring Program partners to discuss the new indicators that need to be developed in order to provide a more complete picture of the health of the St. Lawrence.
In addition to improving the wetlands indicator and providing coverage for emerging contaminants, as discussed earlier, the Monitoring Program teams have set out to establish four new indicators. Two of them will deal with shorelines (monitoring of erosion in the river proper and land use changes). A third indicator will be used to monitor benthic invertebrates, with the first phase of this effort already initiated in Lake Saint-Pierre and the last phase aimed at evaluating uses of the St. Lawrence. Results obtained from these four new indicators will be presented in 2008.
A pilot project targeting recreational uses of Lake Saint-Pierre has been implemented in conjunction with the development of an indicator for assessing uses of the St. Lawrence. The project leaders are working with various recreational groups in the area to collect information. For the bank erosion monitoring effort, an NGO and a ZIP committee have already loaned observers to the project, as was done for the invasive plant survey in Lake Saint-Pierre.
At present, six environmental organizations are participating in various projects with the main partners of the Monitoring Program. The current program thrust is to get as many riverside communities involved as possible given the benefits they derive from their proximity to the St. Lawrence.
One possibility that is being explored is the establishment of an ecowatch network that would track invasive aquatic species in as broad an area as possible. Another goal is to set up a network of volunteers to assist in recording the presence of benthic invertebrates in shoreline areas. Isabelle Saulnier said: “We do not have a specific objective for increasing community participation, but it is clear that the success of our Monitoring Program depends in part on public involvement.”
The next Rendez-vous St. Lawrence, in 2009, will provide an indication of whether the efforts to increase community participation have borne fruit. The main objective of that meeting will nonetheless be to provide an updated picture of the health of the St. Lawrence encompassing all of the indicators.
State of the St. Lawrence Monitoring Program |
The State of the St. Lawrence Monitoring Program is one of the initiatives implemented under the St. Lawrence Action Plan to track and report on the health of key ecosystem components at regular intervals: water, riverbed, banks, biological resources and uses. The Monitoring Program partners are Environment Canada, the Quebec Department of Sustainable Development, Environment and Parks, Fisheries and Oceans Canada, the Quebec Department of Natural Resources and Wildlife, the Canadian Space Agency and the Parks Canada Agency. Stratégies Saint-Laurent, a non-governmental organization, is also involved in the program. |
For information:
Mme Isabelle Saulnier
Monitoring the State of the St. Lawrence Committee
Quebec Water Quality Monitoring and Surveillance Section
Environment Canada
Mme Hélène Bouchard
Monitoring the State of the St. Lawrence Committee
Quebec Water Quality Monitoring and Surveillance Section
Environment Canada
Mme Linda Tapin
Monitoring the State of the St. Lawrence Committee
Direction du Suivi de l’état de l’environnement
Ministère du Développement durable, de l’Environnement
et des Parcs
Date modified: 2008/05/01 – Important Notices
