Monitoring of Aquatic Ecosystem Indicators
What are the effects of industries, highways, urban development, forestry and agricultural land uses on Ontario’s aquatic ecosystems? How are these ecosystems changing in response to these pressures, and what are the long-term implications for safeguarding their quality and integrity? In our 1999/2000 annual report, the ECO noted that provincial ministries are operating without accurate or current evaluations of ecosystem health. We recommended then that the Ministries of the Environment and Natural Resources both develop “current and comprehensive information that would allow for the development of scientifically defensible rationales for habitat protection activities and the identification of emerging ecosystem problems.”
The ECO returned to this theme in our 2001/2002 annual report when we reported that substantial reductions had been made to the monitoring of provincial surface water quality. We reported that between 1995 and 2000, the number of monitoring network stations was reduced from 730 to 240. This trend has now been reversed, and in spring 2004, MOE advised the ECO that the number of stations has grown to approximately 380 stations. The purpose of this network is to compile long-term data on water quality, consisting of information on some 39 parameters, mainly nutrients, metals and ions such as chloride. Selected stations are sampling for priority organic pollutants such as PCBs, while others are sampled more frequently to provide information to the International Joint Commission about sediment and nutrient quantities exported from watersheds to the Great Lakes.
The assessment of water chemistry alone, however, leaves much out of the equation. In 2003/2004, MOE, Environment Canada and the Conservation Authorities initiated a program called the Ontario Benthos Biomonitoring Network, which will ultimately have the capability of providing a more holistic picture of the health of the aquatic systems throughout parts of the province. The monitoring program staff will gather data and conduct statistical analyses of numbers of various taxonomic groups of benthic (bottom-dwelling) invertebrates such as aquatic insects, crustaceans, worms, and mollusks. Based on the observation that some of these groups are more sensitive to pollutants than others, a careful population analysis can provide a good assessment of the health of the system at the selected location and time. There are numerous metrics and indices of stream health that can be derived from the data, and therefore part of the initial challenge will be the development of a standardized approach.
Currently, MOE and its partners have selected and sampled some 200 benthos “reference sites,” which are largely natural or non-impacted stream locations. MOE plans to proceed with monitoring of test sites in spring 2005 and 2006. Once this biomonitoring network is fully established, data from test sites will complement the water quality monitoring network, overlapping some existing sampling sites and introducing new ones.
Examining contaminants in fish is another way of gauging the health of aquatic ecosystems. MOE and MNR have long operated the Sportfish Contaminant Monitoring Program, publishing the Guide to Eating Ontario Sport Fish every two years. The data on PCBs, pesticides, metals, mercury, dioxins and furans in sport fish flesh from the province’s waterways and lakes are used to provide consumption advisories. The data have been useful in showing trends – for example, a long-term improvement in levels of toxaphene, mercury and PCBs in Lake Superior lake trout.
In the wake of the Walkerton tragedy, the provincial government has increased funding to ensure that drinking water quality is adequately monitored and regulated. In 2003, the protection of the primary sources of drinking water became a major thrust of program development. Early initiatives include the installation of a substantial groundwater monitoring program under the Provincial Groundwater Monitoring Network, consisting of some 400 sites established by MOE in cooperation with Conservation Authorities. But provincial ministries need to ensure that these initiatives do not starve other monitoring programs covering a variety of aquatic ecosystem components around the province.
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Aquatic ecosystems of the north
Some of our most valuable and pristine aquatic ecosystems are found in lakes and waterways in the northern parts of the province. Transboundary pollution, including atmospheric deposition originating in other continents, has had measurable effects, particularly noticeable on the aquatic ecosystems of sensitive northern lakes. For example, 96 per cent of all walleye lakes and 76 per cent of all lake trout lakes in the north have some recommended level of restriction of fish consumption because of mercury contamination (see also Ecosystem Impacts of Mercury). As well, climate change has implications for the sustainable management of lake trout populations because of the potentially significant reductions in the amount of suitable cold-water, high-oxygen habitat needed by this sensitive species.
The construction of logging roads and timber harvesting have the potential for major impacts on aquatic ecosystems. For example, logging road development opens up access to sensitive lake trout lakes and exposes them to possible overexploitation. The ECO is aware of one small lake where lake trout were fished out in a short period of time following road development. In this particular case, ongoing experimental monitoring was able to document this over-fishing, but in tens of thousands of other northern lakes and rivers, no monitoring is done. Over vast areas of the province, there is nothing in place to detect such impacts. (See also Roadless Wilderness Areas.)
Under one of the terms of the 1994 Timber Management Class EA, MNR was required to carry out long-term scientific studies to assess the effectiveness of provincial guidelines for the protection of fish habitat. Studies were done in the Coldwater Lakes Experimental Watersheds near Atikokan, and coldwater streams near Thunder Bay. Included in the many findings from these studies was the observation that the timber management guidelines for the protection of fish habitat protection were insufficient for protecting small, unmapped streams. However, recommendations arising from the studies also included a suggestion that the buffer widths specified in the guidelines could be relaxed to allow limited timber harvesting right to the shoreline of some lakes. MNR is currently revising the Timber Management Guidelines for the Protection of Fish Habitat, based on these findings.
In 2003, the Timber Management Class EA was replaced by a Forest Management Declaration Order (see also Forestry Operations Compliance System) and the former Class EA’s detailed requirements for long-term impact assessment studies were replaced with the rather weak requirement to “maintain a program of scientific studies to assess the effectiveness of the guides.” The ECO believes that changes to forest management policy – such as changes to the fish habitat protection guidelines – need to be made cautiously, and that strategically planned long-term ecosystem monitoring programs should be in place to assess subtle or gradual changes to the aquatic resources of the northern forests.
Cottage country
Throughout “cottage country” there is a growing need to monitor lake ecosystems. One long-standing program is MOE’s Lake Partners Program, involving individuals and cottage owners associations in the sampling of about 500 inland lakes. The focus of data gathering and analysis is on water clarity and phosphorus. Phosphorus overloading to lakes is still a serious issue and community involvement can help with its control. However, introductions of invasive alien and native species are looming ever larger as a concern demanding attention in recreational lake areas. (See also Invasive Alien Species – A Threat to Biodiversity.) Expanding public involvement and awareness of ecological threats, possibly by further introducing aquatic ecology components into programs such as the Lake Partners Program, might be one useful approach. MNR should also consider supporting more aquatic community assessments and surveys, particularly in areas where these invasions are most active.
Lake trout
In our 2001/2002 annual report, the ECO called attention to the sensitivity of the lake trout. We pointed out the need for a province-wide strategy to support the sustainable management of this exceptional sport fish. The first challenge is to characterize and classify lakes that should be afforded protection as lake trout lakes. This is particularly the case in southeastern Ontario. Ongoing knowledge of the population sizes and reproductive success of naturally reproducing populations of lake trout is needed on a broader scale than currently exists. Currently, long-term data are available from only 31 out of 2,200 lake trout lakes in the province.
In spring 2003 and 2004, MNR advised the ECO that a pilot State of the Resource monitoring program had been successfully completed and that it is evolving into a proposal for a province-wide monitoring program. MNR had stated that a discussion paper outlining options for such a program would be available by August 2003, but the ECO has not seen this as of May 2004.
Summary
Climate change, invasive alien species, development, resource extraction and other human activities are causing serious stress in many aquatic ecosystems. The provincial agencies responsible need to ensure that both targeted studies and long-term monitoring strategies are in place to monitor the impacts of these threats to the province’s vast but highly vulnerable aquatic resources.
| This is an article from the 2003/04 Annual Report to the Legislature from the Environmental Commissioner of Ontario. |
Citing This Article
Environmental Commissioner of Ontario. 2004. "Monitoring of Aquatic Ecosystem Indicators." Choosing our Legacy, ECO Annual Report, 2003-04. Toronto, ON : Environmental Commissioner of Ontario. 64-68.
