Eurasian tench, an invasive species found in Canada and the United States, has been rapidly expanding its range into the St. Lawrence River in recent years. Its upstream spread has reached as far west as Lake St. Francis in southeast Ontario Great Lakes researchers, scientists, and resource managers are concerned the tench could wreak havoc on native fish and their habitat if it enters the Great Lakes.
Tench are native to Europe and western Asia, and were introduced to North America by the U.S. Fish Commission in 1877 for use as a food and sport fish, according to the US Geological Survey. That effort continued into the 20th century, but in most areas where the fish was introduced, it did not become established. However, a population introduced illegally to the Richelieu River by an unlicensed fish farm in 1986 has spread rapidly to the St. Lawrence River and Lake Champlain, according to McGill University Ph.D student Sunci Avlijas, who has studied the tench.
Ever since the fish were first detected in the St. Lawrence River in 2006, Avlijas said, a monitoring program run by the Quebec government and commercial fishermen has been in place. The population has grown exponentially every year between 2009 and 2014. They’ve also spread downstream on the St. Lawrence toward Quebec City and upstream toward Lake Ontario.
“We’re concerned about it moving toward the Great Lakes since the tench prefers slow-moving waters in wetland areas, and there are many such habitats in the Great Lakes,” said Avlijas, whose findings were presented at the International Association for Great Lakes Research conference in June 2017. “(Once) tench enter the Great Lakes there’s the Bay of Quinte, which is even better habitat than we find in the St. Lawrence.”
Once established in an ideal environment, tench form dense populations. Avlijas said tench will eat a variety of macroinvertebrates – zooplankton, mollusks and mussels, insects, and crayfish – mainly from the water bottom, but in calm waters they’ll even go to the surface for food. They also tend to kick up mud and sediment, reducing water quality. Aside from direct competition with native fish for food, tench also carry non-native parasites that aren’t known to be present in the Great Lakes, Avljias said, making them potential disease carriers for native fish. Tench also are known for eating zooplankton that can keep algae in check, potentially worsening the amount and size of harmful algal blooms.
What’s more, they can survive in low-oxygen environments, and cover themselves in mud to survive outside of water for a limited period, allowing them to be introduced into new water bodies, Avlijas said. There have been documented cases of tench being mailed in wet sacks and arriving alive a day later.
“They’re a prime candidate for being transported by people,” she said.
While tench are eaten by native fish like walleye, northern pike, smallmouth bass, largemouth bass and bowfin, once they grow longer than about 12 inches (30 centimeters), they become too large for most predators to consume. Avlijas said this has happened in Lake St. Pierre, where the fish are abundant.
The extent to which tench could impact the Great Lakes is still debated, but it’s predicted they could become established here, said Jeff Brinsmead, senior invasive species biologist with the Ontario Ministry of Natural Resources and Forestry.
While most Great Lakes states don’t ban tench, Wisconsin has a prohibition on the species dating back to when its own invasive species rule went into effect in 2009. Under the rule, the transportation, possession, transfer and introduction of Eurasian tench is illegal in the state. According to Joanne Haas, a Wisconsin Department of Natural Resources public information officer, tench had been stocked in some lakes in the past, and has been known to exist in surrounding states like Ohio, Indiana, Illinois and Michigan – albeit with few reproducing populations. Wisconsin is still concerned about reproductive potential, however, and sees tench as a potential competitor to minnows and native sportfish.
While tench are not regulated as an invasive species in Ontario, rules that apply to all fish species in the province also apply to the tench: a fish can only be released into the water body it was found in unless the releasing person or organization has a license. The use of tench as a baitfish is also illegal in the province, and residents are asked to alert the Ministry of Natural Resources and Forestry if tench are found in the wild by calling the Invading Species Hotline at 1-800-563-7711, or going online to www.EDDMapS/Ontario. Illegal activities involving tench can be reported to the ministry’s enforcement branch at 877-TIPS-MNR (877-847-7667). More information can be found on Ontario’s Invading Species Awareness Program website.
Once an invasive species becomes established in a new environment, it is very difficult, if not impossible, to eradicate. However, it may be possible to slow or block the spread of the species. Education and outreach are critical to ensure that people are aware of the rules that apply to moving live fish. Brinsmead said that since tench are related to Asian carp, it’s possible that similar techniques could be effective in containing the spread of tench, like electric barriers. However, testing specific to tench hasn’t been done yet, and Brinsmead noted that other species – like the endangered American eel – travel through the St. Lawrence River too, so any measures to block tench would need to keep the passage of these species in mind.
Avlijas suggested that to limit the spread, people throughout the lakes follow provincial and state regulations.
“People just consider it non-invasive because after its (legal) introduction it was not spreading,” she said. “It was ignored for a long time.”
Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.
By Dr. Michael Izard-Carroll, US Army Corps of Engineers
The US Army Corps of Engineers, Buffalo District, has been active in response efforts to assist New York State communities along Lake Ontario during ongoing historic high water levels. Since Gov. Cuomo’s request for assistance on May 9, 2017, Corps efforts have included direct and technical assistance as part of Public Law 84-99 Response Operations.
Direct assistance has included the distribution of government-furnished materials in the form of 180,000 sandbags, while technical assistance has included Corps personnel deploying to affected areas identified by the New York State Office of Emergency Management.
A total of 20 field visits to 17 affected areas in all eight impacted counties were conducted between May 12 and May 26. The Corps of Engineers Regulatory team also has worked closely with the New York State Department of Environmental Conservation (NYSDEC) to ensure synchronized and streamlined permitting processes for residents seeking to implement shoreline protection measures.
The Corps has been closely monitoring the water level of Lake Ontario and reports indicate water levels have decreased by about 3 feet since levels peaked in late May. In terms of assistance, the Corps has transitioned from emergency assistance to focusing on educating coastal communities about the need for permanent measures to increase coastal resiliency and mitigate future risk to public infrastructure.
Corps planners have met with members of the NYSDEC to discuss options. Any permanent projects would most likely be conducted under the Continuing Authorities Program (CAP), which supports shoreline protection, erosion mitigation or flood risk management.
The Continuing Authorities Program provides the Corps of Engineers with the authority to plan, design and construct water-resource projects in partnership with local sponsors without the need for Congressional authorization. The program decreases the amount of time required for a local community to budget, develop and approve a potential project for construction. CAP allows the Corps to plan and implement smaller, less complex and less costly projects in a more efficient manner.
CAP projects have a feasibility phase followed by a design and implementation phase. For the feasibility phase, the federal government covers half of the cost; the federal contribution is 65 percent for the design and construction phase. The cost-sharing aspect of CAP program is attractive for communities that would have challenges funding these types of projects on their own.
The types of projects under CAP Section 14, Stream Bank and Shoreline Protection and Section 103, Hurricane and Storm Damage Reduction, typically take two to three years for the feasibility study, under a year for design, and one year to construct. Therefore, communities interested in flood prevention measures are encouraged to reach out to the Corps of Engineers as soon as possible. For a brochure on the CAP program, see www.lrb.usace.army.mil/Missions/Civil-Works/Overview/Continuing-Authorities-Program/.
Dr. Michael Izard-Carroll is the public affairs specialist for the US Army Corps of Engineers, Buffalo District.
By Rob Caldwell, International Lake Ontario-St. Lawrence River Board
There has been much speculation and many theories put forth as to what factors contributed to the high-water crisis on Lake Ontario and the St. Lawrence River this year, from rain to snow, water levels and regulation Plan 2014.
The truth is there were many factors. But as a colleague recently summed up, the main ones were “Rain, rain, and more rain!”
Of course, this is an over-simplification, but in retrospect, the high water levels stemmed mainly from four rain-related factors: an unusual mild and wet winter, above-normal inflows from the upper Great Lakes, a record-setting spring freshet in the Ottawa River basin, and heavy rainfalls across the Lake Ontario and the St. Lawrence River system that have continued through spring and early summer.
This unprecedented combination of climate conditions presented the International Lake Ontario-St. Lawrence River Board with a most difficult challenge. Let’s take a closer look at how things unfolded during the first half of 2017, including the factors leading to the record-high levels and how the board has taken into consideration these exceptional conditions in its decision making.
2017 Brings New Plan
On Dec. 8, 2016, the International Joint Commission issued a Supplementary Order, replacing Plan 1958-D and adopting Plan 2014 as the new regulation plan effective Jan. 7, 2017. Plan 2014 prescribes a new set of rules that the board must ordinarily follow in setting the outflows from Lake Ontario through the St. Lawrence River, which are controlled at the Moses-Saunders generating station at Cornwall, Ontario and Massena, New York.
At the time Plan 2014 was implemented, Lake Ontario’s water level was 6 centimeters or 2.4 inches below its long-term (1918-2016) average for that time of year, and at about the same level as each of the past two years. The upper Great Lakes, including Lake Erie, which supplies about 85 percent of the total inflow of water to Lake Ontario via the Niagara River and Welland Canal, were somewhat above average, but not significantly so and also at similar levels to recent years. Finally, at the start of January, ice was already forming on the St. Lawrence River in the Beauharnois Canal (located between Moses-Saunders and the city of Montreal further downstream on the St. Lawrence). The board had already reduced outflows from Lake Ontario to the rate required for ice formation, which applied under the old and new regulation plans, allowing a seamless transition.
A Mild and Wet Winter Season (January to March)
When ice starts forming at critical locations in the St. Lawrence River, outflows must be temporarily reduced to ensure the formation of a safe and stable ice cover. Doing so reduces the risk that the ice cover will collapse or that the fast-moving water will generate what’s known as frazil ice (ice crystals suspended in water that is too turbulent to freeze solid), possibly resulting in an ice jam. Such an occurrence would significantly reduce outflows, causing immediate flooding upstream, and rapidly declining levels downstream. Once a stable ice cover has formed, the board can safely increase outflows.
By Jan. 17, the Beauharnois Canal was half-covered with ice and the unusual winter weather began. Unseasonably mild temperatures combined with a number of heavy precipitation events in January caused much of the precipitation to fall as rain, particularly in the more southerly parts of the basin. Much of the snow that fell also melted with the mild weather, running off into local streams and tributaries, and making its way to Lake Ontario and the St. Lawrence River.
Notably, daily high temperatures were above freezing for about a week straight from Jan. 16-23. With an extensive, prolonged thaw under way, the ice that had formed in the Beauharnois Canal began to disappear, and eventually receded to the point that Lake Ontario outflow was safely increased back to values previously passed during the open-water season. But by Jan. 25, following another period of colder weather, ice had started forming again and the flow was reduced again on Jan. 28. But mild weather returned, and so flow was again increased on Jan. 31.
This cycle of freezing and thawing continued in February, and flows were adjusted six times that month in response to fluctuating temperatures and ice conditions. A few days of typically cold winter weather at the start of February were followed by several days of milder, but below freezing temperatures, allowing ice to form slowly. However, the last half of the month was exceptionally warm: daily high temperatures recorded at Dorval, Quebec, near Beauharnois, were above freezing for 13 straight days from Feb. 18 through March 2 and reached 14.5 Celsius (58 Fahrenheit) on Feb. 25. The ice cover was gone by Feb. 26, and this permitted the board to increase the flow several times by month’s end.
At the same time, water levels throughout the system began to increase gradually as snowmelt and wet weather continued. Lake Ontario rose significantly more than normal in February, as inflows were above average and outflows were restricted by fluctuating ice conditions. St. Lawrence River levels near Montreal also gradually edged upwards until suddenly shooting above average on Feb. 26 as snowmelt combined with rare February thunderstorms and rainfall.
Normally, by February, a solid ice cover has formed on the St. Lawrence River and remains in place, while occasionally, milder temperatures cause the ice cover to melt during this month. Either condition allows flows to be safely increased thereafter. At no time in recorded history had ice begun forming in March, and the board had no reason to believe this year would be any different. But between March 4 and March 30, substantial ice cover formed and disappeared twice in the Beauharnois Canal during what were two of the coldest stretches of weather seen all winter. As a result, Lake Ontario outflows varied considerably, being reduced as ice formed during a good part of the first half of the month, and then increased four times by a total of 18 percent from March 17- 22. Once increased, flows remained relatively stable for the rest of March.
Overall, the winter saw five periods of ice formation punctuated with thaw cycles in between, the most ever seen in the St. Lawrence River.
While highly variable ice conditions restricted outflows at times, the main driver of rising water levels throughout the Lake Ontario-St. Lawrence River system during the first three months of 2017 was the above-normal amount of water the basin received. This water came from precipitation, snowmelt and runoff from within the basin, and above-average and increasing inflows from Lake Erie, which also saw wet conditions and generally rising water levels throughout this period. From January through March, the net total water supply (i.e., total inflow) to Lake Ontario was above average, and the 12th highest for this three-month period since records begin in 1900. At the end of March, water levels were where they were in 2016, and the mid-March 90-day forecasts from Canada and the US suggested average precipitation was expected in April, May and June.
Record Ottawa River freshet (April and May)
The unusual wet winter transitioned quickly to an exceptionally wet spring. Water levels on Lake St. Louis, located on the St. Lawrence River just upstream of Montreal, generally rose quickly throughout the first three weeks of April following a significant thaw event marked by thunderstorms and rainfall. This event, while relatively large, was not entirely unusual; the Ottawa River enters the St. Lawrence at this location and at this time of year snowmelt and rainfall tend to rapidly increase flows out of this large basin. Nonetheless, the peak flow of 6,877 cubic meters per second (242,900 cubic feet per second) on April 20 was a record for this date, and the highest Ottawa River flow since 1998.
From April 1-5, the Plan 2014 rule curve flow was followed. Thereafter, a series of rainstorms passed through the region, with areas to the north and east of Lake Ontario and into the Ottawa and St. Lawrence River basins being particularly hard-hit. This led to two dozen adjustments to Lake Ontario outflows during the month of April in response to the rapidly rising and highly variable Ottawa River and local tributary flows.
These adjustments were done in accordance with the Plan 2014 “F-limit,” which was designed to mimic the board’s decision making strategies under the previous regulation plan, Plan 1958-D, during high-water events in the 1990s (whereby flooding and erosion risks and impacts upstream on Lake Ontario and in the 1000 Islands were balanced with those downstream from Lake St. Louis through Lake St. Peter). During periods of wet spring conditions, as levels on Lake Ontario reach higher and more critical values, this multi-tiered rule also allows increased levels downstream at Lake St. Louis, which acts as somewhat of a barometer for other areas downstream, and Lake Ontario outflows are adjusted accordingly. The total inflow to Lake Ontario during the month of April was the second highest recorded since 1900.
While the wet weather continued, Lake Ontario and St. Lawrence River levels continued to rise, reaching record high levels and resulting in flooding and related impacts throughout the system. Lake Ontario’s end-of-week level reached what is known as the criterion H14 upper trigger level on April 28. Criterion H14 is another rule, again part of Plan 2014, that when exceeded, authorizes the board to follow an alternative strategy and release outflows to provide all possible relief to riparians living along the shorelines of the entire system. There are four upper trigger levels per month (48 per year) and these thresholds can be expected to be exceeded 2 percent of the time, by definition, given historical water supplies. However, at the time, given the exceptional conditions, the board consensus was that the best way to balance the effects of water levels upstream and downstream and minimize flood and erosion impacts to the extent possible throughout the system was to continue to follow the “F-limit” of Plan 2014. As a result, deviations from the plan were not employed.
Unfortunately, as conditions remained critical, the wet weather only worsened in May. The total inflow to Lake Ontario during the month was the highest recorded since 1900. The month began with a so-called “perfect storm.” There were two extremely large and slow-moving storm systems that passed through the region, the first on April 30 and the second from May 4-8. These storms combined to dump a minimum of 75 millimeters or 3 inches of rain over most of the Lake Ontario, Ottawa and St. Lawrence River basins, while some areas around Lake Ontario received twice that amount. Heavy rain also fell upstream of Lake Ontario on Lake Erie, where water levels also were rising and inflows to Lake Ontario increased to well above average values.
As a result, during the first third of May, water flowed into Lake Ontario at record-high rates and about 25 percent higher than any release the board can physically pass down the river. At the same time, the daily mean Ottawa River outflow (at Carillon Dam) peaked at 8,862 m3/s (313,000 cfs) on May 8 – a new all‐time record maximum, which resulted in significant flooding in many parts of the Ottawa River basin, in the Montreal area and in many areas of the St. Lawrence further downstream.
In response, outflows from Lake Ontario were reduced quickly and significantly over the first week of May to moderate the sharp rise in St. Lawrence River levels near Montreal. As Ottawa River flows subsided, the Lake Ontario outflow was increased rapidly, rising from a low of 6,200 m3/s (219,000 cfs) on May 7 to a high of 10,200 m3/s (360,200 cfs) on May 24 (i.e., raised 35 percent in 17 days). In so doing, the board continued to balance upstream and downstream levels according to the “F-limit,” exceeded the Plan 2014 flow and initiated major deviations in accordance with criterion H14 to provide all possible relief to riparians upstream of the dam.
The flow of 10,200 m3/s (360,200 cfs) was equivalent to the record-maximum weekly mean values passed under Plan 1958-DD in 1993 and 1998 and also equivalent to the maximum “L-limit” value, another rule within Plan 2014. This limit defines the maximum outflow that will maintain adequate levels and safe velocities for navigation in the International Section of the St. Lawrence River when Lake Ontario levels are very high – from above 75.70 meters until 76 meters (248.36 feet until 249.34 feet). The St. Lawrence Seaway imposed several mitigation measures to ensure safe vessel transits remained possible.
Despite these record high releases, inflows also remained well above normal seasonal values, and Lake Ontario levels remained high and peaked near the end of May at 75.88 meters or 248.95 feet, a new all-time record value. Montreal area levels, after their rapid rise toward record values throughout the first third of May, generally declined slowly thereafter as Lake Ontario outflows were increased, but Ottawa River outflows decreased at a faster rate.
In total, Lake Ontario outflows were adjusted 23 times in May.
Heavy Rainfalls Continue (June and July)
By June 2, water levels on Lake St. Louis had started to decline. On June 14, the board initiated additional major deviations from Plan 2014 flows, increasing the Lake Ontario outflow to 10,400 m3/s (367,300 cfs). This was a new record-maximum weekly flow, the highest ever released from Lake Ontario. The St. Lawrence Seaway imposed further mitigation measures and undertook an assessment of this higher outflow for several days, concluding that it was the absolute maximum outflow possible to maintain adequate levels and safe velocities for navigation in the International Section of the river. After some deliberation regarding the impacts of increasing the outflows further, the board decided to maintain this outflow for the remainder of the month and into July.
The monthly mean outflow from Lake Ontario in June averaged 10,310 m3/s (364,100 cfs), 38 percent above the June long-term average (1900-2016) and a new record-high value for any month, exceeding the previous record of 10,010 m3/s (353,500 cfs) set in May and June of 1993.
Wet weather continued in June. A particularly noteworthy storm on June 23 dropped 20.5 mm or 0.8 inches of rain on the Lake Ontario basin. After gradually declining for most of the month, Lake Ontario levels rose slightly as a result. The total inflow to Lake Ontario during the month was the second highest recorded in June since 1900. Nonetheless, the record-high outflows allowed Lake Ontario levels to fall 9 cm or 3.5 inches overall in June – much more than the typical 1 cm or 0.4 inch decline, and the 11th highest June decline on record. By the end of June, Lake Ontario was 10 cm or 3.9 inches below the peak level recorded on May 29. About 6.6 cm or 2.6 inches of that water was removed from Lake Ontario, owing to major deviations undertaken since May 23. The remainder was due to high outflows prescribed by Plan 2014 and the fact that inflows, while still high, had begun to decline.
Montreal area levels generally fell through the middle of June as Ottawa River outflows declined, but rose slightly at the end of June and even further during the first week of July, reaching high levels and flooding similar to that seen earlier in the spring.
The board agreed to continue releasing 10,400 m3/s (367,300 cfs) into July. Despite these efforts, the continuing wet conditions sustained the high levels and severe impacts to Lake Ontario and St. Lawrence River property owners, recreational boaters, businesses and tourism. Lake Erie remained well above average, and combined with significant rainfall during the past month, the total inflow to Lake Ontario remained high.
Decisions and the Path Forward
The first several months of 2017 have been an especially challenging time for those living and working throughout the Lake Ontario-St. Lawrence River system. Many have been impacted by the exceptionally high water levels. While levels have begun to decline, the effects continue to be felt and may continue for months to come.
For its part, the board has made every effort to address the exceptional weather conditions and reduce levels to the extent possible. Outflows were continuously adjusted from January through March during what was a generally wet winter, with highly variable temperatures and challenging ice conditions. As the weather turned from bad to worse, the board continued to adjust outflows in April and May, this time to address the extreme precipitation, record inflows and rapidly rising water levels which have caused severe flooding and associated impacts throughout the system. Since then, the board has increased outflows to record-high values in an attempt to lower the extraordinary levels of Lake Ontario and provide relief to those impacted, while also considering the impacts to riparian interests downstream on the St. Lawrence, and to other stakeholders, including commercial navigation and the industries it supports.
Despite these efforts, wet weather has continued and levels have remained high. There are unfortunately no simple solutions, but the board will continue to consider all possible options, as well as associated impacts, in setting outflows from Lake Ontario. High outflows are expected to continue for several weeks, and as warmer and drier summer conditions continue and evaporation rates increase into the fall. The board expects water levels throughout the system will generally continue to decline, providing gradual relief from the high water crisis of 2017. But keep in mind that water levels may remain above normal for some time to come, and autumn brings a higher chance of damaging storms. Strong winds and wave action can cause significant fluctuations on the lake and river, with temporary changes of more than half a meter (2 feet) in certain locations.
By Arun Heer, International Lake Ontario-St. Lawrence River Board
Since the establishment of the International Lake Ontario-St. Lawrence River Board by the International Joint Commission in 1952, keeping people informed about water level and flow conditions in the lake and river has been a top priority. With the Lake Ontario-St. Lawrence River basin covering such a broad geographic area, including communities in New York, and the provinces of Ontario and Quebec, communication has often been challenging and resource intensive. In the past, the board relied on methods such as in-person public meetings, telephone conferences, and mailing news releases and hard-copy letters to connect with people.
Today, the board is reaching out with modern communication tools such as Facebook, webpages, electronic mailing lists, animated videos, and digital press releases to deliver messages quickly. The board’s Facebook page, in particular, has proven to be a great forum for posting information on topics such as water levels, outflow changes and hydrologic forecasts.
The Facebook page had close to 800 “likes” in January, and that number had increased to more than 2,300 as of July 24. Facebook has become a place where the board can interact with the community in real-time, and where members of the public can interact with one another to share and exchange information.
The board encourages everyone to visit its Facebook page for the most up-to-date information on board activities and join the conversation. Additionally, short educational videos, media releases, and other information can be found on the board’s website.
Arun Heer is US secretary for the International Lake Ontario-St. Lawrence River Board and co-chair for the Great Lakes-St. Lawrence River Adaptive Management Committee.
Rob Caldwell is the Canadian regulation representative of the International Lake Ontario-St. Lawrence River Board, and provides technical support and advice to the board from his office in Cornwall, Ontario.
An invader in a massive freshwater basin. An uncountable number of spawning grounds. A fishery on the brink. A desperate search for a solution that ended up becoming the most successful aquatic invasive species control team effort in American and Canadian history. It’s not a movie, but rather the true tale of the sea lamprey’s invasion of the Great Lakes.
The sea lamprey is parasitic fish native to the Atlantic Ocean. As an adult, it latches onto other fish with its suction cup-like mouth, using a rasping tongue to cut into its victim to suck out bodily fluids and blood. In the Atlantic it doesn’t typically kill its hosts, but the fish in the Great Lakes have no such luck. It’s estimated that a single lamprey can destroy an average of 18 kilograms (39 pounds) of fish in its parasitic lifetime, with only about one in seven fish surviving a lamprey attack. It’s not to be confused with native lamprey, which are smaller and have different coloration, and don’t usually kill the host fish.
Sea lampreys were first detected in Lake Ontario in 1835. While there has been discussion on whether it is native to Lake Ontario, it most likely is an invasive species that entered through the Erie Canal, according to Marc Gaden, communications director for the Great Lakes Fishery Commission (GLFC), a binational organization funded by the Canadian and US governments. The 1919 reconstruction of the Welland Canal, which bypasses Niagara Falls to connect Lake Ontario to Lake Erie, likely allowed the sea lamprey to enter Lake Erie and on to the rest of the basin. They were discovered in Lake Erie in 1921, Lake Michigan in 1936, Lake Huron in 1937 and Lake Superior in 1939. The sea lamprey found an immense number of tributaries featuring the combination of rocky nesting grounds to lay eggs and silt for larval lampreys to grow in, making the Great Lakes a lamprey Eden. In its native habitat, the sea lamprey spends most of its life in saltwater, making it the rare species that has adapted to living entirely in freshwater systems like the Great Lakes, similar to the Pacific salmon species introduced to control invasive alewives.
The impact on the Great Lakes fishery was devastating. Prior to the invasion, about 20 million pounds or about 9 million kilograms of fish were harvested commercially each year in the upper Great Lakes – Superior, Huron and Michigan. By the 1960s that amount was reduced to about 300,000 pounds (136,077 kg) per year, while sea lamprey were killing close to 100 million pounds (45.4 million kg) of fish each year, and 85 percent of the remaining fish were scarred with lamprey attack wounds.
“Commercial fishermen and fishery managers first realized they had a problem around 1940, when it became clear what was happening to the Huron-Michigan fisheries from lamprey,” Gaden said. “That’s when the managers and scientists went into high gear and started seeking control measures.”
With little experience with aquatic invasive species, a wide variety of control methods were attempted. These methods included physical barriers to keep lamprey from entering the streams they use to spawn, crude electrical barriers to block their advances and sieves to stop larvae from eventually entering the Great Lakes from those inland streams. Entrepreneurs tried to make sea lamprey a commercially fished species for human consumption, but none of these attempts worked in stopping the sea lamprey.
The breakthrough came after years of searching for a chemical compound that would kill sea lamprey and not harm other organisms. A compound called TFM was discovered and field-tested in 1957, and entered management usage in 1958 through the binational GLFC. It has been used to great success.
The lampricide targets larval sea lampreys living in streams. After hatching from eggs found upstream in rocky areas, larvae make their way to silty areas and burrow into the substrate until they emerge as adults. The lampricide kills them in that weak, larval state by disrupting their metabolism before they can ever grow up to become the top predator in the Great Lakes. After decades of use, Gaden said the sea lamprey population in the Great Lakes has been reduced by about 90-95 percent from their peak in the late 1950s, and dropped the amount of fish killed by the lamprey to about 10 million pounds (4.5 million kg) a year. While it also affects native lamprey species, sea lamprey larvae tend to live and spawn in different areas from the native species; fishery managers focus on those stream areas where sea lamprey larvae burrow to minimize the impact on native species.
Lampricide isn’t the only tool used to control lamprey numbers, Gaden said, as good pest control takes multiple tacks. Physical barriers are still in use to deny lampreys a path to their preferred spawning grounds. And if those lampreys can’t reach a place to spawn, there’s no need use lampricide treatments, which is expensive and time-consuming. The GLFC also deploys traps to catch lamprey entering or leaving the streams to remove them from the system, and has tested sterilizing male lamprey in the St. Marys River to try and overwhelm the number of fertile males. Most recently, Gaden said the GLFC “is on the cusp” of using isolated lamprey pheromones to affect their behavior – drawing lamprey away from ideal spawning locations and toward traps.
“We’re working on unlocking their genome,” Gaden said. “There are things within the lamprey genome we can exploit, like create conditions so they only produce males, but that’s further into the future.”
“They deserve a lot of praise for the progress they have made in combatting this destructive invasive species, and I look forward to the GLFC forging another 10-fold decrease in lamprey numbers at some point in the future,” Burrows said.
While a focused and targeted approach to invasive species can work in smaller inland lakes, the size of the Great Lakes makes controlling aquatic invaders difficult. That they invaded a waterway that also serves as a border between Canada and the United States added an additional wrinkle. It meant both countries needed to work together, even though fishery management is primarily the domain of state, province, tribal and First Nation governments. This team effort has kept sea lamprey from completely dominating the ecosystem of the Great Lakes for decades.
Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.
While each lake is unique, they all tend to follow a similar cycle based on seasonal changes. Water levels typically reach their seasonal low during the winter months before increasing in the spring due to snowmelt and precipitation. Water levels tend to peak during the summer months, before beginning to drop in the fall and early winter.
There are three main factors that impact lake water levels, said Drew Gronewold, physical scientist with NOAA’s Great Lakes Environmental Research Laboratory: the precipitation over the lakes, evaporation of water on the lakes into vapor, and the runoff that comes into the lakes.
These variables, in turn, are affected by changes in air and water temperatures. For example, Gronewold said the timing of big runoff pulses is dependent on the amount of snow building up in the winter months and when it melts in the spring.
A water level decline in the fall is generally driven by evaporation, as air temperatures drop while surface water temperatures are still relatively warm. While water temperatures were relatively warm during the fall and winter months of 2016-2017 – leading to a lack of ice cover – evaporation amounts have been typical for this time of year due to a relatively mild winter air temperatures, Gronewold said.
These recent conditions, coupled with historical data, lead agencies to expect the water level rise to remain fairly typical this spring and into the summer. As water levels are already above their long-term average for this time of year, researchers expect that they’ll remain above average in the coming months, Gronewold explained.
There is still plenty of uncertainty, he added, as the amount of snow on the ground is less than it has been in some recent winters. It’s also difficult to predict continental-wide meteorological and climate patterns that impact Great Lakes weather patterns and temperatures. These can range from an El Niño effect like the one seen in the winter of 2015-2016 or a “polar vortex” that hit the region in the winters of 2013-2014 and 2014-2015. This uncertainty is expressed as a range of possible water levels in the forecasts released by the US Army Corps and Fisheries and Oceans Canada.
Great Lakes water levels also can be influenced by human management. Hydropower plants and a gated dam on the St. Marys River are used to manage outflows from Lake Superior into Lake Michigan-Huron, while a hydropower plant on the St. Lawrence River is used to manage outflows from Lake Ontario. Outflows through these structures are managed binationally by boards and according to orders and criteria established by the IJC. Nonetheless, the control of water flows through these lakes is limited, and weather conditions and water supplies remain the most significant factor affecting water levels.
Water levels are measured based on the International Great Lakes Datum, defined as the height above sea level at Rimouski Quebec on the St. Lawrence River. Agencies have been measuring lake levels since the 1860s, with more reliable levels going back as far as 1918. They base the lakes’ long-term average water levels on that information.
“We expect a range of water level conditions depending on water supplies,” said Jacob Bruxer, senior water resources engineer with Environment and Climate Change Canada. “There’s a lot of variability and uncertainty in weather and water supply forecasts, particularly when looking beyond a few weeks’ time, so we don’t try to forecast any specific trends and instead consider a full range of water supply scenarios that could be expected.”
According to recent forecasts, through September 2017 Lake Superior is likely to remain at or above seasonal averages, with a small chance of falling below its long-term average in July. There is less uncertainty for the spring months; water levels were about 5.5 inches (0.14 meters) above the long-term average by the end of March, and by May that range could be between 2.7 inches to 10 inches above the average (0.07 meters to 0.27 meters). By September, water levels could be as high as 1 foot (0.3 meters) above the long-term monthly average for Superior.
Lake Michigan-Huron, considered as one lake hydrologically, was about 9.4 inches (0.24 meters) above the March long-term average by the end of the month. By September, Michigan-Huron is expected to remain above the long-term average, in a range of 1-16 inches (0.02-0.4 meters). Gronewold said Michigan-Huron saw water levels fall slightly more during the fall months of 2016 than is typical, but that is unlikely to make a discernible difference during this spring and summer.
Higher-than-average water levels are anticipated on Lake Erie, which has seen water levels on the rise in recent months, reaching more than 17 inches (0.44 meters) above the long-term average by the end of March. Water levels are expected to continue to remain above average this spring, before starting to fall around June to a range of 3.9-16 inches above average (0.10-0.41 meters).
Lake Ontario has a slight chance of being just barely below its long-term average going into summer, but will more likely be above it by up to 15 inches (0.38 meters). The forecasted peak is in May, when water levels could be 3.9-21 inches above average (0.10-0.55 meters). Water levels are then expected to fall at about the same degree as they usually do, according to the long-term average.
The US Army Corps publishes 12-month forecasts for Lakes Erie, Huron-Michigan and Superior, as well as Lake St. Clair, based on current conditions and similar historical weather data. Uncertainty grows substantially more than six months out, but most outcomes for Lakes Erie and Michigan-Huron suggest a greater likelihood of continued higher-than-average water levels through the year. Lake Superior also has a better chance of higher-than-average water levels, but faces a substantial possibility of being below that long-term average, too.
By Jacob Bruxer, International Lake Ontario-St. Lawrence River Board
A series of storm events passed through the Lake Ontario-St. Lawrence River system from April 4-10, resulting in significant precipitation across the region. Some eastern parts of the Lake Ontario basin received as much as 80 millimeters (3.2 inches), while areas around the St. Lawrence River near Montreal saw as much as 90 mm (3.5 inches) during the same series of events.
With the ground already fully saturated, the recent rain, coupled with snowmelt in some areas, resulted in high amounts of runoff and rapidly increasing streamflows across the basin. Flood warnings were issued by many agencies in Canada and the US, and many reports of localized flooding have since been received.
The wet conditions have resulted in rapidly rising water levels throughout the Lake Ontario and St. Lawrence River system. Lake Ontario’s level has risen approximately 19 centimeters (7.5 inches) since April 4, increasing the risk of storm damages and leading to concerns among many lake riparians.
Downstream of Lake Ontario on the St. Lawrence River, levels at Lake St. Louis near Montreal, Quebec, have risen almost twice that amount during the same period, by about 37 centimeters (14.6 inches), due to rapidly rising Ottawa River and other local tributary flows. To prevent Lake St. Louis levels from rising further and causing more extensive damage, the International Lake Ontario-St. Lawrence River Board reduced outflows from Lake Ontario in accordance with Plan 2014, in effect since January.
Plan 2014 sets flows to balance the risk of flood damages, both on Lake Ontario and the St. Lawrence River downstream, by keeping the level of Lake St. Louis below a given threshold for a corresponding Lake Ontario level. As the level of Lake Ontario rises, the threshold level on Lake St. Louis also rises, allowing more water to be released from Lake Ontario.
However, it’s important to note that while Plan 2014 tries to balance these impacts, it cannot and does not eliminate the risk that high levels may occur during periods of extreme weather like we’ve experienced recently. In fact, no regulation plan can do so.
To illustrate the limitations of regulation, consider that it would have taken an increase in outflow of more than 6,000 cubic meters per second (211,900 cubic feet per second) above the average flow since April 4 of 7,010 cubic meters per second (247,600 cubic feet per second) to have maintained Lake Ontario at a stable level. A flow increase of that magnitude would be nearly impossible to achieve, physically. It also would cause levels at Lake St. Louis to rise more than 1 m (3 feet), resulting in catastrophic flooding throughout the lower St. Lawrence River.
Extremely high water levels are a concern to all riparians throughout the Lake Ontario-St. Lawrence River system. While impossible to avoid entirely, balancing the risk of high levels and associate impacts, both upstream and downstream, is a key aspect of Plan 2014.
Jacob Bruxer is the alternate regulation representative of the International Lake Ontario-St. Lawrence River Board and senior water resources engineer at the Great Lakes-St. Lawrence Regulation Office, Environment and Climate Change Canada, Cornwall, Ontario.
After 16 years of scientific study, public engagement and consultation with governments, the IJC is moving forward with Plan 2014.
Plan 2014 is a modern plan for managing water levels and flows on Lake Ontario and the St. Lawrence River.
Since 1960, the flow of water from Lake Ontario has been regulated at the Moses-Saunders Dam, located at Cornwall, Ontario and Massena, New York, following requirements in the IJC’s order of approval. While natural factors such as precipitation, runoff and evaporation predominate, regulation can substantially affect the levels and flows of Lake Ontario and the St. Lawrence River.
The need for an update became clear in the 1990s when property owners, recreational boaters and others voiced increasing dissatisfaction with the current regulation plan that was developed in the 1950s. The IJC initiated a study in 2000, which the governments of Canada and the United States funded at about US$20 million. The study directly involved more than 200 technical experts and stakeholders to evaluate hundreds of alternatives. Following the study, the IJC continued to seek a solution that addressed public concerns and balanced the diverse interests. Few water-level management decisions have ever received this degree of scrutiny and fine-tuning.
Plan 2014 will continue to protect the people who live and work on these waters by reducing the severity and duration of extreme high and low water levels. Under Plan 2014, the most extreme high water level on Lake Ontario is expected to be about 6 centimeters, or 2.4 inches higher than under the current plan.
While floods will occur under any regulation plan, regulation has greatly reduced the severity of flooding throughout the system. On Lake Ontario, regulation has eliminated 98 percent of the economic costs associated with flooding. Plan 2014 will continue to protect homes from flooding.
By far the largest economic cost to shoreline property owners is maintaining shore protection structures, such as rock revetments and sea walls. On Lake Ontario, the current plan reduces these costs by about $20 million per year. Plan 2014 will continue to reduce these costs by about $18 million per year. The economic costs associated with shoreline erosion will change very little under Plan 2014.
On Lake Ontario and the upper St. Lawrence River, Plan 2014 will allow for more natural variations in levels to foster the conditions needed to restore 26,000 hectares, or 64,000 acres, of coastal wetlands. Thriving wetland habitats support highly valued recreational opportunities, filter polluted run-off and provide nurseries for fisheries and wildlife.
The range of water-level fluctuations, environmental conditions and coastal impacts on the lower St. Lawrence River, below the Moses-Saunders Dam, will remain essentially unchanged.
In most years, recreational boaters on Lake Ontario and the upper river will find that Plan 2014 provides greater water depths in the fall, extending the boating season and making it easier to pull boats out at the end of the season. Plan 2014 also increases hydropower production and is more reliable in maintaining system-wide levels for navigation.
Plan 2014 further prepares residents on Lake Ontario and the St. Lawrence River for the future in a number of important ways. The plan performs better by reducing impacts under changing climate conditions compared to the current plan. In addition, conditions related to fluctuating water levels, such as costs to maintain shore protection structures and the health of coastal wetlands will be monitored on an ongoing basis.
The process to update the regulation of water levels and flows began with the realization that the current plan no longer meets the needs of the people and environment of Lake Ontario and St. Lawrence River. Now that the governments of Canada and the United States have concurred with the IJC’s proposal, we look forward to better serving our two countries under Plan 2014, which will take effect in January. The IJC will also monitor and assess conditions on an ongoing basis to track whether Plan 2014 performs as expected.
During October’s Great Lakes Public Forum in Toronto, Ontario, Lake Ontario Waterkeeper and the IJC continued gathering stories about our precious shared waters from forum attendees. You can watch, hear, and read all the Great Lakes Watermark stories from this partnership at: watermarkproject.com/ijcgreatlakes. Have a Great Lakes story to share? Submit yours online today.
Canada’s Minister of Environment and Climate Change Catherine McKenna remembers growing up on the shores of Hamilton Harbour on Lake Ontario and hopes that the rehabilitation efforts there will make it swimmable in her lifetime.
Great Lakes Trust founder and Wilfrid Laurier University professor Loren King couldn’t swim on his local Lake Ontario beaches growing up, either, but has since swum 51 kilometers from Niagara-on-the-Lake to Toronto to raise funds for its continued restoration and protection.
See previously featured Great Lakes Watermarks here.
Predatory fish like trout and salmon seem to be facing a vitamin deficiency in Lake Ontario, and the culprit could be one of their prey fish species, the alewife.
Researchers noticed in fall 2014 that steelhead trout migrating in the Salmon River were acting abnormally due to seemingly poor vision; anglers were even reporting deaths. After investigating, officials found that these fish were suffering from thiamin deficiency.
Thiamin, also called vitamin B1, isn’t something the fish (or any animal) can make themselves. They need to get it from their diet, which includes invasive species like alewife, rainbow smelt, and round goby. Dr. Jacques Rinchard, associate professor at the State University of New York’s Brockport campus, said thiamin deficiency has been a major challenge to fisheries biologists and managers in the Great Lakes since the late 1960s-early 1970s when problems were first seen in salmon and trout species in Lakes Michigan and Huron. Alewives are not native to those lake systems, and eventually the deficiency was linked to the alewives the fish have been eating.
Alewives are a key part of the salmon diet, Rinchard said. “In Lake Huron when the alewife (population) crashed, we noticed natural reproduction of lake trout in the lake again, indicating a link between alewives and the thiamin deficiency.”
But the impact is clear. Some predatory fish species that eat alewives are unknowingly depleting the thiamin in their system, causing a vitamin deficiency. This was one of the major factors that led populations of trout and salmon to collapse in Lake Ontario when alewives started becoming more abundant: both species were eating more alewives and getting sick because of it (they also suffered from habitat loss, overfishing and invasive species like sea lampreys). To contend with the alewives, Pacific salmon like chinook and coho were stocked in the Great Lakes to control the alewife population and allow lake trout and Atlantic salmon to recover. The thiaminase affects them too, but not as severely.
Rinchard’s lab at SUNY-Brockport is working with the US Geological Survey and Cornell University to research the link between alewives and thiamin deficiency in Lake Ontario. Preliminary results should be available in early 2017.
Fishery programs can help offset the impact of thiamin deficiency. Eggs can be treated with thiamin baths at a hatchery to make sure the fry develop properly and are healthy – a process undertaken by the New York Department of Environmental Conservation (DEC). Naturally producing populations like lake trout or steelhead trout can’t be assisted like that, and alewife control efforts are the main way to help those species. It is possible to inject migrating steelhead with thiamin so that their eggs are healthy, but it isn’t a viable option for a system like Lake Ontario.
Another possibility is letting chinook and coho salmon slash the alewife population, similar to what happened in Lake Huron (though food scarcity also was an issue there). While that would be a boon to native fish populations, LaPan said the sport fishing industry in the area has found success with introduced Pacific salmon species, so managers can’t let the alewife get wiped out if they want to maintain that predator in Lake Ontario.
The thiamin deficiency doesn’t appear to be as severe across the entirety of Lake Ontario, either. LaPan said alewive tissue samples from the Niagara River, Rochester and Cape Vincent found a drop in thiamin amounts from the west end of the lake to the east. This is consistent with the fact that most nutrients entering the lake come from the Niagara River and are used as the water travels eastward.
New York DEC and Ontario Ministry of Natural Resources and Forestry are considering a 20 percent reduction in Chinook salmon stocking, but that is mostly to keep pace with an alewife population weakness after the excessively cold winters of 2013 and 2014, LaPan said. On the New York side of the lake, the state imposes catch limits on lake trout (two a day with size restrictions) and Atlantic salmon (one a day), while anglers can still get take a combination of three Pacific salmon species and steelhead. Ontario allows one Atlantic salmon to be caught per day and up to three lake trout for properly licensed anglers on its side of the lake. The province also allows up to five Pacific salmon species to be caught, and up to three steelhead trout.
Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.
Editor’s Note: This post was updated on Nov. 14, 2016, to correct the type of fish referenced in problems first seen in Lakes Michigan and Huron.
Fishing. Family. Healing. Danger. These and other themes are included in following stories, which are just two from a group of 90 stories first-year students wrote in a course on “Living at the Water’s Edge in Toronto” that I taught at the University of Toronto in fall 2015.
When Darren Cheung was 14, he went fishing with his dad on the Otonabee River near Peterborough, Ontario. They saw some huge golden carp sunbathing on one side of a dam; Darren squeezed through a hole in the fence but his dad was too big to make it through, so he remained on the other side, extremely worried as he watched his son tightrope-walking along a thin concrete wall with white waters and fast currents below.
“After about half an hour I was hooked onto a large carp,” Cheung recalls. “I couldn’t believe the rod bent from the power of the fish and the strong currents. From a distance I could see my Father’s worried smile and he was yelling out ’Be careful Darren!’ After almost an hour of battling the fish I finally landed it. I brought it to him and the first thing he did was give me a huge hug and said, ’Never again’ while we both laughed and smiled in relief.”
Shamaila Bajah’s family regularly spends the day at Woodbine Beach on Lake Ontario in Toronto. Bajah collected this story from her sister, Dure-ajam Bajwah about one visit: “I did not feel well that day because I was on my period,” the sister said. “I really did not want to get wet in the water, but I had heard that if you go in the water during your periods it really helps calm your cramps.
“So I just soaked my feet in the water … I was just sitting and relaxing in the nice water, which was surprisingly helping my cramps, and all of a sudden I see my little brother going too deep into the water. He was only eight years old at the time, and he is developmentally delayed and he cannot swim either.
“So I started yelling at him to not go so deep. I was yelling at the top of my lungs for him to come back to shore, but he wouldn’t listen. Then he finally got to the part where there was a deep plunge in the water and a huge wave rolled him farther down and he started to drown. I could not think of anything at that moment and I ran after him in the water, fully clothed! I grabbed him and dragged him to shore and I made him cough because he had gotten a lot of water up his nose and in his throat.
“That was the most terrifying moment for me, because I honestly thought he was going to drown. I had already lost a brother when I was younger and I couldn’t bear to lose another one, so I completely forgot about my periods and being fully clothed and ran after him. After that incident I’m always careful when taking little kids in the water, because a split second can be life changing. The water can be unpredictable and you always have to be cautious when submerged in it.”
Each student wrote their own story, collected five stories from family and friends, and analyzed the stories. They provided feedback to LOW about the process of story collection, so LOW could refine the project. LOW President and co-founder Mark Mattson and LOW Vice-president and co-founder Krystyn Tully visited the classroom to discuss the project with students.
The course was designed so the students, whether newcomers to Toronto or long-time residents, could think about what it meant to live on and with the Great Lakes during their time at the university. The course blurred the boundaries of a classroom, by asking students to get their feet wet on various experiences around the city: visiting an indigenous-led restoration project on the Humber River and a water filtration plant, paddling on the Humber, and hiking the course of a river now buried in the Toronto sewer system. They also invited community members to speak about their work, including an award-winning photographer who has explored the Toronto sewer system and an Anishinaabe (Ojibwe) water-walker. It also asked students to think about a variety of ways to portray the Great Lakes (in film, poetry, science, ethnography, and travelogues)
One of the ways newcomers arriving in Canada claimed the land from indigenous peoples was by describing the landscapes as empty (terra nullius) and unpeopled. But indigenous people in Canada have long and ongoing histories with and stories about the land and water. This course wove those stories with the students’ stories to create a multilayered picture of the relationship people have with water.
Why do water stories matter for the future of the Great Lakes? Research on the Great Lakes often originates in the sciences, and documents water quality and quantity issues. A focus on water stories might seem “soft” to some. In order to call attention to significant problems, we often focus on the damage done; sometimes we tell people why water should matter to them.
In these stories, people tell us, and themselves, why water matters. The picture they offer is the range of ways that water is entwined with some of the best and most memorable, and sometimes the most difficult, moments of our lives. In these stories, water is not a commodity and not simply a natural resource. The stories are about relationships we have with each other and with the water. The stories also reflect a theory of social change and social action: that change will take place when a broad group of people, not simply those who are water experts, are actively engaged with water issues It may not always be enough to engage people’s heads. We need to engage their hearts, too.
This year, students at the University of Toronto will partner with LOW and the IJC to gather stories from those attending the Great Lakes Public Forum on Oct. 4-6 in Toronto. Some students will also share their stories at this event.
Please look for the LOW booth to share your story, or share your story with the students roaming the event. I hope to do further research on this and other story projects around the Great Lakes, and the theories of social change they reflect and enact. I also hope to build connections with other faculty teaching courses, especially with a social science and humanities component, around, about and on the Great Lakes. Finally, I hope to put together a summer field course jointly taught by scholars in the sciences, social science and humanities that would allow students from the University of Toronto and elsewhere to travel around the Great Lakes to learn with, from and about people working on various issues facing the lakes and their watershed.
Dr. Bonnie McElhinny is an associate professor in the Anthropology and Women and Gender Studies Institute at the University of Toronto. For a copy of the syllabus, you may contact her at firstname.lastname@example.org.