I Intro to Regulating Services

Ecosystem services are broadly defined as the benefits that are provided by ecosystems to humans. These services enrich human life by making it possible for humans to live (Daily, 1997; MA, 2003). Some examples of an ecosystem service are waste decomposition and clean drinking water. According to the Millennium Ecosystem Assessment (2004) there are four broad categories of ecosystem services, they include: provisioning, which are products that are obtained from the ecosystem, they include things such as food and water production; regulating, such as climate regulation; supporting, which are services that are needed for the success of all other ecosystem services, this would be something such as soil formation and water cycling; and cultural services, these are services that are non-material but provide benefits to people, such as, recreation and spiritual enhancement (MEA, 2004). The services that ecosystems provide for us are vital to our being, but their importance is often overlooked. Because ecosystem services maintain the conditions on Earth, we should not take them for granted.

Lake Champlain from above

A regulating service is one of the four broad categories of ecosystem services. The Millennium Ecosystem Assessment  defines these services as ones that are beneficial to humans through the regulation of ecosystem services. An example of a regulating service is crop pollination. The bees act as the service when they pollinate our crops, and we benefit in the way of a food product. Diverse food chains as well as aquatic habitats are other examples of a regulating service; these are so important because we are all a part of the wood web, and the disturbance of a food chain could have negative aspect on our own species. Aquatic habitats are so important because they also “cleanse” the water and reduce toxins; this allows better access to clean drinking water, as well as healthier aquatic species (MEA, 2004). On a very broad scale, climate is regulated by ecosystems. Because of regulatory systems such as soil organisms, land cover, and phytoplankton, the climate of the entire earth is stabilized (Butler, C.D., and W. Oluoch-Kosura; 2006). Regulating services are fundamental to the continuance of life on earth.

II Context of Lake Basins

The Lake Champlain Basin along with numerous other aquatic basins across the country have begun to experience growth in both the number of different invasive species and in their individual populations. Invasive species once present in a basin can be very difficult to maintain and control. (Lake Champlain Basin Program, 2009) Because of this programs consisting of focused and determined individuals are needed to organize and carry out the actions necessary to control and reduce the populations of these different invasive species. (Lake Champlain Basin Program, 2009)

UVM water quality research on Lake Champlai

It is good to know that Lake Champlain accompanied by its sister lakes to the west and others ranging across the country have taken action and implemented these programs. Here in Vermont we are lucky to have two widely known organizations that promote and actively participate in the managing and conservation of the Lake Champlain Basin. The first is the Lake Champlain Basin Program which partners with a range of neighboring State government agencies, local communities, private organizations, and individuals to plan, organize and fund efforts which benefit the Lake Champlain Basin’s water quality, fisheries, wetlands, wildlife, recreation, and cultural resources. (Lake Champlain Basin Program, 2009) The second is the Vermont Department of Fish and Wildlife which consists of five separate divisions and roughly 125 members including a combination of biologist, game wardens, educational coordinators and support staff. (Vermont Fish and Wildlife, 2008). They all believe in and work for one mission “To protect and conserve our fish, wildlife, plants, and their habitats for the people of Vermont.” (Vermont Fish and Wildlife, 2008). As far as reducing invasive species goes the department contributes in various ways including monitoring and collecting crucial data from the Lakes boat launches, reviewing thousands of water projects, and protecting over 130 miles of river and lake shore lines. (Vermont Fish and Wildlife, 2008).

Aside from the Lake Champlain basin others have also taken a stand to invasive species. Ever since the first settlers of the region arrived in the 1800s the Great Lakes and St. Lawrence Sea way have remained vulnerable to the introduction and spread of new invasive species. (Great Lakes Information Network, 2009). As time has progressed and the human population has increased so has the number of new invasive species, more than one third being introduced in the last thirty years. (Great Lakes Information Network, 2009). Because of their size the Great Lakes require much more attention to detail and constant monitoring. One of the many programs focused on this matter for Great Lakes region is the GSI or the Great Ships Initiative. The Great Ships Initiative focus is to end the problem of ship-mediated invasive species in the Great Lakes-St. Lawrence Seaway System (The Great Ships Initiative, 2009). They plan on attacking this problem through a variety of different methods including consistent harbor monitoring and significantly accelerating research, development and implementation of effective ballast treatment systems for ships that visit the Great Lakes from overseas (The Great Ships Initiative, 2009).

Similar programs are also being conducted in the western part of the U.S. The California department of Fish and Game has its own Marine Invasive Species Monitoring Program. This program “conducts biological monitoring to determine the location and geographic ranges of introduced species in the California’s coastal and estuarine waters. The ongoing monitoring is also a mechanism to detect new introductions” (MSIP, 2007). In Colorado, the Division of Wildlife promotes mandatory boat inspections and regulations to help prevent the spread of the zebra mussel which has been encroaching on the lakes and river systems of Colorado and other surrounding states. These boating regulations include routines such as cleaning, draining, and drying of each water vessel after it leaves the water in order to reduce the spread and introduction of the mussel into new waters (Colorado Division of Wildlife, 2010).

There are a lot of similarities between the different programs searched across the U.S. These programs consistently monitor and observe the lakes and basins in order to catch any changes or new introductions as soon as possible. Many of the programs have taken on these control efforts because they are rather simple, cost-efficient, and effective. The larger lakes that have more funding are able to conduct more research studies and extend their efforts to off-shore laboratories which in turn provides them with more crucial information including things such as where the species may have originated from, where it is currently, and what can be done to control and reduce its presence.

III. Context of Lake Champlain

The plant and animal communities that interact in the Lake Champlain dictate the health of lake’s complex food web system. Biodiversity within Lake Champlain allows for nature to exhibit a natural food web with interactions between the plants and animals. When there is a healthy relationship between plants and animals native fish diversity thrives, there is overall improved habitat, and enhanced water quality (Young et al., 2000). This leads to a more pleasing environment where self-sustaining populations are able to support industries such as fishing (Young et al., 2000).

Every single interaction and member of the aquatic community is important, from the little phytoplankton and zooplankton to the more complex organisms at the top of the food web including largemouth bass, northern pike, lake trout, and even humans (State of the Lake, 2008). Any disruption in this food chain throws the entire system out of line. Recently there have been changes in the phytoplankton community due to the increasing prevalence of cyanobacteria (State of the Lake, 2008). The consequences of this disruption are still unknown; however, the problems can escalate up to the higher levels of the food web. It is currently being monitored by the Lake Champlain Basin Program (State of the Lake, 2008).

Lake Champlain Food Web (State of the Lake, 2008)

Other potential disrupters of the food web include nonnative plants and animals. In order for native communities to thrive and for there to continue to be ecosystem services, it is necessary to ensure that interferences are managed accordingly. Currently there are 15 nonnative plants in Lake Champlain (Young et al., 2000). The main problem with invasive plants is that they crowd out native species in the lake. For example, the water chestnut and Eurasian watermilfoil began infiltrating into the South Lake in the 1940s (State of the Lake, 2008). These two invasive plants have displaced native plants, which provide habitat and food to the fish populations. There have been some invasive species programs in order to combat the spread of these harmful plants. In 2006, 12,000 of these plants were removed by hand (State of the Lake, 2008). It was reported in 2007, that there were less water chestnuts and the health of the lake was improving in the South Lake and Main Lake; however, the amount of water chestnuts in the Missisquoi Bay were increasing (State of the Lake, 2008).

Zebra mussels

The presence of invasive animals also threatens Lake Champlain’s biodiversity and aquatic health. There are over 80 native animal species and 15 nonnative species (State of the Lake, 2008). Three of the most prevalent and most discussed nonnative species include aleweifes, white perch, and zebra mussels. Alewifes were discovered in Lake Champlain in the 1960s (Young et al., 2008). They compete for food with native species, eat native fish eggs, and eat zooplankton (Young et al., 2008). All of these actions reduce the native fish population and further change the natural environment of the lake. It is thought that the alewifes also compete with smelt, which is an essential food for all pelagic fish in the lake (Young et al., 2008). White perch entered the lake a little later in 1984, and they are now found all throughout Lake Champlain (State of the Lake, 2008).  This species is especially threatening because they are opportunistic feeders that prey on eggs of native species. Finally, zebra mussels are the most known nonnative species in the lake.  They entered the lake fairly recently in 1993 (State of the Lake, 2008). The zebra mussels are filter feeders, meaning that they eat plankton. The plankton is an essential part of the lake habitat and provides food for many fish. The disappearance of the plankton is clearing the lake in only some areas, although zebra mussels can now be found in every segment of the lake (State of the Lake, 2008). They are a fast growing species that are suffocating the growth of native mussel species.

One last important species to note are sea lamprey. Although they are thought to be a native species in the lake, the sea lamprey population is currently extreme. Sea lampreys survive by sucking on the body fluids of other fish, which eventually kills them (State of the Lake, 2008). There are 20 known tributaries in Lake Champlain where sea lamprey reproduce (Vermont Fish and Wildlife, 2008). Because of this great infestation, 29.4 million dollars was lost annually due to fishermen fishing somewhere else (Vermont Fish and Wildlife, 2008). There have been monitoring programs since 1985 to track the prevalence of sea lamprey in Lake Champlain. The sample average number of wounds due to sea lamprey per 100 fish was found to be 25 for lake trout and 15 for salmon. However, the latest data from 2007 greatly exceeds these averages with 46 wounds per 100 for lake trout and 71 wounds per 100 for salmon (State of the Lake, 2008). Since 1985, the number of wounds exceeded the sample average by more than 50% for lake trout and salmon, except for one data sampling between 1993 and 1998 where the data was within 50% of meeting the target for lake trout and salmon (State of the Lake, 2008).

V References

California State Lands Commission. (2007). Marine Invasive Species Program. Retrieved from http://www.slc.ca.gov/Spec_Pub/MFD/Ballast_Water/Ballast_Water_Default.html

Colorado Division of Wildlife. (2010). Mandatory Boat Inspection. Retrieved from http://wildlife.state.co.us/Fishing/MandatoryBoatInspections.htm

Berry, Tom. Conserving Lake Champlain’s Biological Diversity. Nature Conservancy. Retrieved from http://www.nature.org/wherewework/northamerica/states/vermont/files/lake_champlain_biodiversity_report.pdf

Butler, C. D., and W. Oluoch-Kosura. 2006. Linking future ecosystem services and future human well-being. Ecology and Society 11(1): 30. Retrieved from: http://www.ecologyandsociety.org/vol11/iss1/art

Fishman, D.B., Adlerstein, S.A., & Vanderploeg, H.A. (2009). Causes of phytoplankton changes in Saginaw Bay, Lake Huron, during the zebra mussel invasion, Journal of Great Lakes Research, 35(4),482-495. Retrieved from http://www.snre.umich.edu/scavia/wp-content/uploads/2009/11/jglr_fishman_et_al_-_model.pdf.

Great Lakes Information Network. (2009). Invasive Species in the Great Lakes Region. Retrieved from: http://www.great-lakes.net/envt/flora-fauna/invasive/invasive.html

The Lake Champlain Basin Program. (2008). Aquatic and Invasive Species in Lake Champlain & the Basin. Retrieved from http://www.lcbp.org/nuissum.htm.

Lake Champlain Basin Program. (2009). Aquatic Nuisance Species Spread Prevention. Retrieved from http://www.lcbp.org/ans-spread.htm

Lake Champlain Committee (2010). Invasive Species. Retrieved from http://www.lakechamplaincommittee.org/lcc-at-work/invasive-species-in-lake/.

Modely, Margaret D. (2008). Aquatic invasive species rapid response planning partnerships in the Lake Champlain basin: Bridging international, political, social, and economic gaps. Water SA, 34(4), 476-480. Retrieved from http://www.wrc.org.za/Knowledge%20Hub%20Documents/Water%20SA%20Journals/Manuscripts/2008/05/WaterSA_2008_05_Paper%209.pdf.

Millennium Ecosystem Assessment, 2005. ECOSYSTEMS AND HUMAN WELL-BEING: WETLANDS AND WATER Synthesis.

World Resources Institute, Washington, DC.

State of the Lake. (2008). Lake Champlain Basin Program. Retrieved from http://www.lcbp.org/PDFs/SOL2008-web.pdf.

Vermont Fish and Wildlife. (2004). Vermont Fish and Wildlife. Retrieved from  http://www.vtfishandwildlife.com/.

Watzin, M.C., Joppe-Mercure, K., & Rowder, J. (2008). Significant fish predation on zebra mussels Dreissena polymorpha in Lake Champlain, U.S.A. Journal of Fish Biology, 73(7), 1585-1599. Retrieved from http://www3.interscience.wiley.com/cgi-bin/fulltext/121510225/PDFSTART.

Young, B. A., Bouffard, W.R., & Chipman, B.D. (2000). Strategic Plan for Lake Champlain Fisheries. Fisheries Technical Committee of the Lake Champlain Fish and Wildlife Management Cooperative, Retrieved from http://www.vtfishandwildlife.com/library/Reports_and_Documents/Fisheries/Strategic_Plan_for_Lake_Champlain_Fisheries.pdf.

Outline – Regulating 2

I Intro to Service Category (Brooke)

· Ecosystem Service

o provided by ecosystem that benefits humans (Millennium Ecosystem Assessment, 2005)

o transformation of ecosystems can alter the benefits they provide us (MEA, 2005)

o Includes provisioning, supporting, regulating, and cultural services (MEA, 2005)

· Regulating Service

o ex: climate regulation, water, disease (MEA, 2005)

o Aquatic habitats

§ “cleanse” water

§ reduce toxic wastes

§ On a global scale, climate is in part regulated by ecosystems, including land cover, soil organisms, and phytoplankton (Butler, C. D., and W. Oluoch-Kosura. 2006)

o Harm imposed by humans

§ land use changes

§ CO2

§ Green House gases (MEA, 2005)

II Context of Lake Basins (Jon)

· What is being done in response to invasive species in Lake Champlain.(LCBP 2005,VT Fish & Wildlife 2009)

· Actions of basins programs across the country to prevent the spread of invasive species in their areas including approaches, tactics, and future planning in relation to efforts in Lake Champlain.

o In Lake Michigan (GLC 2009)

o Great Lakes and St. Larwence Seaway (GSI 2009)

o In the state of California (MISP 2009)

o Colorado’s control approach ans the states lawas and regulations towards controlling the spread of zebra mussels (USDA 2009)

· Similarities and differences between programs, what’s working and what isn’t.

III Context of Lake Champlain (Natalie)

· Biodiversity Food Web

o Importance

§ Self-sustaining populations support fishing (Young et al., 2000)

§ Native fish diversity thrives, improved habitat, and improved water quality (Young et al., 2000)

§ A more pleasing environment (Young et al., 2000)

o Connection between plants and animals

§ Complex feeding relationship of species in Lake Champlain

§ Simplest organisms at the bottom of the food chain

· Examples = phytoplankton and zooplankton (State of the Lake, 2008)

§ More complex organisms at the top of the food chain

· Examples = humans, largemouth bass, northern pike, lake trout and salmon (State of the Lake, 2008)

§ Recent changes in phytoplankton community

· Due to increasing prevalence of cyanobacteria (State of the Lake, 2008)

· Consequences of this disruption are still unknown, but they can affect higher levels of food chain (State of the Lake, 2008)

· Monitored by Lake Champlain Basin Program (State of the Lake, 2008)

o Invasive Plants

§ 15 nonnative plants (Young et al., 2000)

§ Crowd out native species

§ Examples:

· Water chestnut and Eurasian watermilfoil – infiltrations in South Lake in 1940s (State of the Lake, 2008)

o Displaces native species and is not eaten by animals (State of the Lake, 2008)

o In 2006, 12,000 plants removed by hand (State of the Lake, 2008)

o In 2007, the trend was improving (less water chestnuts) in South Lake and Main Lake, but increasing in Mississquoi Bay (State of the Lake, 2008)

o Invasive Animals

§ Background

· Over 80 native species and 15 nonnative species (State of the Lake, 2000)

§ Alewifes

· Discovered in Lake Champlain in 1960s (Young et al., 2008)

· Compete for food with native species, eat native fish eggs, and eat zooplankton (Young et al., 2008)

· May compete with smelt which is an essential food for all pelagic fish in the lake and as well as provides winter fishing (Young et al., 2008)

· Could pose big threat, but unsure at this time (Young et al., 2008)

§ White Perch

· Entered South Lake in 1984 and now found in entire lake (State of the Lake, 2008)

· Opportunistic feeders and prey on eggs of native species (State of the Lake, 2008)

§ Zebra mussels

· Discovered in Lake Champlain in 1993 (State of the Lake, 2008)

· Filter feeders – eat plankton which clears water (State of the Lake, 2008)

· Caused decline in native mussel species (State of the Lake, 2008)

· Now found in every Lake segment and have altered food web (State of the Lake, 2008)

o Nonnative Animals

§ Sea Lamprey

· Kill other fish by sucking on their body fluids (State of the Lake, 2008)

· 20 known tributaries in Lake Champlain where sea lamprey reproduce (Vermont Fish and Wildlife, 2008)

· Sample average number of wounds per 100 fish to be 25 for lake trout and 15 for salmon (State of the Lake, 2008)

· 29.4 million dollars lost due to fishermen fishing somewhere else due to sea lamprey problem annually (Vermont Fish and Wildlife, 2008)

· Data from 2007 greatly exceed with 46 wounds per 100 for lake trout and 71 wounds per 100 for salmon

· Since 1985, the target has been exceeded by more than 50% fro lake trout and salmon except between 1993 and 1998 when the rating was fair (State of the Lake, 2008)

IV Service Analysis (Holly, Mark, Jake)

· Plants

o The Littoral zone (less than 50 ft) of the lake is a very productive area of the Lake and hosts the most diverse plant life in the Basin (Berry)

o This littoral zone and its native plant species have suffered from many disturbances including invasive plants, animals, human development and agriculture, loss of riparian buffers, and pollution (Berry)

o Eurasian Milfoil and Variable leaved watermilfoil greatly threaten native plant species. These plants spread by broken pieces, seeds and extensive root systems and they outcompete native plants (LCBP, 2010)

· Phytoplankton as an indicator of lake health

o Biodiversity

§ recently disrupted by overabundance of blue-green algae (State of the Lake, 2008)

o Management/Regulation, Lake Champlain

§ Blue-green algae: a primitive organism with the ability to photosynthesize (State of the Lake, 2008)

§ Cynobacteria in excess caused by high levels of phosphorous and nitrogen (State of the Lake, 2008)

§ Link between phosphorous and cynobacteria not fully understood, might be in correlation to water temperature and changes to the food web. (State of the Lake, 2008)

§ Link between phosphorous and presence of cynobacteria is definite, thus management of phosphorous is required to maintain low levels of blue-green algae blooms. (State of the Lake, 2008)

§ Effects of cynobacteria include: gastrointestinal problems, skin irritation, etc. (State of the Lake, 2008)

o Management/Regulation, Other Lakes

§ Lake Huron

· 1991, Saginaw Bay. Zebra mussel invasion. Initially cleared waters and lowered the overall biomass of cynobacteria.

· 3 years after the waters cleared, the cynobacteria returned.

o Suggested maintenance: removal of algae particles, increasing recycling of available phosphorus throughout summer, selected rejection of certain Mycrocystis strain

· short term experiments prove an increase in the zebra mussel population leads to a decrease in the cynobacteria population.

· 1990-1996 Saginaw Bay observations: disappearance of light sensitive phytoplankton; rise in dominance of centric diatoms (Cylotella spp.) beginning in 1992; return of summer blooms of Microcystis spp. and other colonial chrococcoid cynobacteria such as Aphanocapsa incerta from 1994 to 1996.

· Community changes most apparent among centric diatoms, pennate diatoms, filamentous cynobacteria and chrococcoid cynobacteria.

· Model for regulation of zebra mussels and cynobacteria filtration developed for the establishment of phosphorus point source controls for all the Great Lakes.

· Used equations describing physical transport, phytoplankton growth, nutrient recycling, grazing. Added zebra mussel filtration and excretion effects. (Hershener, C. & Havens, K.J. 2008)

Biodiversity in Lake Champlain Fish Populations

Biodiversity in fish species provides people with multiple benefits, including food, recreation, culture, employment and income. In most aquatic ecosystems, these benefits are threatened by invasive or nuisance fish species.

  • Establishment of non-native species can disrupt native fish communities and challenge management objectives (Young, 2009)
  • Some invasive species may cause adverse affects on human health (Modley, 2005)

In Lake Champlain, invasive species are causing problems for the native fisheries and ecosystems of the lake. There are various organizations collaborating to reduce the impact of invasive species in the lake.

  • The disturbance, fragmentation, and alteration of both in-stream aquatic and riparian habitats coupled with the introduction of non-native species negatively affects fish and wildlife resources and the economy of the Lake Champlain basin (Modley, 2005)
  • 88 fish species, 15 non-native (Young, 2009)
  • Hudson River has twice and the Great Lakes have four times as many exotic species (threat of more invasive species) (Lake Champlain Committee, 2010)
  • Not all invasives problematic, alewife and white perch particularly damaging (State of the Lake, 2008)
  • Strategic Plan for Lake Champlain Fisheries has the main goal of increasing native species for the purpose of sport fishing (Young, 2009).

Connect structure to function

  • Fisheries provide wholesome food, recreation, cultural heritage, employment and income (Young, 2009)
  • White perch and alewife prey on eggs of other species (reducing populations), may lead to algal blooms, compete with native fish for food (State of the Lake, 2008)
  • Stocking programs for threatened fish, sea lamprey control methods using chemicals and physical barriers (State of the Lake, 2008)

The number of invasive species in Lake Champlain has been steadily increasing over the past 100 years. It is difficult to quantify the benefits of biodiversity and healthy ecosystems in the lake, but the clear economic benefit is sport fishing. Controlling invasive species in order to sustain the angling industry is a major goal of lake advocates.

  • Fishing derbies important to many lakeside communities (State of the Lake, 2008)
  • Lake whitefish once supported thriving commercial fishery in Champlain, steady decline in catch since the 1970s (State of the Lake, 2008)
  • Sea lamprey greatly impact Lake Champlain fisheries and recreational sport fishing (State of the Lake, 2008)
  • Current fishery based on angling of walleye, yellow perch, basses, smelt, and pikes. Angling and bait harvest only sources of commercial sales (Young, 2009)
  • Estimate from 1991 that between 200,000 to 750,000 lbs of fish were sold (Young, 2009)
  • In general, lake biodiversity is hard to quantify (Carpenter, 2005)
  • Cost state and federal agencies millions of dollars every year to manage (Modley, 2005)
  • Creation of a plan for rapid response to new introductions has an opportunity to save a significant amount of money (Modley, 2005)
  • Sea lamprey control methods cost approximately $850,000 per year (Lake Champlain Basin Program, 2005)

V References

Berry, Tom. Conserving Lake Champlain’s Biological Diversity. Nature Conservancy. Retrieved from http://www.nature.org/wherewework/northamerica/states/vermont/files/lake_champlain_biodiversity_report.pdf

Butler, C. D., and W. Oluoch-Kosura. 2006. Linking future ecosystem services and future human well-being. Ecology and Society 11(1): 30. Retrieved from: http://www.ecologyandsociety.org/vol11/iss1/art

Fishman, D.B., Adlerstein, S.A., & Vanderploeg, H.A. (2009). Causes of phytoplankton changes in Saginaw Bay, Lake Huron, during the zebra mussel invasion, Journal of Great Lakes Research, 35(4),482-495. Retrieved from http://www.snre.umich.edu/scavia/wp-content/uploads/2009/11/jglr_fishman_et_al_-_model.pdf.

The Lake Champlain Basin Program. (2008). Aquatic and Invasive Species in Lake Champlain & the Basin. Retrieved from http://www.lcbp.org/nuissum.htm.

Lake Champlain Committee (2010). Invasive Species. Retrieved from http://www.lakechamplaincommittee.org/lcc-at-work/invasive-species-in-lake/.

Modely, Margaret D. (2008). Aquatic invasive species rapid response planning partnerships in the Lake Champlain basin: Bridging international, political, social, and economic gaps. Water SA, 34(4), 476-480. Retrieved from http://www.wrc.org.za/Knowledge%20Hub%20Documents/Water%20SA%20Journals/Manuscripts/2008/05/WaterSA_2008_05_Paper%209.pdf.

Millennium Ecosystem Assessment, 2005. ECOSYSTEMS AND HUMAN WELL-BEING: WETLANDS AND WATER Synthesis.

World Resources Institute, Washington, DC.

State of the Lake. (2008). Lake Champlain Basin Program. Retrieved from http://www.lcbp.org/PDFs/SOL2008-web.pdf.

Vermont Fish and Wildlife. (2004). Vermont Fish and Wildlife. Retrieved from  http://www.vtfishandwildlife.com/.

Watzin, M.C., Joppe-Mercure, K., & Rowder, J. (2008). Significant fish predation on zebra mussels Dreissena polymorpha in Lake Champlain, U.S.A. Journal of Fish Biology, 73(7), 1585-1599. Retrieved from http://www3.interscience.wiley.com/cgi-bin/fulltext/121510225/PDFSTART.

Young, B. A., Bouffard, W.R., & Chipman, B.D. (2000). Strategic Plan for Lake Champlain Fisheries. Fisheries Technical Committee of the Lake Champlain Fish and Wildlife Management Cooperative, Retrieved from http://www.vtfishandwildlife.com/library/Reports_and_Documents/Fisheries/Strategic_Plan_for_Lake_Champlain_Fisheries.pdf.

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