How much do lake trout and Chinook salmon really eat?

Chinook salmon have been the most important predator in Lake Michigan for decades. With baitfish on the decline, some anglers believe that lake trout are now eating more than salmon.

It takes a lot of food for a lake trout to grow this big, but a Chinook salmon eats much more on an annual basis.

It takes a lot of food for a lake trout to grow this big, but a Chinook salmon eats much more on an annual basis. Photo: Michigan Sea Grant

The food supply in Lake Michigan is not what it used to be. Invasive species like quagga mussels, nutrient reductions in open waters, and high numbers of predatory fish to feed all play a role in “squeezing” baitfish like alewife. The result can be an imbalance of predators and prey. In other words: too many mouths to feed for the amount of food available in open water.

Of course, this is a simplistic way of looking at things. Different species of fish are not the same in terms of the energy they consume and use. They grow at different rates, prefer different water temperatures, and utilize food more or less efficiently.

These factors become important when considering the total number (or biomass) of baitfish being consumed by predatory salmon and trout in Lake Michigan. Many anglers are particularly concerned about the impact of native lake trout versus introduced Chinook salmon. Both species are currently stocked in Lake Michigan, but both species also reproduce naturally.

Chinook salmon are prized gamefish with a very high growth rate and a short lifespan — they typically spawn and die at age 2.5 or 3.5 with a very few surviving to age 4. Lake trout are also a good gamefish, but they do not draw anglers to the lake in the same way that the spectacular fighting ability of the Chinook salmon does. Mid-sized trout are excellent table fare, but large, old lake trout tend to accumulate more contaminants than salmon. Lake trout can also live much longer than salmon (over 20 years), but they grow much more slowly.

Since there is a limited number of baitfish in the lake, there is a limited amount of energy (calories) available to trout and salmon. How does this all play out in terms of the amount and types of prey fish being eaten by lake trout and Chinook salmon?  To find out, I relayed some questions on the topic to two people who have been studying Lake Michigan fish for a combined total of over sixty years: Chuck Madenjian (USGS) and Jory Jonas (MDNR).

How would a lake trout and Chinook salmon compare in terms of the energy they consume each year?

C.M.: For the period of time from age 1 through age 12, annual food consumption by a lake trout in Lake Michigan averages 13 lbs. This estimate is based on the assumption that the annual food consumption for age-10 and age-11 lake trout is similar to that for lake trout of ages 7-9. For the period of time from age 0 through age 3.5, annual food consumption by a Chinook salmon in Lake Michigan averages 42.5 lbs. Thus, Chinook salmon in Lake Michigan are feeding at a rate more than three times higher than that of lake trout.

J.J.: I agree with Chuck’s summary above, but would also add that Chinook salmon grow faster, inhabit warmer waters than lake trout on average, and are much more active. All of these factors lead to increased demand for energy (food) relative to lake trout.

So, on an annual basis a Chinook salmon eats more than a lake trout of the same size. We know that lake trout live longer than Chinook salmon, though. How much does an average lake trout eat over its entire lifetime as opposed to an average Chinook salmon?

C.M.: The answer to this question partly depends on the definition of an entire lifetime for a lake trout. Based on the bioenergetics modeling by Don Stewart and others, an average lake trout consumes 143.3 lbs. of food between the time of stocking as a yearling into Lake Michigan and age 12. A Chinook salmon consumes 147.7 lbs. of food between the time of stocking as an age-0 fingerling into Lake Michigan and age 3.5, when a Chinook salmon is ready to spawn.   

J.J.: Chuck did a nice job of summarizing lifetime consumption of the two species above. When asking a question like this, it is important to consider why it is being asked. Total lifetime consumption of prey does not equate to information valuable in determining sustainability of the system. New year-classes of fish are always being produced and individual species have different life-spans and life-histories. Several generations of alewife and Chinook salmon will have cycled during the life-span of a lake trout. For example, during the lifespan of a lake trout age 12 which consumed 143.3 lbs. of prey there will have been four generations of Chinook salmon each consuming 147.7 lbs. of prey (590.8 total lbs.). Because of fluctuations in births and deaths and the lack of life-span synchrony among species, we typically summarize population levels of predators and prey on an annual basis in order to monitor for changes over time.

Fish are cold-blooded animals, so water temperature must affect how often they eat and how quickly they digest food. Do temperature preferences play a big role when comparing bioenergetics of lake trout and Chinook salmon?

C.M.: Temperature does play a role when comparing bioenergetics of lake trout and Chinook salmon. However, the main driver of the difference in consumption rates between lake trout and Chinook salmon is the difference in growth rates between the two species. In other words, the main reason for the much higher rate of food consumption by Chinook salmon compared with that by lake trout is that Chinook salmon grow substantially faster than lake trout. Average summer temperatures experienced by lake trout in Lake Michigan range from 46.4 to 50°F, whereas average summer temperature experienced by Chinook salmon in Lake Michigan ranges between 53.6 and 55.4°F. Metabolic costs typically increase with increasing temperature, and so Chinook salmon would be expected to have higher metabolic rates than lake trout. Nonetheless, the primary reason for the higher food consumption rate for Chinook salmon compared with that for lake trout is the higher growth rate by Chinook salmon compared with that for lake trout.

J.J.: Chinook salmon are also more active than lake trout, travelling large distances and generally moving around more. Combine higher activity levels with the factors mentioned by Chuck above, including higher temperature occupancy, and you have a higher demand for calories to support Chinook salmon.

Fish need energy to maintain basic body functions, chase down prey, and reproduce. Additional energy can be used for growth. How do lake trout and Chinook salmon compare in terms of their ability to use food energy for growth?

C.M.: Gross growth efficiency (GGE) is equal to growth (increase in weight) divided by the amount of food consumed to attain that growth. Thus, GGE is a measure of the efficiency with which a fish converts food consumption into its growth. According to the bioenergetics modeling by Don Stewart and others, the GGE for a 3.5-year-old Chinook salmon is 13.3%. That is, the 3.5-year-old Chinook salmon converted its food into its growth with a 13.3% efficiency. The GGE for a 12-year-old lake trout is estimated to be 8.0%. Thus, a Chinook salmon is considerably more efficient at converting food into growth than a lake trout in Lake Michigan.

Large, old lake trout are a common catch in central and southern Lake Michigan. These fish might weigh over 20 pounds and be 20 years old or older. Computer models that calculate how many baitfish are being eaten in Lake Michigan treat a 20-year-old lake trout the same as a six-year-old. Does a 20-year-old lake trout really eat only as much as a six-year-old?

C.M.: To answer this question, a growth trajectory for lake trout from ages 1 through 20 would be needed. Stewart et al. (1983) estimated mean weight at age for ages 1 through 10 only, so information on mean weight at age for ages 11 through 20 would be needed to answer this question. According to Stewart et al. (1983), annual consumption of food by an average lake trout in Lake Michigan remained relatively constant at a value of about 17.6 lbs. between the ages of 6 and 10. In other words, annual feeding rate of lake trout did not increase as lake trout age increased from 6 to 10. Mean weight at age 6 was 6.6 lbs., and mean weight at age 10 was 10.6 lbs. Thus, even though the weight of an average lake trout increased by 4 lbs. between ages 6 and 10, annual rate of food consumption by lake trout did not increase between ages 6 and 10 (Stewart et al. 1983). Note that annual weight gain by lake trout decreased between ages 6 and 10. If the annual weight gain (annual growth) continued to decrease between ages 10 and 20, a large increase in annual consumption over ages 10-20 would not be expected.

J.J.: It is true that larger fish on average require more energy than smaller fish, all else being equal. As lake trout age, the annual growth rate is much less, reducing energy demands, as mentioned by Chuck above. In more recent catch-at-age modelling efforts in eastern Lake Michigan, the mean weight of a lake trout at age 6 was 5.7 lbs., at age 10 was 9.7 lbs. (a change of 4 lbs. in 4 years) and was 11.2 lbs. at age 15 (an increase of 1.5 lbs in 5 years). By age 7 most lake trout are spawning so fish age 7-15 should be experiencing similar energy demands for spawning. Despite this, growth rate (body weight added per year) continues to decline as the fish ages.

Studies on Great Lakes salmon and trout bioenergetics were conducted back in the 1980s. Do they still hold true today with so many invasive species in the food web and changes to the strains of lake trout being stocked?

C.M.: Bioenergetics models for Chinook salmon and lake trout are sufficiently flexible such that they can accommodate changes in the Lake Michigan food web and changes in lake trout strains being stocked. Inputs to the bioenergetics models include growth of the fish (predator), temperature regime experienced by the fish, diet schedule for the fish, energy density of the prey, and energy density of the fish (predator). All of these inputs can be adjusted to more accurately reflect changes in the food web or changes in lake trout strains stocked. Bioenergetics model estimates of food consumption by Chinook salmon and lake trout are especially sensitive to estimates of growth by Chinook salmon and lake trout, so changes in growth over time would need to be taken into account when estimating food consumption by these fishes over decades of time. In the laboratory, the lake trout bioenergetics model performed equally well for both Marquette and Seneca Lake strains of lake trout, so lake trout bioenergetics was very similar among strains of lake trout. The Seneca Lake strain does inhabit slightly cooler water than the Great Lakes strains of lake trout, but this slight difference in temperatures between strains had only a small effect on food consumption. Laboratory performances of both the Chinook salmon bioenergetics and the lake trout bioenergetics model are reasonably good. On average, the model estimates of food consumption are within 5% of observed consumption.           

Now we know how much individual trout and salmon eat, but how many baitfish are eaten annually by all predators in Lake Michigan? How did estimated lake trout consumption compare to estimated Chinook salmon consumption on a lakewide basis in 2016?

J.J.: In 2016, lake trout consumed 13.7 kt of prey and Chinook salmon consumed 38.4 kt. Even though numbers of Chinook salmon in 2016 were at all time low levels lake-wide, they consumed nearly 3 times as much forage as lake trout. In 2016, the biomass of Chinook salmon in Lake Michigan was estimated to be 5.0 kt and lake trout 5.9 kt. Just four years’ prior, in 2013, Chinook salmon biomass was substantially higher at 15.7 kt and lake trout were 7.0 kt.

Until now we have only been discussing how many baitfish are being eaten, but we know that Chinook salmon depend almost entirely on alewife while lake trout can eat a variety of prey including round gobies. Have lake trout moved away from eating alewife in Lake Michigan?

J.J.: Lake trout tend to be opportunistic feeders and will take advantage of a variety of prey items, whereas Chinook salmon are more specialized preferring almost exclusively alewife as prey. Since about 2003, lake trout have been taking advantage of a relatively new prey source in Lake Michigan, the round goby. Because of increased public interest in understanding the role of lake trout as predators in Lake Michigan, a variety of new initiatives have begun to better understand this more complex predator. For the last few years, diet collections have been occurring outside of the standard spring assessments which conclude in mid-June, and on broader spatial scales. Preliminary comparisons indicate that there is a seasonal component to lake trout feeding whereby they consume larger numbers of round goby in the spring and increased dependence on alewife as the year progresses. Smelt and bloater have been abundant in the diets of lake trout in the past, but for the recent 5 years over 75% of lake trout diets have been comprised of alewife and round goby. We continue to explore new and more robust methods for keeping up with the changing trends in lake trout consumption. Some of these include evaluation of fatty acid or isotopic signatures which can represent a longer period of lake trout consumption (in the case of isotopes up to one-year). We are seeking funding to conduct broader data collection efforts to better understand changing patterns throughout the lake and in different seasons.

So, we don’t yet know exactly what percentage of Lake Michigan lake trout diet is alewife, but what was the realistic range of possible alewife consumption by lake trout in 2016?

J.J.: It’s still early, but most of us are comfortable with an average alewife diet proportion of around 50% for lake trout, which we currently use in consumption models. Preliminary investigations indicate that in the spring (April to mid-June) alewife comprise between 7% to 20% of the diet of lake trout, and from mid-June to August alewife can represent from 50% to 80% of the diet. We continue to pursue improvements to describe feeding patterns of this more complex predator in the Lake Michigan basin.

Thanks Jory and Chuck for providing detailed answers to these questions.

In summary, when anglers point out that lake trout need more food to reach a given weight they are correct. A lake trout needs about 125 pounds of food to reach a weight of ten pounds while a Chinook salmon needs around 75 pounds of food (based on differences in gross growth efficiency). However, the Chinook salmon consumes this amount of food over a very short period of time when compared to a lake trout.

In fact, a typical Chinook salmon consumes roughly three times as much food in a given year as a typical lake trout does. This is critically important because alewife (and other prey fish) reproduce and grow each year. The absolute amount of food consumed by a salmon or trout in its lifetime is therefore less important to maintaining a good predator-prey balance than its annual demand for prey.

Chinook salmon do burn through alewife much more quickly than lake trout, but that does not mean that lake trout consumption is completely insignificant. Science is always improving, and the upcoming study on predator diets is one example of an effort to better understand what lake trout are eating at different times and in different parts of Lake Michigan.

Despite the never-ending quest for better information, fishery managers must make decisions in real time based on the best available scientific information. We know that an individual Chinook salmon consumes more alewife than a lake trout does, but we also know that Chinook salmon are no longer the only important species to consider when looking at predator-prey balance in Lake Michigan. In the future, scientists will be taking a harder look at diet and consumption of other predators like lake trout, coho salmon, and steelhead.

More information:

Michigan Sea Grant helps to foster economic growth and protect Michigan’s coastal, Great Lakes resources through education, research and outreach. A collaborative effort of the University of Michigan and Michigan State University and its MSU Extension, Michigan Sea Grant is part of the NOAA-National Sea Grant network of 33 university-based programs.

References

Bergstedt, R.A., Argyle, R.L., Krueger, C.C., and Taylor, W.W. 2012. Bathythermal habitat use by strains of Great Lakes- and Finger Lakes-origin lake trout in Lake Huron after a change in prey fish abundance and composition. Transactions of the American Fisheries Society 141(2): 263-274.

Madenjian, C. P., D. V. O’Connor, S. M. Chernyak, R. R. Rediske, and J. P. O’Keefe. 2004. Evaluation of a chinook salmon (Oncorhynchus  tshawytscha) bioenergetics model. Canadian Journal of Fisheries and Aquatic Sciences  61:627-635.

Madenjian, C. P., S. R. David, and S. A. Pothoven. 2012. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model. Transactions of the American Fisheries Society 141:1328-1337.

Madenjian, C. P., S. A. Pothoven, and Y.-C. Kao. 2013. Reevaluation of lake trout and lake whitefish bioenergetics models. Journal of Great Lakes Research 39:358-364.

Stewart, D.J., and Ibarra, M. 1991. Predation and production by salmonine fishes in Lake Michigan, 1978-88. Canadian Journal of Fisheries and Aquatic Sciences 48: 909-922.

Stewart, D.J., Kitchell, J.F., and Crowder, L.B. 1981. Forage fishes and their salmonid predators in Lake Michigan. Transactions of the American Fisheries Society 110: 751-763.

Stewart, D.J., Weininger, D., Rottiers, D.V., and Edsall, T.A. 1983. An energetics model for lake trout, Salvelinus namaycush:  application to the Lake Michigan population. Canadian Journal of Fisheries and Aquatic Sciences  40: 681-698.

Student video promotes awareness of Great Lakes marine debris

While plastic monsters invade Michigan’s Great Lakes and inland waterways, Alpena Elementary students create video to foster awareness of this issue among their local community.

Alpena Public Schools students get ready for action while filming their video

Alpena Public Schools students get ready for action while filming their video “Plastics 101.” Photo: RC Laugal

What is marine debris? It’s essentially human-made trash – large and small – that finds its way to oceans, our Great Lakes and inland waterways. A group of fifth-grade students from Alpena, Mich., want to help everyone understand what it is and what can be done to fight this problem. They created a movie and offer ideas about how everyone can contribute toward solutions. Watch their student-created film at: http://bit.ly/Plastics101.

The National Oceanic and Atmospheric Administration (NOAA) has championed an initiative to foster awareness, understanding, and citizen engagement in a growing issue of marine debris in our oceans and inland waterways. Through the Northeast Michigan Great Lakes Stewardship Initiative (NEMIGLSI) network, Michigan Sea Grant, Michigan State University Extension, and the NOAA Thunder Bay National Marine Sanctuary are partnering with schools, educators, and youth leaders to raise local awareness about this Great Lakes problem.

How did these students get involved?

In fall 2016, Bob Thomson’s Ella M. White Elementary fifth-grade students visited Thunder Bay River, where they used nets to trawl for plastics, and were shocked to find microplastics in our Northeast Michigan watershed. After analyzing samples from the river, fifth-grader Tucker Bright said, “If there are this many microplastics in this little sample, just imagine how many there are in the Great Lakes!” To raise awareness about finding plastics in the river and finding solutions to this problem, these Alpena Public Schools students developed a film, “Plastics 101.”

Through the NEMIGLSI network, they worked with community partners, including Huron Pines AmeriCorps, Michigan Sea Grant, and Thunder Bay National Marine Sanctuary, to complete the film. The effort also was supported by DonorsChoose.org through Tom’s of Maine Green Your School Campaign.

Before filmmaking, the students researched the topic of marine debris and found that microplastics are a problem in both our Great Lakes and oceans. The students consulted with fisheries expert, Brandon Schroeder (Michigan State University Extension, Michigan Sea Grant Educator), and microplastics expert, Dr. Sherri Mason (Professor of Chemistry, The State University of New York at Fredonia), to verify their research. Next, the students outlined the films’ goals and began creating a storyboard. The students also crafted props, recorded audio, captured video footage while having fun and learning.

‘Plastics 101’

The film “Plastics 101” emerged with entertaining insights into the troubles of a throwaway culture and the effects on the Great Lakes and oceans. Students also learned about potential career options while applying classroom learning goals. Thomson said, “The video provided a perfect opportunity to develop a cross-curriculum project that focused on targets from English Language Arts, Science, and Social Studies.” Thomson recently was named 2017 Michigan Science Teacher Association Elementary Science Teacher of the Year.

Students also learned more about how their actions impact their community and ultimately the world. When plastics are improperly disposed, they could end up in a local stream, river, or the Great Lakes by the wind, rain, and through storm drains. Students were surprised to learn plastics absorb toxins, such as DDT, PAH and PCBs, and that these toxins can enter our food web through plastics. Since plastics don’t biodegrade, they don’t go away; they simply photodegrade into tiny pieces that can be consumed by plankton or small fish and then move up the food chain. To showcase solutions to this problem, the students highlight how to take action and protect our Great Lakes and ocean.

“Plastics 101” now will serve as an educational tool through the Northeast Michigan Earth Day Bag Project, an effort where third-, fourth-, and fifth-graders learn about the harms of single-use plastics to our Great Lakes and ocean and solutions to this growing problem. After watching a series of short films and discussing the information, students across northeast Michigan will decorate paper bags with conservation messages (e.g. Refuse to Single Use; Protect our Great Lakes), which will then be distributed to customers at local grocery stores on Earth Day, April 22, 2017.

Michigan Sea Grant and Michigan State University Extension serve in providing leadership for the NEMIGLSI network, which is part of a larger, statewide network and partnership, the Great Lakes Stewardship Initiative (GLSI). Established in 2007 with funding from the Great Lakes Fishery Trust, the GLSI supports place-based stewardship education in schools and communities across Michigan. Partnerships are invaluable in our endeavor to support stewardship of our Great Lakes and natural resources.  Through the NEMIGLSI network, and applied place-based education strategies, our students may perhaps prove the most inspirational educators of all in addressing important Great Lakes issue such as marine debris.

Michigan Sea Grant project looks at cisco restoration in Lake Michigan

How can cisco restoration efforts be tailored to fit the needs of Lake Michigan stakeholder groups?

A school of cisco swim in Lake Superior near Isle Royale National Park. Photo: Ron Kinnunen | Michigan Sea Grant

A school of cisco swim in Lake Superior near Isle Royale National Park. Photo: Ron Kinnunen | Michigan Sea Grant

The alewife supported the salmon fishery in the Great Lakes but had negative qualities such as high levels of thiaminase which interferes with reproduction of trout and salmon. The alewife also is a predator on many of our native larval fish and thus affects recruitment of species such as lake trout and walleye. The cisco, which is a native species, does not share these negative attributes of the alewife.

In recent years the alewife population has declined in lakes Huron and Michigan which has led to a window where the native cisco might recover in areas where there are remnant populations or be reintroduced into areas where it no longer exists. Many stakeholders have promoted the reintroduction of cisco. Though many stakeholder groups are interested in restoring cisco, they disagree on the best approach. Some advocate helping remnant populations recover, while others recommend stocking Lake Michigan with young cisco from Lake Michigan’s remnant population or from elsewhere in the Great Lakes region. Michigan Sea Grant has an integrated assessment project underway on Cisco Restoration in Lake Michigan (PDF). During an integrated assessment project researchers work closely with stakeholders to examine an issue from many perspectives, identify challenges, and evaluate feasible solutions.

If stocking of cisco is to occur some issues that need to be resolved are the development of hatchery facilities that can produce large numbers of cisco and the genetic lines that should be used in this rehabilitation effort. Restoration through hatchery production can result in loss of genetic variability because eggs and milt often are taken from a relatively small number of individuals that may not be a good representation of the gene pool of the entire population. Ecological conditions in the lakes have changed drastically and there is concern whether cisco could survive once stocked.

As part of the Michigan Sea Grant project a research team led by Sara Alderstein, an associate research scientist at the University of Michigan, will use existing data and guided workshops and discussions to help stakeholders create a path for cisco restoration in Lake Michigan. Michigan Sea Grant Extension recently presented information on this project at the Lake Michigan Technical Committee meeting and at the Annual Michigan Fish Producers Association Conference. A workshop is planned this summer during the Lake Michigan Technical Committee. Through the workshops, the project team will provide a framework for helping managers and the fishing community advance a preferred option for Lake Michigan cisco restoration.

Salmon Ambassador volunteers had mixed success for Chinook salmon in 2016 on Lake Michigan

Research shows wild salmon made up the majority of the catch in most regions.

Results from around Lake Michigan show that wild fish make up the majority of the catch, especially in Michigan ports near high-quality tributaries like the Manistee River and Pere Marquette River.

Results from around Lake Michigan show that wild fish make up the majority of the catch, especially in Michigan ports near high-quality tributaries like the Manistee River and Pere Marquette River.

The Salmon Ambassadors program is an angler science project led by Michigan Sea Grant and Michigan State University Extension, and funded in part by Detroit Area Steelheaders. Anglers who volunteer for the program share information on their season’s catch with one another—and with biologists. Since 2014, anglers around Lake Michigan and northern Lake Huron have been collecting data on stocked and wild Chinook salmon.

Volunteers measure the length of each Chinook salmon caught over the course of the fishing season and look for a clipped adipose fin that indicates a stocked fish. At the end of the season, volunteers complete a short survey and return their data sheets. Results from 2016 were released this week and are now available as fact sheets posted on the Salmon Ambassadors web page.

Increased angler satisfaction in Wisconsin

Overall angler satisfaction among volunteers increased in 2016. On a scale of one to five (five being the highest), average satisfaction with fishing experiences increased from 2.4 in 2015 to 3.1 in 2016. While this was encouraging, most of the increase was due to improvements in fishing on the west side of Lake Michigan, and in Wisconsin in particular.

In Wisconsin waters, angler satisfaction increased from 2.5 in 2015 to 4.2 in 2016. This coincided with big increases in catches of Chinook salmon, coho salmon, brown trout, and steelhead reported by Wisconsin DNR (lake trout catch decreased in Wisconsin waters in 2016).

In Michigan, anglers did not fare so well – perhaps in part due to weather patterns that kept cool water along the Wisconsin shore for much of the summer. Angler satisfaction for Salmon Ambassadors fishing Michigan waters of Lake Michigan remained relatively low (2.4 in 2015; 2.5 in 2016).

Lake Huron anglers fared better, with volunteers in the northern part of the lake reporting that angler satisfaction increased from 2.3 in 2015 to 4.6 in 2016. The number of fish caught by Lake Huron volunteers also increased dramatically, from only 35 Chinook salmon in 2015 to 159 in 2016.

Wild salmon still dominate catches, particularly in Michigan

Since the lakewide program began in 2014, wild Chinook salmon have outnumbered stocked in all areas of Lake Michigan. In Michigan waters, the percent wild has consistently been highest at ports such as Manistee and Ludington, which are located at the mouths of rivers that offer excellent spawning habitat to migrating salmon.

Results from Michigan waters in 2016 found:

  • 83% wild in Manistee (including Onekema)
  • 86% wild in the Ludington area (including Pentwater)
  • 68% wild in the Grand Haven area (Whitehall to Saugatuck)
  • 67% wild in southwest Michigan (South Haven to St. Joseph)

In Wisconsin, stocked fish made up a slightly larger portion of the catch. This is probably due to a combination of factors including the lack of good spawning rivers in Wisconsin, higher number of stocked Chinook salmon in Wisconsin waters, and higher survival rate for Chinooks stocked in Wisconsin waters.

Results from Wisconsin waters in 2016 found:

  • 59% wild in Door Peninsula (including Kewaunee to Washington Island)
  • 60% wild in southern Wisconsin (including all ports form Sheboygan south to the state line)

Volunteers in Illinois and Indiana found that 70% of Chinook salmon in their catches were wild, while those fishing northern Lake Huron from the Mackinaw Straits to Rogers City found that only 33% of their catch was wild. This is likely due to the good number of mature ‘kings’ being caught in Rogers City as they returned to the Swan River in late summer.

Narrow margin of support for Lake Michigan stocking cuts

A proposal to reduce Chinook salmon in Lake Michigan was announced in June 2016. While the vast majority of anglers were supportive the 2013 stocking cut, the 2016 proposal was met with mixed reactions. Opponents of the proposed 62% Chinook salmon stocking reduction called for additional cuts to lake trout stocking.

Salmon Ambassadors were asked about their support for, or opposition to, a revised proposal that included a 21% reduction to lake trout stocking and a 50% reduction to Chinook salmon stocking. Volunteers expressed strong opinions on both sides of the issue, and many offered insightful comments regarding the state of the fishery and the need to adjust to a rapidly-changing ecosystem.

All in all, 51% of volunteers who responded to the survey (N=55) supported the revised stocking proposal. For Wisconsin and Michigan anglers, state of residence did not have a significant effect on support or opposition. Volunteers from Wisconsin and Michigan demonstrated similarly high knowledge of Great Lakes fisheries biology, and anglers from both states were also similar in their moderate level of trust in the ability of science to reflect actual conditions in Lake Michigan.

Volunteers trusted “percent wild” calculations more than other fisheries statistics, perhaps because of their own involvement in collecting this data. On a scale of 1 to 5 (with 5 being the highest), volunteers rated their trust in “percent wild” at 4.0 as opposed to 3.5 for general trust in fisheries science and 3.0 for trust in estimates of alewife biomass. Most anglers agreed or strongly agreed that participation in Salmon Ambassadors made them more aware of what is going on in the Lake Michigan fishery (average 4.7 on the five-point scale).

Due to the success of this program and the support of anglers, fishing clubs, and natural resource agencies the Salmon Ambassadors program will be expanded and continued in 2017. See the MSUE article “Fishing for Answers” for more details.

CISMAs work together to manage invasive species

Homeowners can seek help from Michigan’s 17 Cooperative Invasive Species Management Areas.

by Kip Cronk

Michigan’s Cooperative Invasive Species Management Areas (2016) are shown. There are 17 CISMAs in the state.

Michigan’s Cooperative Invasive Species Management Areas (2016) are shown. There are 17 CISMAs in the state.

Don’t feel alone in the battle against invasive species. In Michigan, there are 17 Cooperative Invasive Species Management Areas (CISMAs) that will assist private landowners with invasive species control. You can think of CISMAs as regional invasive species organizations – sort of a clearinghouse of expertise that brings managers together towards a common management goal. “Partner organizations, big and small, are what allow a CISMA to thrive,” said Katie Grzesiak of the Northwest Michigan Invasive Species Network. “Many partners have supported a plethora of successful projects, from controlling invasive phragmites in Grand Traverse Bay to creating the ground-breaking Go Beyond Beauty program that encourages the voluntary removal of invasive species from ornamental landscapes.”

If you are dealing with an invasive species such as invasive phragmites, Japanese knotweed, or flowering rush, it can be overwhelming. Your local CISMA can assist you with technical assistance, identification, training, treatment, monitoring and a partnership. Each CISMA has its own priority species as there are too many invasive species in Michigan for each CISMA to manage them all. The most common invasive species being addressed by CISMAs at this time are invasive phragmites, Japanese knotweed and garlic mustard. “CISMAs are an excellent source of assistance for local landowners. They will help with a range of invasive species activities –—from teaching landowners simple steps for prevention, to helping with identification of unknown plants, to treatment and control,” said Christina Baugher of the Michigan Department of Natural Resources (DNR). “I am continually impressed by the work of Michigan’s CISMAs. As a state, we would not be where we are in the fight against invasives without them.”

If you are a private landowner battling invasive species, you should contact your local CISMA early to find out what their priority species are and what assistance they offer. Even if you have a species that is not one of their priorities, they most likely will be able to offer technical assistance through brochures and websites to help manage that specific species. Many CISMAs hire a summer Strike Team that manages their priority invasive species through identification, treatment and monitoring. At this time, some of the CISMAs do not charge for any of their services, whereas others have a cost share program. “The Saginaw Bay CISMA is proud to provide landowners with free treatment of their small infestations of invasives such as phragmites and Japanese knotweed. Without these treatments, the infestations are likely to spread and become a larger detriment to not only the initial landowner, but to their surrounding neighbors,” said Fallon Januska, coordinator of the Saginaw Bay CISMA.

The battle against invasive species can be difficult, but it is good to know that Michigan has so many organizations willing and able to assist private landowners and build partnerships with local organizations. It is recommended you manage invasive species on your property when they are first discovered. The larger the infestation, the more difficult they are to control. Take time today to contact your local CISMA. Take time today to volunteer with your local CISMA. Take time today to spread the word about your local CISMA. The Michigan Invasive Species Coalition has a list of all of the Michigan CISMAs and contact information on their website.

Request for Proposals: Great Lakes Clean Marina Network

Event Date: 4/17/2017

Michigan Sea Grant, as co-coordinator of the Great Lakes Clean Marina Network, is soliciting proposals for projects supporting Great Lakes Clean Marina Programs in 2017. Michigan Sea Grant anticipates awarding two grants with $5,000 as the maximum annual funding allowance per grant. The projects will run for up to one year, to be completed by April 30, 2018.

This request for proposals is open to all eight Great Lakes states of the Great Lakes Clean Marina Network (IL, IN, MI, MN, NY, OH, PA, WI). The network’s mission is to ensure that quality of life, economic prosperity, and environmental quality are achieved in the Great Lakes region by increasing participation in Clean Marina efforts.

This request for proposals focuses on two categories: 1) projects to expand the territory for Clean Marina certification within the Great Lakes Basin, or 2) projects that evaluate and/or support Clean Marina Program sustainability.

See: Funding Opportunities

2017 Fisheries Workshops Series

Event Date: 4/4/2017
End Date: 5/24/2017

Michigan Sea Grant, in partnership with fisheries agencies and stakeholder organizations, hosts public information workshops annually. The workshops focus on current research and information related to the regional status of Great Lakes fisheries. These workshops are open to the public and provide valuable information for anglers, charter captains, resource professionals and other interested stakeholders.

If you’re interested in attending a workshop, please register using the information below so the organizers can plan accordingly.

Workshop Schedule

Port Huron
Tuesday, April 4
6–9 p.m.
Charles A. Hammond American Legion Hall, 1026 6th Street, Port Huron, MI 48060
Register Online

Bay City
Wednesday, April 12
6–9 p.m.
Bangor Township Hall, 3921 Wheeler Rd, Bay City, MI 48706
Register Online

Harrison Township
Thursday, April 13
6–9 p.m.
Sportsman’s Direct, 38989 Jefferson Ave, Harrison Township, MI 48045

South Haven 
Thursday, April 20, 2017
7–9:30 p.m.
South Haven Moose Lodge, 1025 Wells St., South Haven, MI 49090

Oscoda 
Wednesday, April 26
6–9 p.m.
American Legion Oscoda, 349 S. State Street, Oscoda, MI 48750
Register Online

Cedarville 
Thursday, April 27
6–9 p.m.
Clark Township Community Center, 133 E. M-134, Cedarville, MI 49719
Register Online

Harvey
Wednesday, May 24
6–9 p.m.
Chocolay Township Hall, 5010 US-41, Harvey, MI 49855
Register Online

National Invasive Species Awareness Week series highlights threats Michigan faces

Damage caused by invasive plants alone costs the U.S. estimated at $34.7 billion a year.

The claws of the red swamp crayfish have bright red spiky bumps. Photo: Mike Murphy

The claws of the red swamp crayfish have bright red spiky bumps. Photo: Mike Murphy

The Michigan Department of Natural Resources (MDNR) defines invasive species as non-native, rapidly reproducing species which threaten the integrity of natural areas. Once established in an area, they can have devastating effects. They often out-compete native species for limited resources including food and habitat, alter and damage existing habitat, displace native species, and in some cases prey directly upon native species. Invasive species have been identified as serious threats to global and local biodiversity.

According to the Weed Science Society of America (WSSA), it has been estimated the damage caused by invasive plants alone costs the U.S. an estimated $34.7 billion a year. Despite the profound impacts of invasive species, WSSA believes the key to being able to manage invasives and prevent their spread is awareness.

February 27 to March 3, 2017, is National Invasive Species Awareness Week and the goal is to draw attention to invasive species and what individuals can do to stop the spread and introduction of them. The program’s website lists several events around the country related to invasive species, including meetings in Washington, D.C.

To help bring local awareness to invasive species, Michigan State University Extension  and Michigan Sea Grant will feature an article on a terrestrial or aquatic invasive species each day that have invaded, or pose a potential threat to invade Michigan’s environment.

Additional information about invasive species can be found at the Extension website.

Read the complete 2017 Invasive Species Series:

Seminar: Fish Spawning Reef Planning Techniques

Event Date: 5/15/2017

reef-restoration-graphic

This seminar will be held in conjunction with the International Association for Great Lakes Research (IAGLR) 2017 conference in Detroit. You do not need to register for IAGLR to participate.

A number of factors, including construction of shipping channels, land use changes and dams, have degraded rocky fish spawning habitat or made it inaccessible to native, migratory fish. One method for compensating for spawning habitat losses is to construct fish spawning reefs, essentially beds of loose rock placed on the river bottom that provide adequate protection and flow through the rocks for egg incubation. Though simple in concept, reef projects need to be carefully sited and designed to avoid accumulating sediment, attract desired fish and support young fish through the critical early life stages.

This team- taught seminar will share techniques developed through eight reef projects established in the St. Clair and Detroit River System over the past fifteen years. Specific topics will include: site assessment and selection, hydrodynamics and sedimentation concerns, reef design and construction strategies and monitoring of early life stages of fish.

One highlight of the workshop will be a practical lesson on river hydraulics and sediment transport and a hand-on exercise with free river modeling software, led by a scientist from the USGS Geomorphology and Sediment Transport Lab. This interactive seminar is open to all types of restoration practitioners, including professional engineers, project managers, researchers and anyone hoping to champion, design or monitor a constructed spawning reef in Great Lakes nearshore areas, connecting channels or larger rivers.

Date: Monday, May 15, 2017
Time: 9:00 a.m. to 4:30 p.m.
Location: IAGLR’s Great Lakes Research Conference, Cobo Center Room 258, 1 Washington Blvd, Detroit, Michigan
Continuing Education: Seminar participants will receive a certificate showing they completed 7 hours of continuing education suitable for professional license renewals.
Cost: $75 for professionals, $30 for students 
Registration deadline: 5:00 p.m., May 10, 2017
Cancellation: No refunds will be issued for cancellations after May 5.

For professionals ($75):
 

For students ($30):

For questions, contact:
Lynn Vaccaro
University of Michigan Water Center
Lvaccaro@umich.edu
(734) 763-0056

Quiet Water Symposium

Event Date: 3/4/2017

quiet_water_symposium_arena_exhibits_2015

Mark your calendar and make plans to attend the 22nd Annual Quiet Water Symposium, which promotes non-motorized outdoor recreation.  Visit our Michigan Sea Grant booth and try your luck at winning a prize!

Last year’s Symposium featured over 200 exhibits, speakers and demonstrations. This year will feature presentations by noted travel writers, Jim DuFresne, Kevin Callan, Hap Wilson and the dean of outdoor writers, Cliff Jacobson.

Campers, hikers, cyclists, sailors, anglers, and of course paddle sport enthusiasts will all find something interesting at the symposium.

We hope to see you there!

When: Saturday, March 4, 2017
Where: Michigan State University Pavilion, 4301 Farm Lane, East Lansing, MI
Time: 9:00 AM to 5:30 PM
Cost: Adults $10.00, Students with I/D $5.00, under 12 free.

www.quietwatersociety.org