Learn more about declining Great Lakes prey fish populations

A cross-basin overview reviews status and trends of prey fish from 1978 to 2016.

The research vessel Sturgeon conducts prey fish trawl surveys on the Great Lakes. Photo: Great Lakes Fishery Commission

The research vessel Sturgeon conducts prey fish trawl surveys on the Great Lakes. Photo: Great Lakes Fishery Commission

There were massive changes in the Great Lakes fish communities during the 20th century. During that time proliferation of sea lamprey, alewife, and smelt occurred. In the mid-20th century the collapse of native fish communities, such as lake trout and ciscoes occurred. In the late 20th century there was stocking of trout and salmon; the invasion and proliferation of zebra mussels, quagga mussels, spiny waterfleas, and round gobies; declines in Diporeia (small, shrimp-like crustacean), alewife, and rainbow smelt; and the oligotrophication of Lakes Huron, Michigan, and Ontario because of low phosphorus inputs and the cropping of phytoplankton by quagga mussels. An oligotrophic lake has a deficiency of plant nutrients, usually accompanied by an abundance of dissolved oxygen.

Given this scenario questions are asked on how similar or different are the changes in fish communities across the Great Lakes and what could be causing these changes? Michigan Sea Grant and Michigan State University Extension recently held an educational session at the Michigan Fish Producers Association Annual Conference. At the conference Chuck Madenjian of the U.S. Geological Survey Great Lakes Science Center discussed this topic and reviewed data prepared by his colleague Owen Gorman with other contributors from U.S. Geological Survey, Ohio Department of Natural ResourcesNew York Department of Environmental ConservationPennsylvania Fish and Boat Commission, and Ontario Ministry of Natural Resources and Forestry. Here is a summary of his presentation on Great Lakes prey fish:

Assessments of Great Lakes prey fish stocks have been conducted annually by the U.S. Geological Survey since the 1970s using bottom trawl surveys. The focus of the surveys has been on the prey species cisco, bloater, rainbow smelt, alewife, and round goby. Total prey fish (alewife, rainbow smelt, bloater, and cisco) biomass declined during 1978-2016 in Lakes Superior, Michigan, and Huron. Lake Ontario is now different based on a new correction factor and prey fish biomass was not available for Lake Erie.

Coregonids

There was a synchronous decline in coregonid (whitefish, cisco or lake herring, bloater, kiyi) biomass in Lakes Superior, Michigan, and Huron during 1978-2016 with peak biomass occurring during 1989-1992. Lake Huron showed a coregonid rebound during 2008-2012. Predation does not appear to be the primary driver of bloater dynamics during 1978-2016. Some fishery biologists believe predation on bloaters by salmon and trout is more important nowadays than during the 1980s and 1990s, but most of the diet data do not support this contention. There may be population-intrinsic factors (sex ratio); changes in climate patterns; changes in trawl catchability over time due to changes in bloater behavior or increased water transparency in Lakes Michigan and Huron.

Alewife

In Lakes Huron and Michigan there was a synchronous decline in alewife biomass during 1978-2016. Alewife is the dominant prey fish in Lakes Huron, Michigan, and Ontario. It is rare in Lakes Superior and Erie. Predation has been the primary driver of alewife dynamics in Lake Michigan since the 1960s and it is likely the main driver of alewife dynamics in Lakes Huron and Ontario as well.

Rainbow smelt

Rainbow smelt had a synchronous decline in Lakes Superior, Huron, Michigan, and Ontario during 1978-2016. Lake Superior peaked earlier than the other lakes in 1978. In these four lakes, rainbow smelt was an important prey species before the mid-1990s and is now a minor prey species. Predation appears to be the primary driver of rainbow smelt dynamics in Lake Superior but not in Lake Michigan.

Round goby

Round goby biomass increased in Lakes Michigan, Huron, Erie, and Ontario during the 1990s or 2000s, then peaked, perhaps even decreased somewhat, and appears to have leveled off in all four lakes. Further increases in round goby biomass are not expected. Round gobies in Lake Superior are mainly limited to harbors. Round goby populations in Lakes Michigan, Huron, Erie, and Ontario now appear to be under some degree of predatory control as they are fed upon by smallmouth bass, lake whitefish, burbot, lake trout, brown trout, yellow perch, other fish and birds. There are relatively high annual mortality rates (> 60% each year) in open waters of Lakes Michigan, Huron, and Erie.

Hiring: Special Projects Outreach Specialist

Michigan Sea Grant is seeking a fixed-term special projects outreach specialist. Position positing is available: http://careers.msu.edu/cw/en-us/job/498631/specialist-outreachfixed-term

Position Summary

As part of the Michigan Sea Grant College Program, this position has dual responsibilities providing leadership in special projects for facilitating integration and partnership among NOAA, Great Lakes Environmental Research Lab, National Sea Grant Network, and Michigan Sea Grant/Michigan State University about their research, extension, education and other programs; and (2) developing collaborative extension, communications, and outreach programs that draw upon the collaborators’ work and that are directed towards specific Great Lakes stakeholder audiences and/or the general public.

This position will collaborate across collaborators, work with faculty, specialists and educators for advancement of the needs of NOAA, NOAA GLERL, and Sea Grant; designs, implements and evaluates programming based on basic and applied research and the needs of partners; ensures dissemination of science-based information through various methods, including multi-media, personal education and written articles; and serves as an informational resource.

Michigan Sea Grant, a cooperative program of Michigan State University and the University of Michigan, helps to foster economic growth and conserve Michigan’s coastal and Great Lakes resources through education, research, and outreach. Sea Grant Extension educators and specialists are involved in planning, organizing, and implementing university-based educational programs that apply knowledge and understanding gained through research. Sea Grant staff support Great Lakes stakeholders with information and tools to make informed decisions to conserve Michigan’s coastal and Great Lakes resources and enhance coastal communities.

Sea Grant Extension staff serve a variety of stakeholder groups, but no single staff can be an expert in all areas of concern to all potential stakeholders. Therefore, staff are part of a collaborative team within Michigan Sea Grant and Michigan State University (MSU), specializing in particular areas; and sharing their knowledge and skills with colleagues in other parts of the state, Great Lakes region and nation. 

The person in this position will work collaboratively with the team of Sea Grant, MSU, and NOAA professionals to provide overall leadership on special projects for NOAA GLERL, NSGO, and Michigan Sea Grant/MSU. This person will collaborate with other partners to support activities related to facilitating NOAA, Sea Grant, and Extension integration and partnerships for collaborative research, extension, education, or other programs; and develop collaborative special projects.  

This position is a full-time, end-dated appointment renewable annually based upon successful performance and continued funding.

Required Degree

  • Master’s degree

Minimum Requirements

  • Master’s degree from an accredited institution in a field of study related to freshwater coastal wetlands, fisheries or wildlife ecology, water quality, land use, planning, natural resources, or related field must be earned by date of hire;
  • Demonstrated ability and skill in educational program planning, implementation and evaluation;
  • Proven ability to create and carry-out a project plan from research of initial concept to project completion and follow-up;
  • Other requirements per MSU employment guidelines.

Desired Qualifications

  • 3-years’ experience in Extension program delivery or demonstrated ability and skill in educational program planning, implementation and evaluation (relevant experience acquired within the last 5-years preferred);
  • Demonstrated effectiveness in leadership, facilitation, human relations, and written and oral communications;
  • Proven record of working with State, Federal, and community based organizations and groups;
  • Experience in establishing collaborations and community-based initiatives;
  • Computer skills, including use of word processing, spread sheets, GIS, presentation software and the development of multimedia programs;
  • An understanding of educational program planning and successful experience in proposal development;
  • Demonstrated success in grant writing and experience managing operating budgets;
  • Documented understanding of and commitment to equal opportunity, affirmative action and diversity/pluralism; and
  • Demonstrated ability to work effectively with diverse audiences of all socioeconomic levels and cultural backgrounds.

Required Application Materials

  • Applicants are asked to provide a current resume/CV, cover letter and four (4) professional references that will be contacted by the department if requested.

Special Instructions

  • Review of applications will begin on 2/28/2018 and will continue until filled.

www.michiganseagrant.org

Lake Superior water levels nearing monthly record highs

Shoreline erosion and coastal damages likely. Water will also make its way down through the other Great Lakes, too.

U.S. Army Corps of Engineers

U.S. Army Corps of Engineers

Monthly forecasts for Great Lakes levels in February 2018 have just been released by the U.S. Army Corps of Engineers. Many people are keeping a close eye on current lake levels and future predictions, particularly for Lake Superior. The preliminary data just in for January 2018, show Lake Superior just set the second highest monthly record level, a mere 2 inches below its all-time record for the monthly average January (record set in 1986). The recently released forecast also indicates a high probability Lake Superior could be within 2 inches of its all-time record high levels for every one of the next six months. Put simply, there is a lot of water in Lake Superior and all of that water will eventually make its way through the other Great Lakes.

100 years of data

Also, 2018 marks the centennial year of accurate lake level measurements from the series of binational gaging stations. The measurements for Lake Superior are taken in Duluth, Minn.; Marquette, Mich.; Pt. Iroquois, Mich.; Thunder Bay and Michipicoten, Ontario. There are now 100 years of coordinated data ­—this geographically dispersed gaging network accounts for seiches and provides excellent information – and thus 100 January monthly averages.

Isn’t Lake Superior’s water level controlled? 

The International Lake Superior Board of Control has a Regulation Plan 2012 and is responsible for regulating the outflow and control works in the St. Mary’s River. This Board has been in place since 1914 and has compensating works which allow for some limited variation. This plan must meet multiple objectives including hydropower; municipal and industrial water supply, navigation through the locks, and maintaining a minimum flow for protection of fish habitat in the St. Mary’s River. The January 2018 control board update states:

In consideration of the continuing high water levels in the upper Great Lakes, the International Lake Superior Board of Control, under authority granted to it by the International Joint Commission (IJC), will continue to release outflows of up to 2,510 cubic metres per second (m3/s) through the winter months. This flow is 100 m3/s more than the normal winter maximum prescribed by Regulation Plan 2012. Actual outflows may vary depending on hydrologic and ice conditions, as well as maintenance activities at the hydropower plants on the St. Mary’s River, all of which have been directed to flow at their maximum available capacity.” 

Additionally, the Board noted:''

“The high levels coupled with strong winds and waves have resulted in shoreline erosion and coastal damages across the upper Great Lakes system. As lake ice begins to form this may provide a level of protection to some areas of the shoreline, but additional shoreline erosion and coastal damages may occur this winter should active weather continue.”

System snow in Lake Superior impacts the spring seasonal rise as the snow turns into liquid water. We’re still in the thick of winter so time will tell if the 2018 seasonal rises are low, average, or high. Regardless of how much changes over the next few months, notable shoreline erosion and coastal damages can be expected on Lake Superior shores. (View above image)

Tools to help visualize changes

One tool for shoreline owners and other interests is the Great Lakes Shoreview risk assessment tool (http://www.greatlakesshoreviewer.org/#/great-lakes). This tool, funded by the Michigan Department of Natural Resources Office of the Great Lakes, is a web-based mapping tool that shows photos from the Lake Superior shoreline, some nearshore LIDAR data, and some risk rankings.

One other tool to note is the NOAA Lake Levels Viewer tool. Similarly, this web-based mapping tool allows users to artificially fluctuate levels up or down and see impacts on the shore. The tool is found on NOAA’s Digital Coast website at https://coast.noaa.gov/llv/. Select the lake you are interested in, zoom to your geographic area, and use the legend bar to vary the lake levels. You will see impacts on the screen.

It has been a bit of a coastal dynamics wild ride, just 5 years ago all-time record-low lake levels were noted in some of the Great Lakes; now we’re dealing with almost all time highs. Keep your seat belts buckled!

Contact Mark Breederland, Michigan State University Extension Sea Grant if you want more information on living with the ever-changing dynamic coastlines of the Great Lakes.

MSU grad’s work in Northeast Michigan will support place-based stewardship education

A childhood filled with beach trips, nature camps, and Ranger Rick magazines helped Hannah Hazewinkel choose her career path early on.

MSU graduate Hannah Hazewinkel is one of 26 Huron Pines AmeriCorps members serving this year with conservation stewardship agencies and organizations across Michigan. Courtesy photo

MSU graduate Hannah Hazewinkel is one of 26 Huron Pines AmeriCorps members serving this year with conservation stewardship agencies and organizations across Michigan. Courtesy photo

The Northeast Michigan Great Lakes Stewardship Initiative (NEMIGLSI), a place-based stewardship education network and partnership, has gained a new set of helping hands through the Huron Pines AmeriCorps program. Hannah Hazewinkel, a Michigan State University graduate, joins as one of 26 Huron Pines AmeriCorps members serving with conservation stewardship agencies and organizations across Michigan this year. Hannah received her Bachelor of Science degree in Environmental Biology and Zoology in May 2017.

As part of the NEMIGLSI network, Hannah will be supporting place-based stewardship education activities that facilitate school-community partnerships and support educators through sustained professional development. Most of all, her service will help engage youth, through their learning, in environmental stewardship issues and projects that make a difference in communities across northern Michigan.

In collaboration with MSU Extension and Michigan Sea Grant, Huron Pines is a leadership partner to the NEMIGLSI network and since 2009 they have placed AmeriCorps members annually in service of this education initiative. These members have been crucial in establishing and expanding this educational network of school and community partners in northeast Michigan communities.

So what do we have to look forward to in Hannah’s expertise and service in the coming year? Let’s meet and learn more about Hannah in her own words.

Tell us about yourself and what inspired you to pursue a career in environmental or conservation stewardship?

A childhood filled with beach trips, nature camps and Ranger Rick magazines had me convinced at the age of 9 or 10 that working in environmental conservation was the life path for me. For years I plastered my room in nature photos and articles and I dedicated myself to the study of natural science. In July of 2015, I realized the incredible power of environmental stewardship when I helped facilitate a tree planting event as an intern with the Department of Conservation in New Zealand. That day changed my life. I spent the following two years volunteering/interning/working at Fenner Nature Center, engaging with the educational programs and volunteer coordination, as well as becoming a Staff Naturalist. The support team and the experiences I had there taught me so much about nature and community relationships and inspired me to pursue stewardship and education as a career path.

What do you most look forward to in your upcoming service with the NEMIGLSI network and partnership?

I’m really looking forward to working with the youth and providing them with opportunities to engage with the land and the lakes and be touched by these encounters as I was. I love being able to witness these interactions firsthand and watch students and community members learn and grow in their connection to nature. I’m also excited to get out to these natural places in Northern Michigan and have as much of an engagement and learning experience as the students.

Looking forward and after nearly a year of service – what would you like to have accomplished?

I hope to gain a breadth of experience with place-based education and a better understanding of how we can integrate it into our educational systems to foster good student-community interactions and raise good environmental stewards. I want to build a good skills portfolio but also have my service mean something to the communities and the natural areas that I interact with. If I can change the life and perspective of at least one student and create a more sustainable future for at least one natural region, then at the end of the day I can be assured that I have made at least a small contribution to the Earth and reciprocated a fraction of the gifts that I have been given. For me, service is not about getting myself ahead, but rather showing humility and gratitude for the human and natural communities that have blessed and supported me throughout my life. 

How has your experience at MSU prepared you for this role and opportunity?

MSU and Lyman Briggs College provided me with a great natural science education, and diverse opportunities to explore different career paths, countries, cultures and activities. Their partnership with Massey University in New Zealand allowed me to have a life-changing study abroad and internship experience. Through the science and humanities-based curriculum in LBC, I was able to gain a better comprehension of how science is integrated in society, and how we need a well-rounded and open perspective to understand and solve the world’s problems.

What are some of your favorite Great Lakes and natural resources hobbies or memories? What Great Lakes and natural resources experience are you most looking forward to experiencing?

I’ve always been an avid beach-goer and paddler. One of my favorite stories from my parents is the time they took me down the Lower Platte River in a raft when I was less than two years old. I enjoy kayaking adventures and trips to Lake Michigan every summer and fall, and last year I completed my first Great Lakes tour, swimming in every Lake over the course of the summer. Fond memories from that trip include swimming in Lake Huron when the solar eclipse peaked and almost being denied entry into Canada because the immigration officers didn’t believe that anyone would be traveling just for the sake of seeing the Lakes. I’m looking forward to spending more time in Lake Huron, hiking, and paddling northeast Michigan rivers, particularly the Au Sable of which I am very fond.

Clean Marina Classroom Live: Harrison Township

When: March 27, 2018
Where: Thomas Welsh Activity Center, Lake St. Clair Metropark, 31300 Metro Parkway, Harrison Township, MI 48045
Workshop Host: Joe Hall and Sue Knapp

The Clean Marina Classroom is going on the road! In spring 2018, the Michigan Clean Marina Program will offer several in-person workshops. Michigan Sea Grant staff and Clean Marina certification specialists will cover important lessons from the online classroom tied to mandatory and recommended best practices for becoming a Clean Marina. Pledged marinas, as well as marinas due for re-certification in 2018, are invited to attend.

For the Classroom Live workshop to be effective, participants must take the following steps before the workshop:

    • Register for the workshop (dates and locations below).
    • Sign the Clean Marina pledge form (new and re-certifying marinas) and pay the required pledge fee (new marinas only).
    • Log in to the online classroom and complete the marina self-assessment (also called the certification checklist).
    • Bring your self-assessment, a notebook (paper and pencil or laptop) and your calendar to the workshop.

In return, each marina will leave with:

  • Clean Marina Classroom certificate
  • Scheduled certification site visit date
  • Prize for completing the workshop evaluation and survey

Other Locations

Petoskey

When: March 14, 2018
Where: City of Petoskey Winer Sports Park, 1100 Winter Park Lane Petoskey, MI 49770
Workshop Host: Kendall Klingelsmith, City of Petoskey Marina

Clean Marina Classroom Live: Petoskey

When: March 14, 2018
Where: City of Petoskey Winer Sports Park, 1100 Winter Park Lane Petoskey, MI 49770
Workshop Host: Kendall Klingelsmith, City of Petoskey Marina

The Clean Marina Classroom is going on the road! In spring 2018, the Michigan Clean Marina Program will offer several in-person workshops. Michigan Sea Grant staff and Clean Marina certification specialists will cover important lessons from the online classroom tied to mandatory and recommended best practices for becoming a Clean Marina. Pledged marinas, as well as marinas due for re-certification in 2018, are invited to attend.

For the Classroom Live workshop to be effective, participants must take the following steps before the workshop:

    • Register for the workshop (dates and locations below).
    • Sign the Clean Marina pledge form (new and re-certifying marinas) and pay the required pledge fee (new marinas only).
    • Log in to the online classroom and complete the marina self-assessment (also called the certification checklist).
    • Bring your self-assessment, a notebook (paper and pencil or laptop) and your calendar to the workshop.

In return, each marina will leave with:

  • Clean Marina Classroom certificate
  • Scheduled certification site visit date
  • Prize for completing the workshop evaluation and survey

Other Locations

Harrison Township

When: March 27, 2018
Where: Thomas Welsh Activity Center, Lake St. Clair Metropark, 31300 Metro Parkway, Harrison Township, MI 48045
Workshop Host: Joe Hall and Sue Knapp

Teachers: GLEP Registration Open

Award-winning program advances Great Lakes literacy and stewardship among K-12 students throughout southeast Michigan.

Teachers: Register now for the 2018 Great Lakes Education Program and think spring!

The Great Lakes Education Program begins its 28th year of classroom and vessel-based education in April. More than 3,400 teachers have joined the program on the water over those years.

GLEP education provides teachers and students with an award-winning learning opportunity that includes classroom, vessel-based and shoreside education. Students are the future stewards of our incredible Great Lakes, and this is an effective and memorable way to engage them in both learning about the lakes and in developing a personal sense of stewardship. We share a common ownership of and stewardship responsibility for the lakes. Teachers can register their class to participate and help students understand how important the Great Lakes are in Michigan.

Helps meet science standards

The program helps teachers meet Michigan’s Grade Level Content ExpectationsMichigan K-12 Science Standards, and the regional Great Lakes Literacy principles. Not to mention that 95 percent of students report they felt more knowledgeable about Great Lakes science after participating.

More than 115,000 students and adults have joined the program and learned more about the Great Lakes since 1991. Designed as a collaborative effort of  Michigan State University ExtensionMichigan Sea Grant, the Huron-Clinton Metroparks, and the National Oceanic and Atmospheric Administration, the Great Lakes Education Program provides students, their teachers and adult chaperones with an unforgettable on-the-water learning experience. With locations on both Lake St. Clair and Lake Erie, it is easy for schools throughout southeast Michigan to participate.

Register now

Registration is now open for the spring 2018 Great Lakes Education Program season, which runs from mid-April through mid-June. For more complete information on the program, the spring season calendar, locations, cost, and how to register go to the Great Lakes Education Program website.

Great Lakes Conference, ANR Week

The annual Great Lakes Conference held on March 6 will investigate the opportunities and challenges our Great Lakes face. Photo: Michigan Sea Grant

The annual Great Lakes Conference held on March 6 will investigate the opportunities and challenges our Great Lakes face. Photo: Michigan Sea Grant

The Great Lakes are one of Michigan’s most valuable resources, providing countless benefits in the present and offering tremendous opportunities for the future. Learn more about the opportunities and also the challenges facing the lakes during the annual Great Lakes Conference at Michigan State University.

The 28th Great Lakes Conference is an important part of MSU’s Agriculture and Natural Resources Week. The conference will be presented 9 a.m. to 4 p.m. March 6, 2018, at the MSU Kellogg Center auditorium on the East Lansing campus. The conference is sponsored by the MSU Institute of Water Research, MSU Department of Fisheries and Wildlife; Michigan Sea Grant; and the Office of the Great Lakes.

Workshop presentations

This year the Great Lakes Conference will focus on topics including beach monitoring, autonomous vehicles used in research, ice cover, Harmful Algal Blooms (HABS), and more:

  • The Geomorphology and Evolution of Coastal Dunes along Lake Michigan – Dr. Alan F. Arbogast, Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing.
  • Seasonal, Interannual and Decadal Variability of Great Lakes Ice Cover – Dr. Jia Wang, Great Lakes Environmental Research Laboratory, Ann Arbor.
  • Beach Monitoring using “Poop Sniffing” Dogs – Dr. Laura Symonds, Environmental Canine Services LLC, East Lansing.
  • New Aquatic Invasive Watch List Species – Sarah LeSage, Water Resources Division, MDEQ, Lansing.
  • Autonomous Vehicles in the Great Lakes for Exploration, Mapping and Environmental Monitoring – Dr. Guy Meadows, Michigan Tech Great Lakes Research Center, Michigan Tech University, Houghton.
  • Forecasting Harmful Algal Blooms to Help Lake Erie Stakeholders – Devin Gill, Outreach Specialist, Cooperative Institute for Great Lakes Research, Ann Arbor.

Registration is open

The conference is open to the public. Registration is $10 through March 1; $12 at the door (students are free). If you are a K-12 or informal educator, you may be eligible to attend the Educator Luncheon and receive a stipend in support of your participation. Educators may contact Steve Stewart via email at stew@msu.edu.

Register online and don’t miss this opportunity to learn more about our present Great Lakes and planning for the future.

4-H Great Lakes and Natural Resources Camp – registration now open!

 

4-H Great Lakes and Natural Resources Camp will be held Sunday, August 5 through Sunday, August 11, 2018, at Camp Chickagami in Presque Isle.

This camp is for teens aged 13-15, or going into 8th-10th grades in the fall. The cost is $375.00 for 4-H member and $395.00 for non-4-H members.

Please visit the below link for the online application process. If you have youth that will try to find funding from 4-H Council, please have the family pay in full, and the 4-H Council reimburse the family. This will keep payment processing with Events Management efficient.

The deadline for application is May 1.

https://events.anr.msu.edu/event.cfm?eventID=02B2D330861D46B4

If you have a youth that is interested in applying to become a counselor, please visit the same link and they will find the link for counselor applications. Youth must be at least 16 years of age, and have some experience in camp counseling.

We look forward to another great year at 4-H Great Lakes and Natural Resources camp!

See: Brochure (PDF)

Contact

Laura Potter-Niesen  |  Educational Program Events Coordinator
Michigan State University Extension  |  Children & Youth Institute
Justin S. Morrill Hall of Agriculture
446 W. Circle Drive, Room 160
East Lansing, MI 48824
Phone: 517-432-2963 
Fax: 517-353-4846
Email: potterla@msu.edu

Great Lakes net-pen aquaculture—real and perceived risks to the environment

Michigan Sea Grant addresses environmental issues surrounding net-pen aquaculture in the Great Lakes at recent Annual No-Spills Conference.

Great Lakes net-pen aquaculture—real and perceived risks to the environment

In the last several years there has been a great deal of discussion about net-pen aquaculture in the Michigan waters of the Great Lakes. Much of the attention about Great Lakes net-pen aquaculture is the generation of large quantities of fish waste from these fish production operations as well as the consequences if these fish escape into the environment. The main issue with fish waste is the release of phosphorus which is the growth limiting nutrient for primary production in freshwater ecosystems. Although some phosphorus is necessary to drive the freshwater food chain, concern arises when excess amounts of phosphorus are available which can result in significant algal blooms and other aquatic plant growth. In addition there is a concern about fish diseases and genetics, which may be the consequence of the interaction of fish raised in Great Lakes net pens and native fish in the surrounding environment.

Discussing environmental issues

To address these concerns Michigan Sea Grant was invited to speak at the 28th Annual No-Spills Conference in January 2018, to discuss environmental issues surrounding net-pen aquaculture in the Great Lakes. Currently there are seven net-pen aquaculture operations that exist in northern Lake Huron on the Canadian side of the lake. These operations are sustainably producing more than 5,000 tons of rainbow trout per year with some being sold in retail markets in Michigan. They provide 340 direct and indirect jobs with a $100 million contribution to the Canadian economy. These net-pen aquaculture operations take up a small footprint in the environment; one of these operations that produces 500,000 pounds of rainbow trout per year would fit into an average size Michigan marina.

Fish disease risks and genetic dilution can be minimized

For Great Lakes net-pen aquaculture to be environmentally sound it must have practices that prevent disease transmission and escapement of fish into the wild, as escapees could affect the genetic integrity of surrounding fish populations. These operations must also be non-polluting with minimal and recoverable impacts. With regards to fish diseases, the commercial aquaculture industry is highly regulated and is held to the same standards as state and federal hatchery programs. Fish disease risks are minimized and prevented through regulation, biosecurity, and best management practices.

In 2014 the state of Michigan stocked more than 20 million fish, produced from gametes collected from wild fish. This equated to 325 tons of fish stocked, 9 different species, 370 stocking trips, 732 stocking sites, with 100,000 miles of travel from several fish hatcheries. In comparison Canadian net-pen operations in Lake Huron typically stock one cohort, certified as specific pathogen free, then raise the fish to harvest and truck them one way to a fish processing facility. The net results are that Michigan hatcheries have a much higher risk of disease transmission than the current system for growing trout in Canadian net pens.

The Great Lakes already have rainbow trout which are non-native to the region. They were introduced by fishery management agencies years ago and many of these fish are now naturalized, spawning on their own in local rivers, with additional enhancement from government fish hatcheries. Rainbow trout produced in Great Lakes net-pen operations can be female triploids which are sterile and will not reproduce should they escape into the environment. So the risk of genetic dilution can be eliminated by use of these female triploid rainbow trout.

Low phosphorus, digestible fish diets help minimize phosphorus waste

During the height of the Great Lakes net-pen aquaculture discussion there were media reports that a typical net-pen operation with 200,000 fish would produce as much waste as a city of 65,000 people. In reality a city of 65,000 people would produce 21 times more fecal matter than a 200,000 fish net-pen operation. This same city would produce 5 times more phosphorus compared to the net-pen aquaculture operation. The city would also generate 24 kg/yr of E. coli with none coming from the net-pen operation.

Canadians have had net-pen aquaculture operations in their northern waters of Lake Huron since 1982. To help address the issue of excess phosphorus discharge from freshwater net pens, Fisheries and Oceans Canada completed a study on Freshwater Cage Aquaculture: Ecosystems Impacts from Dissolved and Particulate Waste Phosphorus. Fish receiving digestible phosphorus in specific amounts to meet their growth requirements excrete only small amounts of dissolved phosphorus. Dissolved phosphorus is most often the form of concern in impaired waters. The other form of phosphorus excreted from fish is particulate phosphorus which settles to the bottom sediments. The particulate phosphorus which accounts for the majority of the waste from net-pen operations is transported to the bottom sediments and is not immediately available for uptake into the ecosystem. In sediments it can be consumed by the benthic organisms and enter the aquatic food chain. Both dissolved and particulate phosphorus wastes produced by fish are the results of the diets they consume. The development of low phosphorus, highly digestible diets has been a tool to help minimize phosphorus waste by aquaculture operations.

The Fisheries and Oceans Canada study found that based on net-pen aquaculture production in northern Lake Huron in 2006 contributed about 5 percent of the annual total phosphorus loading to the North Channel. The study concluded that the likelihood of phosphorus additions to the environment from net-pen aquaculture operations resulting in eutrophication to Canadian freshwater environments under the current level of fish production can generally be characterized as “low.” The greatest concerns for phosphorus are in the nearshore areas where excess aquatic plant growth can foul the shorelines. In contrast, offshore phosphorus loading is of less concern and higher phosphorus concentrations may be considered a means to help mitigate declining populations of forage fish and the poor condition of sport and commercial fish species.