Development of aquaculture in Michigan

Aquaculture systems that exist or are being explored in Michigan.

A flow through raceway for trout production. Photo: Ron Kinnunen | Michigan Sea Grant

A flow through raceway for trout production. Photo: Ron Kinnunen | Michigan Sea Grant

Michigan Sea Grant and Michigan State University Extension were recently involved with the completion of the Michigan’s Aquaculture Industry Integrated Assessment. This report summarized from the Michigan aquaculture industry perspective the various scenarios to expand aquaculture development in Michigan.

In recent months many in Michigan have heard about exploring the potential of net-pen aquaculture operations in the Great Lakes. These types of operations are not new to the Great Lakes as there have been at least nine such businesses in existence for some time now in Canadian northern Lake Huron. Net-pen aquaculture has also been used as a production method in the oceans for many years as well to a smaller degree in inland bodies of water.

There are other aquaculture production systems that include flow through, ponds, and recirculating aquaculture systems. Trout production in Michigan and the U.S. is usually associated with the culture of fish in flow through systems. In flow through systems water is diverted from streams, springs, or artesian wells to flow onto the farm by gravity. Pumping water from wells or other water sources to the flow through production units is usually cost prohibitive and is not often used in the industry other than operating small hatcheries. Most commercially and publicly produced trout in the U.S. are grown on trout farms with concrete raceways and are in series where water flows from one rearing unit to the next one below. The use of water from wells, springs, or surface water for aquaculture facilities is regulated by various public agencies depending on the specific water laws of each state and is considered non-consumptive use.

Trout production farms in the U.S. evolved from earthen pond systems, the most popular shape of which was long and narrow with sufficient slope to allow for aeration by gravity between ponds. Earthen ponds are still in use today, particularly on small farms. A primary disadvantage of earthen ponds is erosion of the banks when water flows are maintained at the desired rates. The low capital investment makes earthen ponds systems popular for fish culture and these types of ponds have been popular for catfish production in the south. Ponds that do not rely on flow through are typically used to grow cool and warm water fish such as bluegill, yellow perch and largemouth bass.

Recirculating aquaculture systems (RAS) have been touted as the wave of the future for aquaculture development because of their ability to reuse water and better manage the production of fish waste. These systems operate by continually pumping water between fish tanks and filters. Solids are captured and a percentage of new water is added for replenishment. Excess ammonia from protein in fish feed is converted to nitrate (less toxic form) using biofilters. Disadvantages of these systems are high complexity, energy costs, investment costs and failure rate. Currently in Michigan RAS is used only at small or hobby scale, mainly in conjunction with hydroponics. This type of system is called aquaponics and involves growing fish and plants in the same system.

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, Michigan Sea Grant is part of the NOAA-National Sea Grant network of 33 university-based programs.

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