Ecosystem based management (EBM)

Fishing & ecosystem-based management

The Minnesota DNR is committed to managing the state's natural resources using an ecosystem-based approach. What does this mean for Minnesota anglers and other conservationists? Read on to find out.

Q: How will ecosystem-based management affect my angling?

A: Ecosystem-based management will help angling by ensuring the long-term health of fish populations. As anglers and conservationists have long known, you can't have healthy fish populations without healthy habitats. The goal of ecosystem-based management is to work with nature to produce healthy, functioning ecosystems, also known as habitats. If we want sustainable trout populations in the future, we need to maintain healthy stream ecosystems. If we want to fish for walleyes with our grandchildren, we need healthy lake and river ecosystems. It means working to maintain productive habitats for the long term to provide good fishing for this generation and the next.

Q: What is an ecosystem?

A: An ecosystem is a geographic area including all the living organisms (people, plants, animals, and microorganisms) and their physical surroundings (such as soil, water, and air). All of these elements are interconnected. Managing any one resource affects the others in that ecosystem. Ecosystems can be small (a single pond) or large (an entire watershed including hundreds of lakes and streams across many different ownerships), depending on what is being studied or managed. For example, an ecosystem including a river catfish's migration routes would be quite large, while the ecosystem of interest to a lake association may be a small watershed.

Q: So what does an "ecosystem-based" approach mean in the way Minnesota's natural resources are managed, and how is this different?

A: It means that we consider how our management actions affect all resources, not just individual resources (such as walleyes, pulpwood, or deer) in isolation. Ecosystem-based management also means more participation and involvement by the public, local units of government, other agencies, and the business community in natural resource education, planning, and decision-making.

Q: How will this look in the field?

A: Fish populations aren't expected to change much as a result of ecosystem-based management. What anglers will see, however, is that the DNR will manage lakes and streams more naturally. For example, there will likely be less stocking on lakes where the practice doesn't work, and more wetland restorations on areas surrounding lakes, and more attempts to protect vulnerable spawning habitat.


By Jack Skrypek, Former Chief, DNR Section of Fisheries

What does ecosystem-based management mean to a Minnesota angler? To put the answer in simplest terms it means making sure we have fish on the end of the line now and in the future. As humans continue to put pressure on natural resources, only an ecosystem-based approach can prevent the deterioration of fish community health and the resulting decline in fishing quality. This method has worked to some degree on portions of the Mississippi River, and it is our best hope for maintaining the long-term health of other fisheries in Minnesota.

To make our homes healthy and efficient, we repair damaged features, keep things clean, and strengthen family relationships. Managing a fish community works the same way. We consider the complex variety of factors influencing fish populations-called an ecosystem-and then figure out how to keep the ecosystem functioning effectively.

Fishery managers and many anglers have known for years that fish communities are affected by the physical and chemical characteristics of waters, and that the characteristics of waters are affected by the characteristics of watersheds. We've learned that when people alter the watershed, fish communities in the streams and lakes can be harmed--even when the alterations occur miles away.

Ecosystem-based fisheries management looks beyond the shoreline and stream bank for factors that affect water quality and aquatic habitat. Years ago, fishery management consisted mostly of trying to manipulate fish populations for the benefit of anglers--primarily through stocking and rough fish removal. Though these techniques can work and are used even today, too often they treat symptoms and never achieve long-term health and sustainability of fish communities.

Consider, for example, Pool 2 of the Mississippi River (from Hastings upstream to the Ford Dam in St. Paul). This river stretch is regarded by many anglers as one of the best walleye fisheries in the state. Both walleye and sauger are abundant and of exceptional size. Yet just 25 years ago, the fishery in this part of the river was practically nonexistent. In 1964, I conducted test netting that showed almost no fish from the Pigs Eye Sewage Treatment Plant in southeastern St. Paul to Gray Cloud Island, which is just upstream of Hastings. The river had almost no dissolved oxygen during part of the year and contained toxic levels of ammonia. In many areas, the river bottom was covered with areas of black, tar-like sludge. Some of the nets I used to sample fish near stormwater outfalls actually came up covered with toilet paper.

So, how did it come about that an open sewer could become one of the state's best fisheries? Ecosystem-based management (though it wasn't called by that name back then). In the early 1970s, it was obvious that the environmental requirements for game fish in that portion of the Mississippi were not being met. The oxygen needed to be increased, toxic materials needed to be eliminated from the water, and the bottom needed to be cleaned up so fish could spawn and food organisms could grow. There was no way the state fisheries program could do all that. Collective action needed to be taken.

The process of cleaning up the river began after federal, state, and city officials recognized the pathetic state of the river environment and decided to work together to make changes. Water quality standards were raised and improvements were made in sewage treatment. The long and expensive process of separating storm sewers from waste sewers began. Improvements in sewage treatment and land use practices were started on the Minnesota River and continue today.

These steps have considerably improved the water quality and bottom conditions of the Mississippi River from St. Paul to Hastings. Aquatic insects such as mayflies are abundant, indicating a much healthier ecosystem. DNR test nets show a wide range of fish species with abundant walleye, sauger, and bass.

This simple example illustrates how a fish population can benefit by the ecosystem-based approach: various interests look at the big picture and work together to create an improved aquatic environment. And if we take care of where fish live, they can generally take care of themselves.