by Rachel Obermoller
Did you know that over 80 percent of invasive species that transfer between bodies of water do so via ducks, geese, and Minnesota’s own common loon? Did you also know that 27 percent of all statistics are fabricated? In case you weren’t sure, I made that up. All of it. Yet invasive species are a real concern, and their encroachment into previously uncontaminated waterways grows with each passing year.
News media presents clips of giant flying carp on rivers, government agencies enforce new procedures for preventing the spread of destructive species like milfoil and zebra mussels, and rivers and lakes have restrictions on operations and usage. Invasive species present many potential issues for seaplane pilots as well as boaters. Some states have taken a tightly restrictive stance on seaplane operations to attempt to curb the spread of various non-native plants and animals. Other states are more permissive, yet that does not mean a risk does not exist for contamination.
Seaplane pilots are generally a conscientious bunch, particularly when it comes to issues surrounding access to waterways in their aircraft. We enjoy relatively unrestricted access to usable waterways in Minnesota and many other Midwestern states. Through continued stewardship of these resources, as well as responsible flying practices, seaplane pilots can help ensure this remains the case.
So, what’s a seaplane pilot to do when trying to prevent the spread of both invasive species, as well as undesirable species of plants and waterborne animals?
The first step for seaplane pilots is to know the waterways where you want to operate. The Minnesota Department of Natural Resources (DNR) maintains a website devoted to education about invasive species and preventing their advance throughout Minnesota, as well as a list of known infested waterways. Know the lakes and rivers you will be using and whether they contain invasive species. Then, make decisions about whether you will use those bodies of water, and what precautions you will take.
You can find these DNR resources at: http://www.dnr.state.mn.us/invasives/index_aquatic.html. The first choice when a waterway is infested with an invasive species is to avoid its use. If that option isn’t realistic, there are other options available to prevent the spread of aquatic plants and animals.
If your aircraft is of the amphibious variety, consider a brief stop at a land airport to clean off your floats and remove any evidence of contamination. You can also scrub your floats and any other areas of your aircraft that came into contact with water with a handled brush you keep in the aircraft or your float compartment. This includes portions of the float or hull, as well as water rudders and other components, which lie at or below the water line. Even if you can’t get the aircraft out of the water, doing this before you depart can loosen anything which might be attached and help prevent its transfer to other bodies of water.
It should go without saying that when you pump your floats out, pump them into the body of water you have been using to prevent contamination between water bodies, or pump them onto land where they will not drain into another water body. Pilots should also remove any evidence of aquatic plants and animals attached to the floats or aircraft prior to departure.
What about these items you might pick up between starting the engine and your takeoff run?
One obvious measure is to avoid taxiing through areas where vegetation is present. Not only can weeds impair the use of water rudders, but in thick weeds, water rudders may lift out of the water and become significantly less effective. Avoid these areas whenever possible and cycle your rudders prior to departure to shed anything which might be attached. Once airborne, you can also lower and raise the water rudders while over the body of water you just departed to try to loosen and remove anything attached to them. If you are amphibious, you might consider cycling the gear as well, but make sure it goes back to the desired position.
As far as aircraft storage is concerned, the best storage option for minimizing the potential for transfer of undesired aquatic species is to store the aircraft on land. By removing it from the water, it is easier to find and remove anything attached to the aircraft. By allowing the aircraft to dry, items, which require water to survive, will in time die.
The DNR recommends removing or killing hard to see invasive species which might be harbored in or on boats by allowing them to dry at least five days on land before entering a new water body or spraying with hot, high pressure water. While this may not always be practical for the average seaplane, when possible, a thorough scrub of the floats, especially with hot or high pressure water, or allowing it to dry out of the water whenever possible, presents the best option for controlling invasive species.
Another decontamination method recommended by some to prevent the spread of invasive species involves using a bleach solution to kill anything, which might be harbored inside of damp or wet float compartments. A five-part water to one-part bleach solution can be sprayed after any standing water has been removed to kill anything, which might have taken up residence in your floats. YouTube also has a short yet comprehensive video about cleaning and decontaminating seaplanes, and can be found by searching for “Seaplane Inspection & Decontamination Training 2010” at www.youtube.com
Within Minnesota, the DNR has identified several invasive species they watch and attempt to control. Some you may have heard of, like zebra mussels or milfoil; others might be more obscure, like curly-leaf pondweed, spiny water flea, and various forms of snails.
Descriptions of known invasive species, how they are spread, what they look like, and information about preventive measures can all be found on the DNR’s website. With a little advance planning, a little elbow grease with a scrub brush, and an attitude towards responsible stewardship of natural resources, seaplane pilots can help prevent the spread of invasive species as they are out exploring and enjoying the many seaplane-friendly lakes and rivers throughout the Midwest.