Aquatic Invasive Species

David Lung

Professor Cooke

Writing 20- Invasive Aquatic Species

19 March 2010

All for One Regulation and One Regulation for All

Peters and Lodge (2009) suggest there needs to be consistent regulation on a regional scale that goes beyond political boundaries in order to viably control the spread of an invasive species. In their investigation of the spread of rusty crayfish, Peters and Lodge (2009) discovered a large disparity in the regulation of the many invasive crayfish that are present in the Great Lakes region. For the anglers, aquaculture industry, pet industry, and bait dealers, what is illegal varies considerably, making controlling the spread of invasive crayfish difficult since there are many ways for the crayfish to invade new habitats. As a result of policies among states that range from having a total ban on using crayfish to complete freedom of use, invasive crayfish have spread a significant distance over the course of 3 years (Minnesota to Pennsylvania). Acting on Peter and Lodge’s (2009) study, it is necessary to enact regional policies versus political policies.

Peters and Lodge (2009) make an excellent case and in my review of giant salvinia, it is necessary for broad regulation of invasive species instead of a smaller jurisdiction (state, local, etc.) making their own policies that run counter to those of another. Giant salvinia has been listed as a noxious weed in Florida, North Carolina, Mississippi, Texas, California, Arizona, Louisiana, Alabama, South Carolina and Georgia. Being listed as a noxious weed, there is a consistent regulation in the Federal Noxious Weed Act of 1975 that prohibits transporting the weed in interstate or foreign commerce. Should each state of had their own policy to deal with giant salvinia, then the spread of the fern may go farther than it already has. Invasive species, as Peters and Lodge (2009) have stated, do not recognize political boundaries nor do they adhere to any laws. As a result, there needs to be a uniform set of regulations over an entire region or an area that an invasive species has currently spread; otherwise, the example set by the invasive crayfish will come to be a common occurrence among all invasive species.

References:

http://www.fws.gov/laws/lawsdigest/FEDNOX.HTML

http://plants.usda.gov/java/profile?symbol=SAMO5

Peters JA, DM Lodge.  2009.  Invasive Species Policy at the Regional Level:  A Multiple Weak Links Problem.  Fisheries 34: 373-381.

One thing that I found particularly interesting about aquatic invasive species policy is the “weakest link” problem of gaps in regional policy. The main article I read about this in was the Peters and Lodge et al 2009 paper titled: “Invasive Species Policy at the Regional Level: A Multiple Weak Links Problem”. The article talks about how invasive species that affect an entire region – in this case, Rusty Crayfish (Orconectes rusticus) in the Laurentian Great Lakes region – can be under several different sets of policy controls. The entire Great Lakes region has declared rusty crayfish to be a major concern and a dangerous invasive species (Peters and Lodge et al 2009). However, not all of the states in that region have effective controls enacted against these crustaceans. For example, there are no regulations against anglers possessing crayfish in the state of Michigan, but in Wisconsin it is illegal to possess ANY crayfish (Peters and Lodge et al 2009).

The differences in policy in a high-traffic region such as the Laurentian Great Lakes make it difficult to control invasive species that have negative effects on all surrounding areas. It also took most of the states surrounding the Great Lakes around 30-40 years to enact policy after the first crayfish establishments had been recorded (Peters and Lodge et al 2009). It seems clear that if the entire region has determined rusty crayfish to be a viable threat, the entire region should enact uniform policies in order to halt the spread and reduce crayfish populations. However, neighboring states continue to have conflicting policies that only make it harder to effectively control the rusty crayfish invasions. I believe that enforcing region-wide policies is the first step to being able to manage rusty crayfish populations and eventually reduce their negative impacts.

Peters JA, DM Lodge. 2009. Invasive Species Policy at the Regional Level: A Multiple Weak Links Problem. Fisheries 34:373-381.

Rusty Crayfish

First discovered in 1960 in a Minnesota lake, Rusty Crayfish have since spread to lakes in over seventeen states in the United States Midwest and parts of Canada. The fact that these Rusty Crayfish are not originally native to these Midwestern lakes creates quite an unsavory predicament for the native marine life, mostly due to the Rusty Crawfish’ aggressive invasion tendencies. Rusty Crayfish tend to displace other native crayfish species, but they also harm native fish populations by feeding on their unhatched eggs which lie at the bottom of the lakes. Finally, these pesky crustaceans also severely reduce the amount of aquatic vegetation in lakes.

Although not confirmed, the spread of Rusty Crayfish is believed to be linked with careless anglers who dump their bait buckets or do not pay attention to what live bait they are using. Even transferring only a few Rusty Crayfish can be detrimental to a lake’s ecosystem, since females can carry both fertilized eggs and male sperm. This means that feasibly all that is needed to start a new population of Rusty crawfish is a single female. There have been attempts however, to regulate this spread stemming from when the species was declared a regulated invasive species, simply meaning that the spread of Rusty Crayfish into the wild is illegal.

Although Rusty Crayfish are very harmful to native Midwestern lake ecosystems, many strides have been made in legislature to control the population. Starting with declaring Rusty Crayfish to be an official regulated invasive species, it is now illegal to spread Rusty Crayfish into the wild and even simply sell them as live bait. Of course, some penny-pinching fisherman will still inevitably opt to use live Rusty Crawfish as bait, which is why it would probably be a good idea to start cracking down on the bait industry to make sure all live bait is regulated and Rusty Crawfish-free. In terms of getting rid of the current infestation of Rusty Crawfish inhabiting lakes, a few options are available. Some suggest the use of chemicals to kill the invader, but nothing has yet been discovered that kills the Rusty Crayfish that doesn’t also kill native crawfish as well. Interestingly enough, it was once actually proposed to use the invasive Rusty Crawfish to regulate the population of the also invasive Eurasian Watermillfoil, but this idea was swiftly turned down. The best option, it seems, would be to ask fishermen to use Rusty Crawfish in lakes where they have already established a home in as bait whenever possible. While this method will definitely not eradicate the population, it will surely prove to be damage-control at the very least, most likely protecting many native aquatic plants and animals.

Sources

http://www.dnr.state.mn.us/invasives/aquaticanimals/rustycrayfish/index.html

http://www.seagrant.umn.edu/ais/rustycrayfish

http://www.seagrant.umn.edu/ais/rustycrayfish_invader

Rusty crayfish are indigenous to the Ohio River Basin area, but they have spread to many other states such as Michigan, Illinois, and Wisconsin. They have rapidly increased in those areas. Rusty crayfish are mostly likely spread by fishermen who use them as bait. They could also be spread by schoolchildren who have them as pets and release them.

Rusty crayfish pose several problems as an invasive species. One is that they tend to drive out native crayfish species. Rusty crayfish are often better suited to compete for food and shelter, so the native species tend to be forced out. Rusty crayfish can also harm fish populations because they eat fish eggs. Rusty crayfish also pose a threat to aquatic plant beds, especially because of their high metabolisms compared to other crayfish.

I think that rusty crayfish seem to be a serious threat. They seem to be more hardy and tougher than a lot of indigenous species. I think they could also easily wipe out aquatic vegetation with their increased appetites. I wonder what they are doing to fight them and if they have found any effective methods. I also am curious as to how much money this problem is costing.

http://www.seagrant.umn.edu/ais/rustycrayfish_invader