Advances in invasive species management have necessitated a distinction between short-term management solutions and long-term remedies. Short-term solutions have emerged largely due to technological developments making it easier to detect established invasive populations earlier and to respond accordingly. Transportation, particularly shipping, acts as a significant pathway of introduction for non-native species into foreign ecosystems. Ship’s ballast water can contain thousands of organisms, which are transferred from port to port as ships take on and jettison ballast water. The threat posed by these “stepping stone invasions” is considerable. Approximately four degrees of separation exist between every port worldwide. Recent advances in pathway specific scientific analysis provides an excellent short-term solution. Analysis of temperature and salinity allow researchers to match ports where the conditions are conducive to the establishment of a specific non-native species. This approach allows for a targeted management effort and more effective use of limited management dollars. However promising, scientific advances do not have the power to force significant change on a long term and global scale. Policy and legislation is key to preventing the spread of invasive species in the long term. For example, legislation regulating the ballast water treatment systems on all ship provide a long term and cost-effective solution to transportation-mediated introduction of non-native species. Unfortunately, the majority of policy concerning the transfer of non-native species is too limited in scope and inefficient, particularly that of the United States. The Lacy Act is so inefficient most banned species are already established in the United States and the “innocent until proven guilty” listing criterion does nothing to prevent the further establishment of new invasives. A middle ground system, such as that implemented in Australia, has proved most effective at regulating the influx of non-native species without stifling trade. As short-term solutions are developed and implemented, policy-based long term solutions must not be forgotten as they play a crucial role in the future regulation of invasive species.
Governmental policies have failed to control the spread of aquatic invasive species in a number of ways. Particularly, they have not devoted substantial attention to the pathways, or vectors, that allow species to travel to new locations. According to Dr. David M. Lodge of the Center for Aquatic Conservation and Department of Biological Sciences at the University of Notre Dame, an invasion can be broken down into five steps: the presence of the species in a pathway, transportation and subsequent release, establishment of a population, spread, and impact. For any of the other steps in an invasion to occur, a species must first enter a pathway. Therefore, the method most sure to prevent invasions is to stop them from ever beginning, by obstructing the pathways they require. Dr. Lodge describes two main types of pathways for invasive species: “incidental” vectors, or unintentional side effects of transportation, and “intentional” vectors, or commerce involving the species in question. It is essential that governments take steps to regulate both of these types of pathways.
The two main incidental vectors are airplanes and ships, as technology has effectively shrunk the world and created an interconnected network between continents. In fact, ship routes connect any given port to nearly every other port in the world by four or fewer steps. Although it would be impossible to stop intercontinental transportation, or to require complete purity of ballast water and ship hulls, it is possible for authorities to focus on ports around the world that are environmentally similar in water temperature, salinity, and other such factors, therefore making them more susceptible to invasions. Locations with high numbers of arriving ships and substantial similarities to other environments could then be targeted for increased transportation regulations.
Intentional vectors pose an equally potent threat to ecosystems around the world. At present in the U.S., there are only three sets of laws governing importation of species: the Public Health Service Act of 1946, the Plant and Animal Health Protection Acts of 2000 and 2002, and the Lacey Act of 1900. Any species not listed in these acts are assumed harmless and may be imported. Most of the few species that are listed had already established populations by the time they were incorporated, effectively rendering the laws useless. Most importantly, all regulations up until this point have been of an “all or nothing” mentality, either forbidding the transportation of a species or else allowing it unconditionally. Instead, authorities should use niche and spread modeling to predict the particular impact each species will have if imported, and create bioeconomic policies that allow some importation – creating economic benefits – while providing regulations that prevent invasions, creating environmental benefits as well.
Lodge, David M. Lecture at Duke University, March 16, 2010.
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.
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.
Invasive species have become a costly problem for the United States. Invaders have ruined numerous local fishing economies and ecosystems. Though this problem was inevitable, there was a point in US history at which someone could have taken decisive action and implemented policies that could have slowed the spread of invasive species and saved the US a great deal of money. Unfortunately, as Dr. Lodge noted in his lecture, few legal actions have been taken to control the problem of invasive species, and all of these actions have proven to be extremely ineffective.
In addition to ineffective management of these invaders at the national level in the US, variations in species regulation at the local level also contributes to this problem. Peters and Lodge (2009) investigated crawfish regulations in the Laurentian Great Lakes area as an example of how poorly the movement of species is managed. They found great disparities in the severity of these regulations among different areas surrounding the Great Lakes, which confuses crawfish vendors and exacerbates the problem of invasive species. The variance in regulations is likely present among regulatory laws for other species as well.
In order to successfully manage invasive species, consistent and firm regulations need to be implemented at the state or national level; local regulations are ineffective. If management of invasive species is to be done at the state level, states need to work closely to prevent confusion that may result from the transport of these species. Peters and Lodge (2009) also recommend that any harm that comes from the introduction (accidental or otherwise) of a foreign species be the responsibility of the person or organization that allowed the introduction. This is a promising idea that would probably decrease the amount of “accidental” introductions of invasive species. Regardless of which path legislators decide to take, action should be taken to increase invasive species regulations as soon as possible.
Peters JA, DM Lodge. 2009. Invasive Species Policy at the Regional Level: A Multiple Weak Links Problem. Fisheries 34: 373-381.
Lodge et al. (2006) identified six different actions that should be taken by the United States government in order to improve invasive species policy. The first one is to use new information and practices to better manage commercial and other pathways to reduce transport and release of potentially harmful species. I think this is one of the most important factors in policy making. If you do not stop the spread of invasive species, it does not matter how much money or effort you put in to trying to clean them out of one area because chances are they will be back. One pathway that policy needs to deal with is shipping traffic. It is one of the most active pathways and it has the potential to spread millions of species per day. Lodge discusses this issue in his paper and he makes additional recommendations. He talks about how there needs to be more enforcement of existing policies in the US. Also, new technologies available for species detection and removal need to be implemented more than they are. Finally, while a lot of countries, including the United States, have developed regulations for dealing with ballast water, they cannot be fully effective until there is and international standard and uniformity. The International Maritime Organizations (IMO) has come out with some regulations and recommendations, but the issue is that while most countries are adhering to these, they are still vague and leave a lot of room for countries to make their own decisions. The differences that arise in policies from this can cause the measures taken against the spread of invasives not to be as effective.
Lodge, D.M. , S. Williams, H. MacIsaac, K. Hayes, B. Leung, L. Loope, S. Reichard,
R.N. Mack, P.B. Moyle, M. Smith, D.A. Andow, J.T. Carlton, and A. McMichael.
Biological invasions: recommendations for policy and management (Position Paper for
the Ecological Society of America). Ecological Applications 16:2034-2054.
The United States of America has often been called the “melting pot” of the world, as it accepted people from all parts of the globe. However, an undesirable byproduct of such mixing was the introduction of many different species. While some people intentional bring exotic animals and plants to this country, an exponentially larger number are transported unknowingly. The current world is incredibly connected; even the landlocked ports of the Great Lakes can be associated with ports in Egypt, Australia, and Argentina. In fact, Dr. David Lodge demonstrated how the laurentian Great Lakes are connected to such ports by a maximum of four degrees of separation. Along their journeys, the ships have a tendency to pick up hitchhikers and other unwanted passengers. Even though most of these species aren’t able to survive due to differences in salinity and temperature, those that do survive are incredibly resilient. Their effects have already proven costly, such as the Zebra Mussel infestation in the Great Lakes. Additionally, San Francisco Bay has become the ultimate melting pot for different species, as noted in Dr. Lodge’s lecture.
How can we control this problem? Federal regulation seems to be the best starting point, but enforcement is the largest issue. Treatment or replacement of ballast water proves promising, as the removal of species offshore could help preserve the ecosystems of our port cities. However, until these systems become cost effective, many shipping companies would either forget or simply refuse to implement them. The Coast Guard in conjunction with Port Authorities would be the general enforcing agents. Legislation regarding which species may be brought in is much more clear cut and straightforward than which species are barred from our borders. The Lacey Act is a prime example of the ultimate failure to protect our natural habitats from invaders (other than ourselves). While this would be time-consuming, it would prove very cost-effective and allow researchers to model the effects of different species introduction. These are just a few of the many ways to protect our borders. Above all, the greatest asset to limiting foreign species invasions is clearly the enforcement of current laws, and the formation of stricter ones to preserve our native species.
Dr. David Lodge’s March 16th lecture was particularly interesting because of its relevance to the literature review I just finished writing. In the literature review I discussed the future direction of research on methods of controlling invasive cane toads in Australia. I ultimately recommended that methods involving the introduction of new species not be pursued because of the possible unknown consequences of doing so. Dr. Lodge began his lecture by saying that he thinks the introduction of non-native species could now be done in a safe manner, refuting my assumption that these introductions were as dangerous as ever.
The information Dr. Lodge went on to discuss turned out to validate much of the logic that led to my policy recommendation. He discussed the way in which models of invasion have been developed, and what limitations of these models exist. Essentially, among several weak points in invasion modeling, one of the most significant is modeling the spread of an invasive species. Many models claim to predict the potential spread of a species, but according to Lodge most of these models fail. When I asked about the contradiction between this statement and his claim that species could now be safely introduced, Dr. Lodge said that while modeling techniques have improved, we are far from knowing everything about species invasion. I therefore think that the assumptions made in my literature review are completely reasonable, and we cannot continue to introduce species with unknown consequences.
Many attempts have been made to try and control the spread of aquatic invasive species and not went as well as intended, one of which being legislative doctrines such as the Lacey Act. These doctrines, the Lacey Act in particular, have proved to be quite ineffective. This is not only because the Lacey Act lists a mere nineteen species, but also because most of the species listed were already established in North America at the time when they were included in the Act. Congress apparently takes much too long a time when passing new amendments to the Lacey Act to make it an effective doctrine. This is why targeting the invasive species problem on the trade regulation level is a more effective path.
Stricter food and drug trade regulation laws with other countries seem to be one of the best methods to go about solving the aquatic invasive species problem. Many people oppose the inspection of each ship that comes into North American ports because it is relatively costly. However, it seems to be the safest route, since according to Lodge’s lecture nearly every port in the world is connected to a body as small as the Great Lakes by only four degrees of separation. This means that, due to the incredible connectedness of the world’s shipping industry, any single port can feasibly receive goods from nearly any other port on the planet Earth! For this reason, it does not seem as if one could possibly classify any water body as a “danger zone” since the world’s ports are apparently so connected. Therefore, it appears that, although costly, more rigid trade inspection and regulation laws are necessary, even if it means the inspection of every ship that comes into North American ports.
United States law currently allows for the importation of any species that is not specifically named on one of various blacklists maintained by a myriad assortment of disparate agencies. This loose regulation has allowed for the introduction of many species that pose potential harm to US ecosystems and responses to these threats are slow due to the cumbersome process of adding to these lists (i.e. Lacey Act). Ecologists demand that this essentially ‘non-regulatory’ system be scrapped for that assumes a species guilty of harm until proven innocent. This position is diametrically opposed by both transportation and pet industries. David Lodge, a researcher from Notre Dame University, believes that the solution to this debate is an approach that singles out individual species or invasion pathways for aggressive monitoring, thereby affording a greater degree of ecological protection without hampering the national economy.
Lodge’s solution is only possible due to advances in environmental modeling and transportation network mapping. By comparing a particular ecosystem’s abiotic factors to those of other ecosystem across the globe, Lodge’s team of researchers was able to identify the most likely source of invasive species for that particular ecosystem (i.e. Laurentian Great Lakes). These results were then compared with a map of shipping routes to show which ships entering the Great Lakes ports could be linked to these “hot zones” of invasive species. Lodge holds that monitoring these ships for invasive species is the most effecient preventive measure given the limited resources of most monitoring agencies.
I agree with Lodge’s assessment that the best available management option is selective screening of transportation pathways based on ecoystem comparisons and transportation network analyses. Government agencies tasked with monitoring these transportation routes are often underfunded and faced with tremendous political pressure not to slow the progress of commerce. Therefore, utilizing a strategy that focuses efforts on the most likely sources of invasion is clearly the most viable option.