Invasive Species (Aquatic Ecosystems)

From Science Online

Contents 1 What is considered to be an Invasive Specie 2 Looking at Invasive Species Historically 3 What is the main problem with Invasive Speices 4 Long Term Effects of Invasion 4.1 Correlation of Extinction and Invasive Species 5 Economic Parts of Life Affected by Invasive Species 6 Worldwide Issues With Invasive Species 7 Common Invasive Species 7.1 Invasive Species in Freshwater Ecosystems 7.2 Invasive Species in Saltwater Ecosystems 8 An Example Invasive Speices Taking Charge 9 Solutions 9.1 Congressional Action for Solutions to Invasive Species 9.1.1 Nonindigenous Aquatic Nuisance Prevention and Control Act 9.1.2 National Invasive Species Act 9.2 Prevention of Invasive Species in Nonnative Aquatic Habitats 10 References

What is considered to be an Invasive Specie

An invasive specie is a specie that is non native to a community or environment that has infringed by intrusion. (Steinmetz, 1993) Often the invasive species travel to the area by way of human interaction through ship ballasts and canals.(Science Daily, 2004) Bringing plants and animals from other ecosystems for personal ponds or aquarium trade or purposefully importing live food or aquaculture as feed or stocking fisheries.(Bax, 2003) A more natural form of invasion could be that a bird can catch a fish or some other animal and lost it in flight in another lake or pond. (North American Invasive Aquatic Plants and Animals, 1999) Historically speaking, an invasive specie may have some shared traits with other invasive species. Common traits are rapid growth to maturity, the ability to reproduce asexually and sexually, or high tolerance to highly heterogeneous environments. The pioneer habits are often found in invasive species with the r-selected reproductive and growth habits, with high fecundity, rapid growth of young, and short life spans. (Sakai, 2001) These organisms tend to have a much more aggressive behavior and competativeness and a high tolerance to a broad spectrum of envrionments. (Sakai, 2001)

Looking at Invasive Species Historically

Invasive organisms are an issue worldwide and can affect every type of body of water. Invasive organisms can be found in the ocean, rivers, lakes, and ponds and have been noted throughout history as an issue in different shapes and forms. Ever since the introduction of ships into human history, unwanted organisms have traveled across the world invading foreign ports and ecosystems.(Bax, 2003) These organisms ranged from bivalve to bacteria and have made an impact worldwide. This is why it may be difficult in the modern day to really know what the original habitat may have been present. (Bax, 2003)

What is the main problem with Invasive Speices

Invasive species are slowly becoming more and more prominent in the natural ecosystems. Invading their non native habitats, species are altering their new envrionment often at the expense of the native species and the biodiversity of the community. (Sakai, 2001) Historically based data has pointed toward every 32-85 weeks, a new marine species invades one of the top six ports in New Zealand, Austalia, and the Unites States. This rate appears to be increasing. Lots of the species which are moved through ballast water just fall into the background while others become invasive and problematic to the natural habitat. Invasive speices are now thought by scientists to be a major factor in global habitat change and global diversity. (Sakai, 2001)

"Invasive species have large effects on native biodiversity, cause hundreds of billions of dollors in economic damages, and complicate the management of natural ecosystems around the world." (Strayer, 2006)

Long Term Effects of Invasion

Its important to look into the long term effects of the invasive species on the natural habitat, it can be varied and pervasive. (Strayer, 2006) After studies have been done on different sites around the world, the major impacts are mostly found in the native biodiverstity. Major effects are the diversity and structure of a community, genetics, and population size. (Strayer 2006) Some effects of a nonnative species present may cause the native species may become less and less evolutionarily fit. A native specie may weaken due to an invaded species and may weaken the entire community which may allow for more invasions. (Sakai, 2001) Or looking at the other side of the situation, because of introduced genes from the native species to the nonnative species, the invader may become even more fit for survival in the new environment. (Sakai, 2001) Once a new marine specie enters a new habitat, it is a permanent resident, not only does the specie come to stay, but also alters the habitat. (Bax, 2003)

Correlation of Extinction and Invasive Species

As a result of the effects of the invasive species, the natural diversity of the native species are realizing the correlation of invasive species and extinction of native species. Although it is difficult in some cases to pinpoint the exact cause of extinction, many factors say that the invading species lead to the extinction. (Clavero, 2005) Native species may decline because of their inability to resist foreign pathogens introduced by the invaders. The invaders will generally be more capable of living with foreign species and in a foreign environment while the natual species may not be capable. The general characteristics of an invasive specie may allow the organism to be more fit for extreme changes in environment leaving the other native organisms to suffer the consequences. (Bax, 2003)

Economic Parts of Life Affected by Invasive Species

The economy is largely affected by invasive species by the amount of money the organisms cause in damage each year. Goods traded in markets are affected by disruptive invasive organsisms, costing many businesses and countries loads of money. "The EPA estimates the annual economic cost of the damage to the United States to be $100 billion." (Cangelosi, 2002) Then private businesses and businesses based off of aquaculture of any sort can be affected because of disrupted hatcheries and ruined crops, costing the businesses loads of money to reverse the problem. (Strayer, 2006)

Worldwide Issues With Invasive Species

The debate lies mainly between two main groups, one group favors the protection of their coasts while the group favors the protection of their port based economies, also defined as the "flag states" and the "port states". The "flag states" are nations who register many ships a day, such as Cyprus, Liberia, and Panama. "Flag states" do not wish to have stricter global regulation because of the detriment it would put on their port systems. "Port states" favor much more regulations on the ports worldwide to ensure the safety and protection of their costal regions, such as the United States, Australia, and Norway. As a result of this debate, global regulation of ship ballast has not yet taken place because of the conflict of intrests.

Common Invasive Species

Invasive Species in Freshwater Ecosystems

Parrot Feather (Myrophyllum spicatum)

Brazilian Waterweed (Egeria densa)

Hydrilla (Hydrilla verticillata)

Zebra Mussels

Invasive Species in Saltwater Ecosystems

New Zealand Screwshell (Maoricolpus roseus)

Asian Clam (Potamocorbula amurensis)

An Example Invasive Speices Taking Charge

This story is the tale of a habitat completely changed due to an invasive situation. Eelgrass is the harvesting key to a part of this wetland habitat for fish and other sea crabs and creatures. When boats began to dredge up the substrate and wash in other types of plants, the Eelgrass had to fight for its life. The invading species could have been the factor that caused the Eelgrass so much harm, or was it the increased human interaction with the peaceful habitat.

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Solutions

"The management of vectors carrying alien marine species will reduce the risk of marine invasive species entering a new are, but not prevent it. Ongoing monitoring would help detect a new invasion quickly, allowing control efforts to commerce quickly, as well as providing up to date information for ballast water." (Bax, 2003)

Congressional Action for Solutions to Invasive Species

Nonindigenous Aquatic Nuisance Prevention and Control Act

-In 1990, the Nonindigenous Aquatic Nuisance Prevention and Control Act (NANPCA) was passed as the first federal attempt to prevent the transportation of nonnative organisms by way of ships into the Great Lakes. The options were to either discharge the water in the open ocean or treat the water with an environmentally friendly technique. (Cangelosi, 2002)

National Invasive Species Act

-In 1996, NANPCA was reinstated as the National Invasive Species Act (NISA)expanding the attempt to a national level making sure to have ballast operation records of the ships coming into the ports. (Cangelosi, 2002)

Prevention of Invasive Species in Nonnative Aquatic Habitats

The solutions to invasive species are tricky and complicated to figure out. Monitoring ballast water can prevent invasive species from entering a foreign habitat, but not completely control the situation. (Bax, 2003) When it comes to treating ballast water, the treatment must also be environmentally friendly meaning some of the methods such as heat treatment, ultraviolet treatment, ultrafiltration, chemical filtration, and more. (Bax, 2003) All of these treatment processes must leave the water livable for the rest of the habitat when put back into the watercycle.

If a species does successfully transport itself to another habitat and is detected shortly after, the situation can be reversed and the invader eradicated. (Bax, 2003) Prevention at a global or regional level seems to be the most affective solution rather than attempting to control marine species invasion.

References

(USGS)

(Swayne, 2004)

(North American Invasive Aquatic Plants and Animals)

(Sakai, 2001)

(Bax, 2003)

(Issues in Science and Technology)

(Strayer, 2006)

(Clavero, 2005)

(Elkhorn Slough Foundation)

(Steinmetz, 1993)

(Science Daily, 2004)

References