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How can a nation prevent and control alien invasive species like water hyacinths, water lettuce, hornwort and others?





One of the great threats to the health of aquatic ecosystems and fisheries habitats is what is referred to as alien invasive species or AIS. It is one of the greatest threats because the invasive alien species have the capacity to outcompete the species native to the habitats and alter the environment. Some of these invasive alien species include water hyacinth, water lettuce, and hornwort. They are also able to spread diseases and parasites. They can reduce the availability of food in the ecosystem. In this article, we will discuss the various methods that can be employed to prevent and control these alien invasive species so that countries can take control of their fisheries habitat to make maximum gain from them.


Awareness creation

One of the most effective methods that can be used in the prevention and control of alien invasive species is to create awareness. It is probable that many people do not know about the negative effects of these alien invasive species. People need to be aware, be able to identify the plants, its mode of propagation etc., This awareness creation may take the form of public campaigns using flyers, adverts on Television and radio, banners at vantage points along water bodies. One can also use Social Media handles to drive this awareness creation. Public discussions on the issue on radio and TV is another option. These campaigns will educate people on the importance of preventing and controlling the invasive alien species.

Screening at entry points

Another method to use in preventing and controlling the alien invasive species is by screening people who enter the country through the entry points. In many parts of the world, people use different routes to enter another country. People may use land borders, air and Sea ports. Others may even use unapproved routes as their point of entry. In all these cases, measures must be put in place to ensure that whatever plant species or seeds they are bringing in is properly scrutinized. This will ensure that if there are any invasive alien species coming in, they can be seized and destroyed.

(Water hyacinth)

Enforcement of plant protection laws

Countries can also prevent and control alien invasive species by their enforcement of plant protection laws.  The state must as a matter of agency pass legislation, if they do not already exist, and make sure that these legislations are enforced to the letter. Anyone who flouts these regulations must be made to face the full rigours of the law. In Ghana, there is the Plant Protection & Regulation Services Department of the Ministry of Agriculture in Ghana. In Nigeria they have the Nigerian Agricultural Quarantine Service. In Liberia, there is the Liberia Plant Protection Regulatory Services Bureau under the Mistry of Agriculture. It is the candid opinion of this writer that if the laws are enforced, it would lead to the prevention and control of these invasive alien species.

Physical control

Though this method is labour intensive, alien invasive plant species can be physically controlled. For example, gangs of young men can be employed and transported to the Volta Lake, for example, where they would manually cut water hyacinth into canoes and brought back ashore. Small boats fitted with cutter can also be taken onto the water body to mechanically cut these invasive plant species and brought ashore for onward destruction. This can cut down on the rate of propagation.

Biological control

One can also prevent and control alien invasive species biologically. Natural enemies of these species can be introduced into the ecosystem to overpower them. For example, the natural enemies of water hyacinth, like weevils, and beetles can be introduced into the space. Since the beetles or weevils feed on these invasive species, it can suppress its growth. Also, when sediments are removed from the bottom of the water, it can prevent or slow down the rate of growth and spread.

Incentive and reward mechanisms

Also, we can use reward and incentives to prevent and control alien invasive species. We cam institute a reward mechanism for reporting sighting of alien invasive species in or on water bodies. For instance, if an individual or organization reports sighting an alien invasive species, that individual is rewarded in cash or in kind. If the rate of participation is high and sightings are promptly reported, it can go a long way to control water species like water hyacinth and water lettuce for example.

Research and development

Further research into the phenomenon of alien invasive species is another method that can be used to control and prevent alien invasive species. Where research and development is already established to research into alien invasive species, governments can also support with funding to ensure there is enough available to research into the issue and come up with workable solutions to solve the problem.

Other methods that can be used include, public-private partnerships, early warning and rapid response systems, promotion of best practices, development of risk management mechanisms.


The complexity of the control and prevention of alien invasive species is not something to be glossed over. Since this is a matter national emergency, it is important for governments, businesses, and individuals to come together and work to identify the sources of invasions and to assess its effects the environment and subsequently on the economy. If the above discussed methods are implemented, we can the impacts of alien invasive species can be managed.

Also Read:

What are the characteristics of alien invasive species?

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