How to Stop Marine Invasive Species

Preventing Invasive Species

Antifouling paint is applied to boat hulls below the waterline as defense against barnacles and other marine hitchhikers. Liam Bailey/Photographer's Choice RF/Getty

By guest contributor Deborah Seiler

The oceans contain the vast majority of Earth’s ecosystems, providing habitat over 70% of the Earth’s surface, and depths that can reach more than 6 miles. However, the National Ocean Service estimates that just five percent of the ocean has been explored.

What scientists do know is that, in addition to other stressors, many ocean coastal habitats are threatened by invasive species.

Oceans naturally aid the dispersal of plants and animals by allowing them to float to new locations, but this natural dispersal is still limited by currents, winds, and local conditions. Invasive species are those transported to a new habitat by human activity. In the case of oceans, the primary sources of invasive species are the shipping industry and deliberate release of pets, plants or live bait along coastal waters. This means that future invasions can be prevented through a combination of good policy and personal action. The following prevention measures can help make ocean protection a reality.

Support smart shipping regulations

Commercial shipping has historically been the largest source of marine invasive species, which “hitchhike” with the ships through ballast water and biofouling. Biofouling is when a marine organism – such as a mussel or seaweed – attaches to a wet part of the ship where it can survive, such as sea chests, propellers, anchors or chains.

Ballast water is the seawater that ships take in to counterbalance the weight of their cargo. When ships pump ballast water in and out different ports, marine organisms are moved with them. The International Maritime Organization estimates that anywhere from 3 to 5 billion tons of ballast water are moved annually.

Fortunately, solutions exist for both these transfer methods. Many international, national and local governments have enacted regulations that require ships to discharge their ballast in deep waters away from shore, where the coast-adapted organisms they intake while in port are less likely to survive. Scientific investigation is ongoing for technologies that can decontaminate the ballast water, although there is debate over the effectiveness of these methods and discordant policies. Despite the challenges, ballast regulations on the St. Lawrence Seaway – which connects the Atlantic Ocean to the Great Lakes – appear to have greatly reduced the introduction of new invasive species to the Great Lakes.

Biofouling regulations focus on regular cleaning of hulls and ship parts where invasive species attach. Ultimately, public and industry support for shipping protection measures can have a significant positive impact on ocean health.

Don’t dump bait, pets or plants

Many invasive species are spread when people dump live bait in or near the water, or release an exotic aquatic plant or pet from their aquarium. The invasive lionfish, which is damaging fisheries on the Atlantic and Caribbean coast, is thought to have escaped from a seaside aquarium and/or been released by pet owners.

Unwanted bait should always be disposed of in the trash. Unwanted pets or plants can usually be returned to an aquarium supplier. Importantly, aquarium owners or gardeners should consult their state and federal lists of prohibited invasive species before purchasing or transporting a new plant or animal.

Follow prevention steps for recreational boating

Many invasive species can be transported from an infested marine port to surrounding areas by recreational boats and equipment. This is how zebra mussels were transported from the Great Lakes to inland lakes and rivers in the Midwest. More recently, the invasive seaweed Sargassum horneri, which threatens ocean kelp forests, was transferred from Long Beach Harbor in California to the Channel Islands by local boat traffic.

The prevention steps for freshwater invasive species can help boaters in marine areas stop the spread of invasive species.

See Also: How to Stop Freshwater and Terrestrial Invasive Species.

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Your Citation
Seiler, Deborah. "How to Stop Marine Invasive Species." ThoughtCo, Dec. 30, 2016, Seiler, Deborah. (2016, December 30). How to Stop Marine Invasive Species. Retrieved from Seiler, Deborah. "How to Stop Marine Invasive Species." ThoughtCo. (accessed November 25, 2017).