By Melissa Tanji

WAILUKU, Maui (The Maui News, July 12) - Freighters, cruise ships and fishing boats that stop in Hawaii during trips across the Pacific are prime suspects in bringing unwanted aquatic organisms — algae, mollusks and fish — that can invade the waters around the islands. 

But species brought in for aquariums or aquaculture that are accidentally or intentionally released are also part of the problem, according to a draft "Aquatic Invasive Species Management Plan" developed by the state and The Nature Conservancy. 

The state Division of Aquatics Resources and the conservancy are seeking public comments on the plan that deals with the economic and ecological impacts of non-native aquatic species being brought into Hawaii. 

The plan cites the $1 million cost of cleaning up Oahu’s Lake Wilson of an introduced freshwater plant, Salvinia molesta, as an example of the kind of problems that can occur when alien species are allowed to propagate in island waters. 

Hawaii’s ocean waters, streams and lakes already have been invaded by a number of non-native species that cause problems. 

In addition to the Salvinia, also known as Kariba weed, a number of potentially damaging plants, mollusks and fishes already have been introduced by a number of mechanisms.

Water hyacinths were brought in as an ornamental plant for backyard ponds but have been let loose and like the Salvinia can overtake a waterway. Apple snails were brought in as aquarium snails, but when released in the wild, they continue to grow and have become a pest to taro farmers. Tahitian prawns were brought in as an aquaculture species for commercial production, but now have invaded streams across the islands, where they feed on native oopu and opai. 

Two public meetings on the draft plan are still scheduled in Maui County — from 5:30 to 7:30 p.m. Tuesday at the Lanai Public Library and from 6 to 8:30 p.m. Thursday at the Mitchell Pauole Center in Kaunakakai.

According to Andi Shluker, aquatic invasive species management plan project coordinator, a meeting already was held on Maui. But the public still can comment on the plan by writing to Shluker by July 23 at: The Nature Conservancy, 923 Nuuanu Ave., Honolulu 96817, or by e-mail at ahshluker@tnc.org

Shluker said the problem of invasive species in the ocean and streams is as serious as the problem with non-native plants and animals on land but "people were not looking." 

The aquatic invasive species plan is intended to increase public awareness of the issues, as well as to develop programs for dealing with introduced pest species and to prevent new species from being introduced. 

Shluker said the Hawaii plan is a result of a federal Non-Indigenous Aquatic Nuisance Prevention and Control Act of 1990 and a National Invasive Species Act of 1996 that call for the development of such state and regional management plans. 

Federal matching funds for activities in the plan may be available pending approval, she said. 

The federal acts were in response to the invasion of the zebra mussel in the Great Lakes, a small mollusk that grew into massive tracts on shoreline rocks and piers and was swept into irrigation canals, water systems, aquaculture facilities, and fisheries. All were hit hard economically by the invasive species, she said. 

Shluker said the Hawaii plan will look at what is being done to control and study native aquatic species that are also problems. The plan cites algae blooms involving both an introduced seaweed and two indigenous seaweeds that have caused serious economic losses in the resort areas of West Maui and South Maui. 

In both areas, an introduced red seaweed, Hypnea musciformis, and a native green seaweed, Ulva fasciata, regularly have blooms that result in masses of the seaweeds washing up along beaches. 

According to the study, Hypnea blooms cost Maui hotel operators an estimated $20 million a year as "a result of reduced property values and reduced occupancy rates in hotels and condominiums in impacted areas, as well as direct costs associated with removal of rotting and foul-smelling algae on the beaches." 

Cladophora sericea, a green, stringy algae commonly found in deeper waters, has bloomed occasionally in waters off West Maui where the accumulation interferes with fishing, underwater tours and related activities. 

Shluker said research is being conducted by the University of Hawaii, with the support of federal, county and community agencies. 

The draft plan also notes that introduced aquatic species include insect pests such as mosquitoes that are responsible for the spread of a number of serious diseases including dengue fever, malaria, yellow fever, West Nile virus and encephalitis. 

"Potential pathways of invasion for aquatic insects include being transported and imported in recycled material such as tires, aquatic plants, aquaculture material, ship ballast, shipments with aquarium fish, airplanes, building material, greenhouse plants, imported soil and in baitfish or other moist packing material," the plan says. 

In citing commercial ships coming to Hawaii, the plan says the invasive species can be brought in ballast water, on vessel hulls, in bait-holding wells, in piping systems and on fishing gear. 

They also can be imported in the aquarium trade, with aquaculture products or as hitchhikers with legitimate import species. 

The draft plan proposes a number of steps to deal with the issue, including improved coordination among agencies responsible for overseeing ships and importation of aquatic products, developing an effective monitoring and detection program, increased education of the public, and research on controlling invasive species.

July 14, 2003

The Maui News: www.mauinews.com 


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