NEW & NOTEWORTHY: Invasive Snakes, Invasive Algae

posted in: March 2010 | 0

Snakes on Planes: The brown tree snake has long been among the most feared of potentially invasive species in Hawai`i. An article in the current edition of Pacific Science sets forth in dire detail some of the economic reasons such fears are justified. Authors Stephanie Shwiff, Karen Gebhardt and Katy Kirkpatrick, all of the Department of Agriculture’s National Wildlife Research Center in Fort Collins, Colorado, and economist Steven Shwiff of Texas A&M University looked at the potential blows to the state’s economy should the reptile become established in the Hawaiian islands.

Bottom line: the cost to the state in lost tourism dollars, power outages, and medical treatment of snake bites “would range from approximately $593 million to $2.14 billion” a year. If even one percent of tourist traffic were lost as a result of the BTS, the result would be 1400 fewer jobs and a loss of revenue of $137.8 million a year. If losses to tourism were as high as 10 percent – a level that the authors estimate is reasonable, given their surveys of tourists – the resulting economic impact could be $1.4 billion a year and the loss of 13,000 jobs. The cost of treatment of snake bites, the authors found, was inconsequential in comparison to that of tourism losses and power outages.

The authors did not even attempt to estimate damage to other sectors of Hawai`i’s economy, especially agriculture, and its native species, especially birds.

The article, “Potential Economic Damage from Introduction of Brown Tree Snakes, Boiga irregularis (Reptilia: Colubridae), to the Islands of Hawai`i,” appears in the January 2010 edition (Volume 64, Number 1) of Pacific Science, published by the University of Hawai`i Press.

Another study published in the same issue (“Potential Distribution of the Alien Invasive Brown Tree Snake…”) describes the vulnerability of other areas to invasion by the snake. Authors Dennis Rödder and Stefan Lötters attempted to identify areas outside the snake’s existing range (Southeast Asia and Australia) where current conditions could lead to the snake’s eventual establishment. Globally, they found a wide range of environments where the snake could thrive, including large areas of Central and South America, the broad coastal plain of the southeastern United States, and much of Africa. Areas of greatest vulnerability, however, are those where accessibility and proximity, as well as lack of competing snakes, compound the risk. These include Hawai`i, Fiji, the Northern Mariana Islands, and New Zealand.

Invasives at NELHA: The Hawai`i Invasive Species Council report to the 2010 Legislature makes for some interesting reading. Among other things, it notes, the Aquatic Invasive Species Team (AIST) was notified by a pond foreman at one of the Kona resorts that he was concerned that a species of algae was invading one of the resort’s ponds. The algae was determined by AIST to be Gracilaria salicornia,one of the most dreaded of invasive marine algae. According to HISC, “the source was traced back to an aquaculture facility in Kona at the Natural Energy Laboratory of Hawai`i Authority (NELHA).” The algae at the pond was eradicated by physical removal as well as by lowering the pond’s salinity, the report states.

Concerns over species brought in by NELHA tenants has been a longstanding concern – of existing tenants, environmentalists, and other state agencies. In 2005, the Board of Agriculture was sued over its failure to require preparation of an environmental impact statement for the introduction of so-called biopharm algae proposed to be grown at NELHA. That lawsuit resulted in a decision by the Intermediate Court of Appeals that the proposed importation was subject to Chapter 343, the state’s environmental disclosure law.

More recently, a NELHA tenant, NoriTech, proposed importing a type of seaweed used for nori, and instead of preparing an environmental impact statement or environmental assessment to address the risks, it went the route of proposing that the Board of Agriculture change its rules to allow the algae to be put on the BOA list of species approved for importation. The Department of Land and Natural Resources’ Division of Aquatic Resources objected strongly to the proposal, explaining that the species proposed for import had a number of characteristics that suggested it could easily become invasive. Last October, ignoring DAR’s objections, the BOA approved the proposed change.


Volume 20, Number 9 — March 2010


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