Hawai'i's BioInvasion II: The Frog-Caffeine Dilemma

(This series first appeared in HIJ in 2001)

The Island of Hawai‘i may be about to receive a massive jolt of caffeine. And it won’t be from Starbucks.

The State Department of Agriculture and Department of Land and Natural Resources are in the process of implementing a program to control the spread of Caribbean land frogs, especially the coqui frog, which has gained a noisy foothold in many Big Island communities. A key component of this campaign is an emergency EPA permit to spray with a caffeine concentrate that is 55 times as powerful as normal coffee.

The spray would be available for use by certified applicators in homes, commercial nurseries, forests, farms, lawns, and golf courses, and may become mandatory for plant shipments from commercial nurseries in frog-infested areas of the island. Because of the “emergency” nature of the application, the permit has bypassed normal EPA testing requirements. DOA officials admit that they have almost no scientific data on what effects such massive caffeine dosages would have on plants, pets, birds, reptiles, insects, or humans.

Critics of the program call it an over-reaction and worry that the cure may be a bigger problem than the disease. Supporters, including some environmentalists, say it’s an appropriate reaction, given the island’s long and woeful experience with invasive plants and animals. They say the tiny frogs with big appetites, big voices and a very high reproductive rate may be poised to repeat the history of mongooses, cane toads, rats, mosquitoes, and a long line of other biological invaders.

The frog-caffeine controversy has raised fresh debates about the dilemma of invasive species in general. In most of the islands’ lowlands, native species survive only as remnants, not as an intact ecosystem. Some areas are still forested with an overstory of native ‘ohi‘a trees, but the native understory has been crowded out by invaders such as waiwi (strawberry guava), yellow guava, and tibouchina. In some areas “weed trees” such as African tulip trees, gunpowder trees and banyans are pushing out the ‘ohi‘a trees themselves. In the island’s few freshwater or brackish water wetlands, imported cattle egrets are far more common than Hawaiian coots. Anchialine ponds—those delicate, clear brackish-water pools along the ocean’s edge—have changed into scummy puddles, as the native shrimp that controlled algae growth are gobbled up by introduced aquarium fish. Avian-malaria-carried by imported mosquitoes has wiped out most native birds in the lowlands, and the descendants of released caged birds such as Indian minas, Japanese white-eyes and Java sparrows have taken their place. One expert has estimated that on average, a new alien species arrives in the islands once every 18 days.

Given this massive problem and the state’s very limited resources, questions about invasive species start to resemble those involved in triage process at an overloaded MASH unit. Which case is most urgent? Who can be saved? Which cases are hopeless?

“This is Making Hawaii Sick”

The coqui is a good example of that process in action. The tiny frog has actually been in the islands for over a decade, but in the past two or three years the population has exploded exponentially. Coquis go through no tadpole stage; they lay their eggs on dry land and are born as miniature frogs. As a result, they are not limited to areas near ponds, and can spread rapidly, hitch-hiking on plants from infested nurseries and discount stores. A single breeding pair can quickly breed into thousands. Residents in infested areas complain about the frogs’ extremely loud breeding calls; environmentalists worry that if the coquis become established in the island’s remaining native forests, they will threaten native insects and compete with native birds for food. The frogs have already appeared as high as the Volcano area, well above the altitude limits of their normal range in Puerto Rico and well within the range of Hawai‘i’s remaining viable upland forests.

But the frogs also have their supporters. Chief among them is Sydney Ross Singer, founder of the Coqui Hawaiian Integration and Re-education Project.

“I’m a medical anthropologist,” says Singer. “I challenge the cultural things that make people sick. And when I heard about this thing, I said, this is making Hawai‘i sick.” Singer claims that there is no actual medical evidence that the frogs present a health problem by keeping people awake at night—but that by making that allegation, anti-frog forces can convince people that they are being affected, essentially creating a problem by saying there is one. Likewise, he says, “propaganda” about the frogs may affect real estate values more than the presence of the frogs themselves otherwise would, and the only threat to agriculture that the frogs present is the danger of an agricultural quarantine imposed to prevent the frog’s spread. In fact, Singer maintains, the frogs may benefit agriculture by eating insect pests.

“It (the coqui) can’t do anything intrinsically to damage the economy unless it’s done by the eradicators,” maintains Singer.

Singer has accused environmental groups and state officials of whipping up “frog mania” in order to get funding for the monitoring and eradication programs.

Long time environmental activist Nelson Ho takes issue with Singer’s reasoning. Ho works with Operation Miconia, whose Miconia Hotline has also taken on the job of helping to monitor the frogs’ spread. “The people who are doing the research already have lots to do,” Ho says. “The people who are doing Operation Miconia might be taken away from miconia work because the Department of Agriculture does not have enough personnel to handle this.”

Miconia is another invasive species, a fast-spreading tree that has wiped out much of the native forest in Tahiti and is threatening to spread into Big Island rainforests as well.

Ironically, one criticism leveled at the DOA’s frog control proposals is that they may stretch the department’s limited quarantine resources to the breaking point. “They don’t have the inspectors, or even a driveway big enough for how long the trucks would have to be in there,” believes Susan Hamilton of Plant It Hawaii, a local fruit tree nursery.

Caffeine and Quarantines

The DOA’s proposals were still in the draft stage at press time for this article. But according to Domingo Carvalho, Invertebrate and Aquatic Biota Specialist for the DOA’s Plant Quarantine Branch, the program to limit the frog’s spread would probably include several elements. Plant shipments would be inspected by spraying samples with a pyrethrum-based pesticide, which doesn’t kill the frogs, but is known to irritate them, causing them to jump from the plants and be discovered. Infected shipments would then have to go through an approved treatment before shipping. At this point, the only approved treatment would be with the super-caffeine solution.

“What we’re hoping is that the nurseries that are currently infested with frogs...can get rid of them prior to this inspection,” adds Carvalho.

State officials held a series of meetings with Hawai‘i Island nurserymen last month about the quarantine plan. Some members of the industry criticized the plan as too costly, too impractical—and too late.

“I do not believe there is an attempt to put us out of business in these strained economic times, but the regulations and procedures outlined to the Big Island Association of Nurserymen at Wednesdays meeting could do just that,” wrote Hamilton to a state official, after one such meeting. Hamilton went on to outline her own suggested six-point “smart plan” for a more comprehensive, coordinated effort to deal with invasive species. Among her recommendations were more effective inspections of plants entering the state; better education for nurserymen and their customers; inspection and eradication in frog-infested retail facilities; inspection of interisland barges and other modes of transport, and careful selection of target areas for eradication efforts. She pointed out that while Lava Tree State Park, for instance, was heavily infested, the frogs there were unlikely to travel anywhere else, while a frog-infested nursery or discount store was likely to disseminate hitch-hiking frogs with their plants.

Hamilton felt that the quarantine rules on interisland plant shipments were “too restrictive.”

“Our nursery drives to Lanikaula before every dock or plane shipment is sent,” she noted. “The time spent there cannot exceed a certain length of time, as all dock orders have to be down at the dock before noon. Some days we have three truckloads of palettes. We must wrap them to secure them for transport. Are we to unwrap each palette so that you may spray “hot shot” [a pyrethrum spray] on every load to see no frogs emerge? And then palette wrap them again at the inspection? What will the cost be of this extra step and time on the inspectors? I know it will put undo economic pressure on our nursery, as well as many others.”

Instead, Hamilton suggested quarterly inspections for the nurseries, with frog-free nurseries being allowed to ship interisland without restrictions.

Carvalho noted that some of the inspections might actually be performed at the nurseries, rather than at the docks or the quarantine facilities.

Choosing Among Unknowns

At the heart of the coqui/caffeine controversy, as with many invasive species issues, is a basic question: which is more dangerous and costly, the invaders or the countermeasures? Bio-pollution, or chemical pollution?

And too often, troublingly, the answer is “We don’t know.”

In the case of coqui vs. caffeine, the unknowns are even more troubling than usual. Singer points out that the potential of the coqui to damage the environment is still largely a matter of speculation: that no studies have been done of the affects of frog noise on human health, for instance. And since the frogs are not known to have invaded the native upland forests in significant numbers, Singer maintains, their effect on native habitat is unproven.

But Ho and other environmentalists maintain that the predictions about the coqui are more than mere speculation; they are based on hard experience with other creatures.

“There is concern that the frog exhibits the characteristics of an invasive species,” Ho maintains.

“Invasive species” is a specific name, applied to creatures that exhibit specific characteristics. According to Hawai`i’s Invasive Species, edited by George W. Staples and Robert H. Cowie, those characteristics include adaptability to different habitats; tolerance of a wide range of conditions; the ability to “eat and survive on a diversity of food sources”; the ability to live in environments disturbed by human or natural events; easy dispersal to new areas; rapid reproduction; and long or year-round breeding seasons. Invasive species are classic examples of old-fashioned Darwinian evolution; they simply out-reproduce and out-compete their more specialized rivals.

The coqui has most of these characteristics. To biologists, that spells trouble.

But there are also a huge number of unanswered questions about the proposed caffeine treatment.

“I know that frogs and snails and slugs have been identified as sensitive to caffeine. Any other species, I really don’t know,” admits DOA Pesticide Program Manager Robert Boesch Boesch.

The DOA and DLNR did subcontract for tests on the caffeine and frogs, says Boesch, but “that was primarily to identify chemicals that could be used to control the frogs.” One role of the applications under the emergency permit, he says, will be to study the caffeine’s effects on “non-target species.”

The super-caffeine solution’s effects on plant life are also largely unknown.

“We did find studies relating to an onion root, where apparently they were looking at caffeine’s effects on mitosis [cell division], says Boesch, “and there were instances of abnormal mitosis, which would suggest that it could be phytotoxic [toxic to plants].” Boesch suggests that before applying the chemical to large groups of plants, growers should test it on small sample plots first.

The EPA did identify four human populations for whom the super-caffeine formula might pose special health risks: Pregnant women, toddlers under two, people with hypertension or high blood pressure, and children with Attention Deficit/Hyperactivity Disorder (ADHD).

“If they’re directing sprays upwards into trees, any sensitive person will have to be kept at least 100 feet away from the area that’s being treated. That way, we should be able to manage the risk to acceptable levels,” maintains Boesch. The EPA permit allows only properly certified professionals wearing protective clothing to apply the caffeine, and restricts access for 24 hours after spraying. But Boesch admits that there is no data on how long the caffeine requires to dissipate after it is applied.

Uplands vs. Lowlands

In asking whether the invader or the treatment is the higher risk, the questioner may also need to ask which area he or she is most concerned about: the surviving native forests or the human-dominated lowlands.

For environmentalists and biologists struggling to help the native forest survive the assaults of pigs and mongooses, rats and yellowjackets, faya trees and kahili ginger, yet another invader could prove the final straw that causes the whole ecosystem’s collapse.

But in the lowlands, that collapse has already happened. If the upland forests are a battleground, then the lowlands are a biological riot, where hundreds of invasive species compete with each other for every inch of ground that’s not paved or cultivated. For environmentalists, there often seems nothing left there to protect.

For the Sierra Club’s David Kimo Frankel, the choice seems clear.

“The coqui is a far greater threat to the Hawaiian environment than caffeine, because the coqui as an alien species disrupts the native ecosystem,” he maintains. “I know that the review [for the caffeine permit] was shorter. That’s true. The emergency had to be justified, though. It is an emergency. It already may be too late.”

But for lowland residents, the invaders are more familiar than native life forms, and sometimes more cherished. When four acres of mostly non-native jungle were bulldozed near the heart of Pahoa recently, for instance, it raised a storm of protests. But residents seemed to have relatively little to say when another development claimed nearly 8 acres of ‘ohi`a trees on the edge of town.

And a little-understood pesticide applied next door may seem a more urgent than protecting birds and insects that residents have never seen.

Which is more important? What can be saved, and at what cost?

Until Hawai‘i can develop better safeguards against invasive species entering the islands to start with, residents will keep facing those dilemmas.