What’s destructive, disruptive, and invading all over? Invasive species! An invasive species is commonly defined as a non-native organism “whose introduction causes or is likely to cause environmental harm, or harm to human, animal, or plant health.” According to a February 2019 senate hearing, there are more than 5,000 invasive species in the United States, which cause more than $120 billion in annual economic damage. An estimated 42% of threatened or endangered species are at risk due to invasives. From the spread of a common aquarium plant in the rivers of Alaska, to massive Burmese Pythons in the Florida Everglades, and numerous others, invasive species are an environmental problem that is too often overlooked.
Invasives tend to be particularly destructive because their populations grow unchecked by natural predators and competitors once they are removed from their natural habitats. Biological life is driven to reproduce and thrive, but, in natural ecosystems, food chains maintain balance between different species. Introducing a species from another continent throws that balance out-of-whack. Many invasives can outcompete natives for food and resources, allowing invasives to proliferate.
Invasives also cause serious damage to infrastructure and other economically valuable resources. The National Invasive Species Council lists “property values, agricultural productivity, public utility operations, native fisheries, tourism, and outdoor recreation” among the leading sectors affected by invasives. Many millions of dollars are spent each year on state and federal mitigation efforts, ranging from prevention and early detection to habitat restoration and public education.
Although invasive species can occur naturally—turning up in new places after extreme weather or traveling in or on other species—humans have helped spread invasives in multiple ways. Some invasive plants were introduced in an effort to make gardens more interesting and beautiful. Some were introduced for practical purposes, like Saltcedar for erosion control along riparian areas in the Southwest. Some hitched rides on the train of globalization—as exotic pets or traveling in or on clothes or vehicles. Still others have migrated away from their native habitats due to climate change. Invasives have persisted throughout human history and, more often than not, are now too widespread to be completely eradicated.
Controlling the introduction and spread of invasives presents a vexing legal and policy challenge. It is not practical to quarantine, inspect, find, and/or remove invasives throughout an ecosystem twenty-four hours a day, seven days a week. Still, given the potential for even more serious damage in the future, government at all levels is taking action to address the issue. Going into 2020, anticipated federal regulation will significantly affect the nation’s response to the Emerald Ash Borer and aquatic invasives in ballast water.
An End to the Emerald Ash Borer Quarantine?
The Emerald Ash Borer (EAB), a terrestrial invertebrate native to East Asia, was first discovered in the United States in 2002. It likely arrived in the U.S. hidden in wood packing materials and has now spread across the East Coast and into the Midwest. It has since killed millions of Ash trees in North America. The U.S. Department of Agriculture (USDA) estimates the response cost to EAB infestation from 2009 to 2019 at $10.7 billion.
As of October 1, 2019, a federal EAB quarantine is in effect for parts of 35 states. This means that regulated articles, such as firewood, cannot be removed from specific areas without federal permits. In addition, transport of ash wood between states may require individual state permits; the regulated item must be inspected and determined to be apparently free of the beetle before a permit can be issued.
In September 2018, USDA’s Animal and Plant Health Inspection Service (APHIS) proposed a repeal of the domestic quarantine for the EAB. APHIS says the quarantine is resource-intensive and believes available resources can be used more effectively by investing in non-regulatory control efforts and continuing research. The comment period for the rule closed in November 2018, and comments are still under review according to the APHIS website, as of Nov. 25, 2019, with a final rule likely to be published in 2020. That the federal government is proposing to make this radical change in strategy for addressing the EAB may simply illustrate how challenging the problem is.
New Ballast Water Treatment Standards Expected for Invasives
A lack of effective regulation has already led to a proliferation of invasives in U.S. lakes and rivers. The Zebra Mussel, an aquatic invertebrate originally from Eurasia, was first introduced into Lake Erie in the 1980s. By 1990, the mussels infested all of the Great Lakes, consuming plankton that native fish would otherwise eat, and fostering algae blooms. In addition, the mussels attach to boats, pipes, and other infrastructure, costing the Great Lakes region an estimated $500 million each year. From the Great Lakes, the Zebra Mussel has spread to other waterbodies in virtually all other sections of the United States.
Ballast water introduced the Zebra Mussel into the Great Lakes, and numerous additional invasives could be introduced into the Great Lakes and other U.S. waters in the future through the same path. Ballast water serves to improve a boat’s stability and is pumped in and out of tanks, depending on the weight of the cargo being transported. The amount of this pumped water can range from hundreds to millions of gallons. Because ballast water is typically collected at one location and discharged at another (perhaps on the other side of the world), new nonnative populations can be established as a result of ballast water discharges.
The Vessel Incidental Discharge Act requires U.S. Environmental Protection Agency (EPA) to promulgate new national ballast water treatment standards to address the threat of invasives by December 2020. These standards will regulate ballast water from small vessels (less than 79 feet) and all fishing vessels. The Act also requires the U.S. Coast Guard to issue implementing regulations two years later. Large, non-fishing vessels will continue to follow requirements from the 2013 EPA Vessel General Permit (VGP), the Coast Guard, and state and local governments.
In crafting new ballast standards, EPA must take into account a 2015 ruling by the U.S. Court of Appeals for the Second Circuit that struck down parts of the 2013 VGP as being arbitrary and capricious. The court ruled that EPA failed to sufficiently explain why it did not adopt stricter treatment standards; why onshore ballast treatment options were not considered; and why pre-2009 Lakers (vessels trading exclusively on the Great Lakes) were exempted from ballast discharge limits. To account for this ruling, forthcoming standards should be supported with fact-based analysis of what is economically and technologically feasible to implement.
As these examples illustrate, a basic question with invasives is how we can use limited money and other resources most effectively to address the problem. There have been promising developments in control technology, such as a new drone-mounted spectral resolution camera to help hunters identify Burmese Pythons, and even efforts to convert invasives into food. Santa Cruz Island off the coast of Southern California represents a notable invasives success story. After The Nature Conservancy managed to purchase most of the island, and capture the sheep and feral pigs that had ravaged the landscape, Santa Cruz Island experienced an “ecological rebound.” In 2014, three of the island’s native fox species were taken off the endangered species list. Thus, there is reason to be hopeful in 2020. But invasives pose unique challenges and these challenges will require effective and creative responses. Future solutions may come from investments in technology and research, but action is needed now for the preservation of biodiversity and local economies. It’s time to talk about invasives.