Invasive species. You might have heard the term, but have you ever stopped to consider why you should actually care? It’s easy to dismiss them as just another environmental issue, but the truth is, invasive species pose a significant and growing threat to our economy, our health, and the natural world we depend on. From rising costs for everyday goods to new health risks and the destruction of our beloved landscapes, the impact of these unwelcome intruders is far-reaching and increasingly difficult to ignore.
The Economic Drain: Invasive Species and Your Wallet
The economic consequences of invasive species are staggering. In the United States alone, the expenses linked to ecological damage and managing these invaders have reached hundreds of billions of dollars annually and continue to climb. Globally, the costs are equally alarming, with invasive insects alone costing North America tens of billions each year. These aren’t abstract numbers; they translate directly into higher prices for consumers and strain on vital industries.
Consider the impact on industries vital to Wisconsin’s economy. Sport and commercial fishing, forestry, and agriculture are all battling the economic fallout from invasive species. Power companies, industrial water users, and municipal water plants also bear the burden, passing these costs onto you, the consumer, through increased water and electric bills.
The Great Lakes fishing industry, a powerhouse valued at nearly $4.5 billion and supporting 81,000 jobs, faces an existential threat. Invasive species like the round goby are disrupting the food chain by consuming the eggs of native sportfish, including smallmouth bass and trout, in crucial nearshore habitats. Furthermore, restrictions related to Viral Hemorrhagic Septicemia (VHS) to control its spread have negatively impacted baitfish sales and fish hatchery operations, adding further economic strain.
The impact extends beyond commercial sectors. Property values are also at risk. Studies have shown that lakes infested with Eurasian watermilfoil can experience property value decreases of up to 19%. Imagine the financial hit to homeowners and local communities due to the spread of a single invasive plant.
Forestry, another major Wisconsin industry contributing $28 billion annually and supporting 66,000 jobs, is also under siege. Invasive shrubs like non-native buckthorns and honeysuckles hinder the regeneration of young trees, creating a long-term and severe threat to the industry’s sustainability. In 2015 alone, Wisconsin spent millions combating invasive species, funds that could have been allocated elsewhere if these threats were better managed.
Invasive plants often spread along transportation and utility corridors, highlighting how easily these species can proliferate across landscapes, impacting both natural areas and agricultural lands. The seemingly isolated problem of invasive species is deeply interwoven with our daily economic lives.
Health Hazards: Invasive Species and Your Well-being
The threats posed by invasive species aren’t just economic; they directly impact our health. While perhaps less obvious than economic costs, the health risks are real and growing. For example, the introduction of cholera-causing bacteria through ship ballast water in Alabama demonstrates the potential for invasive species to introduce serious pathogens. Even seemingly minor nuisances, like the sharp shells of zebra mussels, can pose a physical hazard to swimmers.
However, health risks extend far beyond waterborne threats. Consider wild parsnip, a roadside and grassland invader rapidly spreading across Wisconsin. Simply brushing against this plant with bare skin can cause severe burns and blisters, a painful and often unknown danger for those enjoying outdoor spaces.
Perhaps most concerning is the increasing role of invertebrates as vectors for diseases. The expanding range of the lone star tick in Wisconsin, previously confined to southern regions, has brought with it a rise in tick-borne diseases. Wisconsin now faces at least six serious tickborne illnesses, affecting thousands of people annually. These diseases can have debilitating long-term health consequences, underscoring the direct human health impact of invasive species.
Ecological Disruption: Invasive Species and Our Natural World
Beyond economics and health, invasive species wreak havoc on our ecosystems. They disrupt natural communities and ecological processes, altering the delicate balance of competition and predation. Species like ruffe and round goby outcompete native species, triggering cascading effects throughout the food web and diminishing biodiversity.
Invasive plants such as garlic mustard, honeysuckle, purple loosestrife, and Eurasian watermilfoil displace native flora, degrade habitats, and reduce species diversity. These invaders can also act as vectors for diseases that threaten entire ecosystems. Often, the natural controls present in their native ranges, like diseases and pests, are absent in Wisconsin, allowing them to proliferate unchecked at the expense of native plants and animals.
Human activities are the primary drivers of this ecological disruption, creating conditions where invasive species thrive. This happens in three main ways:
- Introduction: We introduce non-native species from other regions or countries, often unintentionally. Lacking natural predators and competitors in their new environments, these species can flourish uncontrollably.
- Disruption: We disrupt the balance of native ecosystems through habitat alteration, pollution, and climate change. These changes can make ecosystems more vulnerable to invasion and even cause native species to become invasive in altered environments.
- Spread: We inadvertently spread invasive species through activities like moving boats without cleaning them, roadside mowing practices, and transporting firewood.
The result is a decline in native plant and animal diversity as invasive species dominate forests, grasslands, wetlands, and waterways. Alarmingly, invasive species are a primary threat to approximately 42% of species listed under the federal Endangered Species Act.
The rapid spread of zebra and quagga mussels in waterways exemplifies the profound environmental changes caused by invasive species. These mussels consume vast quantities of microscopic plants and animals, drastically altering food webs and promoting the growth of nuisance algae and aquatic vegetation.
In woodlands, garlic mustard can blanket entire forest floors, outcompeting native wildflowers for light and nutrients. It even releases chemicals into the soil that inhibit beneficial fungi essential for tree growth, with long-term consequences for forest health.
Invasive species even impact our recreational activities. Once-open forests and grasslands become impenetrable thickets of thorny multiflora rose and dense buckthorn, hindering hunters, hikers, and birdwatchers. As habitats change, wildlife dependent on native plants decline. Invasive animals, like mute swans, can displace native waterfowl, further diminishing wildlife viewing opportunities.
Changes in soil composition and structure caused by non-native earthworms and increases in generalist native species like white-tailed deer in weedy habitats further contribute to the decline of native plant diversity and the proliferation of non-native weeds. Even gardeners are impacted, finding it difficult to grow certain plants in soils altered by invasive Asian jumping worms.
Fishing trips can be ruined by aquatic invasive species. Eurasian watermilfoil clogs boat motors, and invasive rusty crayfish decimate aquatic plants, destroying habitat for native fish and even consuming the eggs of sport fish. This threatens the recreational and commercial fishing industries we rely on.
Why You Should Care: Protecting Our Future
Invasive species are not just an environmental problem; they are an economic, health, and societal challenge that affects everyone. From the rising costs of goods and services to increased health risks and the degradation of our natural heritage, the impacts are undeniable and demand our attention. Understanding why you should care is the first step towards addressing this growing threat and protecting our economy, our health, and the environment for future generations.
References
1 Pimentel, D., S. McNair, J. Janecka, J. Wightman, C. Simmonds, C. O’Connell, E. Wong, L. Russel, J. Zern, T. Aquino and T. Tsomondo. 2001. Economic and environmental threats of alien plant, animal, and microbe invasions. Agriculture, Ecosystems & Environment 84(1): 1-20.
2 Bradshaw, C.J.A., et al. Massive yet grossly underestimated global costs of invasive insects. Nat. Commun. 7, 12986 doi: 10.1038/ncomms12986 (2016).s
3 Wisconsin Invasive Species Program Report
4 Olden JD, Tamayo M (2014) Incentivizing the Public to Support Invasive Species Management: Eurasian Milfoil Reduces Lakefront Property Values. PLoS ONE 9(10): e110458. doi:10.1371/journal.pone.0110458
5 Wisconsin Department of Health Services – Illnesses Spread by Ticks
