Understanding and Addressing Invasive Species

Photo from: New York State Department of Environmental Conservation, water chestnut bed at Beacon

Spring is officially here! Tulips will soon be emerging from the ground, buds blossoming on trees and, unfortunately, invasive plant species will begin their annual growing cycle. No type of habitat or region of the globe is immune to the threat of invasive species (“invasives”). Invasives create major impacts on ecosystems throughout the world, and freshwater ecosystems and estuaries are especially vulnerable because the establishment of such species in these habitats is difficult to contain and reverse.

This blog provides an introduction to invasive aquatic species, including information that will help you prevent the spread of invasives in the waterways of your community.

Defining Invasive Species

Invasive species can be defined as non-native occurring in an ecosystem that is outside its actual natural or native distributional range. Although the colonization of an ecosystem by non-native species can occur naturally, it is more often a function of human intervention, both deliberate and accidental. For aquatic ecosystems some species have become established as a result of the aquarium trade, fish culture practices and/or transport of plants and animals in the bilge and ballast water of trans-oceanic shipping vessels.

One of the primary reasons invasives are able to thrive, spread rapidly, and outcompete native species is that the environmental checks and predators that control these species in their natural settings are lacking in the ecosystems and habitat in which they become introduced. The subsequent damages they cause occur on many ecological levels including competition for food or habitat (feeding, refuge and/or spawning), direct predation and consumption of native species, introduction of disease or parasites, and other forms of disruption that lead to the replacement of the native species with the invasive species. As a result, invasives very often cause serious harm to the environment, the economy, and even human health. A prominent example is the Emerald Ash Borer, a non-native, invasive beetle that is responsible for the widespread death of ash trees.

As noted above, there are a large number of aquatic invasive species. Some of the more commonly occurring non-native aquatic plant species that impact East Coast lakes, ponds and reservoirs include:

Understanding How Invasives Spread

Either intentionally or unintentionally, people have helped spread invasives around the globe. This is not a recent phenomenon but rather something that has been occurring for centuries. “Intentional introductions,” the deliberate transfer of nuisance species into a new environment, can involve a person pouring their home aquarium into a lake or deliberate actions intended to improve the conditions for various human activities, for example, in agriculture, or to achieve aesthetics not naturally available.

Photo by: Tom Britt/CC Flickr, zebra Mussels adhered to a boat propeller“Unintentional introductions” involve the accidental transfer of invasives, which can happen in many ways, including aquatic species attached to the hull of boats or contained in bilge and ballast water. A high-profile example is the introduction of zebra mussels to North America. Native to Central Asia and parts of Europe, zebra mussels accidentally arrived in the Great Lakes and Hudson River via cargo ships traveling between the regions. The occurrence, density, and distribution of Zebra mussels occurred at an alarming rate, with the species spreading to 20 states in the United States and to Ontario and Quebec in Canada. Due to their reproductive fecundity and filter-feeding ability, they are considered the most devastating aquatic invasive species to invade North American fresh waters. They alter and diminish the plankton communities of the lakes that they colonize leading to a number of cascading trophic impacts that have especially negative consequences on fisheries. Zebra mussel infestations have also been linked to increased cyanobacteria (bluegreen algae) blooms and the occurrence of harmful algae blooms (HABs) that impact drinking water quality, recreational use, and the health of humans, pets, and livestock.

Additionally, higher than average temperatures and changes in rain and snow patterns caused by climate change further enable some invasive plant species to move into new areas. This is exemplified by the increased northly spread of hydrilla (Hydrilla verticillate), a tropical invasive plant species that has migrated since its introduction in Florida in the 1950s to lakes, rivers, and reservoirs throughout the U.S.

Regardless of how any of these invasive species first became established, the thousands of terrestrial and aquatic invasive species introduced into the U.S. have caused major ecological, recreational and economic impacts.

Measuring the Impacts of Invasives

After habitat loss, invasive, non-native species are the second largest threat to biodiversity. According to The Nature Conservancy, “Invasive species have contributed directly to the decline of 42% of the threatened and endangered species in the United States. The annual cost to the nation’s economy is estimated at $120 billion a year, with over 100 million acres (an area roughly the size of California) suffering from invasive plant infestations. Invasive species are a global problem — with the annual cost of impacts and control efforts equaling 5% of the world’s economy.”

Of the $120 billion, about $100 million per year is spent on aquatic invasive plant control to address such deleterious issues as:

  • Human health (West Nile Virus, Zika Virus)
  • Water quality impacts (Canada geese)
  • Potable water supplies (Zebra mussel)
  • Commercial fisheries (Snake head, lamprey, Eurasian ruffe, round goby)
  • Recreational activities (Eurasian watermilfoil, water chestnut, hydrilla)
  • Biodiversity (Purple loosestrife, common reed, Japanese knotweed)

Invasive species can change the food web in an ecosystem by destroying or replacing native food sources. As the National Wildlife Federation explains, “The invasive species may provide little to no food value for native wildlife. Invasive species can also alter the abundance or diversity of species that are important habitat for native wildlife. Additionally, some invasive species are capable of changing the conditions in an ecosystem, such as changing soil chemistry…”

Addressing Invasives

Our native biodiversity is an irreplaceable and valuable treasure. Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can help protect our native heritage from damage by invasive species.

What Can We Do?

  • Reduce the spread
  • Routinely monitor
  • Document and report
  • Spread the word

Reducing the Spread:
The best way to fight invasive species is to prevent them from occurring in the first place. There are a variety of simple things each of us can do to help stop the introduction and spread of invasives.

  • Plant native plants on your property and remove any invasive plants. Before you plant anything, verify with your local nursery and check out this online resource for help in identifying invasive plants.
  • Thoroughly wash your gear and watercraft before and after your trip. Invasives come in many forms – plants, fungi and animals – and even those of microscopic size can cause major damage.
  • Don’t release aquarium fish and plants, live bait or other exotic animals into the wild. If you plan to own an exotic pet, do your research to make sure you can commit to looking after it. Look into alternatives to live bait.

Monitoring:
The Lake Hopatcong Foundation Water Chestnut prevention brochureInvasive plant monitoring is one of the most valuable site­-level activities people can support. Contact your local watershed organizations to inquire about watershed monitoring volunteer opportunities. For example, the Lake Hopatcong “Water Scouts” program was established to seek out and remove any instances of the invasive water chestnut species.

If you are a lake or watershed manager, the best way to begin an invasive plant monitoring project is with an expert invasive plant survey to determine which invasives are most likely to be problematic in your watershed and identify the watershed’s most vulnerable areas. Contact us to learn more.

 

Documenting and Reporting:
It’s important to learn to identify invasive species in your area and report any sightings to your county extension agent or local land manager. For example, in New Jersey there is the Invasive Species Strike Team that tracks the spread of terrestrial and aquatic invasives and works with local communities in the management of these species. Additionally, consider developing a stewardship plan for your community to help preserve its natural resources. Princeton Hydro’s team of natural resource scientists can help you get the ball rolling by preparing stewardship plans focused on controlling invasive species and protecting the long-term health of open spaces, forests habitats, wetlands, and water-quality in your community.

Spreading the word:
Many people still don’t understand the serious implications of invasive species. Education is a crucial step in stopping the spread of invasives, which is why it’s so important to talk with your neighbors, friends and family about the hazards and ecological/economic impacts of invasive species.

Also consider talking with your community lake or watershed manager about hosting an educational workshop where experts can share their knowledge about invasives specific to your area and how best to address them. Princeton Hydro’s Director of Aquatic Programs Dr. Fred Lubnow recently gave a presentation to the Lake Hopatcong Foundation titled, “Invasive Species in Watershed Management.” View it here.

 

We encourage you to share this article and spread your invasive species knowledge so that together we can help stop the introduction and spread of invasive species.

Ecological Uplift in an Urban Setting

The City of Elizabeth, the fourth most populous in New Jersey, is not exactly the first place that comes to mind when envisioning a wild landscape. This bustling urban area is well known for its Port Newark-Elizabeth Marine Terminal and the Philips 66 Bayway Refinery, and sits at the intersection of several major roadways like the NJ Turnpike and the Goethals Bridge. The landscape, which was once teeming with dense wetlands and associated habitats, is now heavily urbanized with a vast mix of residential, commercial, and industrial properties. The largely channelized Elizabeth River courses through the city for 4.2 miles before draining into the Arthur Kill waterway. However, in this 14-square mile city, native flora and fauna are taking root again thanks to ecological restoration and mitigation efforts.

Urban landscapes like Elizabeth can pose significant challenges for restoration efforts, but they also provide an array of opportunity for significant ecological uplift.

In 2004, Princeton Hydro was retained to restore an 18-acre site adjacent to the Elizabeth Seaport Business Park, which is located in an area that was once part of a large contiguous wetland system abutting Newark Bay. The site was comprised of a significantly disturbed mosaic of wetland and upland areas and a monoculture of Phragmites australis, also known as Common Reed, on historic fill. Historic fill consists of non-native material, historically placed to raise grades, and typically contains contaminated material not associated with the operations of the site on which it was placed.

The highly invasive Phragmites australis had overtaken most of the wetland areas, and the upland woodland areas only contained four tree species, mostly Eastern Cottonwood, with very low wildlife value. The 18-acre site had huge potential but was significantly degraded and was being vastly underutilized. Overall, the mitigation plan focused on the enhancement of existing wetland and transition areas to increase the area’s wildlife value through the establishment of a more desirable, diverse assemblage of native species subsequent to eradication of non-native-invasive species.

2005 (Before Plantings)
2019
In 2004, Prologis hired Princeton Hydro to restore an 18-acre area adjacent to the Elizabeth Seaport Business Park, which a significantly disturbed and degraded mosaic of wetland and upland areas. This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.

The freshwater wetland aspect of the mitigation plan, which included inundated emergent, emergent, and forested habitat, was designed to be a combination of wetland creation (2.40 acres) and enhancement (8.79 acres), emphasizing the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife food value.

The upland forest aspect of the mitigation plan involved the enhancement of 5.40 acres and creation of 1.45 acres of upland forest to foster the development of a species rich and structurally complex upland forest. The upland areas targeted for enhancement/creation consisted of areas where woody vegetation was lacking or forested areas that were dominated by eastern cottonwood.

2008
2019
The 18-acre site in Elizabeth, NJ had huge potential but was significantly degraded and was being vastly underutilized. The mitigation plan emphasized the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife habitat value.

The project team worked to remove Phragmites australis from the site utilizing a combination of herbicide and mechanical removal techniques. Once the Phragmites australis was cleared, the team installed 27,000 two-inch native herbaceous plant plugs in the wetland portions of the mitigation site, and 2,705 native trees/shrubs throughout the site.

In order to ensure the continued success of the mitigation project, monitoring is regularly conducted at the site. A monitoring report conducted at the end of 2019 revealed a plethora of well-established habitat areas, a diverse community of plant and tree species, and a thriving, highly-functional landscape.

2004 (Before Plantings)
september 2019
In 2004, before the restoration work began, the site consisted of degraded Phragmites australis dominated wetlands and an urban woodland area dominated by Eastern cottonwood. The planting component of the mitigation project commenced in 2015, and the installation of all woody plant material began Fall 2015 and was completed in Fall 2016. The 2019 Monitoring Report revealed the plantings are well-established and the area is thriving.

Presently, the Elizabeth Seaport Business Park Mitigation Site boasts a variety of productive wildlife habitats that are rare in a highly urbanized setting and provides valuable ecosystem services, including sediment retention and roosting, foraging, and nesting opportunities for both resident and migratory bird species with over 150 bird species identified within the mitigation site.

2008
2019
The Elizabeth Seaport Business Park site was comprised of a monoculture of Phragmites australis, also known as Common Reed. The mitigation plan focused on enhancing the existing wetland by eradicating non-native-invasive plant species, like Phragmites, and establishing more diverse population of productive, native species with high ecological value.

This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.  If you’d like to learn more about this project from our Natural Resources Senior Project Manager Michael Rehman, check out the video of his presentation at the 2020 Delaware Wetlands Conference below.

We’re at the Delaware Wetlands Conference and our Senior Project Manager, Michael Rehman, is presenting on a successful urban wetland restoration in Elizabeth, NJ.

Posted by Princeton Hydro on Thursday, January 30, 2020

 

If you’re interested in learning more about our wetland restoration and mitigation services, go here!

Free Webinar: Engaging the Media on Clean Water Issues

The American Sustainable Business Council (ASBC) launched the “Clean Water is Good for Business” campaign that gives businesses a strong voice to advocate for water quality protection, reduced nutrient pollution, improved water infrastructure, and policies that make businesses more resilient to floods and droughts. Ultimately, ASBC is hopeful that the campaign helps to shift the dialogue on water issues so that there is a greater balance of business perspectives, including the economic reasons for sensible clean water regulations.

As part of ASBC’s campaign, the organization hosted a series of online training sessions for businesses to help elevate their voice on clean water issues. The most recent webinar, titled “Making the Business Case on Clean Water Issues to the Media,” focused on helping businesses find and approach the right journalists, make the most compelling arguments for policy agenda, enhance credibility and confidence, and much more!

The webinar was lead by Bob Keener, Deputy Director of Public Relations at American Sustainable Business Council; Dana Patterson, Marketing & Communications Manager at Princeton Hydro; Rita Yelda, Outreach & Communications Manager at Coalition for the Delaware River Watershed; and Colton Fagundes, Policy Associate at American Sustainable Business Council.

Dana’s presentation focused on how to build substantive values-based narratives; how to develop engaging media content and effective headlines; how to build relationships with key members of the media; and best practices for media outreach.

If you missed the webinar and are still interested in learning how to build relationships with elected officials and members of the media so you can make your business’ voice heard on the issues and policies that matter, it’s not too late! You can watch the complete webinar on YouTube. And, you can view all of the presentation slides, by clicking here.

For more information about upcoming ASBC events, visit their website. To learn more about Princeton Hydro, go here.