Marine and Great Lakes Invasive Species
An invasive species is any species that is introduced or non-indigenous to an ecosystem, and whose presence causes or is likely to cause economic or environmental harm or harm to human health (Executive Order 13112, 1999). Invasive species are increasingly changing the natural landscapes of our ocean, coastal and Great Lakes National Park Units. Invasive species harm natural and cultural resources in our parks by:
[+] Outcompeting native species
Many invasives species contribute to the decline of native biodiversity by changing the natural trophic structure of the invaded ecosystem. By outcompeting native species for limited resources, invasive species deplete the available resources for all consumers. This effect is particularly harmful when it occurs at or near the base of food webs. Invasive quagga mussels (Dreissena rostriformis bugensis) deplete plankton populations, a critical food source for a broad range of Great Lakes species, destroying the trophic balance throughout the lakes.
[+] Threatening the safety of park employees and visitors
Several invasive species have biological characteristics that pose a danger to the safety of park employees and visitors. Lionfish (Pterois volitans and P. miles), which have invaded many of the southeastern ocean and coastal parks, have poisonous spines that can be hazardous to people snorkeling and SCUBA diving. Often the danger presented by invasive species is unexpected by park employees and visitors; improving awareness of these dangers is critical to reduce further harm.
[+] Changing/degrading the experience of park visitors
Visitors travel to National Parks to experience and observe the natural scenery and biodiversity, and to experience the nation's natural and cultural heritage. Reduction of native animal and plant populations, extensive habitat alteration by invasive species, and efforts to maintain habitat integrity by eradicating invasive species may detract from visitors' appreciation and experience of National Parks.
[+] Requiring intensified maintenance and monitoring
Park staffs must increase monitoring of park habitats and plant and animal communities for evidence of disturbance and invasion. This puts pressure on limited budgets and park employees to maintain the unique natural beauty of each park. Physical removal and/or control of invasive species are intensive activities that require long-term and diverse management techniques.
[+] Altering natural ecological processes
Some invasive species physically alter the natural structure of park habitats and landscapes. Baby's breath (Gypsophila paniculata) is an invasive dune-dwelling plant in many coastal and Great Lakes parks that prevents the natural movement of sand dunes, critical habitat for many native plants.
Ocean, coastal and Great Lakes parks are working to identify invasive species within their boundaries, understand how these species are impacting park resources, and determine what park managers can do to prevent these species from further damaging natural and cultural resources.
This website and database will help visitors learn more about the invasive species in National Parks they visit to increase critical awareness. As more information is collected, the database will grow; check back to see what has changed in the parks you visit.