The Port of Portland is a partner in the fight against invasive species. Below are 5 ways that the Port of Portland actively supports the Council's statewide objectives to protect Oregon from species that aggressively compete with our native species for resources such as food, nesting sites, or space.
1. Prevention: Stop the Invasion
The Port of Portland owns and manages over 900 acres of mitigation lands, or natural habitats that compensate for impacts during development projects. The Port manages the sites under the guidance of a Natural Resources Policy. To optimize the health of these natural areas, effective invasive species management is a critical component of the Port's stewardship role.
Wetland mitigation sites are home to a diversity of native plants and animals, such as frogs and wildflowers, and are managed closely for invasive plants to maintain their health. It’s critical that these sites meet the vegetation and habitat criteria set by the Oregon Department of State Lands and U.S. Army Corps of Engineers that issue permits for mitigation sites. Beyond that, sites that have already met permitting requirements continue to be monitored and maintained by the Port so that invasive species do not take hold.
To coordinate across different sites, habitats, staff and partners, the Port’s Mitigation Management team developed a Vegetation Management Plan. Invasive plants are ranked according to the City of Portland Classification System in their Nuisance Plants List and it highlights management techniques, timing and procedure for invasive species management. It’s updated every two years to respond to changes in new invaders, regulations and site locations.
An example of an invasive plant managed by the Port is the White Water Lily (Nymphaea odorata). While it bears a deceptively pretty flower, this plant is from the eastern US and has invaded west coast wetlands. It thrives in shallow water areas around the edges of ponds and rivers where it can form dense stands when it takes over.
In 2013, a small population of White Water Lily was discovered at the Port's Ramsey Lakes wetland mitigation site next to the Columbia Slough. By 2015, this species had taken over, covering around 75 percent of the wetland. Because it was growing so close to the Slough where it had the potential to spread, and due to its dense growth that reduced space available for native plants and animals, the Port applied herbicide treatments to stop the invasion. This work resulted in a significant reduction of the plant. Like any effort to manage invasive species, the site will remain under close monitoring while the native vegetation returns to full diversity; it may require additional treatments.
2. Early Detection and Rapid Response: Monitoring for Invasive Mussels
Zebra and Quagga Mussels (Dreissena spp.) are aquatic invasive species native to Eastern Europe. These tiny bivalves are about the size of a fingernail and breed prolifically in freshwater. Upon invasion these mussels have had catastrophic effects, such as in the Great Lakes where they have altered the food web reducing food for sportfish like salmon and steelhead. While detected in a number of states, they are not yet in Oregon.
To stand guard against this threat, the Port Natural Resources team monitors marine terminals to determine whether invasive Zebra or Quagga mussels are present. Two samplers are at Terminal 4 and three samplers are at Terminal 6. Each station is checked monthly and all species are recorded and identified. This information can be shared with local and state wildlife agencies and researchers to work together in a shared response, which is hopefully never needed.
3. Control and Management: Diverse Tools—Even Goats!
New methods to control invasive species are under constant evaluation by the Port in search of options that may be more effective, less costly, and use fewer chemicals. In 2014, the Port experimented with using goats to remove Himalayan blackberry, Scotch broom, and teasel at PDX. And, the goats successfully cleared the area!
While effective, their hungry appetites were not a permanent solution as management needs to be sustained over time. This experiment proved goats to be another tool in the toolbox that minimizes the carbon footprint and herbicide use. When do goats work best? They are a good alternative for areas where time is not an issue, machinery is not an option, vegetation is thick and/or where safety is a concern.
4. Control and Management: Trapping European Starlings at PDX
European Starlings (Sturnus vulgaris) were introduced into North America in 1890 as part of a plan to introduce all birds mentioned in the works of Shakespeare. Since then, they have spread to occupy most of the continent, and are now considered invasive in many areas.
Starling flocks near airports pose an aircraft safety hazard because of the high bird strike potential. Some starling to aircraft collisions result in aircraft damage or loss and, at times, in human injuries. In 1960, Electra aircraft in Boston collided with a flock of starlings soon after takeoff, this event caused the aircraft to crash resulting in 62 fatalities.
The annual abundance of starlings at PDX exceeds all other bird species combined. During the non-breeding season, starlings come together in large flocks that may travel many miles between roosts and feeding areas. As part of a larger Aviation Wildlife Management Program, the PDX Wildlife Team traps starlings to reduce the probability of a bird strike. While the traps are active, the starlings are provided with food, water, and shelter from the weather. The team makes every attempt to provide humane conditions for the birds in traps. During seasons where they are abundant, the team removes them frequently, amounting to between 2,000 and 10,000 birds per year!
5. Coordination & Leadership: Working with Partners
Coordinating with partners is critical in the fight against invasive species. Identifying emerging threats and the right strategies to address them takes cooperation with local, state and federal agencies.
- Local/Regional efforts - The 4-County Cooperative Weed Management Association is a regional partnership of organizations in Southwest Washington and Northwest Oregon dedicated to combating invasive species for the benefit of native habitat. The Port participates in work groups, strategic planning and shares research. Close communication is especially intensive about aquatic invasive species in the Columbia Slough watershed where Port Natural Resources team works with the City of Portland, Metro, Multnomah County Drainage District and the Columbia Slough Watershed Council.
- State - The Port annually contributes funds to help trap and treat infestations of invasive Japanese Beetles at PDX, and facilitates trapping efforts across all properties. The Port recently coordinated with the Oregon Department of Agriculture to support the eradication of European and Asian Gypsy Moths in North Portland.
- Federal - The Port maintains open and active communications with US Department of Agriculture Animal and Plant Health Inspection Service personnel that lead inspections of ship and plane cargo to prevent new invasions, providing support and assistance where needed.
Everyone has a role in preventing, detecting, eradicating and managing invasive species. The Oregon Invasive Species Council has a hotline (1-866-INVADER), mapping tool and online form available to report invasive species—learn more at the Council's Take Action page. There are also many local volunteer opportunities where Oregonians can contribute to efforts to protect Oregon's unique forest, wetland and grassland habitats. To see volunteer opportunities in the Portland area specifically, visit the Intertwine Alliance or SOLVE websites.
—Written by Lisa Appel of the Port of Portland.
Port of Portland's Maureen Minister is a 2016-2017 member of the Oregon Invasive Species Council. One of 10 at-large members.