How do you tell an invasive species from a natural colonizer?

 

By now, you’ve probably heard of the 66-foot-long, 7-foot-tall, 188-ton “tsunami dock” that washed ashore near Newport, Ore., this summer – perhaps the most dramatic chunk of debris to reach the West Coast in the aftermath of last year’s tsunami in Japan. You’ve probably heard that state workers sliced it up like a giant block of concrete cheese in August with a diamond-studded wire before hauling it away in more manageable chunks. You may have also heard that, beforehand, state officials painstakingly scraped the entire thing clean. Not to keep the works from getting gummed up, mind you, but to remove and safely bag potential invasive species – 13 pounds of them per square foot, and an estimated 100 tons overall.

We think a lot about invasive species here at High Country News – in part because we’re the sort of nerds that bring floss and GRE word books on backpacking trips, and in part because, in our intractably mixed up world, scientists are beginning to think differently about how they apply limited resources to rearranged ecosystems. (For examples, see Nick Neely’s recent HCN cover, "The Salt Pond Puzzle"  and stay tuned for online editor Stephanie Paige Ogburn’s upcoming feature examining the ongoing fight against cheatgrass, the invasive scourge of Western rangelands).

The Pacific Coast, in particular the Bay Area, is an especially invaded ecosystem, thanks to international shipping ports and the number of people that traffic through by air, sea, car and foot. It’s understandable that scientists are alarmed by the prospect that, say, a seaweed like wakame – a tsunami dock hitchhiker which has made some “worst invaders” lists and already has a foothold in SoCal and San Francisco Bay – might colonize waters off the Northwest Coast.

The blitzkrieg reaction to the dock is interesting, though, because a species transported by a natural disaster or event is, in our ecological lexicon, perceived much differently than one that hitches a ride on a boat hull or in ballast. Islands were and are colonized by species naturally in part thanks to such events, which may transport trunks, seeds and other natural debris from one place to another, along with whatever takes shelter upon them. North America was the same, thanks to Ice-Age-prompted sea-level retreat and the emergence of the Bering Land Bridge (people were among that wave, of course). In fact, many of the plants we now know as native in the Intermountain West moved in from elsewhere after the last Ice Age.

To be fair, much of the tsunami debris (and marine debris in general) headed this way is man-made and more buoyant than natural debris (pdf), increasing its chances of reaching our coast. But it does raise interesting questions about what our priorities are when it comes to “protecting” our environment. Are we really managing for a nature defined by human values – including the notion that ecosystems have a correct “balance” based on a specific window in time – rather than managing for the dynamic nature that is?

On the flipside, I wonder if it’s even possible to distinguish “natural” colonization from human-abetted invasion these days. After all, we can expect more frequent severe storms and surges thanks to climate change, and many animals are already moving northward and upward into habitats made more hospitable by climate change, sometimes pushing out the “natives” that make their home there.

Sarah Gilman is HCN's associate editor

Image of tsunami dock on Oregon coast courtesy Flickr user Wolfram Burner

Image of wakame seaweed in Japan courtesy Flickr user Roberto De Vido

High Country News Classifieds
  • CONSERVATIONIST? IRRIGABLE LAND?
    Stellar seed-saving NGO is available to serious partner. Package must include financial support. Details: http://seeds.ojaidigital.net.
  • EXPERT LAND STEWART
    Available for site conservator, property manager. View resume at http://skills.ojadigital.net.
  • ANCESTRAL LANDS ADMINISTRATIVE MANAGER
    Starting Salary: Grade C, $19.00 to 24.00 per/hour Location: Albuquerque or Gallup, NM Status: Full-Time, Non-Exempt Benefit Eligible: Full Benefits Eligible per Personnel Policies Program...
  • GRAND CANYON DIRECTOR
    The Grand Canyon director, with the Grand Canyon manager, conservation director, and other staff, envisions, prioritizes, and implements strategies for the Grand Canyon Trust's work...
  • ADMINISTRATIVE ASSISTANT
    Great Old Broads for Wilderness seeks a part-time Administrative Assistant to support the organization's general operations. This includes phone and email communications, office correspondence and...
  • HISTORIC LODGE AND RESTAURANT - FULLY EQUIPPED
    Built in 1901, The Crazy Mountain Inn has 11 guest rooms in a town-center building on 7 city lots (.58 acres). The inn and restaurant...
  • ONE WILL: THREE WIVES
    by Edith Tarbescu. "One Will: Three Wives" is packed with a large array of interesting suspects, all of whom could be a murderer ... a...
  • PROGRAM DIRECTOR, SALAZAR CENTER FOR NORTH AMERICAN CONSERVATION
    The Program Director will oversee the programmatic initiatives of The Salazar Center, working closely with the Center's Director and staff to engage the world's leading...
  • WILDEARTH GUARDIANS - WILD PLACES PROGRAM DIRECTOR
    Salary Range: $70,000-$80,000. Location: Denver, CO, Portland, OR, Seattle, WA, Missoula, MT or potentially elsewhere for the right person. Application Review: on a rolling basis....
  • RIVER EDUCATOR/GUIDE + TRIP LEADER
    Position Description: Full-time seasonal positions (mid-March through October) Organizational Background: Colorado Canyons Association (CCA) is a 10 year old nonprofit organization fostering community stewardship of...
  • BOOKKEEPER/ADMINISTRATIVE ASSISTANT
    Position Description: Part-time, year-round bookkeeping and administration position (12 - 16 hours/week) $16 - $18/hour DOE Organizational Background: Colorado Canyons Association (CCA) is a 10...
  • LAND STEWARD
    San Isabel Land Protection Trust seeks a full-time Land Steward to manage and oversee its conservation easement monitoring and stewardship program for 42,437 acres in...
  • EXECUTIVE DIRECTOR
    Ventana Wilderness Alliance is seeking an experienced forward-facing public land conservation leader to serve as its Executive Director. The mission of the Ventana Wilderness Alliance...
  • COMMUNICATIONS AND DEVELOPMENT DIRECTOR
    The Quivira Coalition (www.quiviracoaltion.org) is a Santa Fe-based nonprofit that builds resilience on arid working lands. We foster ecological, economic, and social health through education,...
  • GRANT WRITER
    "We all love this place we call Montana. We believe that land and water and air are not ours to despoil, but ours to steward...
  • DEVELOPMENT DIRECTOR
    The Development Director is responsible for organizing and launching a coherent set of development activities to build support for the Natural History Institute's programs and...
  • WILDLIFE PROJECT COORDINATOR
    Founded in 1936, the National Wildlife Federation (NWF or Federation) is America's largest and most trusted grassroots conservation organization with 53 state/territorial affiliates and more...
  • EXECUTIVE DIRECTOR
    The Cinnabar Foundation helps protect and conserve water, wildlife and wild lands in Montana and the Greater Yellowstone Ecosystem by supporting organizations and people who...
  • OLIVERBRANCH CONSULTING
    Non-Profit Management Professional specializing in Transitional Leadership, Strategic Collaborations, Communications and Grant Management/Writing.
  • GREAT VIEWS, SMALL FOOTPRINT
    Close to town but with a secluded feel, this eco-friendly home includes solar panels, a graywater reuse system, tankless hot water, solar tubes, and rainwater...