Aquatic Invasive Species: The Need for Comprehensive Federal Action July 28, 2005 HC-8 Dr. James T. Carlton Professor of Marine Sciences, Williams College and Director, Williams-Mystic, The Maritime Studies Program
Georges Bank Cape Cod Over six square miles of the invasive Asian seasquirt Didemnum -- in 150 feet of water in the open ocean! Source: USGS
ource: USGS Expanding lobes of the seasquirt Didemnum, covering many different substrates
Source: USGS Didemnum covers sea scallops: one of New England s major shellfisheries
Pacific seasquirt Styela clava smothering Atlantic commercial mussel farms: Prince Edward Island
New Zealand Burrowing Pillbug 1/4 long San Francisco Bay: up to 3 feet landward erosion per year Invades California In the 1890s
With coastal warming, The isopod Sphaeroma invades Oregon in the 1990s: Styrofoam dock floats are destroyed by the isopod ( styropod ): A pillbug population (100,000 individuals) is calculated to release more than 20,000,000 styrene particles per day into the ocean 1000s of burrows in a 3 x 3 foot styrofoam block: Coos Bay, Oregon
Source: Tim Davidson
Source: Tim Davidson
When the phone rings: Expect surprises (Part 1) We cannot predict: Who the next invader will be Where the next invasion will occur When the next invasion will occur
When the phone rings: Expect surprises (Part 2) We cannot predict: What a species will always do in its new environment
Japanese rocky shore crabs expand to 6 habitats in America Average Number of H. sanguineus /Tray at Each of Seven Habitats 25 Average Number Crabs/Tray 20 15 10 5 Japanese shore crab Hemigrapsus sanguineus: The most abundant crab of Long Island Sound (it arrived there in 1993) 7/13/2004 7/28/2004 8/11/2004 8/25/2004 0 RIZ RSZ Marsh Fouling SAV Mud Sand Habitat Color bars: 4 sampling dates in July and August 2004 Source: Nicole Dobroski (2005)
Surprise Reduction: Appreciating Vector Diversity Is the Key to Prevention (The vector is the Achilles heel of invasion ecology) Know: What vectors are operating Where they originate Who s aboard One of our greatest challenges: Global bioflow is now supported by more human-mediated vectors than ever before (it s not just ballast water)
10 Vectors Double Every 100 Years 8 6 4 2 DISPERSAL VECTORS OF THE EUROPEAN SHORE CRAB CARCINUS MAENAS Rock ballast Hull fouling Rock ballast Hull fouling Water ballast Oyster movements Water ballast Hull fouling Oyster movements Seaweed with bait Platforms / rigs Shellfisheries Aquaculture Bait Aquarium/Pet Trade Supply Houses 0 1800 1900 2000 YEAR
Vector Diversity Challenges 2005: more than 20 active human-mediated vectors spread marine, freshwater, and terrestrial species It s a busy, web-based world: new genetic data (Orrell & Wright, 2005) demonstrate that Northern Snakeheads from Potomac River, Crofton Pond (MD), Philadelphia all come from different sources Peeling back another layer: order 1 species, get a dozen: vectors are dirty
Number of Species Associated with Shipments of Bait, Seafood, Marsh Plants, and Research/Education Shipments (Sea Grant funded project) PURPOSE Species Shipped Additional species found in shipment BAIT Baitworm Nereis 18 species (from Maine) SEAFOOD Blue crab Callinectes 12 species (from Chesapeake Bay) MARSH RESTORATION Spartina (Maryland) 10 species RESEARCH/Education Seasquirts (California) 104 species
With finite management (human) resources, ranking vectors is important, but challenging The Chinese Mitten Crab invades San Francisco Bay in the 1990s A single adult crab is the size of a quart jar (and makes a burrow to suit): there are millions of mitten crabs in the Sacramento -- San Joaquin River system The European Shore (Green) Crab invades San Francisco Bay in the 1990s One of the world s most omnivorous crabs, it subsequently spread north to British Columbia
With finite management (human) resources, ranking vectors is important, but challenging Chinese mitten crab: European green crab: private citizen release to establish populations for harvesting juveniles arrive in seaweed with bait worms from Maine Message: Minor vectors can lead to major invasions: All vectors need attention
The Key is Prevention The Future is Integrated Vector Management (IVM) (the precursor to IPM) Regularly monitored, coordinated, integration of methods and strategies (based on scientific research) that interfaces with the vector at all stages: Origin, En Route, Destination (Uptake = Transport = Potential Release) with the goal of reducing and preventing the transmission and release of living organisms Requres broad federal, state, and international cooperation
New Vector Terminology* is now (July 2005) out: Provides Greater Focus for IVM: Cause: Route: Corridor: Vector: Why a species is transported, whether accidentally or deliberately (if the latter, the purpose) The geographic path, from the origin (donor area) to the destination (target or recipient area) The physical conduit over or through which a vector moves within a route (e.g., canals, shipping lanes, roads) How a species is transported (the physical means) = all four distinct phenomena are referred to as pathways * Carlton and Ruiz, 2005 in: Invasive Alien Species: A New Synthesis
INVASIONS ARE ONE OF THE BEST SIGNALS OF ENVIRONMENTAL CHANGE: FISHERIES (removal of predators, alteration of biomass, habitat destruction, biodiversity destruction) HABITAT DEVASTATION GLOBAL CLIMATE CHANGE CHEMICAL POLLUTION AND EUTROPHICATION INVASIONS (= themselves: invasions may beget invasions) = All of these phenomena and processes facilitate invasions
The literature pours forth For facts and (some) guidance Stay with the peer-reviewed scientific literature in recognized journals and technical books Popular magazine articles and popular books need not form the basis for management or policy considerations
PREVENTION The Key Elements: Vector Interception and Management Rapid Response to Newly-Discovered Invasions Innovative Strategies: Think Out-of-the-Vector Build Research, Education, & Management Capacity THE BIG PICTURE Provide States and Regions the Tools and Funding They Need to Prevent, Control, and Eradicate
This slide intentionally blank
This slide intentionally blank
The Invasion Process (1) Probability of interfacing with the vector (2) Probability of vector taking up (engaging) specific species (3) Probability of surviving the transport event (4) Probability of being released (5) Probability of initial survival upon release (6) Probability of establishing the first reproducing population (7) Probability of establishing long-term reproducing populations