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Transcript Marine_Invasives_3_11x

Invasive Species
Monday, March 14th, 2011
Invasive species
 “non-native (or alien) to the ecosystem under consideration
and whose introduction causes or is likely to cause economic
or environmental harm or harm to human health.”
 Non-native
 Introduced via vector
 Established populations
 Harm caused
Invasive species
 A disturbance may be required to allow a population to go from an invading
propagule to a locally sustaining population
 Chinese Mitten Crabs
 Damaged ecosystems more susceptible to invasion
 1998 bleaching event killed 80-90% of the coral reefs in the Seychelles,
leaving them more vulnerable to invasions (
 3 out of 330 spp. were introduced
Hot spots
In areas subjected to the worst pollution, the most intensive fisheries and bottom
trawling, and major shipping routes
In 1999, it was estimated that the total cost of managing invasive species in the
United States was around $120 billion per year (Pimentel et al. 2004)
Characteristics of successful invaders
 Large home range
 Ecological generalists
 High invasion frequency
 High larvae dispersal
Marine Fish invaders
 Rare
 <30 of 550 fish introductions in US were marine
 Most introductions were intentional
 Improvement to ecosystem?
 Few negative effects actually documented
How did they get here?
 Ballast water
 Aquaculture
 Seafood trade
 Pet trade
Major pathways of marine invasive
species infestation
Ballast Water
Zebra mussel (Dreissena polymorpha)
-Native to Eurasia
-First sighted in 1988 in Great Lakes
-Hudson River in 1991
-Now occur in densities as high as 700,000 per m2
• Rearing aquatic animals or
cultivating aquatic plants for
•Animals can escape
•Asian Carp
•Atlantic salmon
Seafood trade
 Intentional or Accidental
 Chinese mitten crab (Eriocheir sinensis)
 northern snakehead fish (Channa argus)
Pet trade
 Escape or release of pets
 Also feed, plants
 “Don’t free Nemo”
Impacts of invasives
 Foodweb interactions
 Competition
 Disease
 parasites
 Loss of biodiversity
What can be done?
 “bounty” for fish capture
 Volunteer surveys, Rapid Assessment surveys
 Utilize invasive as food source
 Biocontrol?
Example 1: 2 invasive crabs
 Carcinus maenas
 European shore crab
Rough map of the distribution of Carcinus maenas.
Blue areas are the native range; red areas are the
introduced or invasive range; and green areas are
the potential range of the species.
Example 2: Sea lamprey
Petromyzon marinus
 Life history:
 Anadramous
 Native to Atlantic coast
Example 2: Sea lamprey
Petromyzon marinus
 Introduction:
 Welland Canal
 1st spotted in Lake Eerie 1921
Example 2: Sea lamprey
Petromyzon marinus
 Spread
Example 2: Sea lamprey
Petromyzon marinus
 Impacts:
 Affected sportfish
 Disrupted foodwebs
 One adult lamprey can
consume 40 lbs of fish in
its lifetime
Example 2: Sea lamprey
Petromyzon marinus
 Response efforts
 Lampricide
 Physical barriers
 Sterile male release
*90% reduction in most
areas where these methods are applied
Example 3: Lionfish
Pterois volitans
•Dorsal, anal, and pelvic spines
•Native to Indian and W. Pacific oceans
Example 3: Lionfish
Pterois volitans
•Biscayne Bay, FL
•Hurricane Andrew, 1992
Evidence for the aquarium trade as the
vector for the introduction of lionfish
● Lionfish are popular in the North American aquarium
● Lionfish were released from an aquarium in Florida
● Other marine aquarium fish have been introduced in
Florida waters
● Color patterns of lionfish off the SE US are similar to
those from the Philippines where many are collected for
the aquarium trade
● No successful introductions of scorpaenids are known
to have occurred via ballast water
● In more than a century, no Pacific marine fish are
known to have been introduced into the western Atlantic
Ocean via ballast water
Example 3: Lionfish
Pterois volitans
 Spread:
 Long distance larvae dispersal
 Females release large egg masses,
fertilized externally, gradually break apart
to release larvae
 Some lionfish reproducing
every few days
 No natural enemies
Example 3: Lionfish
Pterois volitans
Pacific Cornetfish, Fistularia corneta
 Impacts
 Affecting food web, no natural predators in Atlantic Ocean
Example 3: Lionfish
Pterois volitans
 Response efforts
 Bounty
 Research
 Outreach, Education