Transcript Lecture 5 Invasive Speciesx

What is an Invasive Species?
 Exotic species vs. invasive species
Why are Invasive Species
Problematic?
 Alteration of habitat
 Change in the diversity, abundance, and distribution
of members of the preexisting natural communities
 Competition with native species
 Broad and cascading effects throughout communities
and ecosystems
Vectors for Introduction in Marine
Environment
 1. Ocean-going ships, exploratory petroleum platforms
 Ballast water, fouling organisms
Vectors for Introduction in Marine
Environment
 2. Canals
Vectors for Introduction in Marine
Environment
 3. Mariculture (Aquaculture)
Vectors for Introduction in Marine
Environment
 4. Saltwater Aquarium/Pet Industry
Vectors for Introduction in Marine
Environment
 5. Saltwater Bait Industry
Vectors for Introduction in Marine
Environment
 6. Marine and Maritime Plant Community
Restoration/Erosion Control
Vectors for Introduction in Marine
Environment
 7. Scientific Research/Education
Where do invasions occur?
 Deep sea benthic habitats
 Continental shelf pelagic habitats
 Continental shelf sublittoral benthic habitats
 Continental shelf sublittoral kelp beds
 Intertidal zone
 Rocky shores
 Sandy beaches
 Soft sediment shores
Where do invasions occur?
 Coral reefs
 Estuaries
 Mangroves
 Salt marshes
 Supralittoral fringe
Habitat Alteration
Pollution
Climate
Change
Fisheries
Impacts
Introduced
Species
BIOINVASIONS
Changes in Patterns of Fisheries Increased Numbers of
Changes in Trade
and Mariculture
Recreational Craft
Routes/Petroleum Exploration
Adapted from Norse and Crowder 2005, Fig 8.1
Challenges with Understanding
Invasive Species
 1. Strong historical biases in the invasion record
 2. Limitations of taxonomy; cryptic invaders
 3. Decline in the study of marine invertebrates and
algae
Case Study: San Francisco Bay
 Considered to be one
of the most invaded
aquatic regions in the
world
Corbula amurensis
Carcinus maenas
www.exoticsguide.org
Caulerpa taxifolia
wdfw.wa.gov
www.sfgate.com
http://www.bsu.edu
www.spartina.org
Invasive Lionfish
 Pterois volitans; Pterois miles
 Up to 18” long
 Ambush predators
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Spread of Lionfish
Shows a healthy food chain (left) versus one with fishing pressure and introduced lionfish,
demonstrating the negative impact lionfish indirectly have on corals. Size of the organism indicates
relative abundance and thickness of the arrow shows relative strength of the interaction. Solid
arrows are direct effects and dashed arrows are indirect effects. Image taken from: Albins, M. A. and
M. A. Hixon. 2011. Worst case scenario: potential long-term effects of invasive predatory lionfish
(Pterois volitans) on Atlantic and Caribbean coral-reef communities. Environmental Biology of
Fishes:1-7
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