Transcript Slide 1

Zebra Mussels
(Dreissena polymorpha)
Native to: the Caspian Sea region of Asia
Invasive in: the Great Lakes, USA. They
were first observed in Lake St. Clair near
Detroit in 1988, and spread quickly.
Transported by: ballast water
Zebra Mussels
(Dreissena polymorpha)
Impacts:
• deplete the food supply needed by larval
and juvenile fishes (this affects fisheries
too!)
Zebra mussels on a dragonhunter larva (above).
Pipe clogged by zebra mussel growth (below).
• attach themselves to native mussels,
making those mussels more vulnerable
to stress
• clog pipes
• clog cooling water inlets in boats, causing
them to overheat
• take in a lot of chemicals in the water,
which builds up in their bodies and is
transferred to any animals that eat them
European Rabbit
(Oryctolagus cuniculus)
Native to: the Iberian Peninsula in the
Mediterranean
Invasive in: Australia. They were first
brought over in 1788, they were
introduced to the wild in 1859, and there
were additional introductions in the late
1800s.
Transported by: people bringing them
over as pets
European Rabbit
(Oryctolagus cuniculus)
Impacts:
Phillip Island when European rabbits were abundant (above)
and after they were removed from the habitat (below).
• compete with local fauna for food and
shelter
• damage soils, causing erosion problems
• overgraze by killing mature plants and
suppressing recruitment of seedlings
• caused a decline in the bilby (Macrotis
lagotis) population
• caused the burrowing bettong (Bettongia
lesueur) to disappear in the Northern
territory
Burrowing
Bettong
Control: in the early 1950s, Myxomatosis,
a fatal disease only affecting rabbits, was
introduced to Australia to help prevent the
spread of the European rabbit.
Giant Salvinia
(Salvinia molesta)
Native to: southeast Brazil
Invasive in: Australia, New Zealand, and
parts of America
Transported by: people bringing them
over to be used in aquariums and garden
ponds
Giant Salvinia
(Salvinia molesta)
Impacts:
• create floating mats 10-20 cm (up to 60
cm!) thick
• block sunlight to other species
• clog waterways
Waterway covered in a mat of Salvinia growth.
Yes, that’s a WATERway!
• causes low oxygen areas once it dies
• prevents natural gas exchange, killing
species trapped underneath
• problems with flood mitigation, boating,
and irrigation
Salvinia
Weevil
Control: the weevil Cyrtobagous salviniae,
one of salvinia’s natural predators from its
native habitat, was introduced to keep the
population in check.
Common Periwinkle
(Littorina littorea)
Native to: Europe
Transported by: ballast water, 1870s
Common Periwinkle
(Littorina littorea)
Impacts:
• competes with native Littorina species
• reaches very high densities, making it
hard for other species to find free spaces
to occupy
• allows the slow-growing algae Chondrus
crispus to dominate the algal community
by feeding on the faster-growing algal
species
When the periwinkle is present, the algae
Chondrus crispus can completely take over an
algal community.
• allows survival of the parasite that causes
marine black spot disease, which affects
marine fish and birds, by being the first
host for the parasite
Green Crab
(Carcinus maenas)
Native to: the Baltic Sea
Transported by: shipworm burrows in
ship hulls, end of the 18th century
Green Crab
(Carcinus maenas)
Impacts:
• competes with native crabs for resources
• voracious predator and scavenger on
many marine species
• consumes juvenile shellfish, and probably
contributed to the decline of the
softshell clam (Mya arenaria) industry in
Long Island Sound
Clam industry suffered due to the depletion of
clam stocks by green crab predation.
Dead Man’s Fingers
(Codium fragile)
Native to: Asia
Transported by: attached to hulls of
ships
Dead Man’s Fingers
(Codium fragile)
Impacts:
• grows around oyster or scallop
and, as the plant grows, it becomes
buoyant and drifts off with the shellfish
attached; often called the “oyster thief”
or “scallop thief”
Dead man’s fingers growing on an oyster. If the
plant becomes buoyant enough, the oyster will
float away with it.
Lionfish
(Pterois volitans)
Native to: Indian and Pacific Oceans
Transported by: people bringing
them over for aquariums, first observed
here in 2001
Lionfish
(Pterois volitans)
Impacts:
• preys on native species
• has venomous spines
MSX Oyster Disease
(Haplosporidium nelsoni)
Native to: Asia
Transported by: people illegally planting
Japanese oysters in the Delaware Bay in
1957, spread from there
MSX Oyster Disease
(Haplosporidium nelsoni)
Impacts:
• parasite that caused extensive mortality
of Eastern oysters (Crassostrea virginica)
Asian Shore Crab
(Hemigrapsus sanguineus)
Native to: Asia
Transported by: probably ballast, first
observed in Cape May in 1987
Asian Shore Crab
(Hemigrapsus sanguineus)
Blue mussel may be consumed by the Asian
shore crab.
Impacts:
• may consume barnacles, clams, oysters,
and mussels
• competes with native species
• may outcompete green crab, another
invasive crab species
Green crab populations may decline due to
competition with the Asian shore crab.
Asian Longhorned Beetle
(Anoplophora glabripennis)
Native to: Asia
Transported by: came in wooden
packing material in cargo shipments from
China
Asian Longhorned Beetle
(Anoplophora glabripennis)
Impacts:
• causes death of many tree species,
especially maples (Acer spp.), poplars
(Populus spp.), birches (Betula spp.),
elms (Ulmus spp.)
Beetle exit holes (arrow E), and where eggs are
laid (arrow O) on a maple tree.
Control:
• cut down infected trees and destroy the
wood
Tiger Mosquito
(Aedes albopictus)
Native to: Asia
Transported by: eggs laid in tires
Tiger Mosquito
(Aedes albopictus)
Impacts:
• feeds during daytime and dusk
• irritating bite
• may transmit eastern equine
encephalitis, a virus that can affect birds,
horses, and humans
Eastern Equine Encephalitis (EEE)
Japanese Beetles
(Popillia japonica)
Native to: Japan
Transported by: grubs in iris roots
imported from a Japanese nursery, early
1900s
Japanese Beetles
(Popillia japonica)
Impacts:
• pest to about 200 plant species, including
rose bushes, grapes, hops, and others
• damage plants by consuming only the
leaf material between the veins
Japanese beetles on a rose plant.