Invasive Species

Invasive Species

Basics

a species that is not native to a specific location or region
an organism that causes ecological and/or economic harm in a new environment
generally spread by human activities
often unintentionally
capable of causing:

extinctions of native plants and animals
reducing biodiversity
competing with native organisms for limited resources (food, space)
altering habitats

invading species tend to have no natural predators in the new area
they can become the dominant species
changes in the ecosystem can affect life processes of existing organisms

courtship, mating, rearing, feeding

economic changes can occur when certain species die out or relocate
human communities that rely on certain fish may find themselves unable to find those fish

this can cause economic collapse for such communities
i.e. loss of snapper availability

Lionfish

Appearance

distinctively brown or maroon
white stripes covering head and body
fleshy tentacles above their eyes and below the mouth
venomous spines
fan-like pectoral fins
can grow as large as 18 inches, while juveniles may be as small as 1 inch or less

Locations

native to Indo-Pacific region
Indian Ocean and South Pacific Oceans
first lionfish was reported in South Florida waters in 1985
currently flourishing in non-native Southeast and Caribbean coastal waters
located from Florida to North Carolina
juvenile lionfish have been collected in waters off Long Island and Bermuda

Habitats

found in mostly all marine habitat types
such as warm marine waters of the tropics
have been found in water depths from 1 to 300 feet on hard bottom, mangrove, seagrass, coral, and artificial reefs (like shipwrecks)

Population

lionfish population continues to grow and increase its range
lionfish have no known predators in the area
reproduce all year long; a mature female releases roughly two million eggs a year
cannot be eliminated using conventional methods

Control

few options are available to control the outbreak of this species
capture and kill to reduce population
possible solution is to overfish
it is safe to eat these fish
they're apparently delicious
positive economic impact

Wakame

Basics

Undaria pinnatifida
"sea mustard"
edible seaweed
type of marine algae
highly fertile
sea vegetable
brown algae
grows up to nine feet

Habitat

native to cold temperate coastal areas
Japan, Korea, China
recently established in warmer temperate regions
New Zealand, the United States, Belgium, France, Great Britain, Spain, Italy, Argentina, Australia and Mexico
transmitted naturally and through human influence (i.e.: attached to hulls)

Danger

nominated one of the 100 worst invasive species in the world
can cause changes to native community composition at all trophic levels
reduce abundance and diversity of understory algal assemblages
out-compete some native macroalgal species
affect the abundance and composition of gastropods, crabs, urchins and fish

Control

harvest for human consumption
subtly sweet, but distinctive and strong flavor and texture
most often served in soups and salads
cleaning off hulls, buoys, ropes, docks, rocks, etc.

Health Benefits

low in calories; rich in nutrients
may support proper thyroid function
may reduce blood pressure, heart disease risk
may lower cholesterol levels
may decrease blood sugar
may aid weight loss

Veined Rapa Whelk

Appearance

rounded shell with a large body whorl
smooth spiral ribs
end in blunt knobs at shoulder and body whorl
small elongated teeth
some have blue-black vein patterns
shell height can reach 7 inches

Basics

Rapana venosa
large predatory sea snail
marine gastropod mollusc or whelk
in the family Muricidae, the rock shells
feeds on bivalves
clams, oysters, mussels
can live more than 10 years

Location

native to western Pacific

Sea of Japan, Yellow Sea, East China Sea, Bohai Sea

recently found as an exotic in the Chesapeake Bay on the eastern coast of the United States

may spread to S. Carolina, Massachusetts

likely introduced to the bay by larvae in ballast tanks being released

Habitat

burrows deeply into compact sandy areas
can tolerate large temperature fluctuations, polluted water and low oxygen levels
in winter, may migrate to deeper waters to avoid freezing surface waters

Danger

lack of competition from other gastropod species and direct predators

i.e.: thick shell prevents feeding by sea turtles and other local whelk

caused significant changes in the ecology of bottom-dwelling organisms
became marine pests in the Black Sea

Control

bounty program was instituted in Virginia
encouraged capture of live rapa whelks
goal to determine life patterns to develop better control techniques
younger whelks can be eaten by natural predators because of softer shells, but this can't be controlled

Burmese Python

Basics

Python bivittatus
carnivorous
dark-colored snakes with many brown blotches bordered in black down the back
one of five largest species of snakes
can grow to almost 17 ft
females average slightly longer, but are considerably heavier, bulkier than males

Location

native to Southern and Southeast Asia, eastern India, Thailand, southern China, Hong Kong, etc.
needs a permanent source of water
invasion has been particularly extensive, notably across South Florida, Everglades
have been seen in Biscayne Bay, Florida
some are kept as pets

Habitat

lives in grasslands, marshes, swamps, rocky foothills, woodlands, river valleys, and jungles with open clearings
hatchlings have been shown to survive in brackish (slightly salty) water
have been spotted in the ocean
have shown possibility of being able to survive in full marine environments

Danger

in areas where the snakes are well established, foxes and rabbits have disappeared
raccoon, opossum, white-tailed deer, bird, coyote, Florida panther populations are in jeopardy
compete with alligator; prey on each other

Control

hunting
understanding preferred habitat is key
though they can thrive in marsh, tend to prefer places they can blend in
nocturnal
screening mosquito blood for python DNA
hunting contest incentives
2013 Python Challenge