Invasive Species

Michael Barron of the National Park Service took this picture of a carcass of an alligator as it protudes out from the body of a dead Burmese python in Everglades National Park, Florida.

New research published in Molecular Ecology suggests that climate change could trigger the expansion of invasive species into wider ranges.

New research published in Molecular Ecology suggests that climate change could trigger the expansion of invasive species into wider ranges.

The study looked at the genetic history of a goby species in the Eastern Atlantic which appears to have expanded its range dramatically when the world warmed about 150,000 years ago.

The finding has broader implications beyond aquatic reef fish.

The finding has broader implications beyond aquatic reef fish.

While ninety percent of immigrant species do no obvious harm to their new home environment, a small number do disproportionate damage.

Executive Order 13112).

Invasive species disrupt ecosystems primarily by preying on local species and competing with native species over limited resources.

Invasive species disrupt ecosystems primarily by preying on local species and competing with native species over limited resources.

The effect on native biodiversity can be severe -- the Cornell study says that 42% of the species on the Threatened or Endangered species lists are at risk primarily because of non-indigenous species.

Introduced tilapia and Nile Perch have devastated endemic fish populations throughout Africa, while the snakehead, a carnivorous fish capable of walking across land, has raised fears every time it appears in a pond in the Eastern United States.

Introduced tilapia and Nile Perch have devastated endemic fish populations throughout Africa, while the snakehead, a carnivorous fish capable of walking across land, has raised fears every time it appears in a pond in the Eastern United States.

Cane Toads in Australia - Wreaking Havoc Down Under

Cane Toads in Australia - Wreaking Havoc Down Under

Cane toads, properly known as bufo marinus, are the most notorious of what are called invasive species in Australia and beyond.

The mollusk is a problem because it clogs water intakes for factories, interferes with navigation, accelerates, decreases fuel efficiency, damages engines, reduces the amount of food available for other filter-feeding organisms and fish, and competes with native mussels.

Courtesy of STRI.

Much has been made of the economic impacts of recent biological invasions, but what are the implications of invasions in deep time?

"We found that global warming events correspond clearly with major range expansions of gobies from the Indian Ocean into the Atlantic Ocean and subsequently into the Eastern Atlantic," summarizes Rocha.

A chilly Antarctic current--the Benguela upwelling system-- surges up along the western coast of Africa acting as a natural barrier, and has prevented most warm water organisms from the Indian Ocean from making it in to the Atlantic for the last 2 million years.

What evidence do they have that makes them think that Atlantic gobies are invaders?

What future effects of climate change might we expect in the marine realm?

"Genetic analysis told us that fish from the Indian Ocean breached the Benguela barrier in the past, and this barrier seems to open intermittently.

"Genetic analysis told us that fish from the Indian Ocean breached the Benguela barrier in the past, and this barrier seems to open intermittently.