Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Invasive species threaten critical habitats, oyster among victims

21.07.2009
A study of oyster reefs in a once-pristine California coastal estuary found them devastated by invasive Atlantic Coast crabs and snails, providing new evidence of the consequences when human activities move species beyond their natural borders.
Led by marine biologist David L. Kimbro, now of The Florida State University Coastal and Marine Laboratory , the study shows that in Tomales Bay , half the population of California's native Olympia oyster has perished because its habitat has fallen victim to the dysfunctional relationship between native species and non-native ones accidentally introduced.

The work of Kimbro, a postdoctoral associate at the FSU lab, and colleagues from the University of California-Davis and its Bodega Marine Laboratory has magnified concerns that predator-prey mismatches between native and exotic species may lead to further losses of critical habitats that support marine biodiversity and ecosystems.

"What David Kimbro's research reveals about California's Olympia oyster raises a specter for Florida as well," said Felicia Coleman, director of the FSU Coastal and Marine Laboratory.

"First, our state has a remarkably productive native oyster population at risk in the Apalachicola Bay ," she said. "These oysters are sustainably harvested and provide critically important settlement habitat for an amazing array of species, so its loss would be devastating. Second, we know that in Florida's benign climate, exotic species are pretty easily established. One need only follow the trajectories of lionfish, Australian pine, Brazilian pepper and Burmese python for a grim view through the looking glass."

Kimbro and colleagues describe their findings in a paper ("Invasive species cause large-scale loss of native California oyster habitat by disrupting trophic cascades") that was recently published in the online and print editions of the peer-reviewed journal Oecologia .

Their study is expected to help guide habitat management and conservation efforts, including plans now being drawn up along the West Coast to restore native oysters.

"We've identified what my California colleagues call 'an important restoration bottleneck,' the attack on oysters by invasive species, which must be dealt with prior to undertaking oyster population enhancement and the rebuilding of remnant reefs," Kimbro said.

In California, said Kimbro, the artificial predator-prey mismatch has allowed high numbers of invasive snails to destroy the biological diversity of Tomales Bay, a coastal estuary about 40 miles northwest of San Francisco, by consuming and eliminating oyster habitat.

As an example, he points to the invasive European green crab from the Atlantic Coast (inadvertently introduced from Europe, so an exotic species even there). Smaller than California's native crab, it is less effective at controlling the snail population because it uses only brute force to kill its prey -- unlike its native counterpart, which is capable both of crushing the snails and using its claws like a can opener to peel open hard-to-crush larger shells.

Ecological consequences are profound when the species most affected by a predator-prey mismatch is a "foundation species" that supports biodiversity by creating extensive habitat, such as California's native Olympia oyster (Ostreola conchaphila), which provides critical nursery habitat for a suite of species including crabs, anemones and fishes.

Although Olympia oyster reefs are normally preyed upon by native predatory snails, said Kimbro, they are somewhat protected by the presence of native rock crabs that both consume native snails and force all others to spend more time hiding from crabs -- rather than eating the oysters.

But when Atlantic snails and crabs invade, the whole dynamic changes.

"You'd think similar-looking invasive and native species could be swapped in a system without adverse effects," he said. "But we have shown that, functionally, this is not the case."

In Tomales Bay, the exotic species occupy its inner reaches, where saline levels are lower. However, native predators cannot tolerate the inner bay's lower salinity, so they can't help to check the invasive snail population proliferating there. The invasive crabs are stuck in the inner bay because the natives hold the middle, with its higher salinity. Once upon a time, native oysters enjoyed a release from predation in the inner bay -- that is, until the invasive species moved in.

"While native predator-prey interactions that benefit oyster reefs are intricate and took a long time to develop, the invasive crab and snail don't have the historical exposure necessary to recreate these important interactions," Kimbro said. "A fellow researcher likened the native crabs and snails to a long-married couple who have learned to coexist, leaving oyster populations intact. But the lack of experience the invasive crabs and snails have with each other has led to the destruction of parts of the oyster population, much as an incompatible couple might destroy an entire family."

In addition to principal investigator David L. Kimbro of The Florida State University Coastal and Marine Laboratory, co-authors of the paper in Oecologia are Edwin Grosholz, Adam Baukus, Sarikka Attoe, and Caitlin Coleman-Hulbert (University of California-Davis), and Nicholas Nesbitt and Nicole Travis (Bodega Marine Laboratory, Sonoma County, Calif.).

David Kimbro | EurekAlert!
Further information:
http://www.fsu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>