Tweet
Studies look at BP oil spill's effect on insects
wwltv.com
Posted on March 22, 2012 at 12:34 PM
...
A University of Houston ecologist says insects and spiders that live on marsh grass have rebounded. But a Louisiana State University entomologist says her more detailed study shows falling numbers for many kinds of bugs.
They agree that it's too soon to know the lasting effects of the oil on marsh ecosystems....
...
One of the most dramatic changes is in the numbers of ants that live in the hollow stems of the marsh grass and scurry around outside it to forage. In oiled areas, their numbers have dropped steadily since the spill, Hooper-Bui said.
"This year we're hard-pressed to find ants in previously oiled areas," she said. It's usually easy to find them on chilly winter days because they stay inside. In January and February, she said, an hour's search by breaking stems didn't turn up a single colony in areas where oil had landed, compared to six to eight colonies in areas not exposed to the oil.
In warm weather, sweeping a net through the stems picked up an average of 32 ants before the spill. That was down to about 10 in September 2010 in oiled areas. Last September, that average was down to 0.5 ants per net in oiled areas, compared to 17 in non-oiled areas.
Hooper-Bui said large-bodied spiders appear to have been hit harder than small spiders.
In the Atlantic salt marshes, Wimp said, some of the largest spiders are at the top of the Spartina ecosystem food chain. "It's pretty common for things at the top of the food chain to be most heavily impacted when you have some sort of disturbance," she said.
Full text:
wwltv.com
Posted on March 22, 2012 at 12:34 PM
...
A University of Houston ecologist says insects and spiders that live on marsh grass have rebounded. But a Louisiana State University entomologist says her more detailed study shows falling numbers for many kinds of bugs.
They agree that it's too soon to know the lasting effects of the oil on marsh ecosystems....
...
One of the most dramatic changes is in the numbers of ants that live in the hollow stems of the marsh grass and scurry around outside it to forage. In oiled areas, their numbers have dropped steadily since the spill, Hooper-Bui said.
"This year we're hard-pressed to find ants in previously oiled areas," she said. It's usually easy to find them on chilly winter days because they stay inside. In January and February, she said, an hour's search by breaking stems didn't turn up a single colony in areas where oil had landed, compared to six to eight colonies in areas not exposed to the oil.
In warm weather, sweeping a net through the stems picked up an average of 32 ants before the spill. That was down to about 10 in September 2010 in oiled areas. Last September, that average was down to 0.5 ants per net in oiled areas, compared to 17 in non-oiled areas.
Hooper-Bui said large-bodied spiders appear to have been hit harder than small spiders.
In the Atlantic salt marshes, Wimp said, some of the largest spiders are at the top of the Spartina ecosystem food chain. "It's pretty common for things at the top of the food chain to be most heavily impacted when you have some sort of disturbance," she said.
Full text:
Comment