yes, it's happening. now DO something.

Posted by kahea at Feb 25, 2008 07:19 PM |
Filed under:


Bringing to your attention two articles on oceans in the Star Bulletin today:

Satellite images reveal trawling damage
A University of Hawaii zoologist is among a group of scientists decrying the destructive effects of bottom trawling, a type of fishing, visible in satellite images from space.

“Trawling removes much of the life from the sea floor,” said Elliot Norse, president of Marine Conservation Biology Institute, who participated in the session. “The effect is basically to denude the sea floor.”

He said bottom trawling catches more unwanted fish and does more harm to the sea floor than any other kind of fishing. The sediment disturbing the water column can also clog fish gills, possibly reintroduce absorbed carbon into the water and kick up toxic materials that have settled to the bottom, Norse said.

“Now we have images from space showing how much sediment it lofts into the water column,” he said. “Not just affecting the sea floor, it also affects the water column.”

Ten years ago, Norse and Watling completed a study that found bottom trawling covers an area the size of the continental United States every year.

Ocean Desert zone extends to Hawaii
The ocean’s dead zones have expanded in recent years to include part of the Hawaiian archipelago, scientists have concluded from space-observation studies.

The largest ecosystems in the major ocean basins are subtropical gyres, large-scale regions of winds and currents with low chlorophyll for plant and animal growth. These areas cover 40 percent of Earth’s surface and in nine years have expanded 10 to 25 times faster than global-warming models predict, the scientists said.

“What’s happening is, large portions of the area are becoming less productive,” said Jeffrey Polovina, with the National Marine Fisheries Service in Honolulu.

This will likely decrease the carrying capacity for larger animals such as tunas, sharks and marlins, he said in an interview. “We will just have less productivity at the base of the food web.”

He said there might be a change in species composition with the absence of larger, predator animals favoring the smaller fish, such as mahimahi and skipjack.

(photo from Les Walting, published in Star Bulletin online edition.)

“The image on the top is from the Mount Desert Rock site. The area has most likely never been trawled and shows abundant life. At bottom, an area in the Gulf of Maine called Truxton Swell has been heavily trawled and shows little visible animal life.”

Document Actions
Filed under:
Add comment

You can add a comment by filling out the form below. Plain text formatting. Web and email addresses are transformed into clickable links. Comments are moderated.


Empower grassroots efforts to protect Hawaiʻi with your donation today.

E-mail Sign-up
Follow Us