Fly Fishing Forum - Reply to Topic
Our Environment We are stewards of wild places

Thread: Laser roundup of ocean trash Reply to Thread
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the Fly Fishing Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Home Waters
Your home waters
Current Favorite Fly
If you only had one... (change anytime)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options
Miscellaneous Options
Rate Thread
If you like, you can add a score for this thread.

Topic Review (Newest First)
12-29-2003 11:17 AM
Dble Haul
Laser roundup of ocean trash

Posted on: Monday, December 29, 2003

Laser may help target ocean trash

By Jan TenBruggencate
Advertiser Columnist

Scientists are using a new aircraft-borne laser to identify rafts of marine debris at sea, where they can be removed more cheaply than if they are allowed to wash ashore, snagging reefs and damaging marine life.

"I think a pickup at sea can be done fairly inexpensively — a lot less expensively than cutting it off the reef," said James Churnside, a physicist with the National Oceanic and Atmospheric Administration's Environmental Technology Laboratory.

Churnside has been working with a technology called lidar, or light detection and ranging.

A laser is pulsed from an aircraft to the sea at 30 bursts per second. The equipment times how long it takes for the light signal to reflect back to the plane.

The equipment gives a different reading if it is able to enter the water and reflect off plankton, sediment or even bubbles than if it hits debris floating on the surface. "Debris on the surface shows up as a shadow," Churnside said.

He and his associates tested the system in Alaskan waters, first identifying from satellite images the areas where they believed oceanic debris rafts would be found, then confirming it with lidar testing.

"We were able to find concentrations of debris where the satellite data predicted they were," he said.

While lidar work hasn't been done around Hawai'i, Churnside said satellite predictions suggest there are large fields of debris floating in the subtropical convergence zone that normally lies north of the Islands.

The field is likely to be denser in winter, when the currents "are conspiring to sweep stuff together," he said. During El Niño weather conditions, the field can move far enough south that the debris runs ashore in vast quantities on the Northwestern Hawaiian Islands, he said.

Debris including all kinds of floating matter is perhaps most dangerous to marine life when it is made up of great clumps of netting, rope, plastic strapping and fishing gear. Birds, seals, turtles and fish can get tangled in it, and if big piles of it wash ashore, it can rip up coral heads as it rolls in the surf.

The Alaskan work has been supported in part by native communities affected by the marine trash.

"The problem of ocean debris is very real for remote Alaskan native communities," said Tim Veenstra, president of Airborne Technologies, the firm that conducted some of the aerial survey work with lidar over Alaskan waters.

"For instance, the beach at St. Paul in the Pribilof Islands is regularly affected by this debris. Not only is it an eyesore, but it has an impact on returning salmon runs."


Interesting! If the junk can be picked up out at sea before it hits more fragile systems, so much the better. If it's practical, I hope that this catches on elsewhere.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -5. The time now is 05:02 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright (All Rights Reserved)