[Coral-List] Best practice for LIT surveys (Lindsay Sullivan)

[Robert Bourke]

Keith;

The fiberglass tapes are terrific to use because they come on those plastic reels that seem to resist salt water corrosion for years....but "Yes", in a surge they are just about impossible to hold down on a line.  I have a 1-pound lead weighted spike at the free end of the tape and a 2-lb weight taped to the handle of the reel.  While this helps, under even moderate surge conditions the most common item in many of my quad photos is my left fin - trying vainly to hold down the tape.   To circumvent this problem I've taken an old tape and crimped on 1-oz lead weights at 2-m intervals.  This holds the tape well in moderate surge but, of course, means that one must physically coil the tape between each transect.  If you choose to use a lead line rope, note that the fine filaments of certain types of nylon line will easily foul on corals, oysters, or other sharp objects.

Aloha

Bob Bourke
Environmental Scientist
Oceanit
Hawaii

-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Spring, Keith
Sent: Monday, December 29, 2008 9:46 AM
To: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] Best practice for LIT surveys (Lindsay Sullivan)




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Message: 1
Date: Sun, 28 Dec 2008 21:20:43 +0000 (GMT)
From: Lindsay Sullivan <lindssullivan at yahoo.co.uk>
Subject: [Coral-List] Best practice for LIT surveys
To: coral-list at coral.aoml.noaa.gov
Message-ID: <435547.54237.qm at web27302.mail.ukl.yahoo.com>
Content-Type: text/plain; charset=utf-8

Dear Coral-listers,
?
If anyone has experience of using the line intercept transect (LIT) method to carry out benthic assemblage surveys I wonder if you could help me.?
I have been taught that in high surge conditions the fibreglass tape must be secured to?coral colonies to prevent it moving around, wound around massive colonies and through the fingers of branching and digitate colonies for example,?however I have concerns that (a) this is damaging to the coral and (b) the survey?is no longer random or even haphazard, but that the results are selected by the diver as he carefully tucks the tape around coral.
Does anyone have similar opinions or experiences of this method and can offer possible solutions? Despite the common usage of?LITs for coral reef surveys I have been unable to find detailed instructions of how to ensure the tape?remains secured?close the substrate and in a straight line, so wonder if perhaps this is an accepted weakness of the method?
?
Any thoughts would be greatly appreciated.
?
Best regards,
Lindsay




Lindsay,

We've pretty much given up on using a fiberglass tape in reef or benthic surveys where there's any surge and where you want the tape to remain in place. What works just as well is 3/16" diameter lead-core braided polyester line, used in the fishing industry. The slight added weight of the crimped lead core causes the line to lay flat on the bottom, even in moderate swells. We cut the line to whatever lengths we need, stretch it out, and then mark the line at 0.5-m or 1-m intervals with permanent markers. You can lay it out across the reef under a bit of tension and then slack off when it's deployed. It's extremely durable, although a bit heavy when you get up to the 50+m lengths.

Good Luck,

Keith D. Spring
CSA International, Inc.
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