NorCal Underwater Hunters Discussion > Abalone & Fisheries Management

The CDFW methodology for North Coast abalone counts

(1/2) > >>

MATT MATTISON:
 The California Department of Fish and Wildlife's methodology for North Coast abalone assessment and management.
North Coast Abalone Management (CDFW)


Marine Invertebrate Survey and Assessment Project
https://www.wildlife.ca.gov/Conservation/Marine/Invertebrates/Survey-Assessment-Project

Marco Mazza:
Hello all,
It's been quite a while since I've posted in NCUWH, college and work have had me pretty tied up... plus i moved to socal for the time being ::)
but something about this post really stood out to me:

Skip to 4:10 of the video. They're only counting abalone one meter out from their survey line that "can be seen without the aid of a flashlight or turning over rocks. Therefore, emergence survey data typically does not include counts of very small abalone that occur deep in crevices and under boulders"

ANYONE SEE A PROBLEM WITH THIS^^^

They're literally not counting any abs in the holes and crevices, a good number of spots hold the majority of their abs in holes/crevices! Think about how many big tabletop rocks they're swimming over that are loaded with abs, only to count the one or two on top rather than the 10 or 12 beneath it.

Also, "small abs that occur deep in crevices or under boulders"... I'm sure any trophy ab diver will agree that some of their biggest abalone have come from within the deep holes and crevices.

"Dive surveys require a tremendous amount of planning, coordination, and organization. Survey participants are certified scientific divers trained in transit methods of species identification, and are well briefed to insure that the data collected is precise."
BUT YOU DONT LOOK UNDER ROCKS

Please tell me its not just myself who sees a problem with this type of survey method.

That being said, I do have to say that I appreciate the time and effort of the DFW and the divers included in trying to help manage our abalone fishery off the Northern California coast.

MATT MATTISON:
I have been saying this for years Marko, but I was told these are to non intrusive, and when you start flipping over rocks looking in holes with lights it is now an intrusive survey. Someone please correct me if I am wrong, will not be the first time I would be wrong hahahaha

Marco Mazza:
I definitely understand that! But looking into holes being intrusive? I can definitely understand flipping over rocks and hurting fragile marine life, but a flashlight is so minor I would not call that intrusive!

Duckfoot:
I don't know to what degree this has been tested, but apparently, and this surprises me, there isn't a huge difference in results with or without flashlights. For one thing, divers are on SCUBA so bottom time is a different issue. And when on SCUBA your eyes have time to adjust to the darkness.  It is interesting that PISCO uses lights and DFW doesn't but lighting isn't the larger problem. DFG transects are sometimes placed where you won't find abs and that data is incorporated into the survey results anyway. Apparently the department is working on that.

Navigation

[0] Message Index

[#] Next page

Go to full version