NorCal Underwater Hunters Discussion > Abalone & Fisheries Management

The CDFW methodology for North Coast abalone counts

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Chaw III:
I've wondered the same thing about them not looking in the cracks. At the 6:30 mark they do mention that they do sometimes conduct invasive surveys where they'll look in all the nooks and crannies. They probably get a ratio by conducting the two types of surveys in the same location, the compare the numbers. So later they can just count the easy ones, then do the math in order to try to make an inference of the total numbers of abs. If this were the case it would seem pretty unreliable though. I've dove places without a cave for an abalone to hide, but other locations I would have only seen one out of the 60-70 abs that day without a light.

These are all just my guesses though. I'm only two semesters in my marine fisheries major, I'll get back with a definite answer in a couple of years.

Joshua R.:
These methods and how the data is used will be revised during the FMP process. 

lazyhook:
I don't know that a precise count of every single animal is necessarily the goal.  I would think the more important issue is the general trend.

If a particular transect area has a certain number of abalone that are visible without turning over rocks or looking in deep holes, then that might be it's "normal" condition for a baseline.  As long as all the subsequent transects in that area use the same general method, then any potential trends can be noted.

My bigger fear over the current transect method is that the baseline assumptions for healthy or "normal" densities may have been set too high in some cases.  Then, even if follow-on surveys show a "normal" density, that false comparison or trend can cause all the alarms.

Just as I don't pay attention to what one person thinks they remember about the kelp density 3 years ago in August vs. what they see this year at the beginning April.  Their baseline comparison is off.

moon:
I think Lazyhook has it right, and before making assumptions one needs to go to the website given in the video and read the complete report, if it's like any other report it's dry, complicated  and probably boring. I would not criticize nor praise methodology based on a promotional video aimed at the general population.
I used to do research dives in college some were good, and some  were way off.

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