Giant Sea Bass populations in danger

Recent data coming out of Dr. Larry Allen's lab has shown that size of the effective breeding population of Giant Sea Bass may be no larger than 1000 individuals!
Check it out here: https://experiment.com/u/0Wajuw

I wonder what it was back in 1960? 1970? 1980? 1990? 2000?

I've seen more and more Giant Sea Bass over the last decade which is great since I never saw them while diving in the decades prior to about 1998

drbill:

I wonder what it was back in 1960? 1970? 1980? 1990? 2000?

I've seen more and more Giant Sea Bass over the last decade which is great sine I never saw them while diving in the decades prior to about 1998

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Right? Think how much lower it must have been back in the day.

It is too bad we don't have population estimates dating back to the mid 1850s or so (before they were exploited commercially or for "sport"). While there is no question they were in danger back when I started diving here (Catalina), fortunately Fish & Wildlife saw fit to initiate protections that did allow them to rebound over the past few decades. An interesting question might be: "Was there a genetic bottleneck due to the serious lowering of the regional population?" Perhaps new genes are entering the regional population from Mexico and enhancing genetic diversity.

Unfortunately one "danger" they currently face is the large number of SCUBA divers who don't know how to properly dive with these fish. I have seen far too many divers rush at them, scaring them away; flash strobes in their eyes (they do seem to react to that) or otherwise harass them. Breeding aggregations that used to be in Lover's Cove near Avalon and Italian Gardens appear to have dispersed to other locations, and at these new locations divers are once again interfering with them. My guess is that they will move on from them as well. This undoubtedly interferes with courtship since the GSB appears to be very "modest" (tee hee).

So Dr. Bill, do the GSB mate and breed in the shallows in summer? Is that what causes their annual migration up from the deep?

I agree about divers needing to learn sea bass etiquette. If you just chill out, they seem happy to let you hang nearby, or they'll even approach you. A couple of years back, one was stalking us at Bird Rock. The damn thing came up right between my buddy's legs... it looked like he was riding a bronco.
Of course that had to be the dive I forgot my camera.

It's great to harmonize with the fish. I've always thought vibration was our connection to fish. Kind of like my dog that knows when I don't like someone or am afraid of them. The area I lived in had the giant grouper wiped out by fisherman. On islands there are just so many big fish. With fisherman that know how to catch them or divers that know how to shoot them the population declines yearly. People are just waking up to the need for protected areas to allow fish to grow and reproduce. These areas have clearly shown their value. I spearfished 40 years in the Marianas and have watched the population of all the edible fish drastically decline. I hope we learn to help manage the population of all the fish, shrimp, lobster, crab, turtles etc......... Adventure-Ocean

We assume the reason that they come into shallow water during summer is to mate. It is a common reason for animals that spend time in deeper water to migrate into the warmer shallows to ensure their eggs develop faster once fertilized. The behavior exhibited by the giant sea bass in the shallows is also indicative of mating... lots of courtship behavior and pairing off, aggression towards other males, etc. Unless I missed something, no one has seen them actually spawn in the wild (although they have been seen doing so in captivity).

One of the students in my lab was looking at the genetic diversity of these fish and found that it was extremely low in the older fish, but the younger >30 years old, seemed to have much more diversity.

---------- Post added March 1st, 2014 at 07:53 AM ----------

drbill:

We assume the reason that they come into shallow water during summer is to mate. It is a common reason for animals that spend time in deeper water to migrate into the warmer shallows to ensure their eggs develop faster once fertilized. The behavior exhibited by the giant sea bass in the shallows is also indicative of mating... lots of courtship behavior and pairing off, aggression towards other males, etc. Unless I missed something, no one has seen them actually spawn in the wild (although they have been seen doing so in captivity).

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This is why i chose to study them for my research. to clear up the questions everyone has had about these fish for so long.

Interesting about the genetic diversity. Good info to have. I wonder if the increased diversity represents influx from fish off Mexico?

Obviously I am aware of your lab's project and its desire to clarify some of these questions! Look forward to working with you all later this year.

drbill:

Interesting about the genetic diversity. Good info to have. I wonder if the increased diversity represents influx from fish off Mexico?

Obviously I am aware of your lab's project and its desire to clarify some of these questions! Look forward to working with you all later this year.

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that included 15-20 samples from Mexico but I'm not sure if the diversity was found more in their population than ours for the younger ones. But I know the older ones with less diversity, was common in both CA and Mexico

I know you know whats going on Bill, that was more for other people reading the thread