How old are these fish: ? How do you read scale rings ?

I have heard that rock fish grow somewhat more slowly than ling.  Which got me wondering how old some of the fish are that I have caught.  I pulled some scales from the last ling, verm, and blackie that I caught (pics below, except for the black).  The black was smaller than the verm pictured.  The ling was in the 28 to 30 inch range.  I did not actually measure any of the fish.  Since then I photographed one of the scales from each fish under a 4x mag objective.  It took several photos to move across the verm and black scales, they were both about 3/8 inch in diameter.  The ling scale was much smaller at about 1/8 inch diameter.   I put the photos together in tall vertical columns, I hope they post ok.  I have added them below.  I surfed a little online, and in terms of aging fish by scale rings I believe we are looking for transitions in widths of individual rings to mark a change in seasons much like a tree ring.  I have a feeling all three fish were fairly young.

I think you are going to have to click on the scale photos and use your photo viewer to zoom in some.  If we have trouble I could try posting them bigger.

Are you any good at reading rings? How old do you suppose they were?

I don't know how old they are, but I think it's totally cool that you posted this.  Nice work!  

Edit:  I went and Googled...    

- A verm has a lifespan of 22 years (43 max) and can grow to 30 inches.  It's ~14" and 5-6 years at maturity.  An 18" fish is around 10 years old...
- A black has a lifespan of 20+ years (36 max) and can grow to 24 inches (I'd say a little bigger than that!).  And "half reach maturity at 18 inches and at 9-13 years in AK".
- Yelloweye live to ~120 years...

See this link:  http://www.psmfc.org/habitat/fish_lifespan.pdf and this one:  http://www.agelessanimals.org/

For lings:

- males reach max size around age 8 and are mature at 2, and females reach max size around 12 to 14 and mature at 3-5

If I'm not mistaken the only way to check on the age of a fish is to take out an otolith (earbone) and count rings. http://en.wikipedia.org/wiki/Otolith The fisheries biologists on this site all use that method so I guess it's the best way.

Z

Scales can be kinda of tricky,  I don't see much annual banding patterns in your pix.  I do otoliths as my specialty.  The vermillion rockfish can get pretty old, but most of what we catch 22 in or less are probably no older than 20 years.  Lingcod do grow much faster.   My guess is we don't catch much older than 10 years.  Most of the inshore rockfish, black blues etc are also in the teens at most.  Deeper living rockfish can be really old..over 100 years.  If you all save your otoliths in the future you can send them to me and I can age them for you. 

Jim

Jim. thats great of you to do that. It would be most interesting to me. Did you pull the otolith bone from that large striper you caught at Linda Mar this year? How old was that beast? Thanks, Craig

Really cool stuff. In school my thesis advisor Dr. Love was always carving up rockies for otoliths.

In Alaska they make earrings out of them.

One of the older rockfish we sometimes catch (probably more in the northern areas of NCKA) are quillback rockfish which can live to be 90 years old at 24 inches, so a 17 incher would be pretty damn old for a few tacos.

The vermillion rockfish can get pretty old, but most of what we catch 22 in or less are probably no older than 20 years.  Lingcod do grow much faster.   My guess is we don't catch much older than 10 years.  Most of the inshore rockfish, black blues etc are also in the teens at most.   
Jim

Thanks Jim,

Hmm, I dont know how I feel about killing fish 20 years old, I think I might feel better if they were common at that age.  I will have read up on how to extract the otoliths.  I have tossed the carcasses already, actually I fillet in the yak and leave the biomass in the sea, so I guess otolith rings will have to wait until next season

Jim. thats great of you to do that. It would be most interesting to me. Did you pull the otolith bone from that large striper you caught at Linda Mar this year? How old was that beast? Thanks, Craig

Craig, of course.  The bigger of the two, was 11 years old.  I also did the microchemistry and those big females had been the ocean for the last five years.  Which means they have not been going back to spawn every year and that might be one of the reasons why the numbers of baby stripers are down.  So save your striper heads for me.

Microchemistry?.  So here is the skinny.  When the fish go from freshwater to saltwater the concentration of "salts" is obviously greater in salt water.  These salts get incorporated into the earbone (which grows like tree rings).  Using a laser we can vaporize a very small section of the earbone and measure the vapor for salt concentrations. 

Jim, to save the otoliths, should we keep the whole heads or is it simple enough to extract ourselves? In other words, would an untrained person be able to dig it out, or should we forget it and just send you the whole head if we'd like you to age a fish?

Also, out of curiosity, are you also able to find pollutants in the fish with the microchemistry analysis?

Jim. thats great of you to do that. It would be most interesting to me. Did you pull the otolith bone from that large striper you caught at Linda Mar this year? How old was that beast? Thanks, Craig

 So save your striper heads for me.

We have a  beauty of a specimen in the freezer we have been saving for you Jim. It was tempting to use it for crab bait though......

Jim - interesting stuff. Are stripers known or thought to try to spawn every year, or is it common for them to not move into FW for 5 years?  Do you think increased FW flows out of the delta might be associated with such a pattern?  Too much speculation here? John

Stripers are thought to migrate up river every year to spawn.  Dave Secor on the east coast has shown that they will skip spawning and stay in the ocean for several years on east coast.  This is the first evidence that they do it on the west coast and could be important for understanding the recent collapse of young of year striper.  Dave has a great website with a link to his manual for otolith work.  There is a section on how to cut them out of big fish, I think in fact it is striped bass.  It is kind of a pain in the ass.  Those stripers have hard heads.  I'll take heads but if you can yank em that would be great.  They are fragile and often break.  Depending on where they break they might still be usable so try to save all the pieces. 

http://www.cbl.umces.edu/~secor/age-growth.html

So no wonder that fish you caught Jim, was so tasty. No bay pollutants in the system for 5 years. WOW!

Jim. thats great of you to do that. It would be most interesting to me. Did you pull the otolith bone from that large striper you caught at Linda Mar this year? How old was that beast? Thanks, Craig

Craig, of course.  The bigger of the two, was 11 years old.  I also did the microchemistry and those big females had been the ocean for the last five years.  Which means they have not been going back to spawn every year and that might be one of the reasons why the numbers of baby stripers are down.  So save your striper heads for me.

Microchemistry?.  So here is the skinny.  When the fish go from freshwater to saltwater the concentration of "salts" is obviously greater in salt water.  These salts get incorporated into the earbone (which grows like tree rings).  Using a laser we can vaporize a very small section of the earbone and measure the vapor for salt concentrations. 

I'm so glad we have interesting folks like jim to educate us. Buy this man a beer when you get a chance