bluefin growth rates
 

typically how big are these fish at 1, 2 , and 3 yrs old. how old are these 70" fish we were catching last year. are males and females different sizes?

Been told tuna grow on average 3/4 an inch per month

Below is a table I had saved on my computer. From what I understand, a 70" fish is most likely not sexually mature yet.


http://www.informaworld.com/ampp/ima...0_o_f0005g.png

FYI: 70" ~ 175 - 180cm

From what I recall, they start to reproduce at 80" (10 years old)

Most of the other tuna's (YFT, Longfin, BE) is closer to 27" (hence the 27" fork length on the size limit)

BFT is one of the few managed species we can harvest below sexual maturity

I had no idea that only the fish that are that big reproduce, that is amazing!! No wonder it is so hard to keep the population up. Hopefully this class of fish that have been coming back to Stellwagen for the past few years will get to that magic 80" and start making babies!! Only a few more inches for some of them.

so where are all the little ones - 10 to 40 pounds. do they stay out in the warmer waters. just wondering.

It's believed 8 years not 10 at 8 years about 72 inches

I think it is still debated Ronnie. I had read 8 years/72" and 80+ inches before...
from:

http://www.nmfs.noaa.gov/fishwatch/s...uefin_tuna.htm
"Reaches reproductive maturity: Late – western Atlantic bluefin tuna first spawn at age 8 and are believed to take longer to reach maturity than bluefin tuna in the eastern Atlantic. Recent studies indicate most bluefin are sexually mature by about 12 years."

Other thing's I've read said as young a 5 years.

Studies now show that BF reproduce at a much younger age then we thought. We have much to learn about them still. Just a few years ago it was believed that western and eastern tuna did not mix.

One controversial assertion, that may contribute to the confusion about when bluefin become sexually mature, is the claim by some that eastern (Mediterranean) tuna spawn at a younger age (@ 5 years) than western (Gulf of Mexico) tuna (@ 8 years).

I don't think anyone knows for sure.

They show up off BI,RI,most years,and we saw some really small fish on Stellwagen two years back.

They were out at wildcat this year we were sharking out in 600 feet and surrounded by bonito size fish all day.
Posted from my iPhone/Mobile device

There's an upcoming lecture on this very topic-

April 7th, Dr. Walt Golet from GMRI will be giving a lecture titled "Decadal Changes in Condition, Growth, and Distribution of Atlantic Bluefin Tuna in the Gulf of Maine". This is at the Gloucester Maritime Heritage Center, 7pm.

Should be pretty interesting.