Does the growth rate of postlarval gag grouper vary with local weather and diet?

S. Bourgoin*, D. Thistle*, C. Koenig*, and S. Harter#

*Florida State University, #NOAA Fisheries

1. Context• Gag are commercially important.• Gag are threatened by over fishing.

3. Issues• NOAA needs more ecological information to manage the species.• Ecology of postlarvae is little known.• Postlarvae are particularly exposed to weather variability.

4. Our questions• Does growth of postlarvae correlate with local weather?• Does it correlate with aspects of diet?

5.Stations• St. George Sound – two sites.• St. Andrew Bay – three sites.

6. Approach• Continuous measurement of temperature, salinity, and light at the

seabed at each station.• Since 18 Apr 2008, we have sampled for postlarvae 3 times each

week in St. George Sound and once each week in St. Andrew Bay.• We will measure gag age via the “growth rings” on their otoliths (ear

bones). Age together with length when collected will allow us to calculate the growth rate of each individual.

• We will determine gag diet by quantifying the prey types in their guts.

8. Larger contexts• The FSU NGI effort in meteorology and physical oceanography will

provide a climate context for our results• We are partnered with NOAA Fisheries Panama City Laboratory.

2. Life cycle

E. Peebles photo

7. Hypothetical results

Assume weather differences between years 1 and 2 of importance to gag growth.