Red Porgy Study

This study examined the reproductive ecology of the red porgy Pagrus pagrus (Sparidae) in the NE Gulf of Mexico and the temporal, bathymetric, and small scale spatial variability of its life history traits and demographics. Almost 4000 specimens were collected using standardized hook and line gear year-round, Mar 1998-Sep 2001, in the NE Gulf - most (n=2,586) at 9 sites off NW Florida in 30-68 m.

Spawning grounds were widespread, spawning occurred primarily Dec ? Feb, and 50% of females matured at 211 mm and <2 yr. Fish changing sex were found Mar-Nov at all 9 primary sampling sites, and were 206 - 417 mm TL and ages 2 - 9 yr, strong evidence the process is socially controlled. Red porgy are permanently sexually dichromatic, pair spawners, and do not form large, predictable spawning aggregations. Neither protogyny nor their reproductive ecology appears to make them more sensitive than gonochorists to exploitation - they are probably less so in some cases. Traits such as widespread spawning grounds, no tendency to form spawning aggregations, absence of behaviorally-related size or sex selectivity, socially controlled sex change, co-occurrence of sexes year-round, and an extended period of transition, should stabilize or enable rapid compensation of sex ratios in red porgy (preventing sperm limitation or disruption of mating).

Size and age composition, size at age, survival rates, transition rates, sizes and ages at transition, and sex ratios all differed significantly at a scale of only 10?s of km. Environmental heterogeneity and site fidelity probably explain most of those differences, which likely reflect phenotypic, not genetic, effects. Habitat patches likely have variable hydrological, geological, biological, exploitation, and ecological characteristics. Once recruited to a patch, philopatric adults are exposed to a unique suite of factors which could affect growth, mortality, and reproduction. Such small spatial scale differences in many traits suggests a complex structure of local subpopulations; these resemble Crowder et al.?s (2000) sources and sinks or the broadly - defined metapopulation of Kritzer and Sale (2004). Pooled data from such a complex population structure could introduce excessive variability to parameter estimates and bias stock assessments.

1. Collect information on the reproduction and reproductive ecology of red porgy in the NE Gulf, including determine if and how sex ratio, transition rates, size and age at transition, and size and age at maturity varied temporally, bathymetrically or spatially at scales of 10's of km or less.

2. Determine size and age structure, growth, and mortality of red porgy in the NE Gulf, and whether any of those demographics and life history traits varied temporally, bathymetrically, or spatially at scales of 10's of km or less.

3. Gain insight on how fishing might affect protogynous species, and in particular, why red porgy in the South Atlantic Bight off the SE U.S. seemed so sensitive to exploitation and whether protogyny played any role in that sensitivity.

The life history, reproductive ecology, and demography of the red porgy, Pagrus pagrus, in the northeastern Gulf of Mexico

Douglas A. DeVries, PhD Dissertation, Florida State University, 2006

Fisheries Independent Data

Panama City Laboratory

To fishery Scientists and other qualified researchers upon request

NOAA Data Quality Act Documentation and Pre-Dissemination guidelines

Data set is not for use in litigation. While efforts have been made to ensure that these data are accurate and reliable, NOAA cannot assume liability for any damages or misrepresentations caused by inaccuracies in these data, or as a result of these data being used on a particular system. NOAA makes no warranty, expressed or implied, nor does distribution constitute any such warranty

None

This data set is on the PC of the collection item originator as well as on some backup disks. It also has been added to the Panama City Lab's age data base.