Abstract — Little is known about the 
seasonality and distribution of grou- 
per larvae (Serranidae: Epinephelini) 
in the Gulf of Mexico and Atlantic 
Ocean off the coast of the southeast 
United States. Grouper larvae were 
collected from a transect across 
the Straits of Florida in 2003 and 
2004 and during the Southeast Area 
Monitoring and Assessment Program 
spring and fall surveys from 1982 
through 2005. Analysis of these larval 
data provided information on location 
and timing of spawning, larval dis- 
tribution patterns, and interannual 
occurrence for a group of species not 
easily studied as adults. Our analy- 
ses indicated that shelf-edge habitat 
is important for spawning of many 
species of grouper — some species 
for which data were not previously 
available. Spawning for some spe- 
cies may occur year-round, but two 
peak seasons are evident: late winter 
and late summer through early fall. 
Interannual variability in the use of 
three important subregions by spe- 
cies or groups of species was partially 
explained by environmental factors 
(surface temperature, surface salin- 
ity, and water depth). A shift in spe- 
cies dominance over the last three 
decades from spring-spawned species 
(most of the commercial species) to 
fall-spawned species also was docu- 
mented. The results of these analyses 
expand our understanding of the basic 
distribution and spawning patterns 
of northwest Atlantic grouper spe- 
cies and indicate a need for further 
examination of the changing popula- 
tion structure of individual species 
and species dominance in the region. 
Manuscript submitted 28 March 2011. 
Manuscript accepted 16 August 2011. 
Fish. Bull. 110:1-20(2012). 
The views and opinions expressed 
or implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National Marine 
Fisheries Service, NOAA. 
Spatial and temporal distribution of grouper larvae 
(Serranidae: Epinephelinae: Epinephelini) 
in the Gulf of Mexico and Straits of Florida 
Katrin E. Marancik (contact author ) 1 2 3 
David E. Richardson 1 
Joanne Lyczkowski-SIuiltz 2 
Robert K. Cowen 4 
Malgorzata Konieczna 5 
Email address for contact author: Katey.marancik@noaa.gov 
1 Narragansett Laboratory 
Northeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
28 Tarzwell Drive 
Narragansett, Rhode Island 02882 
2 Mississippi Laboratory 
Southeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
3209 Frederic Street 
Pascagoula, Mississippi 39567 
3 IAP World Services, Inc. 
3209 Frederic Street 
Pascagoula, Mississippi 39567 
4 Rosenstiel School of Marine and 
Atmospheric Science 
University of Miami 
4600 Rickenbacker Causeway 
Miami, Florida 33149 
5 Sea Fisheries Institute 
Plankton Sorting and Identification Center 
ul, Kazimierza Krolewicza 4-E 
71-550 Szczecin, Poland 
Adult grouper (Serranidae: Epinephe- 
lini) are commercially and recreation- 
ally important species that are highly 
susceptible to overfishing (Coleman 
et al., 1996), largely due to their 
spawning behavior and slow growth 
(Manooch, 1987; Shapiro, 1987; Cole- 
man et al., 1996). Many species of 
groupers aggregate at consistent loca- 
tions and time of year for spawning 
(Nemeth et al., 2007; Starr et al., 
2007), and these aggregations are 
often targeted by fishermen (Burton 
et al., 2005). Fishing pressure on 
adult grouper and changes to habitat 
at all life-history stages of grouper 
have made evident the need for more 
effective fisheries management strate- 
gies. Most research on Gulf of Mexico 
grouper focuses on single species (e.g., 
Brule et al., 1999, 2003), over a very 
limited area (e.g., single spawning 
aggregations: Nemeth, 2005; off the 
coast of a single state or county: Cole- 
man et al., 1996), or over short tempo- 
ral durations (e.g., Eggleston, 1995). 
Plankton surveys provide a reliable 
source of fishery-independent data 
for fishery management purposes 
and grouper larvae are routinely col- 
lected in these surveys (Houde, 1982; 
Marancik et al., 2005; Hernandez et 
al., 2010). Ichthyoplankton surveys 
provide data on seasonal (Hernan- 
dez et al., 2010), spatial (Ditty et al., 
2004), and environmental character- 
istics associated with spawning (Rich- 
ardson et al., 2009), all of which are 
particularly useful for species that 
are rare, elusive, or endangered as 
adults. For example, data on abun- 
dance and habitat use for early life 
stages have been directly integrated 
into fisheries management of blue- 
fin tuna ( Thunnus tliynnus ) through 
stock assessment calculations (Scott 
et al., 1993). Spatial and temporal 
distribution and frequency of collec- 
tion of larvae reflect changes in the 
juvenile and adult population struc- 
ture (Richardson et al., 2010), which, 
coupled with climate models, may 
provide a means of forecasting the 
abundance and distribution of future 
populations (Hare et al., 2010). 
Recent examination of larval grou- 
per morphological characters from 
the most comprehensive collections 
available in the U.S. southeast region 
resulted in more precise taxon identi- 
