200 
Fishery Bulletin 108(2) 
Table 3 
Summary (90% cumulative percentage and abundance ranking) of the dominant family groups collected during the 2004-2006 
ichthyoplankton survey in the northern Gulf of Mexico off the coast of Alabama and from other ichthyoplankton surveys in the 
general vicinity. 
Family 
This study 
ENTRIX (2006b 
Rakocinski et al. (1996) 2 
Williams (1983) 3 
% (Rank) 
% (Rank) 
% (Rank) 
% (Rank) 
Engraulidae 
50.5 (1) 
32.3 (1) 
82.0(1) 
69.3(1) 
Sciaenidae 
15.9(2) 
10.2 (3) 
4.0(3) 
14.0(2) 
Carangidae 
5.4(3) 
2.7 (8) 
5.0(2) 
2.8(4) 
Clupeidae 
5.0(4) 
15.5 (2) 
4.3 (3) 
Paralichthyidae 
3.9(5) 
8.5(4) 
Gobiidae 
3.6(6) 
4.1 (6) 
Ophidiidae 
2.5(7) 
3.6(7) 
Cynoglossidae 
2.1 (8) 
5.6(5) 
Synodontidae 
0.9(9) 
1.9(9) 
Triglidae 
0.8 (10) 
0.8(13) 
Serranidae 
1.9(10) 
Bregmacerotidae 
1.6(11) 
Labridae 
1.0(12) 
Callionymidae 
0.7(14) 
Stromateidae 
0.4(15) 
Scombridae 
0.3 (16) 
Lutjanidae 
0.2(17) 
Congridae 
0.2(18) 
Ophichthidae 
0.2 (19) 
Tetraodontidae 
0.2(20) 
Cumulative % 
90.6 
91.9 
91.0 
90.4 
1 Samples (oblique) were collected as part of the SEAMAP ichthyoplankton survey (Rester el al., 2000) during the months of June-November from 
1982 to 2002 by using a 61-cm bongo net fitted with 333-pm mesh. Sample stations were limited to the Mississippi and Alabama inner-shelf 
region. 
2 Samples (upper and lower water column) were collected monthly from November 1979 to October 1980 in Mississippi Sound by using a 1-m 
diameter opening-closing conical-ring plankton net with 335-pm mesh. 
3 Samples (surface and demersal) were collected monthly from March 1979 to February 1980 in lower Mobile Bay by using a 1x0. 5-m rectangular 
opening plankton net with 505-pm mesh. 
fisheries resources (Shipp, 1992). The establishment of 
our survey is the first to specifically target larval fish 
assemblages in Alabama shelf waters and is the only 
survey from the northern Gulf of Mexico to combine 
frequent sampling effort (monthly) with high temporal 
replication (64+ samples/month) for a relatively long 
duration (25 months). Few ichthyoplankton surveys have 
been conducted near our sampling location, including a 
one-year survey of lower Mobile Bay (Williams, 1983), a 
one year survey of Mississippi Sound (Rakocinski et al., 
1996), and a summary of SEAMAP ichthyoplankton data 
collected on the Mississippi and Alabama shelf during 
1982-2002 (ENTRIX, 2006). The fisheries-independent 
data collected during our survey, therefore, provide a 
baseline for future comparisons with respect to vari- 
ability in local oceanographic and climatic features (e.g., 
warming water temperatures), water and land usage 
(e.g., Mobile Bay nutrient loading and water outflow), 
and habitat modifications (e.g., artificial reef programs). 
A comparison of results among multiple ichthyoplank- 
ton surveys is complicated because the motives for sur- 
veys often differ, resulting in survey-specific protocols 
and sampling biases. For example, the summary of 
larval fish seasonality reported by Ditty et al. (1988) for 
the northern Gulf of Mexico included over 30 separate 
surveys covering a wide range of spatial extent (Gulf- 
wide to individual bays and passes), sampling depths 
(neuston to 200 m), mesh sizes (0.086-1.05 mm), gear 
types (eight different samplers), sampling frequency 
(biweekly to quarterly), and survey duration (weeks 
to years). In addition, the taxonomic level to which 
ichthyoplankton are identified and at which they are 
reported varies with larval fish size, condition after 
capture, and availability of adequate descriptions. Our 
decision to use a 202-pm mesh size (as opposed to more 
standard sizes, e.g., >333 pm) is the factor that most 
likely biases our survey results when compared with 
previous studies. The effect of mesh size on the reten- 
