252 
Fishery Bulletin 116(3-4) 
The lack of taxa-specific information on extrusion has 
inhibited correcting larval abundances for previous 
damage claims (French McCay et al. 6 ). Other injury 
assessments have assumed a single multiplier for all 
fish larvae abundances to correct for extrusion (Nielsen 
et al. * * 9 )—an approach that our results indicate is an 
inadequate simplification. 
Despite its shortcomings, our comparison study with 
nets of different mesh size provides the first estimates 
of size bias in SEAMAP ichthyoplankton sampling. 
Where previously the effect of extrusion on the small¬ 
est larvae in sampled assemblages was either ignored 
or approximated, the functional models presented here 
can be used to provide more accurate estimates of 
true larval fish abundances, and assessments of bio¬ 
logical injuries due to industrial disasters. Extrusion- 
corrected larval abundance estimates could be used to 
improve the reliability of SEAMAP indices only after 
species-specific identification of the earliest and small¬ 
est larvae of species are attained. These species-level 
identifications could be achieved with more complete, 
traditional morphological descriptions of larval devel¬ 
opment and/or by incorporation of genetic identification 
methods in SEAMAP protocols that explicitly target 
problematic species. 
Acknowledgments 
For significant contributions to this work, we thank 
the Ichthyoplankton Group, Sea Fisheries Institute, 
Plankton Sorting and Identification Center, Szczecin 
and Gdynia, Poland; K. Williams and T. Cullins, collec¬ 
tion managers at the SEAMAP Archiving Center, St. 
Petersburg, Florida; P. Bond, C. Cowan, G. Zapfe, D. 
Hanisko, NMFS Mississippi Laboratories, Pascagoula, 
Mississippi; and crews of the NOAA Ships Oregon II 
and Gordon Gunter. The manuscript benefited from 
discussion with A. Pollack, NMFS Mississippi Labora¬ 
tories, Pascagoula. 
Literature cited 
Bolker, B. M. 
2008. Ecological models and data in R, 396 p. Princeton 
Univ. Press, Princeton, NJ. 
Burnham, K. P, and D. R. Anderson. 
2002. Model selection and multimodel inference: a prac¬ 
tical information-theoretic approach, 2 nd ed., 488 p. 
Springer-Verlag, New York. 
ing the Deepwater Horizon oil spill, 122 p. RPS ASA, South 
Kingstown, RI. 
9 Nielsen, R. D., T. C. Ginn, L. M. Ziccardi, and P. D. 
Boehm. 2005. An evaluation of the approaches used to 
predict potential impacts of open loop LNG vaporization sys¬ 
tems on fishery resources of the Gulf of Mexico, 62 p. Re¬ 
port prepared for The Center for Liquefied Natural Gas Sea¬ 
water Usage Technology Committee. Exponent, Menlo Park, 
CA. [Available from website.] 
Colton, J. B., Jr., J. R. Green, R. R. Byron, and J. L. Frisella. 
1980. Bongo net retention rates as effected by tow¬ 
ing speed and mesh size. Can. J. Fish. Aquat. Sci. 
37:606-623. 
Comyns, B. H. 
1997. Growth and mortality of fish larvae in the north- 
central Gulf of Mexico and implications to recruit¬ 
ment. Ph.D. diss., 150 p. Louisiana State Univ., Baton 
Rouge, LA. 
Ditty, J. G., T. W. Farooqi, and R. F. Shaw. 
2005. Clupeidae: sardines and herrings. In Early stages 
of Atlantic fishes: an identification guide for the west¬ 
ern central Atlantic, vol. 1 (W. J. Richards, ed.), p. 73- 
99. Taylor & Francis Group, Boca Raton, FL. 
Fahay, M. P. 
2007. Early stages of fishes in the western north Atlantic 
Ocean (Davis Strait, southern Greenland and Flemish 
Cap to Cape Hatteras), vol. 1, 931 p. Northwest Atlan¬ 
tic Fish. Org., Dartmouth, Canada. 
Gallaway, B. J., W. J. Gazey, J. G. Cole, and R. G. Fechhelm. 
2007. Estimation of potential impacts from offshore liq¬ 
uefied natural gas terminals on red snapper and red 
drum fisheries in the Gulf of Mexico: an alternative ap¬ 
proach. Trans. Am. Fish. Soc. 137:655-677. 
Gledhill, C. T., and J. Lyczkowski-Shultz. 
2000. Indices of larval kind mackerel (Scomberomorus ca- 
valla) abundance in the Gulf of Mexico for use in popula¬ 
tion assessments. Fish. Bull. 98:684-691. 
Hanisko, D. S., J. Lyczkowski-Shultz, and G. W. Ingram. 
2007. Indices of larval red snapper occurrence and abun¬ 
dance for use in stock assessment. Am. Fish. Soc. 
Symp. 60:285-300. 
Hernandez, F. J., Jr., L. Carassou, S. Muffleman, S. P. Powers, 
and W. M. Graham. 
2011. Comparison of two plankton net mesh sizes for ich¬ 
thyoplankton collection in the northern Gulf of Mexico. 
Fish. Res. 108:327-335. 
Hjort, J. 
1914. Fluctuations in the great fisheries of northern Eu¬ 
rope viewed in the light of biological research. Rapp, 
p.-v. Reun. 20:1-228. 
Houde, E. D., and J. A. Lovdal. 
1984. Seasonality of occurrence, foods and food prefer¬ 
ences of ichthyoplankton in Biscayne Bay, Florida. Est. 
Coast. Shelf Sci. 18:403-419. 
Johnson, D. L., and W. W. Morse. 
1994. Net extrusion of larval fish: correction factors for 
0.333 mm versus 0.505 mm mesh bongo nets. NAFO 
Sci. Coun. Stud. 20:85-92. 
Johnson, D. R., H. M. Perry, J. Lyczkowski-Shultz, and D. 
Hanisko. 
2009. Red snapper larval transport in the northern Gulf 
of Mexico. Trans. Am. Fish. Soc. 138:458-470. 
Llopiz, J. K., R. K. Cowen, M. J. Hauff, R. Ji, P. L. Munday, 
B. A. Muhling, M. A. Peck, D. E. Richardson, S. Sogard, and 
S. Sponaugle. 
2014. Early life history and fisheries oceanography: 
new questions in a changing world. Oceanography 
27(4):26-41. 
Lo, N. C. H. 
1983. Re-estimation of three parameters associated with 
anchovy egg and larval abundance: temperature de¬ 
pendent incubation time, yolk-sac growth rate and egg 
and larval retention in mesh nets. NOAA Tech. Memo. 
NMFS-TM-SWFC-31, 33 p. 
