Ichthyoplankton
Ecology and Taxonomy,
Biophysical Couple in Marine Environments
Research Interests
My research interests focus on the
ecology of marine organisms, primarily coastal and
reef-associated fishes. I am particularly interested
in the early life history stages of fishes and the physical
and environmental processes that affect dispersal, survival
to settlement, habitat selection, and the eventual
recruitment to the adult population. This work involves
describing spatial and temporal patterns of abundance and
distribution with the ultimate goal of providing linkages
between larval fish survivorship and recruitment to adult
populations.
Much of my research is conducted through the Dauphin Island
Sea Lab's FOCAL (Fisheries Oceanography of Coastal Alabama)
program. Within this framework I am currently involved
in research that addresses relationships between biological
and physical processes and larval fish distributions.
We have established a biological survey off the coast of
Alabama that includes the collection of depth-discrete
ichthyoplankton samples to address temporal (diel and
seasonal) and spatial (across-shelf and vertical)
variability. Data collected from the survey, combined
with physical data collected from a permanent coastal
mooring (ADCP and thermister array), provide the necessary
components for biophysical models of fish egg and larval
distributions. Species- and stage-specific models can be
developed to predict larval fish responses to environmental
forcing events in the northern Gulf of Mexico, such as
riverine discharge and coastal hypoxia. Likewise, the
coupling of diel vertical distribution models with physical
models can shed light on transport pathways for the early
life history stages of economically important finfish and
shellfish species.
Inherent in the study of ichthyoplankton is the ability to
identify the early life history stages of fishes.
Unfortunately, larval fish descriptions are available for
only ~ 40% of the fishes in the Western Central Atlantic
(including the Gulf of Mexico). Little is known about
the larval and juvenile stages for many ecologically
significant taxa, many of which are also recreationally and
commercially important. This lack of taxonomic resolution is
troublesome and often leaves many analyses at the family
level. I am therefore interested in combining
traditional methods (e.g., clearing and staining and
morphometric/meristic analyses) with molecular techniques in
order to identify fish eggs and larvae. Towards this
end, I am involved in collaborative efforts with molecular
biologists (DISL) and larval fish taxonomists at the Polish
Sorting and Identification Center (MIR/ZSIOP) and the
National Marine Fisheries Service (among others) that will
hopefully resolve fish egg and larval identifications.
Selected
Publications
Lindquist, D. C.,
R. F. Shaw and F. J. Hernandez, Jr. 2005. Distribution patterns of larval and juvenile fishes at
offshore petroleum platforms in the north-central Gulf of
Mexico. Estuarine, Coastal and Shelf Science. 62:655-665. PDF
of Publication©
Abstract - http://dx.doi.org/10.1016/j.ecss.2004.10.001
Hernandez,
F. J., Jr.,
R. F. Shaw, J. S. Cope, J. G. Ditty, T. Farooqi and M. C.
Benfield. 2003. The across-shelf larval, postlarval,
and juvenile fish community associated with offshore oil
and gas platforms and a coastal rock jetty west of the
Mississippi River Delta. American Fisheries Society
Symposium 36:39-72. PDF
of Publication©
Hernandez, F. J., Jr. and R. F. Shaw.
2003. Comparison of plankton net and light-trap
methodologies for sampling larval and juvenile fishes at
offshore petroleum platforms and a coastal jetty off
Louisiana. American Fisheries Society Symposium 36:15-38. PDF
of Publication©
Hernandez, F. J., Jr.,
and D. G. Lindquist. 1999. A comparison of two light-trap
designs for sampling larval and presettlement juvenile
fish above a reef in Onslow Bay, North Carolina.
Bulletin of Marine Science 64(1):173-184.
Hernandez,
F. J., Jr. and J. A. Hare. In prep. Comparison and application of vertical
distribution models: testing for diel, ontogenetic and
environmental effects in larval spotted hake (Urophycis
regia).
Hernandez, F. J., Jr.,
Beck, A., S. Muffelman, W. Graham and S. Powers. In prep.
A comparison of mesh sizes for the collection of
ichthyoplankton and zooplankton in the northern Gulf of
Mexico.
Hernandez, F. J., Jr.,
S. Powers, W. Graham and K. Park. In prep. Water
column structure and the vertical distributions of
winter-spawned species (Micropogonias undulatus and Brevoortia patronus) off coastal Alabama, USA.
Schobernd, Z., W. Graham, F. Hernandez, Jr.,
S. Powers. In prep.
Determining appropriate sample size for a long-term
zooplankton survey in the north-central Gulf of Mexico.
| Current
Graduate Students |
Technicians |
Lanora Lang - M.S.
|
Adrienne Beck, M.S.
Sarah Muffelman, M.S. |
|
