Marine biology

Research into the chemical constituents of marine organisms is a relatively new
and growing field, given that much of the marine environment has only in the last half
century become accessible. Despite the strides that have been made in ocean exploration,
the marine biome has still been only barely explored. Much of the impetus for the
isolation and identification of chemical entities from marine organisms has been related
to their potential as medicines. For a number of reasons, including synthetic efficiency,
this has meant that many marine compounds isolated and studied have been small
molecules. In recent years, large strides have been made in techniques for the isolation
and identification of biological macromolecules, especially proteins. The understanding
of these molecules, and their relationship to the biochemical processes of the marine
organisms from which they have been isolated, is important not only because of the
potential for this information to help in the synthesis of medicines, but because it may help in the recognition of processes that affect the very viability of marine organisms
increasingly exposed to anthropogenic threats to their environment. This work consists of
four related studies involving the development of methods for the separation and
identification of proteins from a number or gorgon ian species. Chromatographic and gel
based methods were used to isolate an elisabethatriene synthase (ELS) which shows
promise as a biotechnological tool for the production or pseudopterosins. A number of
gorgonians were screened for the presence of proteins that might have antimicrobial
properties, and several organisms were identified that might be of interest in this context.
Two-dimensional gel electrophoresis methods were then developed to allow the
construction of gel maps for the azooxanthellate gorgonian Leptogorgia minimata and the
xoozanthellae gorgonian Pseudopterogorgia e/isahethae, the separated proteins were
digested and analyzed by LC/MSMS. and the information generated was used to examine
the proteome of the organism for functional and phylogenetic relationships.
Finally, the gorgonian Euniceafi<sca was exposed to several environmental stressors in
the laboratory. and the two-dimensional proteomic methods developed were used to
examine the effect of the stressors on the organism .

The wahoo, Acanthocyhium solandri, is a pelagic marine fish which inhabits tropical,
subtropical, and warm temperate waters worldwide. Despite being highly mobile and
economically important over most of their range, there is little scientific data
concerning population structure, movement patterns, or environmental preferences of
wahoo. In this study I investigate wahoo genetic population structure and
phytogeography on a global scale, and deploy pop-up satellite archival tags (PSA T's)
in the western Atlantic Ocean to determine movement patterns and environmental
preferences of wahoo.
Wahoo population genetic structure was examined across their entire global range
with intron six of lactate dehydrogenase-A (ldhA6, 10 locations, N = 213) and
mtDNA cytochrome h (Cyth, 13 locations, N = 322). Results show extensive sharing ofhaplotypes and no significant structure between all locations (mtDNA ~ST <
0.0001, P = 0.634; nuclear FsT = 0.0125, P = 0.1 06). Overall nuclear heterozygosity
(H = 0.714) and mtDNA haplotype diversity (h = 0.918) are both high, while overall
mtDNA nucleotide diversity (n = 0.006) and nuclear nucleotide diversity (n = 0.004)
are uniformly low. Coalescence indicates an effective female population size CNeF) at
- 816,000, and a population bottleneck - 690,000 years ago.
Movement patterns and environmental preferences were investigated by
deploying PSA T's onto four individual wahoo in the western Atlantic Ocean.
Tagging success rate (75%) validates the deployment protocol developed for this
project. Results indicate that wahoo in the western Atlantic ocean spend the greatest
portion of their time between 0 and 20 meters of depth, and between temperatures of
20oC and 26°C. More time was spent near the deeper extremes of their range during
the nocturnal period, and daily visits to the surface were observed. Wahoo were
observed traveling north in Fall and Winter, contrary to previous notions concerning
the migratory movements of this species.
The genetic results indicate a worldwide stock for wahoo, which reinforces the
mandate for international cooperation on fisheries issues. The PSA T results
demonstrate the value of the acquired data to the investigation of important life
history parameters in pelagic species. The information generated from this project
will benefit fisheries managers, marine biologists, evolutionary biologists, and both
commercial and recreational fishing interests.