SEAFOOD
HARVESTING & PRODUCTION
Louisiana’s
fishery stocks and seafood processing operations face intense
competition from imports, plus a variety of challenges to fishery
ecosystems and habitats. Louisiana Sea Grant sponsors research
to promote and encourage sustainable and competitive seafood production,
harvesting and processing.
Assessing
Public Access to Waterways in Coastal Louisiana
Miller, C., Louisiana State University AgCenter
This study
will assess the populations of boaters and anglers in Louisiana
who have been denied access to waterways that cross private lands,
and investigate possible differences in access by user group.
This study will also seek to determine if waterway closures and
limited access affect attitudes toward coastal restoration in
Louisiana. To date, no studies have been conducted to quantify
the extent or distribution of gated waterways in Louisiana. It
is incumbent upon managers and ecologists involved in restoring
Louisiana’s coastal region to understand possible connections
between access and support for restoration programs.
Commercialization
of Cryopreserved Sperm for Marine Species
Tiersch, T., Louisiana State University,
Aquaculture Research Station
The principal
investigator’s goal is to build on previous and ongoing
research to overcome the product quality barriers to commercialization
of sperm cryopreservation for aquatic species. Objectives are
to optimize methods and to provide the necessary technology transfer
through: standardization of sperm concentrations in all aspects
of cryopreservation; assessment of membrane integrity for improving
membrane tolerance to cryopreservation; assessment of mitochondrial
integrity and its relation to sperm motility; assessment of acrosome
integrity and evaluation of methods to maintain sperm quality
by acrosome protection; and training of research and user groups
through outreach activities, including preparation of fact sheets,
hosting of special symposia and training workshops and promulgation
of industrial standards through established professional outlets.
This research is designed for application at dairy bull sperm
cryopreservation facilities, the existing commercial structure
best suited for initial development of a cryopreservation industry
for aquatic species.
Role
of Lysozyme in Eastern Oyster Host Defenses Against Vibrio
vulnificus and Perkinsus marinus, the Parasitic
Protozoan Causing Dermo
La Peyre, J., Louisiana State University, Veterinary
Science
The development
of hatchery technology and oyster aquaculture is dependent on
the production of “domesticated” seed that will outperform
natural seed whether in terms of growth, meat yields, survival
of infection or elimination of pathogens. The project’s
objective is to ascertain the role of lysozyme in the oyster host’s
defense against V. vulnificus and P. marinus.
Results from this research may validate the use of lysozyme as
a selection criterion to facilitate breeding of oysters capable
of eliminating V. vulnificus and P. marinus.
Selection based on various host defense or immunological indicators
has been shown to increase disease resistance, not only in experimental
animals such as mice, but also in farm animals.
Enhancing
Female Triploid Sex Ratios and Maturation for Tetraploid Production
in Crassostrea virginica by Pretreatment of Seed and
Juvenile Stock with Estrogenic Steroids
Lynn, J., Louisiana State University, Biological
Sciences
The goal of
this research is to alter the sex ratio of cultured seed and juvenile
triploid oysters in favor of individuals that are females capable
of responding to estradiol to produce viable oocytes. Objectives
are: compare gonad development in control and estrogen-treated
maturing oysters during their seed or juvenile stages and measure
gonad development in preconditioned oysters at adult stages after
treatment with estrogenic steroids developed from current protocols.
Variability in natural oyster spat production, disease mortality
and meat yields have promoted an economic interest in hatchery
production of spat and triploid oysters with greater meat yield.
Viable farming of triploid oysters will be dependent on hatchery
production of triploid seed stock. To date, the only 100 percent
triploid productions have relied on availability of adult tetraploid
oysters, which are derived from cross fertilizations of oocytes
from triploids and sperm from diploids. Preliminary data on hormonal
supplements to enhance triploid maturation rates have provided
promising results, but the technique is still hampered by the
predominant male sex ratio of adult triploids. As supported by
preliminary trials showing that estradiol treatment of adult triploids
influences sexual differentiation, preconditioning seed triploids
with female hormone derivatives to influence sexual differentiation
will provide increased numbers of triploid females capable of
responding to the estradiol treatments.
Collagen
Peptides from Louisiana Seafood and Wildlife Waste for Bio-Pharmaceuticals
and as Inhibitors of Tumor Growth
Losso, J., Louisiana State University AgCenter,
Food Science Department
This research
will provide a supporting scientific basis and relevant laboratory
data for the further development of a bioactive peptide or mixture
of bioactive peptides that inhibit the process of tumor growth.
These compounds will make use of collagen purified from processing
wastes of marine fish and wild and farmed alligator harvested
and processed in Louisiana. Angiogenesis inhibitors have been
recognized by the Food and Drug Administration as the fourth modality
of anti-cancer therapy because these inhibitors are relatively
less toxic than conventional chemotherapy and have a lower risk
of drug resistance. They may also represent a new class of anti-cancer
agents, some of which have sufficiently reduced toxicity that
they may be safely used long-term. In an earlier Sea Grant project,
the principal investigator’s research group developed a
proprietary process and used it successfully to extract purified
collagen from seafood processing plant wastes including skins
from black drum and sheepshead. Amino acid profiles of collagen
from black drum, sheepshead and alligator carcasses were similar
to amino acid profiles of collagen obtained from shark cartilage
and alligator bone. Neovastat (AE-941) is a peptide from shark
cartilage that is undergoing Phase III clinical trials for the
treatment of non-small cell lung cancer. Anti-tumor compounds
from alligator serum have been identified and recently patented.
Intensive
Propagation of Marine Finfish in Recirculating Systems: Improving
Survival and Growout Efficiency During the Larval Stage
Chesney, E., LUMCON
Developing reliable and cost-effective methods
of rearing larvae and producing fingerlings for rearing systems
remains one of the greatest challenges to success in marine fish
culture. Closed, recirculating systems technology is proving to
be a viable approach for commercial fingerling production that
offers some distinct advantages over pond production. However,
additional research is needed to establish reliable, efficient
and cost-effective methods for intensive larviculture. The project’s
goal is to generate new knowledge for immediate use by members
of the industry. The principal investigator is collaborating with
two industry project partners on research that will improve marine
fingerling production rates and efficiency. Specific research
objectives are to reduce the reliance on live feeds for larviculture
and shorten the larval stage duration by improving growth and
survival rates in the larval stage of growout.
Development
of Formulated Diets for Florida Pompano Trachinotus carolinus
Aquaculture – Part II: Replacement of Fish Meal with Plant
Proteins
Reigh, R., LSU – Agricultural Center
The replacement
of fish meal with plant proteins in the manufacture of aquafeeds
is of particular interest to fish nutritionists and producers
because the global sources of fish used to produce meal are near
maximum sustained yield and world prices remain high. This economic
pressure is driving research with alternative feed ingredients
in several countries, and it is possible that plant proteins derived
from soybeans will eventually become the primary constituents
of diets for pompano and several other farmed species. The challenge
in finding substitute ingredients is two-fold: not only to reduce
feed costs, but to do so while maintaining adequate levels of
essential Omega-3 fatty acids to provide for the dietary requirements
of the fish and ultimately, fish consumers. Florida pompano is
regarded as an excellent candidate species for marine aquaculture
in the future, and the results of this project may serve as a
nutritional model for other marine species as well.
