ANTICIPATING THE GROWTH OF AN OCEAN AQUACULTURE INDUSTRY

In assessing the future expansion of aquaculture in coastal-ocean environments, most studies focus only on the constraint posed by the local environmental assimilative capacity. In open-ocean environments, however, the assimilative capacity is difficult to gauge. We develop an alternative economic approach for projecting the growth of the open-ocean aquaculture industry. We evaluate equilibria in the market for seafood, where the product may be supplied either by a wild-harvest fishery or open-ocean aquaculture or both. In our framework, the net demand for farmed fish determines the size of the aquaculture industry and, in turn, the levels of pollution discharges. We illustrate our approach with a case study of a groundfish fishery and the proposed open-ocean aquaculture of Atlantic cod in New England. We find that, for a range of competitive production costs for aquaculture, the optimal industry structure would comprise both a wild-harvest fishery and aquaculture.     

THE FUTURE OF U.S. SEAFOOD SUPPLY

The United States today imports most of the seafood it consumes. Half of these imports are from aquaculture. Domestic wild capture production is limited and U.S. aquaculture production has declined in recent years. Policy, socioeconomic, and regulatory obstacles stand in the way of expanded U.S. aquaculture production. In this article, we examine the implications of two future paths for seafood supply: an increasing reliance on imports, and a shift toward increased domestic aquaculture production. We examine global trends, likely future developments in U.S. seafood demand and supply, and implications of the path of U.S. aquaculture development for U.S. seafood supply and prices, employment, ecological footprint, and seafood supply security and safety. We conclude with recommendations for a path forward that serves the interests of the nation and the global community in the search for economically sound and sustainable ways to feed a growing population.     

Cultivation-Independent Analysis of the Development of the Lactobacillus spp.Community in the Intestinal Tract of Newborn Piglets

Molecular diversity and development of the Lactobacillus community in the intestinal tract, as influenced by age and intestinal compartment, were studied in one litter of 12 conventionally raised piglets. Piglets were euthanized at each week (3 animals per time). Digesta and tissue samples from stomach, duodenum, jejunum, ileum, caecum, colon, and rectum were collected and analysed by using 16S ribosomal RNA-based methods. DGGE (denaturing gradient gel electrophoresis)profiles revealed that the Lactobacillus communities throughout the GI tract from duodenum to rectum showed good stability at same age. This indicates that fecal Lactobacillus communities can effectively represent the intestinal community.Two dominant bands were found in tissue samples of the small intestine, suggesting that the lactobacilli can adhere to the small intestinal wall. The Lactobacillus communities in different GI tract compartments developed over time. A successional change of Lactobacillus communities was observed from birth, through creep feeding to one week after weaning, showing a trend from simple to complex and back to simple. Furthermore, a clone library of Lactobacillus spp. 16S rRNA gene sequences were generated from jejunal and colonic thymes. Six dominant DGGE bands generated from jejunal chymes were matched with sequences that show 94-98% similarity to the bands derived from L. reuteri, L. delbrueckii, and L. crispatus. Seven dominant DGGE bands generated from colon chymes were matched with sequences that show 88-99% similarity to those derived from L. reuteri, L. delbrueckii, L. amylovorus/L, sobrius, and L. acidophilus. Amplicons related to L. reuteri were found in all DGGE fingerprints from jejunal digesta of age of weeks 1, 3, and 4. Amplicons related to L. amylovorus/L, sobrius were present in all DGGE fingerprints from colonic digesta of age of week 1, 3, and 4. Amplicons related to L. delbrueckii were found before weaning, L. crispatus after creep feeding before weaning and L. acidophilus after weaning. This indicates that L. reuteri and L. amylovorus/L, sobrius probably belong to the permanent composition,while L. delbruckii, L. acidophilus, and L. crispatus probably belong to the temporal groups of Lactobacillus communities in the GI tract of piglets.     

High Quality Composts by Means of Cocomposting Of Residues from Anaerobic Digestion

Advanced treatment of residues from anaerobic digestion of leftovers and kitchen waste originating from an industrial waste treatment plant was carried out by means of cocomposting in order to reveal potential synergistic effects. After a retention time of two weeks in the anaerobic reactor, microbial activity of the residues remained high. The biogas produced is of use in combined heat and power generation. Lab-scale experiments in the liquid phase have demonstrated “cracking” of the anaerobic stabilized organic matter under aerobic conditions. The advanced aerobic treatment of residues from anaerobic digestion by means of cocomposting leads to high quality composts. The addition of output material to biowaste from the separated bin collection may improve the formation of humic substances. Extractable humic acids are considered to represent a reliable parameter in describing high quality composts. Thus, the improvement of humic acid formation by means of composting is a goal to be achieved. Process control was performed by assessing parameters such as loss of ignition, total organic carbon, nitrogen and humic acid content as well as by modern analytic methods like FT-IR spectroscopy and thermogravimetry.