Omnibus Research Projects: 2012-2014
The Louisiana Sea Grant College Program funded seven research projects for the omnibus period that began in Feb. 1, 2012. Below is a synopsis of the projects, along with a list of the principal investigators, Extension personnel and their affiliations.
Development of Alternative Bait for the Commercial Blue Crab Fishery
Julie Anderson (Louisiana Sea Grant, LSU AgCenter)
The cost per pound of bait has significantly increased for Louisiana blue crab fishermen, while other costs, such as fuel and supplies, are also increasing. Atlantic menhaden is a bait of choice, but the current supply line shipping fish to Louisiana has several significant problems, and menhaden are in demand for other uses. Not only does the cost of the fish increase, so does the cost to ship them.
The objective of this study is to determine the feasibility of developing an artificial bait for the blue crab industry using waste byproducts from existing fisheries. Cost-effective bait will reduce expenses for blue crab fishermen and reduce fishing pressure on Atlantic menhaden, as well as add value to currently worthless byproducts.
Role of Adjustable Longline Systems (ALS) in Minimizing Accumulation of Potentially Pathogenic Vibrios in Oysters
Crystal Johnson (LSU)
Vibrios are naturally occurring bacteria that are responsible for thousands of gastrointestinal illnesses annually in the United States, largely due to the consumption of raw oysters. As oysters feed, vibrios accumulate in oyster tissue, and when the oyster is eaten raw, resident vibrios have the potential to cause gastroenteritis in consumers. In adjustable longline systems, oysters are grown in bags suspended in the water column on cables rather than on traditional oyster reefs. Based on the fact that sediment is such a rich source of potentially pathogenic vibrios, it is hypothesized that oysters harvested from estuary sediment carry higher vibrio densities than oysters suspended higher in the water column.
This project seeks to determine the difference in vibrio loads in the sediment and vibrio loads in the water column and to determine the difference in vibrio loads in oysters cultured on-bottom and in off-bottom suspension.
Private Market Alternatives for Maintaining Wetland Viability in Coastal Louisiana: A Double-Hurdle Approach
Walter Keithly (LSU)
Richard Kazmierczak (LSU)
Since 1930, Louisiana has experienced a net loss of more than 1,500 square miles of coastal wetlands. The state’s remaining coastal wetlands are at risk, and 80 percent of these wetlands are under private ownership. While the public benefits of wetland protection and restoration projects are likely to be large, private benefits, measured by changes in net income to the landowner, are likely to be small and, potentially, negative. However, coastal landowner acceptance of and participation in restoration programs are critical.
The primary goal of this research is to develop an economically valid model that examines the factors that motivate private coastal landowners to participate in and generate income from their coastal wetland tracts. With this understanding, the investigators will then design potential policy instruments that provide incentives for private coastal wetland stewardship.
Sediment Dynamics and Biogeochemical Cycling in a Developing Deltaic System: Understanding Land Building and Habitat Quality in a River Diversion
Alexander Kolker (Louisiana Universities Marine Consortium)
Charles Wilson (Louisiana Sea Grant, LSU)
Brian Roberts (LUMCON)
Most experts agree that the best way to restore coastal Louisiana is to reactivate the natural deltaic land-building processes that originally built this system. This involves partially diverting Mississippi River flow, with the goal of bringing in sediments. However, freshwater diversions have potentially negative impacts, and little is known about the interaction between land building processes and water quality in developing deltas.
This project seeks to examine the interactions between deltaic land building processes and sediment biogeochemical cycling rates, a key regulator of water and sediment habitat quality. By studying conditions at the naturally accruing Wax Lake Delta of the Atchafalaya River, researchers will provide valuable information for coastal managers developing future coastal land-building projects.
Contribution of Maximum Freshwater Discharges from Caernarvon Diversion Project to Oyster Mortality Related to Freshwater Inflows in the Breton Sound Estuary, Louisiana
Jerome LaPeyre (LSU AgCenter)
James Geaghan (LSU AgCenter)
Although a number of studies have been conducted on the effects of salinity and temperature on oysters, few studies have examined their combined effects, the effects of very low salinities, the effects of oyster size, or prolonged periods of low salinity.
Spat, seed and market-sized oysters will be produced at the Louisiana Sea Grant oyster hatchery, and their mortality and condition after exposure to salinity and temperature combinations in the range observed in Breton Sound during maximum freshwater discharges will be determined in controlled laboratory experiments and in the field. This project will be critical to better understanding what controls salinities in Breton Sound and, more generally, the impact of freshwater diversions, one of the key restoration/coastal management tools identified in the state coastal management plan, on oyster resources.
Wetland Restoration with Sediment Conveyance: An Experimental Approach to Reduce Uncertainties in Attaining Successful Restoration – Phase 2
Irving Mendelssohn (LSU Oceanography and Coastal Sciences)
Sean Graham (LSU Oceanography and Coastal Sciences)
During the last several years, state and federal resource agencies have implemented sediment conveyance projects for wetland restoration. However, barriers such as cost and ecological-physical uncertainties still exist that prevent the use of this method by individual landowners, municipalities and others.
The goal of this project is to reduce the ecological and geo-physical uncertainties related to the successful use of sediment-slurry restoration using small dredges. This research has three primary aims: (1) develop protocols for the successful use of a prototype mini-dredge to be used by landowners and resource agencies for marsh restoration and rehabilitation; (2) test metrics by which successful restoration of low-salinity, high-organic coastal wetlands can be assessed; and (3) determine the critical threshold for sediment burial that promotes functional equivalency with reference marshes.
Enhancing Seed Versatility and Protection against Biological and Coastal Environmental Variables to Improve Success Rates of Smooth Cordgrass Aerial Seeding
Herry Utomo (LSU AgCenter)
Steve Linscombe (LSU AgCenter)
Vegetation is vital to minimizing coastal land loss in Louisiana, and smooth cordgrass is an important species in this effort. It is usually hand-transplanted, but this technique requires a great deal of time and manual effort. However, it takes less than eight seconds to aerially plant an acre of land using seed broadcast by an airplane. Successful aerial seeding will provide an economical means of conducting large-scale planting for erosion control and reclamation.
The main objective of this research is to determine the most effective way to jumpstart smooth cordgrass seed and to powder-coat the enhanced seed to improve survival, stand density, planting precision and the success rate of aerial seeding. The next step is to enhance physiological and physical properties of the seed to better adapt to coastal environmental variables so that highly reliable aerial seeding techniques can be established.