World Aquaculture 33 system under a boat dock in a protected inlet of Mobile Bay. Additionally, AUSL established and helps maintain a demonstration oyster farm in Sandy Bay, Alabama, as part of a research program assessing the potential for developing an off-bottom oyster aquaculture industry in Alabama (Fig. 2). At the farm site, AUSL researchers are testing various types of oyster grow-out gear and developing best management practices for off-bottom oyster culture in Alabama. At the demonstration farm, AUSL maintains stocks of juvenile and adult oysters for supporting research and commercial interests. During the DHOS, AUSL was concerned with direct oiling of oysters in the broodstock holding area and at the demonstration farm that could potentially cause mortality, impact fecundity of broodstock oysters, or contaminate oysters and gear at the demonstration farm. Despite uncertainty about the nature and timing of potential impacts from the DHOS, AUSL decided to press forward with hatchery production of oysters and the AUSL research agenda. Hatchery operations at AUSL proceeded with alteration of the normal seawater pumping and use protocol. With guidance provided by NOAA oil spill trajectory maps, the AUSL hatchery modified water pumping operations and managed to continue hatchery activities through May and early June to meet obligations for oyster spawning, larval rearing and setting for juvenile oyster production. Initially water was pumped continuously as normal until oil reached near-shore waters in late May 2010. Then, water pumping was suspended at the end of each work day and re-assessed each morning before start up using NOAA oil trajectory forecast maps and a visual and olfactory inspection of nearshore waters. It was anticipated that complete suspension of water pumping would be required at some point in time. For that reason, AUSL maintained 45,425 L of reserve seawater in large reservoir tanks on-site normally used to settle water for larval rearing. Another 45,425 L of water was stored in the hatchery’s discharge sump at the end of each day until pumping operations began the next day. For approximately 20 days in late June and early July, AUSL did not operate pumps because oil was present in local waters (Fig. 3). The hatchery discharge sump and pumping systems were modified to recirculate water through the hatchery during this time. It was possible to maintain post-set oysters in this recirculation system but growth was slowed considerably after naturally occurring phytoplankton was depleted. To maintain post-set oysters, the hatchery incurred unplanned costs for the provision of supplemental algal feed2. Capping of the Macondo oil well in mid-July and favorable wind conditions allowed water pumping to resume during work days with a reassessment of conditions each morning until the first week of August when continuous pumping operations were resumed. Despite the challenges of the DHOS, the AUSL hatchery was able to meet all obligations for oyster larvae and post-set juvenile to support AUSL research and the needs of other institutions and commercial interests. The ability to continue operations allowed AUSL to assist long-time cooperator Dr. John Supan from LSU and Fig. 2. Demonstration oyster farm in Sandy Bay, Alabama. the Louisiana Sea Grant program. Hatchery operations at the Louisiana Sea Grant Program’s Grand Isle Bivalve Hatchery were suspended indefinitely when oil impacted nearshore waters. The AUSL was able to conduct cooperative hatchery operations to provide assistance to meet production needs of the Grand Isle Bivalve Hatchery during the DHOS. Oyster larvae produced for Dr. Supan’s research were set and resulting post-set juveniles were returned to non-impacted, protected waters in Louisiana in July 2010. The adjustable long-line system used to hold shellfish broodstock at AUSL proved to be beneficial in preparation for potential oil impacts. In this system, baskets of oysters are suspended from a large monofilament cable stretched between a series of pilings under a boat dock and the line can be adjusted to different water depths. When the threat of oil to the broodstock area was imminent, the long-line system was adjusted to the lowest possible setting near bottom and below the lowest tide level. This kept oysters submerged and away from oil floating on the surface. In addition, broodstock oysters were protected from surface oil impacts by placement of oil booms across the inlet entrance. There were no visible oil impacts on this area and EPA water sampling nearby indicated no water contamination of concern. Once the threat of oil in the area subsided in early August 2010, the long-line system was readjusted to the normal mid-water position. Effects of the oil spill on fecundity of broodstock oysters have not yet been determined. At the Sandy Bay demonstration farm site, AUSL was conducting research trials on four types of oyster aquaculture gear during the time-frame of the DHOS. The gear under investigation was an adjustable long-line3, a floating pontoon cage4, a floating bag5, and a bottom cage6 (Fig. 2). When oil trajectory maps indicated a threat to the area, the long-line system was adjusted to the lowest possible setting near bottom and below the lowest tide level, keeping the oysters below any surface oil. Similarly,
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