World Aquaculture December 2020

WWW.WA S.ORG • WORLD AQUACULTURE • DECEMBER 2020 45 to assess overall fish welfare is also necessary. The University of Miami’s Division of Veterinary Resources provides that service for UMEH. Broodstock management is complex; it is as much of an art as it is a science. For some species, smaller fish may perform better than larger fish, and for other species, it is the opposite. Likewise, the best sex ratio varies from 2 females:1 male to 2-3 males:1 female. Finally, contrary to anecdotal and popular belief, it is recommended that broodfish be moved routinely to allow tanks to be cleaned to maintain superior-quality rearing environments and allow for close inspection of individual broodfish. At the UMEH, fish are moved, on average, every three months and over the years this regimen has proven to be extremely beneficial to the fish and to management. During such procedures, all fish are checked for parasites and diseases, undergo prophylaxis treatments, and are moved to a new tank to resume spawning. The basic breeding program utilized at the UMEH is aimed at domesticating the stock to create independence from natural stocks. In the case of cobia, we have third-generation (F3) offspring of selectively bred broodstock that have been identified as producers of high-quality offspring. Our cobia breeding program is funded by Open Blue Sea Farms. We are expanding this mutually beneficial agreement to conduct genotype analysis of cobia as well as other species of interest, such as the red snapper, to determine fish fitness, in collaboration with the Center for Aquaculture Technologies. These genotypes are used to select groups of fish with high grow- out performance and track them back to their origin. Genes are then identified that correspond to productive performance parameters such as growth rate, survival rate, disease resistance, feed conversion ratio and fillet yield. These concepts are being applied to cobia and will be used for the red snapper and other species we work with. Progress with a Variety of Marine Fish Species Investigators at UMEH are working on development of a variety of marine finfish species for commercial production through federal and private sector-funded research projects. Species are at various levels of production viability and are discussed as follows with selected details on aspects of the associated research and development activities with each. Cobia Aquaculture activities at UMEH have long been associated with development of cobia aquaculture techniques and technologies. We have been working with this species since the early 1990s and have contributed significantly to the development of its aquaculture technologies at all stages of the production cycle. We have been supporting commercial cobia aquaculture development in the US and abroad since the early stages. Through a long-standing relationship with Open Blue Sea Farms, the world’s largest producer of cobia in offshore cages, operating in Panama, and the Cuna del Mar investment group, the cobia research and development at UMEH has been a mainstay of the program. We maintain multiple groups of spawning cobia broodstock whose eggs are routinely shipped to the Open Blue hatchery in Panama. These eggs are also used to conduct commercial-scale production runs that typically result in 40,000 plus shipped cobia juveniles per run, and small-scale larval-rearing work to support research activities at UMEH. RedSnapper The red snapper is an iconic species of enormous ecological and economic importance. Although the red snapper has been studied as a candidate species for aquaculture for a significant time period by various research institutions throughout the southeastern US, significant roadblocks still hamper the development of a commercial industry. Funded by NOAA and Florida Sea Grant, the key issues addressed by the research associated with this species include: the inability to produce reliable, consistent, high-quality spawns; a lack of a standardized larval rearing protocol; the use of high quantities of copepods in larviculture, which are difficult and costly to produce in commercial-scale quantities; and low overall rates of larval survival through metamorphosis. These difficulties have, in turn, led to a paucity of information on the nursery and grow-out performance of the species that is crucial to assessing commercial viability. We have made significant progress in addressing these problems over the last three years. We began developing our red snapper broodstock program in 2017 and achieved several high-quality spawns before Hurricane Irma caused significant damage to the facility and limited its broodstock conditioning capabilities during repairs. However, by the spring of 2018, a second cohort of broodfish had been added to the hatchery and spawning began copiously and consistently. These two cohorts of red snapper have now spawned regularly since the summer of 2018 and with the implementation of specific conditioning protocols, have spawned year-round –on and off-season. Encouragingly, a reliable larval-rearing protocol has also been developed that has yielded an average of 4.5 percent survival of larvae through the conclusion of weaning onto dry feeds with certain individual replicates surpassing 12 percent survival. As part of this protocol, red snapper larvae spawned at UMEH readily consume highly enriched rotifers as a first feeding source, thus eliminating the need to produce large quantities of copepods that had been used in all successful red snapper larval rearing prior to this project. These developments in broodstock maturation and larval-rearing protocols led to the production of over 32,000 fingerlings during the 2019 spawning season. On average, these fish reached a market size of 450-500 g within nine months of hatching. The fingerlings produced at UMEH have been used for a variety of purposes, including conducting multiple replicated nursery and grow-out trials within the facility as well as the distribution of fish to grow-out partners and educational institutions throughout the US. UMEH has supplied thousands of fingerlings to companies such as Beaver Street Fisheries and Horse Creek Aqua Farm to assess the grow-out potential, marketability, and organoleptic properties of the species. Significantly, MarePesca LLC, a new RAS project being developed in Puerto Rico, has also conducted a full market analysis on hatchery-raised red snapper and received excellent results from the restaurants and fish distributors that were included. Additionally, the snapper that have been grown at UMEH have been distributed to Miami Seaquarium, Phillip and Patricia Frost Museum of Science, The Sound School, and Mote Marine Laboratory and Aquarium for educational and outreach purposes. These programs have allowed tens of thousands of members of the public to learn about the process of producing these fish in captivity. Successfully addressing these problems with the production ( C O N T I N U E D O N P A G E 4 6 )