Mike, and Peter:
here's a copy of a post of mine from the 'how much would you pay' thread regarding the work of Dr. Charles Laidley and Dr. Robin Shields.i'd like to know what you guys think...
A consortium of research organizations has been working on stock enhancement for severely depleted red snapper populations along the Gulf Coast since 1996. Funded through the National Marine Fisheries Service, the group includes the Oceanic Institute, the University of Southern Mississippi's Gulf Coast Research Laboratory (GCRL) and Mote Marine Laboratory in Florida. The focus of the project is to develop technology and tactics for using hatchery-raised fish to restore depleted marine fish populations.
Culture research efforts are being headed by OI's Finfish Program under the direction of Dr. Anthony Ostrowski in a project led by Dr. David Ziemann. Dr. Charles Laidley and Dr. Robin Shields lead broodstock and larval rearing efforts, respectively. The goal is to develop intensive propagation capabilities for stock enhancement and then to transfer that technology to the GCRL.
Spawning of captive red snapper was first achieved in 1978 by Arnold, et al. They were able to accomplish a series of small spawns of 2,000-3,000 eggs, but were unable to keep broodstock populations alive.
About a year ago, OI brought in Charles Laidley, a reproductive physiologist and Robin Shields, a larval physiologist to head two teams in OI's effort. Laidley's team's goal was to spawn the red snapper, while Shields' team tackled rearing the larvae. Not only did they get the fish to spawn, but they also got them to spawn outside of their natural reproductive season. However, Laidley says, "We have made some significant advances, but are really still in the early stages of development. This species is particularly difficult to work with due to the development of intense aggression in correlation with sexual maturity."
The consortium's primary objective is enhancement of the natural stocks. OI's first obstacle was to establish quarantine protocols for working with a non-indigenous species and then to overcome the difficulties related to the constraints of working with transported animals over extended distances. In early 2000, research on transport methods led to greater survival rates for both larvae and broodstock. Although the initial focus of the research was to develop transport protocol for successful transfer of larvae, the natural spawning achieved has, according to Ostrowski, "given us great confidence that we will be able to produce eggs and larvae that will more rapidly advance research and the objectives of the consortium."
Thus having successfully created a more effective transporting system, the OI team focused on developing a technology with which they would have more control of the larval rearing process. This would allow them to provide larvae and fingerlings when they wanted it and as many as they needed.
The spawns produced eggs that were up to 78 percent fertile over a period of about one month. Many of the spawns produced over 150,000 fertile eggs each. Laidley anticipates that OI will be able to do even better in the future. The goal is to create technology to produce spawns of over a million eggs on demand.
When rearing larvae, most institutions are unable to get their fish to even reach mature stages. OI's team was able to rear the red snapper to maturity. This brought them to the same point the researchers had reached in the 1970s. However, through their research they discovered preliminary evidence that aggressive behavior emerges as the red snapper reaches adolescence. The animals become so aggressive that eventually they all kill each other. It was this behavior that halted the research in the 1970s, but not OI's. Through good husbandry protocols, water-quality and feeding practices, OI was able to overcome some of the problems encountered in the 1970s and 80s by other research teams.
Now the OI hatchery team is attacking the obstacles associated with the first-feeding stages of the larvae when in captivity. The larvae are so tiny (0.7 mm) that the artemia and rotifers usually fed to larvae are too big for them to eat. Initial studies by the GCRL show that the plankton-rich brown-water found in the Gulf of Mexico is optimal when filtered and condensed. However, because the natural environment is hardly reliable, OI is developing protocol for the culture of the plankton needed by the red snapper.OI's success also puts a bright spot in the future for farmers. Techniques to ensure year-round spawning and mass culture methods of the larvae (which are difficult to rear) to provide a reliable source of fingerlings are likely to be developed as an outcome of their breakthrough.
