Extensive culture of burbot (Lota lota maculosa) Jimmy Barron
Objectives • Determine growth, condition, survival and optimal density for the extensive culture of burbot. • Determine optimum temperature for growth, condition and survival for burbot transitioned to commercial feed. • Evaluate existing natural ponds based on collaborations with Idaho Fish and Game.
2008 extensive culture preliminary observations • Six 12’ tanks, sunken into the ground were assigned to one of three treatments. • Treatments were stocking time: 15 days on live feed(rotifers only), 30 days on live feed(rotifers only) and 45 days on live feeds(rotifers and artemia). • 5000 larvae counted and stocked per tank.
Intermediate data collection • Water quality tested weekly. • Traps used to check for survival. • Lengths and weights recorded from trapped burbot. • Zooplankton sampling conducted weekly(beginning July 22).
Results • No survival from the 15d and 30d stocking times. • 22 individuals harvested from the 45d stocking.
-FW rotifers stocked -Ceriodaphnia dubia Stocked
Harvest 45d treatment Intensive culture
Main points • Survival only found in tanks stocked with larvae fed for 45 days on rotifers and artemia. Survival of 0.22% • Burbot raised extensively had higher growth rates and survival than those raised intensively. • Burbot density(d) was 5000burbot/6300L = .8 burbot per liter. • At this stocking density in the proposed 10mx10mx2m experimental ponds(200,000L): 160k larvae(45days after first feeding) per pond would be needed, and the estimated harvest(0.22%survival) would be 352 juveniles per pond. • This preliminary trial indicates that burbot can be successfully reared under these specific extensive conditions.
Direction for 2009 • Stock at 45d post 1st feeding • Use density as the treatment. • Divide ponds in some way, thus increasing the # of treatments and replicates. • Seed zooplankton first with freshwater copepods and at a later time Daphnia magna.