Principal Investigator: Clifford A. Goudey, Brandy M. Moran, Mark T. Watson
Table of Contents
- Summary
- Objective 1: Establish intermediate haddock production.
- Objective 2: Culture Haddock eggs.
- Objective's 3, 4, 5, 6
Summary:
We are making steady progress towards meeting the goal of determining the commercial viability of the seasonal production of haddock in open ocean sea cages. Facilities at the MIT Sea Grant Marine Finfish Hatchery were prepared for the 2000 haddock spawn by modifying and expanding the hatching, larval and fingerling production systems. Live feed production was initiated and haddock eggs were obtained from collaborating laboratories when they became available. Survival of egg batches was very variable. The growth rates from the 2000 year class have proven better than a prediction model derived from our previous haddock trials. These fish will be available for May 2001 cage placement at a projected weight of 240 grams. Improvements in culture protocols learned during from the 2000 year class will be applied to the 2001 year class and subsequent project objectives will be met through cage trials to begin in May 2002.
Back to the table of contents.Specific progress to date:
Objective 1) Establish intermediate haddock production capabilities at the MIT Sea Grant marine finfish hatchery on Boston Harbor.
The larval production system has been expanded with one additional 100-gallon tank and the addition of a oxygenation column. The capacity of the fingerling production system has been increased by:
a) adding a swirl separation tank,
b) Increasing the capacity of the bag filter,
c) doubling the biofilter capacity by adding a second bioreactor in parallel, and
d) replacing the foam fractionator with an improved design.
Both systems have been upgraded with the addition of oxygenation systems that include: oxygen tanks, timer/solenoids, flow controls, flow meters, distribution manifolds and diffuser stones. The system is designed to allow the dispensing of oxygen to the larval and fingerling recirculation systems to match feeding schedules.
Components for the intermediate production facility have been acquired, however, the installation of these recirculation systems has been deferred to coincide with the needs of the upcoming 2001-year class.
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Objective 2) Using eggs supplied by the University of Rhode Island CMER project, culture 15,000 haddock to 200 gram size.
On March 7 and March 15, a total of 22,000 eggs were obtained from the University of Rhode Island CMER project. These eggs were of good quality and hatching and larval development proceeded routinely with growth and survival surpassing the results from eggs obtained from them during the 1999 spawn.
To supplement the number of haddock, 250,000 eggs were obtained from the Department of Fisheries and Oceans in St. Andrews, Canada on April 15. This laboratory had provided us an excellent batch of eggs during the 1999 spawn. However, a rapid and near-complete die off of the current batch occurred shortly after day 40. No specific cause or pathology was determined and we have had to conclude that the eggs were of poor quality.
The CMER eggs suffered high mortalities in the early days post hatch. Figure 1 reveals the larvae in tank C (from the earliest CMER spawn) suffered more than those obtained later. Rotifer population crashes are the likely cause of this phenomena, although early spawns have proven week in the past. Unfortunately, the surviving larvae saw several additional stresses including a chiller failure and persistently low DO.
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Figure 1: Haddock Survival from Hatch to First Grading |
The loss of the DFO eggs combined with the relatively small number of survivors from the CMER eggs left us with an inadequate number of haddock to meet the planned production for cage placement in 2001. Our surviving 2000-year class was transferred from the larval system to the fingerling system on D125 at an average weight of 6 grams. Growth of these animals has been excellent since the transfer to the bigger system as shown in Figure 2. The average weight as of October 25 was approximately 45 grams. These measured growth rates currently exceed a growth model derived from our previous experience with various stages of haddock growth and this comparison is shown in Figure 3.
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Figure 2: Length and Weight of Haddock in Growout System |
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Figure 3: Actual Haddock Growth compared to Modeled Growth |
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Objective 3) Stock one of the OOA Demonstration Project cages with haddock.
Pending
Objective 4) Evaluate the growth and survivability of these fish over a May-October growing cycle.
Current growth performance indicates our 2000 year-class 25 was approximately 45 grams. haddock will surpass our target weight of 200 grams by late March. If these growth rates continue, we may opt for cooler culture temperatures for the 2001 intermediate culture process in order to keep the biomass within the planned culture capacity.
Objective 5) Analyze the economics of seasonal haddock production in open-ocean cages.
Pending
Objective 6) Report our findings to industry and other researchers and hold demonstrations and instructional sessions on the techniques developed.
Pending
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