Enhancing
Seed Availability for the Hard Clam (Mercenaria mercenaria) Aquaculture
Industry by Applying Remote Setting Techniques
(755 KB)
Summary
During a 2-year study, funded by Florida Sea Grant, technical procedures
were developed and demonstrated to determine the economic feasibility of
applying remote setting technology used by the Pacific Northwest shellfish
industry to the hard clam culture industry in Florida. Remote setting methods in
Washington, for example, involve high volume production of either Pacific oyster
or Manila clam larvae in the hatchery. Just prior to setting, the shellfish
larvae are then refrigerated and shipped chilled to growers at “remote”
locations for settling and nursing. Biological characteristics associated with
remote setting of hard clam larvae, as well as results from rearing trials
conducted in 2000-1 with participating land-based nursery operations, were
summarized in the July 2002 issue of the Shellfish Aquaculture Newsletter.
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The costs to the nursery
operation of producing 1-mm clam seed using remote setting techniques as opposed
to purchasing 1-mm seed from a commercial hatchery are compared in this study.
The economic analysis provides nursery operators with the basic information to
assess the financial merit of adopting remote setting techniques. In the
analysis, the financial characteristics of the remote setting facility are
described. The initial investment required to construct a pilot-scale system,
consisting of one tank, is estimated at $3,000. The operational costs, such as
supplies, variable, and overhead expenses, are also determined. These costs are
then combined into a total cost estimate expressed on a per unit of production
basis. The production unit assumed in this analysis is based on 1,000 1-mm seed
clams, an industry standard by which post-set seed clams are purchased. The
estimated per unit production cost can then be compared to the current unit
market price. These expenses are computed on the basis of one and two runs per
year when employed at a modest scale - for example, a one-tank remote setting
system stocked with 3 million clam pediveliger larvae per run.
The
financial analysis suggests that the remote setting technology generates a seed
cost savings compared to purchasing 1-mm seed clams from a commercial hatchery.
When operating the system for two runs, the system produces 2.22 million 1-mm
seed clams at a cost of $1.47 per 1,000. This represents a cost savings of $1.53
per 1,000 seed when compared to a market price of $3.00 per 1,000 1-mm clam
seed. (When this study was conducted, $3/1,000 represented the current market
price.) In addition, the initial cost is recovered from these cost savings
during the first year of operation. The survival rate in the remote setting
system would have to fall from the assumed level of 37% to below 18% for the
system to not be able to provide cost savings. However, a risk does exist in
that no commercial source of clam pediveliger larvae is currently available on a
consistent basis. The analysis assumes that 1 million pediveliger larvae would
be available from a commercial hatchery at a cost of $125. This price may change
if this market were to develop. However, the price per 1 million pediveliger
larvae would have to increase to over $692 for the operator to be indifferent to
using the remote setting technology versus buying the 1-mm clam seed. For more
info on the economic analysis, contact Chuck Adams with the UF Food and Resource
Economics Department at (352) 392-1826 ext. 223.
A final report, published by Florida Sea Grant as
Technical Paper 125, is now available to interested hatchery and nursery
operators. Although availability of clam seed is more than adequate today with
prices at an all-time low, some of the management techniques evaluated in this
study may be of benefit in rearing 1-mm seed to a field planting size. For
example, mechanical filtration of the incoming water supply may improve seed
survival if the saltwater source is high in suspended solids. Further,
supplemental feeding with a commercially available algal paste may be a
cost-effective method to increase growth when food is limited, particularly
during early spring start-up of land-based nursery operations.
To obtain the complete document, you may download a
full PDF copy (755 KB)
from Florida Sea Grant or contact the Shellfish
Aquaculture Extension Office.
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