TABLE OF CONTENTS Pages Symposium 1 - the National Sea ...

Ten Year in the Trenches: Perspectives on the Operation
of Large Scale Commercial RAS for the Production of
Hybrid Striped Bass
Joshua N. Goldman, President
Fins Technology, LLC
15 Industrial Rd. Turners Falls MA 01376
(413) 863-8905 • Fax: (413) 863-3575
jgoldman@finstechnology.com
Introduction
Recirculating aquaculture systems (RAS) offer many advantages including reduced water
consumption and environmental impact, and enhanced siting flexibility. Well-designed
RAS provide high levels of control over water temperature and other parameters that can
positively affect the biological performance of the species being cultured which in turn
drives the economics of the business.
A review of numerous commercial projects developed over the last decade suggests that
despite these advantages, RAS have not fulfilled their commercial potential due to three
persistent problems: (i) higher than projected capital costs, (ii) prolonged start-up and
debugging, and (iii) the inability of the life support system to consistently maintain
adequate water quality while sustaining intensive feed input. These factors tend to reduce
output and increase unit production costs. Our economic analysis makes it clear that even
well designed RAS can only be economically competitive if they overcome certain
inherent operational costs by consistently achieving superior biological performance in
term of fish growth, feed conversion efficiency and survival.
How Can Superior Biological Performance Be Achieved in Commercial Systems?
Although a great deal has been learned about the underlying unit processes from which
RAS are constructed, achieving consistently superior biological performance represents a
far broader and more significant challenge. Over the past decade, we experienced a
disturbing gap between our understanding of the system components and the full range of
practical considerations essential for commercial implementation.
As designers of commercial RAS, we are challenged to meet a number of seemingly
contradictory objectives. First, selection and integration of appropriately scaled unit
processes is required to make efficient use of feed, oxygen, electricity, and other inputs.
Second, implementation of the physical systems must be sufficiently robust to meet the
demands of commercial production, minimize maintenance-related downtime and offer
very low cost. Optimally, the system should also link some degree of reserve treatment
capacity to monitoring and control devices capable of minimizing the impacts of feeding
and fish activity in real time. Finally, the configuration of the physical facilities should be
thoroughly integrated with a well-designed management regime. Failure to appreciate the
risks of imprecise management can results in poor utilization of system capacity and
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