Towards an ecosystem approach to aquaculture: Assessment of sustainable shellfish
cultivation at different scales of space, time and complexity
J.P. Nunes
a
, J.G. Ferreira
b,
⁎
, S.B. Bricker
c
, B. O'Loan
d
, T. Dabrowski
e
, B. Dallaghan
f
, A.J.S. Hawkins
g
,
B. O'Connor
h
, T. O'Carroll
f
a
CESAM & Dept. Environment and Planning, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
b
CMA, Dept. Environmental Sciences and Engineering, FCT-UNL, 2829-516 Monte de Caparica, Portugal
c
NOAA: National Centers for Coastal Ocean Science, Center for Coastal Monitoring and Assessment, 1305 East West Highway, Silver Spring, MD 20910, USA
d
Bord Iascaigh Mhara (BIM), Irish Sea Fisheries Board, Office D, Wexford Enterprise Centre, Strandfield Business Park, Kerlogue, Rosslare Rd., Wexford, Ireland
e
Marcon Computations International Ltd., 10 NUIG Innovation Centre, Science and Technology Building, Upper Newcastle, Galway, Ireland
f
Bord Iascaigh Mhara (BIM), Irish Sea Fisheries Board, Crofton Road, Dun Laoghaire, Ireland
g
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth Pl21 0TQ , United Kingdom
h
AQUAFACT International Services Ltd., 12, Kilkerrin Park, Galway, Ireland
abstractarticle info
Article history:
Received 14 November 2010
Received in revised form 27 February 2011
Accepted 28 February 2011
Available online 10 March 2011
Keywords:
Ecosystem approach to aquaculture
Integrated models
EcoWin2000
FARM
ASSETS
Shellfish aquaculture
The need for an ecosystem approach to aquaculture has led to the development of several aquaculture analysis
tools in recent years, working at different scales of space (farm- to system-level), time (seasonal to annual and/or
long-term analysis) and complexity (ease of use to complex process-based modelling). This work has tested the
application of a range of complementary tools to the analysis of aquaculture practices and ecosystem impacts in
Killary Harbour, Ireland. The selected tools included a system-scale, process based ecological model
(EcoWin2000), a local-scale carrying capacity and environmental effects model (FARM) and a management-
level eutrophication screening model (ASSETS). Both the system-scale and farm-scale models used ShellSIM to
simulate individual shellfish growth. The tools were used to analyse the relationship between shellfish
productivity and food sources, the impacts of changes to stocking densities of shellfish, and an overall assessment
of the ecological status of Killary Harbour. EcoWin2000 was able to support a complex analysis, but required a
significant amount of input data and effort for calibration and result analysis. FARM was able to provide similar
(although less detailed) results at the shellfish farm scale with a smaller effort for parameterization and
application, but was limited to testing scenarios with relatively moderate changes to present-day conditions.
ASSETS provided simple, management-level results with a relatively low level of input data, although it is not
appropriate for complex analysis. This paper illustrates the complementary nature of these tools, and how the
uniquecapacities of each can be combined for integrated assessmentof aquaculture in a coastal system. For Killary
Harbour, the combined application of these tools revealed that: (i) the system's eutrophication status can be
classified as Moderate Low, with a future trend of No Change; (ii) there is a large influence of ocean boundary
conditions on shellfish food resources in the system; (iii) the maximum mussel production of the system is
4200 ton year
−1
, but achieving this level would leadtolower harvestweights and longergrowthcycles; and (iv) a
scenario of lower stocking densities proposed for the system should lead to lower mussel productions, but could
result in benefits such as higher mussel weight at harvest and/or shorter growth cycles.
© 2011 Elsevier B.V. All rights reserved.
1. Introduction
Global aquaculture currently stands at a reported production of
about 52 million tons, with a valuation of over 61 billion euros (Food
and Agriculture Organization, 2009). The relative increase in farmed
production, compared to wild fisheries, has generated enthusiasm for
the so-called blue revolution, a “new” paradigm for the supply of
seafood products to world markets, holding the promiseof food security
(Sachs, 2007). Several authors (e.g. Costa-Pierce, 2010) have prescribed
caution with respect to this vision of a marine panacea on the basis of
various factors, including the risk that an ecosystem approach to
aquaculture (EAA, e.g. Soto et al., 2008)maynotaccompanythis
predicted growth. This surge may largely be an “Asian Tiger”
phenomenon, and a deregulated increase in aquaculture production
may cause regional asymmetries and social conflicts, and pose a threat
to food security as a whole.
In Europe, annual growth of aquaculture has declined to 1%, partly
because of market factors, but also because the industry is subject to
Aquaculture 315 (2011) 369–383
⁎ Corresponding author. Tel.: +351 21 2948300x10117; fax: +351 21 2948554.
E-mail address: joao@hoomi.com (J.G. Ferreira).
0044-8486/$ – see front matter © 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.aquaculture.2011.02.048
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