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Journal ArticleDOI

Integrated multi-trophic aquaculture of red drum (Sciaenops ocellatus) and sea cucumber (Holothuria scabra): Assessing bioremediation and life-cycle impacts

01 Feb 2020-Aquaculture (Elsevier)-Vol. 516, pp 734621
TL;DR: The methodology defined here can be a powerful tool to predict the magnitude of environmental benefits that can be expected from new and complex production systems and to show potential impact transfer between spatial scales.
About: This article is published in Aquaculture.The article was published on 2020-02-01 and is currently open access. It has received 40 citations till now. The article focuses on the topics: Integrated multi-trophic aquaculture & Holothuria scabra.

Summary (3 min read)

1 Introduction

  • LCA has been extensively applied to aquaculture systems, with 65 studies and 179 aquaculture systems reviewed in a recent meta-analysis (Bohnes et al., 2018) .
  • LCA has been used mostly to identify problematic stages or components of systems and to compare alternatives such as intensive vs. extensive systems, monoculture vs. polyculture and open water vs. closed recirculating systems.
  • The present study examined environmental benefits and trade-offs for finfish monoculture of shifting to an open-water IMTA system co-culturing suspended sea cucumber culture beneath finfish cages, by assessing the latter's mitigation potential at local and global scales.

2.2 Inventories

  • The LCIs of both systems were developed and their environmental impacts were estimated using SimaPro 8.5 software and its databases (PRé Consultants, Amersfoot, Netherlands).
  • The ecoinvent 3.0 database was used for all background data except feed ingredients, which were taken from the French EcoAlim v.1.3 database.
  • See the Supplementary Material for detailed LCIs.

2.2.1 Description of the monoculture system and its animal production parameters

  • The finfish monoculture system described a scenario of a semi-industrial red-drum farm with floating sea cages located on Mayotte Island, Indian Ocean (see Chary et al., 2019) .
  • Culture cycles are 20 months long with progressive harvests from month 13.
  • Harvested products range from portion-size to 3000 g per individual.
  • No chemotherapeutants (e.g. antibiotics) are used during finfish production.
  • Feed consists of commercial pressed pellets produced on La Reunion Island and imported to the farm by sea shipping.

2.2.2 Assumptions and data sources for the monoculture

  • Annual production data (i.e. feed inputs and finfish harvest volumes) were taken from farm simulations under routine conditions with the FINS farm-scale model (Chary et al., 2019) .
  • FINS is a simple model combining farm production and waste emission modules to simulate farm production, feed requirements and waste discharge for finfish sea-cage systems.
  • FINS includes several submodels (e.g. individual growth model, mass balance model), which were parametrized for red drum.
  • Data on the ingredient mix were provided by a commercial feed-mill manager in La Reunion (data not shown due to confidentiality).

2.2.3 Sea cucumber system assumptions and data sources

  • Sea cucumbers must be processed to obtain a dry cooked commercial product called "bêche-de-mer".
  • The protein content in the final product is 51.2% (Average from Ozer et al., 2004) giving an edible protein content in fresh sea cucumbers of 3.8%.
  • Processing stages into bêche-de-mer were not included in the LCA system boundaries.

2.2.4 Individual bioenergetic model and population model for the sea cucumber

  • On-farm sea cucumber biomass dynamics were calculated by multiplying the number of individuals by the individual weight predicted by DEB.
  • The population dynamics model of sea cucumber represents (i) initial seeding (initial condition), (ii) culture-harvesting strategies, (iii) natural mortality and (iv) culture losses (e.g. poaching, predation).
  • Since maximum stocking density is reached at the end of the culture cycle, it also corresponds to the system's productivity.

2.2.5 Grow-out emissions from monoculture and IMTA

  • In the sea cucumber LCI, net N emissions, net P solid and dissolved emissions and net ThOD were calculated as solid and dissolved emissions from sea cucumber growth minus avoided emissions associated with IFF.
  • ThOD coefficients for sea cucumber feces were estimated as 0.764 kg O 2 per kg.

2.2.6 Inputs imported to Mayotte

  • On Mayotte, most economic inputs used on the farm are imported from La Reunion or France.
  • Therefore, most processes were adapted to include sea transport (1700 km from La Reunion and 9800 km from France) by transoceanic ship from the closest trading ports, and land transport (30 km) by truck from the port to the farm facilities.
  • Fuels were assumed to be imported from Singapore (7000 km).

2.3.2 Life cycle impact assessment and uncertainties

  • It is important to include uncertainty analysis in comparative LCAs, since deterministic results that do not include significance information can lead to oversimplified conclusions (Mendoza Beltran et al., 2018) , especially in ex-ante analysis.
  • Uncertainties due to unrepresentativeness (i.e. degree of reliability, completeness, temporal correlation, geographical correlation, technological correlation and sample size) of foreground processes were estimated with the Numerical Unit Spread Assessment Pedigree following the method of Henriksson et al. (2014) and included in the LCI of the monoculture and the IMTA.
  • The authors simulated 1000 Monte Carlo runs to propagate these uncertainties to the LCIA results per impact category, as commonly done in LCA uncertainty analysis (Avadí and Fréon, 2013) .
  • A paired t-test was used to determine statistical significance of the systems' difference in environmental impacts.
  • The null hypothesis in the t-test was that IMTA and monoculture systems have equal environmental impacts per functional unit.

3.2 LCIA results

  • The authors discuss the mitigation potential of the IMTA system in terms of i) the bioremediation efficiency of sea cucumber system co-cultured with finfish and ii) comparison of the impacts of the finfish monoculture and IMTA systems estimated by LCA.
  • Perspectives are then discussed for decreasing the IMTA's benthic impact and overall lifecycle impacts.

4.1 Sea cucumber bioremediation potential

  • The waste mitigation potential of sea cucumbers may not be sufficient to significantly reduce environmental effects of solid waste deposition on the seabed, and additional analyses are necessary to fully assess local ecological effects of IMTA systems.
  • This is also true to account for other emissions (e.g. GHGs) occurring at the farm and other life-cycle stages and that can have impacts at the global scale.
  • Therefore, to compare environmental performances of monoculture and IMTA systems fully, the analysis must be supplemented with more holistic impact assessment and related to the main functions of both systems, as performed in the LCA.

4.2 LCIA: comparison of monoculture and IMTA

  • Compared to the monoculture, the IMTA system tended to decrease EU and NPPU impacts but increase CC and CED.
  • This eco-intensification reduced the overall amount of feed used per unit of biomass produced, which explained the decrease in NPPU.
  • Ecological intensification of aquaculture (Aubin et al., 2019) , through IMTA, shifted environmental burdens to energy-related global impact categories such as CC and CED.
  • These components were not visible in the contribution analysis because of the large difference in production scales.
  • Close integration of farm activities and infrastructure becomes less likely in IMTA farms with more balanced production between primary and secondary species; therefore, environmental impacts will likely increase if sea cucumber production increases.

4.3 Other perspectives to improve environmental performances

  • Local and global environmental benefits of the IMTA system were generally low because of the low productivity of sea cucumbers; increasing them will require finding practical methods to intensify sea cucumber production.
  • One option is to investigate the choice and design of rearing structures that can increase the culture surface area and thus the bioremediation potential of the system.
  • With a threelevel structures, the CS could be 'virtually' divided by three, i.e. 45:1 and WEE could increase to 2.20%.
  • Finding practical farming methods for sea cucumbers to be added to a pre-existing monoculture system thus remains a challenge.

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Citations
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Journal ArticleDOI
TL;DR: A review of applications of dynamic energy budget (DEB) theory to conservation issues can be found in this paper, where the authors discuss why DEB theory represents a valuable tool to tackle some of the current and future challenges linked to maintaining biodiversity, ensuring species survival, ecotoxicology, setting water and soil quality standards and restoring ecosystem structure and functioning in a changing environment under the pressure of anthropogenic driven changes.
Abstract: The contribution of knowledge, concepts and perspectives from physiological ecology to conservation decision-making has become critical for understanding and acting upon threats to the persistence of sensitive species. Here we review applications of dynamic energy budget (DEB) theory to conservation issues and discuss how this theory for metabolic organization of all life on earth (from bacteria to whales) is well equipped to support current and future investigations in conservation research. DEB theory was first invented in 1979 in an applied institution for environmental quality assessment and mitigation. The theory has since undergone extensive development and applications. An increasing number of studies using DEB modelling have provided valuable insights and predictions in areas that pertain to conservation such as species distribution, evolutionary biology, toxicological impacts and ecosystem management. We discuss why DEB theory, through its mechanistic nature, its universality and the wide range of outcomes it can provide represents a valuable tool to tackle some of the current and future challenges linked to maintaining biodiversity, ensuring species survival, ecotoxicology, setting water and soil quality standards and restoring ecosystem structure and functioning in a changing environment under the pressure of anthropogenic driven changes.

9 citations

Journal ArticleDOI
TL;DR: The experiment provides proof-of-concept of a simple pilotscale RAS, integrating tropical species at 3 trophic levels, and changes in dissolved inorganic nitrogen species support the notion that the sea cucumber tank was the main site of nitrification.
Abstract: Closed recirculation aquaculture systems (RAS) in combination with integrated multitrophic aquaculture (IMTA) are considered best management practices, but high material costs and difficult maintenance still hinder their implementation, especially in developing countries and the tropics. Few case studies of such systems with tropical species exist. For the first time, an extremely low-budget system was tested combining the halophyte sea purslane Sesuvium portulacastrum and a detritivore, sandfish Holothuria scabra, with finfish milkfish Chanos chanos over 8 wk on Zanzibar, Tanzania. In a 2 m3 RAS, milkfish and sea purslane showed good growth, producing an average (±SD) of 1147 ± 79 g fish and 1261 ± 95 g plant biomass, while sea cucumber growth was variable at 92 ± 68 g. The system operated without filter units and did not discharge any solid or dissolved waste. Water quality remained tolerable and ammonia levels were reliably decreased to <1 mg l−1. A NO2 peak occurred within the first 30 d, indicating good biofilter performance of the different system compartments. Changes in dissolved inorganic nitrogen (DIN) species support the notion that the sea cucumber tank was the main site of nitrification, while the hydroponic halophyte tank acted as a net sink of NO3. A nitrogen budget accounted for 63.7 ± 5.3% of the nitrogen added to the system as fish feed. Increasing the plant to fish biomass ratio to 5:1 would fully treat the DIN load. The experiment provides proof-of-concept of a simple pilotscale RAS, integrating tropical species at 3 trophic levels.

8 citations


Cites background from "Integrated multi-trophic aquacultur..."

  • ...…of IMTA is still hindered by various infrastructure, legislation and economic hurdles, and widespread adoption can only be achieved through site-specific targeted approaches and upscaling research and development beyond small tank or laboratory experiments (Chopin 2017, Kleitou et al. 2018)....

    [...]

  • ...However, high material costs, difficult maintenance and inadequate legislation still hinder their implementation, especially in the developing tropics (Chopin 2017, Kleitou et al. 2018, Stenton-Dozey et al. 2020)....

    [...]

Journal ArticleDOI
TL;DR: The use of probiotics is an important tool for sustainable mariculture and it is inevitable that mariculture farming mitigate to more environmentally friendly practices depends on the local context and market demand.
Abstract: Globally, aquaculture is making an increasingly contribution to food security, to increase fish production for a growing global population; aquaculture must grow sustainably at the same time. Commonly, intensive aquaculture in all its aspect affects his environment, in order to provide consumers with a safe and high quality product, waste resulting from high-intensity mariculture is an item that must be considered, so in this review, some practices for sustainable mariculture will be discussed. The use of probiotics is an important tool for sustainable mariculture and it is inevitable that mariculture farming mitigate to more environmentally friendly practices depends on the local context and market demand. The future of seafood production is likely to focus on mariculture, bearing in mind that the protection of the planet and its natural resources (water, biodiversity, climate, etc.) is a key factor in the pursuit of sustainable development in the aquaculture sector.

6 citations

Journal ArticleDOI
TL;DR: Results indicated that sea cucumbers were able to assimilate carbon directly from the cellulose, thus identifying bagasse as a viable resource to improve bioremediation by deposit feeding sea cucumber Holothuria scabra in integrated aquaculture.

5 citations

Journal ArticleDOI
TL;DR: Understanding how different monogenean species respond to changes in the physical and chemical parameters of water during a production cycle can prevent peaks in abundance and subsequent sanitary problems.
Abstract: Fish farming is becoming an increasingly popular agricultural activity, and water quality in these environments is a major concern. Fish parasites, such as monogeneans, respond to changes in abiotic conditions, either with an increase or decrease in population. This study aimed to identify gill monogeneans and analyse their relationships with abiotic factors during the ontogenetic development of Nile tilapia over the fish culture cycle in Mato Grosso do Sul, Brazil. Fish were sampled monthly for eight months, and a total of 200 fish were collected. The physical and chemical water parameters were measured and correlated with the abundance of each monogenean species. Over the fish culture cycle, the physical and chemical parameters fluctuated, and the water quality decreased. The parasites found included Cichlidogyrus tilapiae, Cichlidogyrus thurstonae, Cichlidogyrus sclerosus, Cichlidogyrus halli and Scutogyrus longicornis. The abundances of all species showed significant differences during ontogenetic development (body size) and C. tilapiae, C. sclerosus, C. thurstonae and S. longicornis were correlated with changes in abiotic conditions. However, C. halli was not significantly correlated with any of the evaluated physical or chemical parameters. Understanding how different monogenean species respond to changes in the physical and chemical parameters of water during a production cycle can prevent peaks in abundance and subsequent sanitary problems.

4 citations

References
More filters
Journal Article
TL;DR: Copyright (©) 1999–2012 R Foundation for Statistical Computing; permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and permission notice are preserved on all copies.
Abstract: Copyright (©) 1999–2012 R Foundation for Statistical Computing. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the R Core Team.

272,030 citations

Journal ArticleDOI
TL;DR: Comparisons demonstrate that, if the use of loops is avoided, R code can efficiently integrate problems comprising several thousands of state variables, and the same problem may be solved from 2 to more than 50 times faster by using compiled code compared to an implementation using only R code.
Abstract: In this paper we present the R package deSolve to solve initial value problems (IVP) written as ordinary differential equations (ODE), differential algebraic equations (DAE) of index 0 or 1 and partial differential equations (PDE), the latter solved using the method of lines approach. The differential equations can be represented in R code or as compiled code. In the latter case, R is used as a tool to trigger the integration and post-process the results, which facilitates model development and application, whilst the compiled code significantly increases simulation speed. The methods implemented are efficient, robust, and well documented public-domain Fortran routines. They include four integrators from the ODEPACK package (LSODE, LSODES, LSODA, LSODAR), DVODE and DASPK2.0. In addition, a suite of Runge-Kutta integrators and special-purpose solvers to efficiently integrate 1-, 2- and 3-dimensional partial differential equations are available. The routines solve both stiff and non-stiff systems, and include many options, e.g., to deal in an efficient way with the sparsity of the Jacobian matrix, or finding the root of equations. In this article, our objectives are threefold: (1) to demonstrate the potential of using R for dynamic modeling, (2) to highlight typical uses of the different methods implemented and (3) to compare the performance of models specified in R code and in compiled code for a number of test cases. These comparisons demonstrate that, if the use of loops is avoided, R code can efficiently integrate problems comprising several thousands of state variables. Nevertheless, the same problem may be solved from 2 to more than 50 times faster by using compiled code compared to an implementation using only R code. Still, amongst the benefits of R are a more flexible and interactive implementation, better readability of the code, and access to R’s high-level procedures. deSolve is the successor of package odesolve which will be deprecated in the future; it is free software and distributed under the GNU General Public License, as part of the R software project.

1,264 citations

Journal ArticleDOI
TL;DR: There is a feeling among many limnologists and environmental engineers who study lakes that marine ecosystems also probably are phosphorus limited, and environmental management agencies often assume that phosphorus limitation in marine ecosystems is the rule.
Abstract: The question of nutrient limitation of primary production in estuaries and other marine ecosystems has engendered a great deal of debate. Although nitrogen is often named as the primary limiting nutrient in seawater (3, 17-19, 50, 52, 55, 61, 76, 80), this is by no means universally accepted. Many workers have argued that phosphorus is limiting (58, 71), that both nitrogen and phosphorus can simultaneously be limiting (9), or that primary production can switch seasonally from being nitrogen-limited to phosphorus-limited (6, 46). Others argue that nutrients are not limiting at all in many marine ecosystems, including highly oligotrophic waters (15). To some extent these disagreements result from poor communication due to different definitions of nutrient limitation. Considerable argument also occurs over the various methods and approaches used to estimate nutrient limitation. Limnologists in particular have tended to be critical of the methods often used to study nutrient limitation in marine ecosystems (23). Nutrient limitation in lakes has historically received more study than that in estuaries, and most mesotrophic and eutrophic north-temperate lakes are phosphorus limited (8, 62, 63, 66, 81). Thus, there is a feeling among many limnologists and environmental engineers who study lakes that marine ecosystems also probably are phosphorus limited. Lacking strong mechanistic arguments to explain why nutrient limitation might be different in estuaries than in lakes, environmental management agencies often assume that phosphorus limitation in marine ecosystems is the rule.

988 citations

Book
28 Mar 2000
TL;DR: A comparison of species and living together and the effects of non-essential compounds and multivariate DEB models shows the need to consider the role of language in the acquisition and use of energy.
Abstract: The Dynamic Energy Budget theory unifies the commonalties between organisms, as prescribed by the implications of energetics, and links different levels of biological organisation (cells, organisms and populations). The theory presents simple mechanistic rules that describe the uptake and use of energy and nutrients and the consequences for physiological organization throughout an organism's life cycle. All living organisms are covered in a single quantitative framework, the predictions of which are tested against a variety of experimental results at a range of levels of organisation. The theory explains many general observations, such as the body size scaling relationships of certain physiological traits, and provides a theoretical underpinning to the method of indirect calorimetry. In each case, the theory is developed in elementary mathematical terms, but a more detailed discussion of the methodological aspects of mathematical modelling is also included.

985 citations


"Integrated multi-trophic aquacultur..." refers methods in this paper

  • ...250 251 2.2.4 Individual bioenergetic model and population model for the sea cucumber 252 The ecophysiology of sea cucumbers was simulated from seeding to harvest at a daily time step with the Dynamic 253 Energy Budget (DEB) model (Kooijman, 2000)....

    [...]

Frequently Asked Questions (1)
Q1. What are the contributions in "Integrated multi-trophic aquaculture of red drum (sciaenops ocellatus) and sea cucumber (holothuria scabra): assessing bioremediation and life-cycle impacts" ?

In this paper, the authors evaluated the environmental sustainability of aquaculture using a holistic and multi-scale framework, where organisms of different trophic levels are co-cultured on the same farm.