Changes in microbial water quality in RAS following altered feed loading

Paula Andrea Rojas-Tirado, Per Bovbjerg Pedersen, Olav Vadstein, Lars-Flemming Pedersen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Intensive recirculating aquaculture systems (RAS) with its hyper-eutrophic water offer ideal conditions for bacterial growth, abundance and activity, potentially affecting fish and system performance. Feed composition and feed loading in particular will have significant impact on organic and inorganic nutrients available for microbial growth in RAS. How these nutrient inputs affect and regulate bacteria in RAS water is, however, unclear. To investigate this relationship and the associated water quality dynamics, the effects of altered feed loading on microbial water quality in RAS was studied. The study included six independent, identical pilot-scale RAS, each with a total volume of 1.7 m3 (make-up water: 80 L/day) stocked with juvenile rainbow trout (Oncorhynchus mykiss). All systems had been operating with constant and identical feed loading of 3.13 kg feed/m3 make-up water for a period of three months before the experiment was initiated. Three controlled levels of feed loading where established in duplicates: no feed (0 kg feed/m3), unchanged feeding (3.13 kg feed/m3), and doubled feeding (6.25 kg feed/m3). The experimental period was seven weeks, where microbial and chemical water quality was monitored weekly. Bacterial activity was measured using Bactiquant®, and microbial hydrogen peroxide degradation. Bacterial abundance was quantified by flow cytometry, and water quality parameters by standardized methods The study showed that water quality as well as bacterial activity and abundance were affected by the changes in feed loading. The microbial water quality parameters, however, did not respond to feed loading changes as quickly and straightforward as the physicochemical parameters such as nitrate, chemical oxygen demand and biological oxygen demand. It was presumed that the fixed bed biofilter suppressed microbial response in the water phase. Hydrogen peroxide degradation assay proved to have considerable potential for assessing overall bacterial load in RAS water although further adjustments and standardization procedures are required.
Original languageEnglish
JournalAquacultural Engineering
Volume81
Pages (from-to)80-88
ISSN0144-8609
DOIs
Publication statusPublished - 2018

Keywords

  • Water Analysis
  • Geochemistry
  • Materials Handling Methods
  • Chemical Reactions
  • Chemical Products Generally
  • Inorganic Compounds
  • Agricultural Methods
  • Bacterial abundance
  • Bacterial activity
  • Feed loading
  • Microbial water quality
  • Monitoring
  • Recirculating aquaculture system (RAS)
  • Aquaculture
  • Bacteria
  • Biochemical oxygen demand
  • Hydrochemistry
  • Hydrogen peroxide
  • Nutrients
  • Oxidation
  • Oxygen
  • Peroxides
  • Water quality
  • Recirculating aquaculture system
  • Loading

Cite this

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title = "Changes in microbial water quality in RAS following altered feed loading",
abstract = "Intensive recirculating aquaculture systems (RAS) with its hyper-eutrophic water offer ideal conditions for bacterial growth, abundance and activity, potentially affecting fish and system performance. Feed composition and feed loading in particular will have significant impact on organic and inorganic nutrients available for microbial growth in RAS. How these nutrient inputs affect and regulate bacteria in RAS water is, however, unclear. To investigate this relationship and the associated water quality dynamics, the effects of altered feed loading on microbial water quality in RAS was studied. The study included six independent, identical pilot-scale RAS, each with a total volume of 1.7 m3 (make-up water: 80 L/day) stocked with juvenile rainbow trout (Oncorhynchus mykiss). All systems had been operating with constant and identical feed loading of 3.13 kg feed/m3 make-up water for a period of three months before the experiment was initiated. Three controlled levels of feed loading where established in duplicates: no feed (0 kg feed/m3), unchanged feeding (3.13 kg feed/m3), and doubled feeding (6.25 kg feed/m3). The experimental period was seven weeks, where microbial and chemical water quality was monitored weekly. Bacterial activity was measured using Bactiquant{\circledR}, and microbial hydrogen peroxide degradation. Bacterial abundance was quantified by flow cytometry, and water quality parameters by standardized methods The study showed that water quality as well as bacterial activity and abundance were affected by the changes in feed loading. The microbial water quality parameters, however, did not respond to feed loading changes as quickly and straightforward as the physicochemical parameters such as nitrate, chemical oxygen demand and biological oxygen demand. It was presumed that the fixed bed biofilter suppressed microbial response in the water phase. Hydrogen peroxide degradation assay proved to have considerable potential for assessing overall bacterial load in RAS water although further adjustments and standardization procedures are required.",
keywords = "Water Analysis, Geochemistry, Materials Handling Methods, Chemical Reactions, Chemical Products Generally, Inorganic Compounds, Agricultural Methods, Bacterial abundance, Bacterial activity, Feed loading, Microbial water quality, Monitoring, Recirculating aquaculture system (RAS), Aquaculture, Bacteria, Biochemical oxygen demand, Hydrochemistry, Hydrogen peroxide, Nutrients, Oxidation, Oxygen, Peroxides, Water quality, Recirculating aquaculture system, Loading",
author = "Rojas-Tirado, {Paula Andrea} and Pedersen, {Per Bovbjerg} and Olav Vadstein and Lars-Flemming Pedersen",
year = "2018",
doi = "10.1016/j.aquaeng.2018.03.002",
language = "English",
volume = "81",
pages = "80--88",
journal = "Aquacultural Engineering",
issn = "0144-8609",
publisher = "Elsevier",

}

Changes in microbial water quality in RAS following altered feed loading. / Rojas-Tirado, Paula Andrea; Pedersen, Per Bovbjerg; Vadstein, Olav; Pedersen, Lars-Flemming.

In: Aquacultural Engineering, Vol. 81, 2018, p. 80-88.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Changes in microbial water quality in RAS following altered feed loading

AU - Rojas-Tirado, Paula Andrea

AU - Pedersen, Per Bovbjerg

AU - Vadstein, Olav

AU - Pedersen, Lars-Flemming

PY - 2018

Y1 - 2018

N2 - Intensive recirculating aquaculture systems (RAS) with its hyper-eutrophic water offer ideal conditions for bacterial growth, abundance and activity, potentially affecting fish and system performance. Feed composition and feed loading in particular will have significant impact on organic and inorganic nutrients available for microbial growth in RAS. How these nutrient inputs affect and regulate bacteria in RAS water is, however, unclear. To investigate this relationship and the associated water quality dynamics, the effects of altered feed loading on microbial water quality in RAS was studied. The study included six independent, identical pilot-scale RAS, each with a total volume of 1.7 m3 (make-up water: 80 L/day) stocked with juvenile rainbow trout (Oncorhynchus mykiss). All systems had been operating with constant and identical feed loading of 3.13 kg feed/m3 make-up water for a period of three months before the experiment was initiated. Three controlled levels of feed loading where established in duplicates: no feed (0 kg feed/m3), unchanged feeding (3.13 kg feed/m3), and doubled feeding (6.25 kg feed/m3). The experimental period was seven weeks, where microbial and chemical water quality was monitored weekly. Bacterial activity was measured using Bactiquant®, and microbial hydrogen peroxide degradation. Bacterial abundance was quantified by flow cytometry, and water quality parameters by standardized methods The study showed that water quality as well as bacterial activity and abundance were affected by the changes in feed loading. The microbial water quality parameters, however, did not respond to feed loading changes as quickly and straightforward as the physicochemical parameters such as nitrate, chemical oxygen demand and biological oxygen demand. It was presumed that the fixed bed biofilter suppressed microbial response in the water phase. Hydrogen peroxide degradation assay proved to have considerable potential for assessing overall bacterial load in RAS water although further adjustments and standardization procedures are required.

AB - Intensive recirculating aquaculture systems (RAS) with its hyper-eutrophic water offer ideal conditions for bacterial growth, abundance and activity, potentially affecting fish and system performance. Feed composition and feed loading in particular will have significant impact on organic and inorganic nutrients available for microbial growth in RAS. How these nutrient inputs affect and regulate bacteria in RAS water is, however, unclear. To investigate this relationship and the associated water quality dynamics, the effects of altered feed loading on microbial water quality in RAS was studied. The study included six independent, identical pilot-scale RAS, each with a total volume of 1.7 m3 (make-up water: 80 L/day) stocked with juvenile rainbow trout (Oncorhynchus mykiss). All systems had been operating with constant and identical feed loading of 3.13 kg feed/m3 make-up water for a period of three months before the experiment was initiated. Three controlled levels of feed loading where established in duplicates: no feed (0 kg feed/m3), unchanged feeding (3.13 kg feed/m3), and doubled feeding (6.25 kg feed/m3). The experimental period was seven weeks, where microbial and chemical water quality was monitored weekly. Bacterial activity was measured using Bactiquant®, and microbial hydrogen peroxide degradation. Bacterial abundance was quantified by flow cytometry, and water quality parameters by standardized methods The study showed that water quality as well as bacterial activity and abundance were affected by the changes in feed loading. The microbial water quality parameters, however, did not respond to feed loading changes as quickly and straightforward as the physicochemical parameters such as nitrate, chemical oxygen demand and biological oxygen demand. It was presumed that the fixed bed biofilter suppressed microbial response in the water phase. Hydrogen peroxide degradation assay proved to have considerable potential for assessing overall bacterial load in RAS water although further adjustments and standardization procedures are required.

KW - Water Analysis

KW - Geochemistry

KW - Materials Handling Methods

KW - Chemical Reactions

KW - Chemical Products Generally

KW - Inorganic Compounds

KW - Agricultural Methods

KW - Bacterial abundance

KW - Bacterial activity

KW - Feed loading

KW - Microbial water quality

KW - Monitoring

KW - Recirculating aquaculture system (RAS)

KW - Aquaculture

KW - Bacteria

KW - Biochemical oxygen demand

KW - Hydrochemistry

KW - Hydrogen peroxide

KW - Nutrients

KW - Oxidation

KW - Oxygen

KW - Peroxides

KW - Water quality

KW - Recirculating aquaculture system

KW - Loading

U2 - 10.1016/j.aquaeng.2018.03.002

DO - 10.1016/j.aquaeng.2018.03.002

M3 - Journal article

VL - 81

SP - 80

EP - 88

JO - Aquacultural Engineering

JF - Aquacultural Engineering

SN - 0144-8609

ER -