Micro particles and microbial activity in Danish recirculating rainbow trout (Oncorhynchus mykiss) farms

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Increasing intensities of water reuse in recirculating aquaculture systems (RAS) lead to a build-up of micro particles (< 20 μm) in the water. This build-up may have consequences for other water quality parameters and for the fish. This baseline study was carried out to determine the variation in micro particle levels (numbers, volume and surface area) and accompanying bacterial activity in commercially operated outdoor RAS, as well as the effects of different components in the recirculation loop on micro particle dynamics. Water samples were obtained during spring 2017 from 7 Danish Model Trout Farms (MTFs) producing rainbow trout (Oncorhynchus mykiss) in a total of 20 separate RAS units. Micro particle numbers and size distribution, bacterial activity, and inorganic and organic nutrient concentrations were analysed. Micro particle numbers ranged between 6.0·104 – 7.4·105 ml−1 and large variations were found between seemingly similarly operated RAS units within the same farm. There was a strong, positive correlation (p < 0.001) between micro particle levels and bacterial activity in the systems. Although not significant, biofilters generally seemed to trap particles whereas drum filters seemed to reduce particle volume while increasing particle numbers and surface area. The study sustains that bacterial activity in RAS is strongly associated with fine particle loading, and demonstrates for the first time the overall magnitude and level of variation in particle levels and bacterial activity that exists in commercially operated MTFs.
Original languageEnglish
JournalAquacultural Engineering
Volume84
Pages (from-to)60-66
ISSN0144-8609
DOIs
Publication statusPublished - 2019

Keywords

  • Micro particles
  • Bacterial activity
  • Recirculation aquaculture systems
  • Model trout farms
  • Water quality

Cite this

@article{741862e251a74f0494c57d5e7592f1b2,
title = "Micro particles and microbial activity in Danish recirculating rainbow trout (Oncorhynchus mykiss) farms",
abstract = "Increasing intensities of water reuse in recirculating aquaculture systems (RAS) lead to a build-up of micro particles (< 20 μm) in the water. This build-up may have consequences for other water quality parameters and for the fish. This baseline study was carried out to determine the variation in micro particle levels (numbers, volume and surface area) and accompanying bacterial activity in commercially operated outdoor RAS, as well as the effects of different components in the recirculation loop on micro particle dynamics. Water samples were obtained during spring 2017 from 7 Danish Model Trout Farms (MTFs) producing rainbow trout (Oncorhynchus mykiss) in a total of 20 separate RAS units. Micro particle numbers and size distribution, bacterial activity, and inorganic and organic nutrient concentrations were analysed. Micro particle numbers ranged between 6.0·104 – 7.4·105 ml−1 and large variations were found between seemingly similarly operated RAS units within the same farm. There was a strong, positive correlation (p < 0.001) between micro particle levels and bacterial activity in the systems. Although not significant, biofilters generally seemed to trap particles whereas drum filters seemed to reduce particle volume while increasing particle numbers and surface area. The study sustains that bacterial activity in RAS is strongly associated with fine particle loading, and demonstrates for the first time the overall magnitude and level of variation in particle levels and bacterial activity that exists in commercially operated MTFs.",
keywords = "Micro particles, Bacterial activity, Recirculation aquaculture systems, Model trout farms, Water quality",
author = "{de Jesus Gregersen}, {Kim Jo{\~a}o} and Pedersen, {Per Bovbjerg} and Lars-Flemming Pedersen and Johanne Dalsgaard",
year = "2019",
doi = "10.1016/j.aquaeng.2018.12.001",
language = "English",
volume = "84",
pages = "60--66",
journal = "Aquacultural Engineering",
issn = "0144-8609",
publisher = "Elsevier",

}

TY - JOUR

T1 - Micro particles and microbial activity in Danish recirculating rainbow trout (Oncorhynchus mykiss) farms

AU - de Jesus Gregersen, Kim João

AU - Pedersen, Per Bovbjerg

AU - Pedersen, Lars-Flemming

AU - Dalsgaard, Johanne

PY - 2019

Y1 - 2019

N2 - Increasing intensities of water reuse in recirculating aquaculture systems (RAS) lead to a build-up of micro particles (< 20 μm) in the water. This build-up may have consequences for other water quality parameters and for the fish. This baseline study was carried out to determine the variation in micro particle levels (numbers, volume and surface area) and accompanying bacterial activity in commercially operated outdoor RAS, as well as the effects of different components in the recirculation loop on micro particle dynamics. Water samples were obtained during spring 2017 from 7 Danish Model Trout Farms (MTFs) producing rainbow trout (Oncorhynchus mykiss) in a total of 20 separate RAS units. Micro particle numbers and size distribution, bacterial activity, and inorganic and organic nutrient concentrations were analysed. Micro particle numbers ranged between 6.0·104 – 7.4·105 ml−1 and large variations were found between seemingly similarly operated RAS units within the same farm. There was a strong, positive correlation (p < 0.001) between micro particle levels and bacterial activity in the systems. Although not significant, biofilters generally seemed to trap particles whereas drum filters seemed to reduce particle volume while increasing particle numbers and surface area. The study sustains that bacterial activity in RAS is strongly associated with fine particle loading, and demonstrates for the first time the overall magnitude and level of variation in particle levels and bacterial activity that exists in commercially operated MTFs.

AB - Increasing intensities of water reuse in recirculating aquaculture systems (RAS) lead to a build-up of micro particles (< 20 μm) in the water. This build-up may have consequences for other water quality parameters and for the fish. This baseline study was carried out to determine the variation in micro particle levels (numbers, volume and surface area) and accompanying bacterial activity in commercially operated outdoor RAS, as well as the effects of different components in the recirculation loop on micro particle dynamics. Water samples were obtained during spring 2017 from 7 Danish Model Trout Farms (MTFs) producing rainbow trout (Oncorhynchus mykiss) in a total of 20 separate RAS units. Micro particle numbers and size distribution, bacterial activity, and inorganic and organic nutrient concentrations were analysed. Micro particle numbers ranged between 6.0·104 – 7.4·105 ml−1 and large variations were found between seemingly similarly operated RAS units within the same farm. There was a strong, positive correlation (p < 0.001) between micro particle levels and bacterial activity in the systems. Although not significant, biofilters generally seemed to trap particles whereas drum filters seemed to reduce particle volume while increasing particle numbers and surface area. The study sustains that bacterial activity in RAS is strongly associated with fine particle loading, and demonstrates for the first time the overall magnitude and level of variation in particle levels and bacterial activity that exists in commercially operated MTFs.

KW - Micro particles

KW - Bacterial activity

KW - Recirculation aquaculture systems

KW - Model trout farms

KW - Water quality

U2 - 10.1016/j.aquaeng.2018.12.001

DO - 10.1016/j.aquaeng.2018.12.001

M3 - Journal article

VL - 84

SP - 60

EP - 66

JO - Aquacultural Engineering

JF - Aquacultural Engineering

SN - 0144-8609

ER -