Effects of swimming speed and dissolved oxygen on geosmin depuration from market-size Atlantic salmon Salmo salar

Details

• Journal Title:
  Aquacultural Engineering
• Personal Author:
  Davidson, John ; Summerfelt, Steven ; Grimm, Casey ; Fischer, Gregory ; Good, Christopher
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research)
• Description:
  Common off-flavor compounds, including geosmin (GSM) and 2-methylisoborneol (MIB), bioaccumulate in Atlantic salmon Salmo salar cultured in recirculating aquaculture systems (RAS) resulting in earthy and musty taints that are unacceptable to consumers. To remediate off-flavor from market-ready salmon, RAS facilities generally relocate fish to separate finishing systems where feed is withheld and makeup water with very low to nondetectable GSM and MIB levels is rapidly exchanged, a process known as depuration. Several procedural aspects that affect salmon metabolism and the associated rate of off-flavor elimination, however, have not been fully evaluated. To this end, a study was carried out to assess the effects of swimming speed and dissolved oxygen (DO) concentration on GSM levels in water and fish flesh during a 10-day depuration period. Atlantic salmon (5–8 kg) originally cultured in a semi-commercial-scale RAS (150 m3 tank) were exposed to a concentrated GSM bath before being transferred to 12 replicated partial reuse depuration systems (5.4 m3 total volume). Two swimming speeds (0.3 and 0.6 body lengths/sec) and two DO levels (90% and 100% O2 saturation) were applied using a 2 × 2 factorial design (N = 3), and each system was operated with a 5-h hydraulic retention time, creating a water flushing to biomass ratio of 151 L/kg fish biomass/day. Geosmin was assessed at Days 0, 3, 6, and 10 in system water and salmon flesh. A borderline effect (P = 0.064; 0.068) of swimming speed was measured for water and fish, respectively, at Day 3, where slightly lower GSM was associated with low swimming speed (0.3 body lengths/sec); however, differences were not detected at Days 6 or 10 when salmon are commonly removed for slaughter. Overall, this research indicates that significant improvements in GSM depuration from RAS-produced Atlantic salmon are not expected when purging with swimming speeds and DO concentrations similar to those tested during this trial.
• Keywords:
  Aquatic Science
• Source:
  Aquacultural Engineering, 95, 102201
• DOI:
  https://doi.org/10.1016/j.aquaeng.2021.102201
• ISSN:
  0144-8609
• Format:
  PDF
• Publisher:
  Elsevier BV
• Document Type:
  Journal Article
• Funding:
  Grant no. NA18OAR4170336
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:96fc8e9942e76023128346156394896ea84018226e4adb4004904bf0daceaa74
• Download URL:
  https://repository.library.noaa.gov/view/noaa/59087/noaa_59087_DS1.pdf
• File Type:
  [PDF - 1.21 MB ]