Effects of elevated pH on marine copepods in mass cultivation systems: practical implications

Benni Winding Hansen, Per Juel Hansen, Torkel Gissel Nielsen, Per Meyer Jepsen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Female tolerance to pH (8.0–9.5) by six marine copepods, Oithona similis, Temora longicornis, Acartia spp., Centropages typicus, Pseudocalanus elongatus and Eurytemora affinis was investigated to identify robust species for live feed production. The species with the most oceanic-neritic distribution, O. similis, exhibited 72 h LC50 at pH 8.39 ± 0.11 (±95% CL) whereas the most estuarine E. affinis had LC50 at pH 9.51 ± 0.04. The rest had LC50 at intermediary pH's. Egg hatching by a selection of species, Acartia spp., C. typicus and E. affinis, was unaffected by pH up to 9.0–9.5. Nauplii from both Acartia spp. and C. typicus had higher mortality at pH 9.5 than at the other pH regimes while E. affinis nauplii were not affected by pH. Wild Acartia spp. and A. tonsa from a culture showed some differences in response although of minor practical importance for aquaculture; both produced no eggs at pH 9.5, A. tonsa exhibited significantly higher egg production at all other pH's than 9.5, both showed egg hatching invariant of pH, but gradually increasing nauplii mortality with pH. We suggest active/passive selection to obtain the most pH robust species able to cope with accidently, but frequently, elevated pH in aquaculture systems.
Original languageEnglish
JournalJournal of Plankton Research
Volume39
Issue number6
Pages (from-to)984-993
ISSN0142-7873
DOIs
Publication statusPublished - 2017

Keywords

  • Copepods
  • Elevated pH
  • Egg production and hatching
  • Adult and nauplii survival
  • Live feed
  • Aquaculture

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