Impacts of milkfish (Chanos chanos) aquaculture on carbon and nutrient fluxes in the Bolinao area, Philippines

Marianne Holmer*, Núria Marbá, Jorge Terrados, Carlos Duarte, Mike D. Fortes

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

87 Scopus citations

Abstract

Sediment oxygen consumption, TCO2 production and nutrient fluxes across the sediment-water interface were measured in sediments within and along a transect from four fish pens with production of milkfish (Chanos chanos) in the Bolinao area, The Philippines. The four fish pens were each representing a specific period in the production cycling. There was a positive linear relationship between the rates of sedimentation inside the fish pens and the sediment oxygen consumption indicating that the benthic processes were controlled by the input of organic matter from fish production. The nutrient fluxes were generally higher inside the fish pens, and nitrate was taken up (1.7-5.8 mmolm-2d-1) whereas ammonium (1-22 mmolm-2d-1) and phosphate (0.2-4.7 mmolm-2d-1) were released from the sediments. The sediments were enriched in organic matter with up to a factor 4 compared to outside. A mass balance for one crop of milkfish was constructed based on production data and on measured fluxes of nutrients in the fish pens to assess the loss of carbon and nutrients to the environment. There was a loss to the surroundings of carbon and nitrogen of 51-68% of the total input, whereas phosphorus was buried in the sediments inside the fish pens which acted as net sinks of phosphorus. The results obtained suggest that fish pen culture as practiced in the Bolinao area, leads to even greater impacts on benthic carbon and nutrient cycling than those found in suspended cage cultures.

Original languageEnglish (US)
Pages (from-to)685-696
Number of pages12
JournalMarine Pollution Bulletin
Volume44
Issue number7
DOIs
StatePublished - Jul 24 2002

Keywords

  • Carbon and nutrient cycling
  • Fish farming
  • Mass balances
  • Milkfish
  • Sediment

ASJC Scopus subject areas

  • Oceanography
  • Aquatic Science
  • Pollution

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