Assessment of the removal efficiency of fish farm effluents by grey mullets: A nutritional approach

Ingrid Lupatsch, Timor Katz, Dror L. Angel

Research output: Contribution to journalArticlepeer-review


A field study was carried out to assess the use of the bottom-feeding grey mullet (Mugil cephalus) within benthic enclosures as a means to reduce the benthic impacts of a net cage fish farm in the Gulf of Aqaba. Red Sea. Five experimental 1-m3 net-cage enclosures were stocked with 12 grey mullets each (fish weights 50, 70 or 144 g). The enclosures had no bottom and the mullets had access to the enclosed organically enriched sediments and to particulate matter (PM) falling from the overlying cages. Sediment traps were used to quantify and qualify the PM falling from the fish farm to the sea floor. Simultaneously, a feeding trial was performed with mullets (50 and 70 g) in experimental tanks. In order to estimate the potential growth rate and to quantify energy and protein requirements, the fish were fed a formulated diet with known composition. After approximately 70 days at sea. mullets in the enclosures had used up all the available food in the sediment and gained up to 0.78 g day-1 fish-1. Applying the values for energy and protein requirements for maintenance and growth derived from the experimental trial, estimates indicated that the grey mullets effectively removed 4.2 g organic carbon, 0.70 g nitrogen and 7.5 mg phosphorus kg-1 mullet m-2 day-1 from the organically enriched sediment. Thus deployment of grey mullets may be an efficient means to improve the quality of sediments below intensive net-cage fish farms.

Original languageEnglish
Pages (from-to)1367-1377
Number of pages11
JournalAquaculture Research
Issue number15
StatePublished - 22 Dec 2003
Externally publishedYes


  • Bioremediation
  • Effluents
  • Enrichment
  • Fish farms
  • Nutritional bioenergetics
  • Organic matter

ASJC Scopus subject areas

  • Aquatic Science


Dive into the research topics of 'Assessment of the removal efficiency of fish farm effluents by grey mullets: A nutritional approach'. Together they form a unique fingerprint.

Cite this