Filleting of fish
(filletering af fisk)

Denmark, Africa and USA

Fish for human consumption are often filleted and frozen before transfer to the market.

Process description

The present data refer to filleting of white fish such as codfish and flatfish and oily fish such as herring and mackerel. The main processes are following: 1) pre-treatment (removal of ice, washing and eventually deheading, gutting and cutting of tails), 2) filleting at mechanical filleting machines, 3) eventually removal of skin, 4) trimming (removal of bones and defects, cutting into appropriate pieces), 5) packing, freezing and storage. Wastewater generated in Danish factories is usually treated in municipal wastewater treatment plants. Fish waste is usually converted into fish meal.

Data collection and treatment

Data have been collected from Danish plants and from a few African and American plants in 1990-95 by Jespersen et al. (2001).

Technical scope

Main processes at the factories are included. Packaging is not included.


The figures vary considerably from factory to factory, from fish specie to fish specie and even from fish to fish and the present data should only be seen as an order of magnitude.


Data presented here do not match very well with data presented by Ziegler (2000). Different system boundaries and different processes can possibly explain differences.

Inputs and outputs

Inputs and outputs associated with white and oily fish filleting are shown in the table below. Data are provided per ton of fish entering the filleting factory.

    Unit Quantity
      White fish Oily fish
Inputs Fish ton 1 1
  Electricity kWh 76  75
  Water m3 8  6.5
Outputs Filleted and frozen fish kg 450 500 
  Fish cut off and guts kg 565  425
  Emissions to wastewater treatment plant      
  BOD kg 35  50
  COD kg 50  85
  N-Compounds kg 0 2.5
  P-Compounds kg 0 0.2

Location in database: Processing/Food Processing/Filleting of fish...


Jespersen C, Christiansen K and Hummelmose B (2001). Cleaner Production Assessment in Fish Processing. United Nations Environment Programm; Division of Technology, Industry and Economics. Agri-food forum.

Ziegler, F (2002). Environmental assessment of a Swedish, frozen cod product with a life cycle perspective. A data report. SIK - Institutet för Livsmidel och bioteknik. SIK report no. 696.

Administrative information

Data URL:
Version no.: 1.00
Authors: Per H. Nielsen, 2.-0 LCA Consultants
Data entry: Data have been entered in this format by Per H. Nielsen.

Data completed: July 2003.