|Infobox on Mackerel|
|Example of Mackerel|
|Origin||see general page Fish|
|Stowage factor (in m3/t)||see general page Fish|
|Humidity / moisture||see general page Fish|
|Ventilation||see general page Fish|
|Risk factors||see general page Fish|
For more information, see Fish.
When conducting a survey on frozen mackerel prior to handling on to vessel, the following should be noted:
- Fish should be a maximum 18 hours old upon freezing and must be frozen down to -18°C and maintained at this temperature or lower.
- When loaded on to vessel, no block to have higher temperature than -18°C.
- Fish is usually 1 to 3 pieces per kg, but sometimes 3 to 5 pieces per kg, depending on specification.
- All cartons should be in top merchantable condition and stowed tightly. Any carton with excessive damage, i.e. if fish can be seen, should be rejected.
The procedure as set out below is suggested:
- One carton to be taken at random every 15 minutes during the entire loading operation, and of the samples two cartons per 100 tonnes put to one side for thawing out purposes. The cartons to be weighed, checked for temperatures and quality of packing.
- Block visually inspected for size and approximate number of fish, and any damage, i.e. split bellies. Broken fish, etc.
- Details of carton, together with the marks, i.e. trawler number and production date, notated and entered into a survey report. The cartons then returned to stow.
- The cartons put to one side for thawing accurately checked for pieces per carton to conform to the number of pieces per kilogram required. Check for quality – the fish should have a blue steel sheen, clear eyes, bright red gills and should have a seaweed smell. The stomach of the fish should have a black lining, if the 18 hour time limit has been exceeded before freezing the gut will break down this lining and the fish begin to decompose.