Fish 1 Flashcards
global consumption per person
~ 20 kg and rising, so is the population
World capture fisheries yield how much Fish farming (aquaculture) produces how much
~ 90 million tonnes
over 60mt per yr
Aquaculture has grown
8.2% per yr
production decrease between 2000-10
Types of fish
Fresh water- trout, freshwater eel, carp and tilapia
Seawater, pelagic (swim near surface, oily fish, fat store in muscle) - herring, mackerel, sprat & sardine
Seawater, demersal (swim close to sed bad, lean fish, fat store in liver) - cod, haddock, halibut, plaice
Shell fish & molluscs- squid, octopus, mussels
Crustacea - prawn, crab, lobster, scampi
[store little oil]
Fish muscle is made up of
short segments of fibres
muscle does not need to be tenderised, because of its structure
World fishery production
- food fish supply per person
- aquaculture
- capture for human consumption
- non- food use
(all increased since 1950)
biggest producer of farmed fish and crustacea
Asia, especially China
which fish produced in greatest quantity and where
how much
Freshwater herbivorous/omnivorous fish (plant eating/ mix eating)
- in Asia: carp and tilapia 25mt/ yr
which fish produced in 2nd greatest quantity
Carnivorous fish e.g. salmonids (salmon and trout)
(eat meat) and most expensive
How much marine fish & crustacea production
around 5mt/ year
Europe production
many species include salmonids, carp, seabass, sea bream, cod, flounder, turbot, halibut
How much shrimp production is in warm waters of Asia and S. America
~ 4mt
Fish production forcast by 2016
Aquaculture surpasses capture for human consumption
Aquaculture production by region
- Asia (increasing)
- EU (decreasing) & America (remain)
- Africa (increasing)
Fishery production per fisher/fish farmer by region in 2010
- EU (total) (highest for capture)
- N. America (highest for aquaculture)
- S. America
- Africa
- Asia
World has more aquaculture than capture)
Salmonid production
- norway (increasing greatly)
- Chile (decreasing)
- UK (increasing slightly)
- Canada (remain)
World (increasing)
Aquaculture production in EU
- Salmonid
- Carp
- Cod, haddock, hake
4, Catfish
EU consumption perferrence if given chance
carnivorous fish species:
- salmonids
- sea bass
- sea bream
- cod
- turbot
- halibut.
Salmon production in UK
160k T per yr - in Scotland-mainly, some W. coast and islands
Trout (fresh water) production in UK
throughout UK (7k T)
Shellfish production in UK
farmed (27k T)
include mussels, oysters, scallops and clams. Production areas include South West and N. Wales coasts and Thames Estuary,W coast Scotland and N Ireland
UK production global ranking
20th
Salmon Farming
- Salmon are anadromous
- spawning, hatching, and first feeding in freshwater, then migrate to sea water
At 1yr become smolts-live in sea water
In wild migrate to sea; return to river spawn
Smolts transferred to sea okay into floating sea cages, usually in spring
Farmed salmon smolts at 1yr weigh
20-25g
Carnivorous Fish And Crustacea are cold-blooded
poikilothermic
the metabolism increases with water temperature
Carnivorous Fish And Crustacea energy comes
primarily from fat (up to 40% in feed) and protein
crustacea which cannot utilise high levels- have 5% to 7% in feed
Carnivorous fish and crustacea have high/ low protein requirement in diet?
high protein requirement
~ half of energy intake should be in form of protein, compare to 25% in chicken
Can carnivorous fish and crustacea use up carbohydrate?
- very poorly; can only use starch to any degree
- carnivorous species cannot use structural carbohydrate in general
Feed is reflects on
- composition of fin- body lipid in fish
- in demersal fish, lipid reflects on liver storage, where retain Omega 3
- muscles doesn’t reflect
Composition of salmon feed
high protein (30% ) and fat (30- 35% ) content
- Protein from fish meal (15-35%); and vegetable proteins e.g. soybean meal , wheat and maize glutens ( > 50% )
- Fats from fish oil (15- 35%), some from vegetable oil: rapeseed and soya
- starch from small amount of cereal
How does fish pellets produced?
Extrusion (heat, steam & pressure) to gelatinize starch, to give a porous structure to absorb oil and trap air so the pellet will sink in sea water
Retained (%) Energy and Protein from Feed to Edible Food
Salmon Energy % 27 protein% 30
Chicken Energy % 12 protein% 18
Pork Energy % 16 protein% 13