Fishing Vessels and Equipment
factory ship, also known as a fish processing vessel, is a
large ocean-going vessel with extensive on-board facilities
for processing and freezing caught fish. According to the
FAO, there are about 38,400 vessels greater than 100 tons
in the world's factory fishing fleet.
Contemporary factory ships are automated
and enlarged versions of the earlier whalers and their use
for fishing has grown dramatically. Some factory ships also
function as mother ships.
Contemporary factory ships have their origins
in the early whalers. These vessels sailed into remote waters
and processed the whale oil on board, discarding the carcass.
Later whalers converted the entire whale into usable products.
The efficiency of these ships and the predation they carried
out on whales led to their precipitous decline.
Contemporary factory ships are automated
and enlarged versions of these earlier whalers. Their use
for fishing has grown dramatically. For a while, Russia, Japan
and Korea operated huge fishing fleets centred on factory
ships, though in recent times this use has been declining.
On the other hand, the use of factory ships by the United
States has increased.
Some factory ships can also function as mother
ships. The basic idea of a mother ship is that it can carry
small fishing boats that return to the mother ship with their
catch. But the idea extends to include factory trawlers supporting
a fleet of smaller catching vessels that are not carried on
board. They serve as the main ship in a fleet operating in
waters a great distance from their home ports.
Fish processing ships consist of various
types, including, freezer trawlers, longline factory vessels,
purse seine freezer vessels, stern trawlers and squid jiggers.
Factory stern trawler
factory stern trawler is a large stern trawler which has additional
onboard processing facilities and can stay at sea for days
or weeks at a time. A stern trawler tows a fishing trawl net
and hauls the catch up a stern ramp. These can be either demersal
(weighted bottom trawling); pelagic (mid-water trawling);
or pair trawling, where two vessels about 500 metres apart
together pull one huge net with a mouth circumference of 900
A freezer trawler fully processes the catch
on board to customers’ specifications, into frozen-at-sea
fillet, block or head and gutted form. Factory freezer trawlers
can run to 60 to 70 meters in length and go to sea for six
weeks at a time with a crew of over 35 people. They process
fish into fillets within hours of being caught. Onboard fishmeal
plants process the waste product so everything is utilized.
World's largest freezing trawler
The giant pelagic factory trawler Atlantic Dawn
The world's largest freezing trawler by gross
tonnage is the 144-metre-long Annelies Ilena ex Atlantic Dawn,
presently fishing in the South Pacific. She is able to process
350 tonnes of fish a day, carry 3,000 tons of fuel, and store
7,000 tons of graded and frozen catch. She uses on board forklift
trucks to aid discharging.
Factory bottom longliner
These automated bottom longliners fish using
hooks strung on long lines. The hooks are baited automatically
and the lines are released very fast. Many thousands of hooks
are set each day, the retrieval and setting of these hooks
is a continuous 24 hour a day operation. These ships go to
sea for six weeks at a time. They contain factories for processing
fish into fillets, which are frozen in packs, ready for market,
within hours of being caught. These vessels sometimes also
have fishmeal plants on board.
A purse seiner is a fishing vessel which
uses a traditional method of catching tuna and other school
fish species. A large net is set in a circle around a school
of fish while on the surface. The net is then pursed, closing
the bottom of the net, then pulling up the net until the fish
are caught alongside the vessel. Most of these types of vessels
then transfer the fish into a tank filled with brine (extra
salty refrigerated water). This freezes large amounts of fish
quickly. Trip lengths can vary from 20 to 70 days depending
on the fishing. The fish is held in refrigerated brine tanks
and unloads either directly to the canneries or is trans-shipped
to carrier vessels to freight to the canneries, leaving the
purse seine vessel close to the fishing grounds to continue
fishing. Purse seiners longer than 70 metres are called super
Factory squid jigger
A factory squid jigger is a specialized ship
that uses powerful lights to attract squid and then "jigs"
many thousands of hooked lures from hundreds of separate winches.
These predominantly Japanese and Korean factory vessels and
their crews may fish the oceans continuously for two years,
periodically transferring their catch at the fishing grounds
to larger refrigerated vessels.
Some barges are floating fish processing
factories, which can be towed across navigable waters to receive
catches from commercial fishing vessels. The barges often
contain living quarters for the factory workers.
Commercial fish processing ships can affect
birds, whales, dolphins, turtles and sharks by their broad
reach methods of catching fish.
Purse seine ships, with nets up to two kilometres
in circumference, can encircle whole shoals of pelagic fish,
such as mackerel, herring and tuna.
A major international scientific study released
in November 2006 in the journal Science found that about one-third
of all fishing stocks worldwide have collapsed (with a collapse
being defined as a decline to less than 10% of their maximum
observed abundance), and that if current trends continue all
fish stocks worldwide will collapse within fifty years.
The FAO State of World Fisheries and Aquaculture
2004 report estimates that in 2003, of the main fish stocks
or groups of resources for which assessment information is
available, "approximately one-quarter were overexploited,
depleted or recovering from depletion (16%, 7% and 1% respectively)
and needed rebuilding.
The threat of overfishing is not limited
to the target species only. As trawlers resort to deeper and
deeper waters to fill their nets, they have begun to threaten
delicate deep-sea ecosystems and the fish that inhabit them,
such as the coelacanth. In the May 15, 2003 issue of the journal
Nature, it is estimated that 10% of large predatory fish remain
compared to levels before commercial fishing. Many fisheries
experts, however, consider this claim to be exaggerated with
respect to tuna populations.
From 1950 (18 million tons) to 1969 (56 million
tons) fishfood production grew by about 5% each year; from
1969 onward production has raised 8% annually. It is expected
that this demand will continue to rise, and MariCulture Systems
estimated in 2002 that, by 2010, seafood production would
have to increase by over 15.5 million tonnes to meet the desire
of Earth's growing population. This is likely to further aggravate
the problem of overfishing, unless aquaculture technology
expands to meet the needs of human population.
Overfishing has depleted fish populations
to the point that large scale commercial fishing, on average
around the world, is not economically viable without government
assistance, However EU law prohibits subsidies to fleets of
its member states.