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Monday, September 2, 2013

Fish holds in Trawlers - loading ice....

To non-Mariners, there are lot of things incomprehensible.  The Marine connotation here has nothing to do with Insurance but a reference to person who sails, navigates in water-borne vessels – be it a ship or some smaller vessel. A learned person once told me that me there are many similarities of a ship and hence lot can be understood by knowing about Fishing trawler.

For many of us who have not seen ship in close quarters, the fishing boats offer a good chance.. the trawlers are commonly seen in most coastal areas. They are fishing vessels – slightly bigger boats used to catch fish in sea, or even in lakes and rivers.  Depending on the purpose, the length of voyage and other factors, the vessels vary in size and in their power and capacity.  There appears not much of standardization of fishing boats.. there are some which go for fishing and return in hours, some go early in the morning andreturn mid-day or evening; then there are others which go for 3 / 5 / 7 or more days of voyage.  Smaller boats are made up of fibre glass; bigger ones or are wood and steel too.  Have seen a fishing trawler made of teak wood with aluminum nails…

Trawler gets its name from the way it catches fish ~ it is primarily a dragger – a method of fishing that involves actively dragging or pulling a trawl through the water. Trawl nets are fishing nets that are pulled along the bottom of the sea. There are many variants of trawling gear. Then there is the otter board which keeps the trawl net open ….

In  medium sized and bigger trawlers – there are containers called fish-holds - constructed from a variety of materials from simple baskets of woven reeds, bamboo, cane or grasses, to containers made from wood, metals and plastics. These containers or fish-holds help in preserving the catch of fish and for keeping them for longer periods, ice is kept inside the fish-holds. To prevent faster melting of ice, the fishholds are insulated.  This helps the fishermen in keeping the fish fresh and increasing its saleability.

Everytime fishermen embark on a voyage, they carry provisions, which include the ice that is kept in the fish-hold, rations for keeping them alive.  The cost of fuel [diesel] and the provisions are often prohibitive; the fishermen borrow at heavy rates or many a times, fishing companies advance them ~ and buy [or take away] the catch at pre-determined rates. 

The main functions of an insulated fish container on board is to make handling easier, reducing the handling frequency of fish, protect the catch from physical damage; maintain its quality, make longer trips and optimize their profits.  In order to have best-quality fish for sale to the consumer, care must be taken to reduce spoilage at all stages. Spoilage begins as soon as the fish dies, so it may begin before the fishermen lift the fishing gear out of the water. The use of ice in itself is no guarantee of a better product unless proper handling procedures are fully implemented before the fish are actually stowed in the hold on ice. So, the time between the capture or death of the fish to when they are properly iced assume significance. 

Ideally, the ice used must be clean and has to be in small particle size for maximum contact. The fishermen commonly buy huge blocks and then crush them before loading on the boat and then stocking them inside the fishing holds.  They also have to provide some extra layers and reduce chances of heat penetration into the hold, from the engine room, from direct sun heat and the like.   

Block-ice plants are commonly found nearer fishing harbours… still they have to be crushed to make full use of its cooling power. So ice from factories gets transported in vans, pulled down, broken down manually, then taken inside the fishing boats to be filled in fish-holds…… all these being manual processes, will take longer time and more importantly, the fishing boat will have to be kept closer to the dock to enable easier operation. 

There would always be more modernization in the form of  ~ subcooled flakes, chilled seawater, usage of compressed air and the like.  Whatever I am trying to describe are simply from what I observed and what I think them to be ~ may be I am far away from the actual position too…. !!

On a visit to Kasimedu Fishing harbour in Chennai which has hundreds of fishing boats observed the following….the bar ice is unloaded from truck using iron claws, it is then crushed / broken – not into smaller particles but generally broken, then put on mechanical hoppers which have many layers – at one point ice is crushed and comes down in hose, which is directed into the fishing hold below the engine room.  Quite interesting and speedy too.  Here are some photos taken by me in Nov 2011

Some fishing trawlers~
iceblock from the truck

Getting crushed into smaller pieces

the hoppers
the entrance to fishing holds
ice flowing through hose pipes.

With regards – S. Sampathkumar.
PS :  Was this interesting or informative ? ~  there sure is an innate contradiction – me writing something on fish and fishing ! 
Written on 10th April 2013 and posted here now....

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