Pair trawling is a fishing activity using two boats. Each boat pulls two ropes connected with the large trawl net. The net’s mouth is widely open by a distance between the two boats that are pulling it. Pair trawling has evolved from where were being pulled by a single boat.
Pair trawling is a form of net fishing in which two trawlers each drag a side of a trawling net through the water. The advantage conferred by pair trawling over the normal type is to allow ships with equipment inadequate for single trawling to still engage in the method.
The net’s mouth was small because the two ropes were close to each other as it was being pulled by one boat. The evolution which comes up with two boat help to enlarge the mouth of the net as they pull at a distance between the two, which increase efficiency and catch. The distance between the two boats depends on the depth of the water or the target species.
How does mid-water trawling work?
Mid-water trawling involves a large net dragged by two boats in the mid of the water or on a certain layer of the water. Mid-water trawling is used to catch target species such as squid, shrimp, and pelagic schooling fish. It is mainly carried out in the sea, lake, continental shelf, and deep water. Mid-water trawling is effective when fish are aggregated together in a large number and when fish are distributed within a given water layer.
The most favorable condition of mid-water trawling is when the fish aggregate together in large numbers. When the fish are inactive and there is low water temperature. When fish do not go through rapid depth migration When the light intensity is low, some factors determine the effectiveness of mid-water trawling, which comprises the net shape, thickness of the rope that connects the net with boats, and the towing speed.
When the towing speed is low than the cruising speed of the fish, the efficiency of the fish captured is low compared with when the towing speed is higher than the cruising speed of the fish. The higher speed of towing helps to limit the fish from escaping. However, the speed of the fish depends on the size of the fish and their species.
One of the risks associated with mid-water trawling is that some mammals migrate or swim at the mid-water depth, which is highly likely to be captured by mid-water trawling. Some mammal-like turtles are likely to die if they are held too long in the mid of the water because they breathe when they are on the water surface.
How does a shrimp trawler work?
A shrimp trawler is a type of fishing vessel used to capture shrimp and prawns. Shrimp trawlers work well on a large ocean. Shrimp trawler normally catches shrimps by dragging the trawl net in the water from the fishing boat stern. Once the trawl net is full, it is hauled on board at the fishing boat stern. This trawl net has little catch as it can only grab shrimp in the front of it. Trawlers have side doors that help hold the front of the trawl net open and allow shrimp to enter. Trawl net has a narrow range as it can only catch shrimp that are in front of it.
Due to a competitive market and high profit of shrimp food worldwide, shrimp trawler has been commercialized, which helps to maximize the catch per unit effort. Below are few steps of how one can start shrimping. In the first step, you will need to buy a shrimp boat and a trawl net. Secondly, you will need to get your shrimp license from the authorized body. Third, you will need to learn the policy or regulations that govern shrimp catching. Fourth you will scan the best place for catching shrimp as it will help you catch a large number of shrimp as they move from a large area of water to a smaller area of water. Then start shrimping when water is calm or with low tide. Finally, you will need to stick to the rule.
Why is trawling fishing bad?
Some of the negative effects of trawling comprise; overfishing, by-catch, destabilization of the seafloor, coral damage, and crushing life within the sea bed.
Overfishing is where the volume of the target species captured exceed the required volume in the market. Most of the time, the excess volume ends up dumped, a waste of resources, and environmental destruction.
By-catch is where other species apart from the target species are caught unintentionally. Most of the time, by-catch dies before their released back to the water. Shrimping is the worst type of fishing for by-catch because its small mesh catches small and large species. Most of the time, it catches babies of large species, which end up being a waste. But some fisheries developed a selective trawl net that tries to catch only targeted species.
Destabilization of the seafloor is where the trawl net is pulled along the seafloor. It destabilizes the natural condition in the seafloor, like temperature and current.
Coral damage is the destruction of tropical leaves which grow at the bottom of deep and cold water. These coral leaves are a habitat for the fish and other creatures that live in the water.
Other life lives within the sea bed that is crushed by trawling. Some of these lives include; worms, amphipods, clams, crabs, lobsters, and many more.
How do you fish trawling?
Trawling is a method of fishing where a net bag with a wide-open on the front is dragged through the water by one or two boats to catch the target species. Mostly trawling is used for commercial purposes. There is a various number of step need for an effective fish trawling.
1. You will need to get trawling fishing license from trawling business administrator.
2. Choose the most reliable and appropriate fishing boat or vessel.
3. Learn fishing tips.
4. Search area with the highest number of fish.
5. Setting the trawl net and will depend on the method that one chooses for trawling. For example, if you are using mid trawling, you will need to set a net in the mid of the water and where there is low tide, and most preferably, water is moving from a large body of water to a smaller body of water.
6. The last step is hauling the net when it is full.
Conclusion
Trawling is not the best method of fishing, especially for commercial purposes, because it does not select the targeted species and has a large volume of by-catch. It damages fishery resources like carol leaf and other living creatures, as mentioned above. Also, it harms ecological diversity. For fishery efficiency, we need to have the appropriate tool like the right vessel, selective trawl net, which will only catch the target species and help minimize wastage. Also, there is a need to deploy techniques that will help not to damage fishery resources.
