Seine (fishing)
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A seine is a large fishing net that hangs vertically in the water by attaching weights along the bottom edge and floats along the top.
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[edit] Purse Seine
A common type of seine is a purse seine, named such because along the bottom are a number of rings. A rope passes through all the rings, and when pulled, draws the rings close to one another, preventing the fish from "sounding", or swimming down to escape the net. This operation is similar to a traditional style purse, which has a drawstring.
[edit] Purse seine usage in the Alaska salmon fishing industry
[edit] Equipment
A commercial fishing boat, used for purse seining in the Alaskan salmon fishery, will typically be between 40 and 58 feet long. Toward the bow is a cabin, where the skipper and crew live (typically three to six people). The aft third of the boat consists of a flat deck, with a low rail around it. Amidships are hatch covers, which cover the fish hold, a tank where the fish are placed when caught. The stern is a simple flat area that holds the purse seine when it is out of the water. There are several booms, with various types of pulleys, used for working with the seine, and a deck winch for the same purpose.
There is also a skiff, a small boat used for towing. When not in use, the skiff is usually towed behind the fishing boat, though in rough weather a boom can be used to lift it up and set it on the deck. For long trips where rough weather is likely, the seine will be placed into the fish hold as well, to lower the center of gravity of the vessel and make it safer.
The purse seine itself is usually black in color, with colorful "corks" (floats of some sort) strung along the cork line, and lead weights strung along the lead line. The size and attributes of purse seines are regulated by the Alaska Department of Fish and Game, which oversees the industry. A typical length may be 1200 feet long, by 40 feet deep (distance between cork like and lead line). It is stacked on the stern of the fishing boat with the corkline coiled on the port side, and the lead line coiled on the starboard side, with the web taking up the middle. The seine, when piled onboard, is about the size of a large pickup truck. It's very heavy as well.
A set is a single operation of the purse seine, intended to result in a catch of fish.
[edit] Personnel
Different members of the crew have different responsiblities.
- The skipper's job is to hire crew, manage all operation of the equipment, find the fish, direct the operation, find a market, sell the fish, and pay the crew.
- The skiffman has responsibility for the skiff, keeping the fuel tank supplied, maintaining the engine, and driving it around as needed. The skipper may signal the skiffman aboard if help is needed to either pull up the bag of fish or "brail" the fish into the fish hole.
- The deck hands take care of all of the tasks that need to be done on board during a set, such as detaching the skiff at the start of a set, plunging to scare fish away from the boat where they could escape the net, and cleaning the deck of seaweed and bycatch while the net is deployed, stacking the cork line and lead line as the net is being taken back aboard, removing the odd fish that has become entangled in the net, and assisting with brailing (scooping the fish aboard at the end of a set).
[edit] Operation
Step 1: Find the fish
In day-to-day fishing, the skipper consults his log books of past seasons, considers which areas are open, and chooses a place to fish. (In some cases, pilots of small airplanes are hired to find schools of fish for the boats to catch. They will direct the fishing operation from the air.)
There are a couple of ways to fish. One is to search for schools of fish, and catch them in sets of short duration, where you lay the seine out around the fish and close the ends immediately. The other way is to hold hook', which is to lay the seine out in a large hook shape, and let fish swim into it, then close it up after a longer time (maybe an hour or two).
When looking for schools, the skipper and crew will search for fish. They do this by driving slowly around the area, looking for jumping salmon (jumpers) or other signs of fish. Typically, fish will school up near spawning streams. Regulations specify the distance from such streams that fishermen can operate, so timing of the tides are critical, as the fish will often move into legal waters at lower tides.
If the fishermen will be holding hook, they will find an area, such as a cape, where the fish are swimming past in one direction.
Step 2: Make the set
The boat-end of the seine (at the bottom of the pile) ends with a long towing line. This is attached to the deck winch that is used to "purse" the seine. The skiff-end of the seine ends in a much smaller towing line, which is attached to a ring of some kind on the skiff.
The skipper plans the set, and instructs the skiffman as needed. The skiffman waits in the skiff, with the engine running. When the skipper gives the signal, a deck hand activates a quick-release mechanism(pelican hook), releasing the skiff, which immediately turns around and starts towing on his end of the seine. At the same time, the large boat moves away from the skiff. The net starts falling off of the stern of the boat, which drives in such a way as to lay the shape of the set. The skiffman can do some towing, but mostly just holds it in place.
As the net is flying off the stern, the deck hands are on high alert, watching for anything unexpected, such as a loop of rope snagging on the towing cleat, etc.
If there is time, once the net is all in the water, the deck hands clean the back deck, which had been covered by the seine. If holding hook, the skiff and the boat are far away from each other. They can communicate by radio. The deck hands will use the plunger, a long pole with a cup on the end, to scare the fish away from the water near the boat, where they could easily escape by swimming under the boat.
Eventually, the skiff and the boat will draw closer to each other, towing the net, forming a loop around a section of water containing what is hoped to be a lot of salmon. Dependent upon the boat and equipment a set can be done on to both the port and starboard side with the movement of a small amount of rigging. In a right-handed set, the skiff's bow will eventually come near the bow of the boat, as they head toward each other. The skiff passes the boat on their starboard sides.
The set is made once both ends of the net are attached to the boat.
Step 3: Bring in the seine
Next is a critical moment, in which a lot of things have to happen very fast: The skiffman must drive the skiff and at the same time hand off his end of the seine to the deck hands, who will attach it to the starboard side of the boat. Once the handoff is made, the skipper backs off the throttle of the main boat, and runs down to the deck to help with the net. The skiffman must drive his skiff around the stern of the boat (to get out of the inside of the set, passing under the seine's boat-end towline), then attach a towline to the port side of the boat, for purposes of positioning the boat while the seine is being brought aboard. The deck hands begin bringing the seine aboard using the power block, a large hydraulic pulley with a rubber surface. Now there is some time as the skiffman keeps the net in correct position with the boat's stern, by towing on the port side. At the same time, the crew are shrinking the loop by bringing the net aboard, stacking the corks and leads on the stern as it comes down from the power block. The skipper usually plunges, and checks the position of the net, making adjustments to the speed and towing of the skiff (with hand signals) and the speed of the crew bringing in the net. The skipper also handles the pursing, or pulling on the purse line that runs through large rings set evenly across the leadline. The rings are actually attached to long straps, which are attached to the leadline. This draws the bottom of the net together, and eventually all the rings are alongside the boat.
Once the purse line is completely pulled in, and the rings are next to the boat, the skipper will stop the power block, and signal the skiffman to stop towing for a moment. Then the crew will thread all the remaining rings on an iron hook or bar, and lift the whole bottom of the net out of the water. The net is now pursed, and the fish have no more hope of escape, barring a tear in the web or some other equipment failure.
The rest of the net is then brought in quickly. If there are a lot of fish in the net, care must be taken that they don't all go to the same area, sinking the net and escaping. The skiffman will detach from his towing position, and come around to the other side of the boat, where the net is. He will attach the skiff to the corkline opposite the boat, keeping the net afloat once the loop is very small and full of fish.
Step 4: Bring in the catch
The next step is generally considered the most enjoyable by fishermen, as it means the catch was abundant: brailing. If you have too many fish to lift aboard with the net all at once, the skipper hooks up a large dipnet, the brailer, and the fish are scooped out of the net and into the fish hold.
To end it up, the skiff end of the net is released from the boat, the rest of the net (consisting of heavy mesh web, called the moneybag for obvious reasons) is brought aboard, the skiff is attached and winched up, and the whole process is ready to be repeated, until the boat is full or it's time to unload.
Step 5: Unloading
The skipper usually has arranged with a tender to come and pick up his catch (so that the boat can stay in the fishing grounds, rather than travelling to a processing facility). Unloading usually happens at night, when fishing cannot be done any more. The boat and the tender tie up, and the fish is transferred from the fish hold to the tender, which will deliver it to a processor.
