SDN - Anchor Seine

A net shot in the open sea using very long ropes to lay out the net and ropes on the seabed prior to hauling from a boat at anchor.

More Information

Alternate Names

Danish Seine

Gear Classification
Demersal, Encircling Gear, Herding Gear, Mobile Gear
Similar Gear
Scottish Seine, Beach Seine
Main Target Species (UK)
Cod, Flats, Haddock, Lemon Sole, Plaice, Whiting

Bycatch

Possible Bycatch: Any demersal species, Cod, Flats, Haddock, Immature round fish, Megrims, Monkfish, Plaice

Relevant Selectivity Devices
Square Mesh Panels
Headline Height
Cod-end Mesh Sizes
Diamond Mesh Panels

Environmental Impact

Anchor seine gear is only suitable for fishing on smooth sandy or muddy usually quite mobile sea beds. It cannot be operated on hard rocky sea beds as the gear would get damaged too easily.  The gear consist of a lightly made net usually with only a rope  footrope often called a ‘grass rope’. This  is fixed to the fishing line of the net in bights with two or three lead rings threaded on the bight. The lead rings and bight of soft rope are the only contact with the seabed, the actual net skimming a few inches above the seabed. The light contact of the rope bights on the seabed is enough to  prevent the fish escaping underneath the footrope. The net is towed by long lengths of leaded rope that are laid on the seabed, these are towed over the seabed with a lot of tension in them therefore are very light on the seabed, just scuffing enough to create a light sand cloud to herd the fish into the net. The main seabed impact from anchor seine would be the deployment of the anchor on the seabed.

As the net is never really towed long there is not much energy needed in hauling the gear. The gear can be operated from low lowered vessels with low fuel consumption. Selectivity can by managed by usual means in towed gears such as mesh size and square mesh panels etc.

Further Information

Anchor seine is handled in a similar way to Scottish seine, the main difference being that when the dhan is shot away the vessel also drops a large anchor to which the dhan is attached. They will shoot the ropes and net as in Scottish seine, but when the boat returns to the dhan, the crew pick up the other end of the seine net ropes and lead them to the winch, but they will also moor the boat to the anchor. The seine net ropes and net are now hauled in to the anchored vessel, with the anchor preventing the vessel being hauled astern. Once the gear and catch is on board, the skipper will prepare for the next shot, usually without lifting the anchor. He will shoot the gear in a different direction from the anchor, depending on which way the tide is flowing. If there is a good catch, the skipper will take several hauls from the same anchor point, each one covering a different sector of seabed around the anchor, dictated by the direction of tide as it ebbs and flows. Anchor or Danish seine, as the name suggests, originates from Denmark and is still used by many vessels there to target flatfish. This fishing technique moved over to the English ports of Hull, Grimsby and North Shields, and at one point there would have been several hundred vessels from these ports working the North Sea grounds. Traditionally, these vessels were all being painted in a pale blue colour. Over the years in the UK, this fishing method has all but died away with trawling taking over as the preferred fishing method. Today, there are only a handful of English vessels using anchor seine.

The nets used in both types of seine netting are very similar in design to a trawl net. Usually, they will be of lighter construction, with the physical size of the gear being determined by the size and power of boat operating it. The seine net ropes are made from hard abrasion-resistant rope to stand up to being trailed over the seabed. Each strand of the ropes will have a lead core to give the rope weight to make it sink to the bottom quickly and maintain good contact with the seabed to ensure that it is effective at herding the fish into the net. The length of ropes used can range from 8 to 14 coils on each side of the net. Each coil is 220 metres long (120 fathoms), and are either spliced together or some will be joined with stainless steel split-links enabling them to be disconnected easily to allow different lengths of rope to be shot. Therefore, on each side of the net, there will be anything from 1,700 metres to 3,000 metres of rope enabling the vessel to encircle an area of seabed with the ropes ranging from 600 to 1,000 metres across. Depending on the amount of rope shot, each haul will take between one and a half and three hours to complete. Originally, the ropes were hauled and stored on deck in coils, but nowadays, they are usually stored on large reels in preparation for the next haul. Before the advent of shelter decks and rope reels, the long lengths of rope were shot directly off the deck, often going away in bights and dancing over the deck where the crew were working. This could make seine net a fairly hazardous method of fishing, but with the advent of rope reels and shelter decks, allowing the ropes to be shot and hauled clear of where the crew are working, safety has improved dramatically. Seine netting is a more fuel-efficient method of fishing than trawling because the gear is lighter and it is not being towed by the boat for long periods. Because the fish are only in the actual net for a very short time before the net is hauled and the cod-end emptied, a seine net usually yields a better quality of end product onto the market. Originally, both Danish and Scottish seine nets were seen as methods of fishing on clean, sandy and muddy seabeds. As it has become more mechanised with rope reels, more powerful winches, power blocks, net drums, etc. and improved rope construction combined with state of the art GPS plotters giving accurate positioning, the skippers are tending to work closer to, and actually onto harder seabeds and deeper water in an attempt to both improve catches, and target different species.

The main target species vary for each style of seine net. Anchor seine, traditionally, was a method for targeting flatfish such as plaice, lemon sole, etc. with some haddock and cod on a seasonal basis. Scottish seine, because it is hauled faster, was more efficient for catching haddock, cod and whiting, along with some of the plaice and lemon sole. Both these methods will have some by-catch of other demersal species.
In seine net fishing the fish are slowly herded into the path of the net, swimming ahead of the net until the gear starts to close up as the ropes are hauled in. They only fall back into the net and then into the cod end as the speed of hauling is increased. As the fish are only in the net and cod end for a very short time they are in prime condition when taken on-board the boat. Provided that they are handled well on board the boat seine net fishing will deliver prime quality fish onto the market.

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Media

Two anchor seine vessels in Danish harbour

Anchor seine vessels in a Danish harbour

Rope reels for storing the ropes on a Danish vessel.

Rope reels for storing the ropes on a Danish vessel.

Danish anchor seine vessel showing the rope reels for storing the ropes.

Danish anchor seine vessel showing the rope reels for storing the ropes.