Image: Dave Goad | Creative Commons
Tori line on fishing boat.
Bird scaring lines (tori)
Find out about the seabird safe practice of bird scaring lines. A bird scaring line (BSL) is also called a 'tori line'.

Effect on fish catch

None.

Cost – USD$900

A bird scaring line can be made for around USD$900. This includes a tori pole and bird scaring line materials.

Effectiveness

A bird scaring line can reduce reduce seabird captures by 40% to 80% and scientific proof of this level of effectiveness is high. Effectiveness depends on the types of seabirds in the area, and whether the BSL is designed and used correctly.

How to build a bird scaring line

Tori pole

A tori pole holds the bird scaring line above the baited hooks and prevents tangles with the fishing line.

BSL set up 810.jpg

No tori pole means the bird scaring line will not protect the baited hooks and can tangle with the fishing line.

weak link 390.jpg

Connection of the line to the tori pole. If the bird scaring line tangles with the fishing line, the weak section of rope breaks, and fishing is not interrupted.

Bird scaring line length

The bird scaring line has one section that is in the air (aerial) and the other is in the water (drag). The diagram shows two options for the drag section. For the aerial section, a braided (plaited) line prevents the line twisting.

BSL length 565.jpg

Aerial section

Important measurements for the aerial section of the bird scaring line:

  • height above water
  • distance to the first long streamer, and
  • distance between long and short streamers.

aerial section 565.jpg

Long streamers

Long streamers are flexible, ultra-violet (UV) protected, bright orange tubing. At least nineteen streamers are needed. The streamers reach the water.

long streamers 390.jpg

Flexible tubing is used for long streamers. The long streamers are attached to the line with a double eye swivel so they don’t tangle with the line.

rubber tubing and streamer double eye swivel 810.jpg

Short streamers

Short streamers make the bird scaring line easier for seabirds to see. They can be made of rubber tubing or packing straps.

short streamers 390.jpg

Short streamer made of packing strap.

packing strap close up drag 390.jpg

In water section (drag section)

Two ways to create drag are shown. The first way is to use non-twisting braided rope such as 10 mm polyester or nylon. This type of rope stops the line spinning and tangling the streamers. Attach rubber tubing or plastic straps to the rope.

drag section close up 565.jpg

Plastic straps attached to the drag rope.

packing strap drag 390.jpg

The second way is to use heavy mooring rope to create drag. Cones can be added to add drag as well.

cones drag 390.jpg

Case study

A Fijian women's group has made 62 bird scaring lines for high seas vessels visiting Suva. These are given to vessel captains by BirdLife International’s Port Based Officer.

More about the creation of 62 bird scaring lines story

Download PDF

How to build a scaring line (PDF, 1,600K)

More information

Mitigation practical information on seabird bycatch mitigation measures: Pelagic longline: streamer lines (vessels ≥ 35 m)