The process of long lining for tuna

Lots of people eat tuna, but few have ever seen how they’re caught out here on the high-seas of the Pacific. We’ve been documenting the process from start to finish, and have the gifs to show it.

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The process of long lining for tuna

Lots of people eat tuna, but few have ever seen how they’re caught out here on the high-seas of the Pacific.  We’ve been documenting the process from start to finish, and have the gifs to show it.

Here’s a diagram of the whole process.

Tuna Long Lining InfographicClick here to enlarge.

This is what’s known in the fishing business as a “long liner”.  It’s the main type of boat targeting Pacific albacore tuna (which usually end up in cans in supermarkets around the world).

Tuna Longliner

Note: These images are not all from the same ship. They’re from several. And most of the images are not at regular speed, because GIFs.

Setting the line (putting it out to catch fish):

This is the main line. It comes off this big spool near the front of the ship…

…and travels through a tube on the roof and down to the back of the ship.

It’s pretty long. Often 100km (60 miles) or longer.

Smashing up the bait fish at the back of the ship. It’s kept frozen until they need it.

One fisherman is constantly putting these bait fish on hooks attached to branch lines. There can be up to 4000 hooks on one main line.

About every five seconds an alarm sounds (“wooop!”). A second fisherman hooks the branch line to the main line and both throw the branch line with baited hook overboard.

About every 2 minutes, 30 seconds another fisherman throws a buoy overboard, attached to the main line.  

The buoys holds the main line at the desired depth. The branch lines hang down from that.

All of this usually takes 5 to 6 hours.

The fishing boat will then drifts for 3-4 hours while the line “soaks”, letting the fish have a chance to bite.  This is also when the crew rests.  Radio buoys help them find the line again later.

Hauling:

Hauling the line back in usually takes another 5 to 6 hours, but can take up to 12 hours when there are rough seas. The line (on these ships) is hauled back in along the side.

Here the line is being pulled in, a fisherman unclips the branch lines before it comes on board, and hands them off.

  Crew coiling the branch lines line neatly, because they’ll be setting it out again almost immediately after hauling is done.

A tuna fish is hooked and pulled onto deck with a pole. On this ship, we watched them haul in for about two hours and only saw five tuna caught (and nothing else).

And is tossed into the freezer…

Some fish will stay in these super cooled freezers for months before reaching land.

Some thoughts after watching all of this

All the ships we visited on this trip were built in the last five years.  Their owners are in a rush to make their money back and what profits they can, while there are still tuna to catch.  That’s why these ships and crew are fishing almost constantly, with little time for rest and or ship maintenance.

The bottom line is that there are too many hooks, too many fishing boats, too many hours spent fishing, too much short term thinking. The reality of it all can be pretty depressing when you think about it.

Here’s a picture of a swooping seabird to help you cope…

You can help get tuna companies push for more fair and sustainable tuna fisheries. Get our tuna shopping guide, let store managers know you’re using it, and talk about tuna (online and with people you know).


Together, we can change the tuna industry for the better.