Have you ever had tuna steak in your menu? How would you like it? Prior to cooking in the kitchen and then served, only few people knows the story of the fish. Most tuna we consume in Indonesia come from the southern coast of Java. They are mostly are found at the fish aggregation devices (rumpons) which are installed in the Indian Ocean as far as 180 km from the coast.

Rumpon or FAD usually used in Indonesia. This type is from Jeneponto, South Sulawesi.

Type of Fishes Found in the FAD (Rumpon)

The rumpon (FAD) was deliberately installed to help fishermen catching fishes. First the rumpon will attract small fishes to stay nearby, which in turn will attract bigger fishes and eventually will attract really big fishes such as tuna which could be as big as 70 kg in weight. Tuna at this size will easily sold at one million Rupiah each (more than US$1,000). The fish will then go fish canning factories and could end up in Japan.

Southern coast of Java is the place for tuna fishing. One of the fish unloading site (Tempat Pendaratan Ikan/TPI) here is Sendang Biru in the Southern Malang regency and our team started the survey at this site.

Tuna live in Indian Ocean. Adult tuna prefer tropical ocean temperature of 20-21^o C. Preferred ocean temperature for various type of tuna are as the following:
Blue fin tuna: 14-21^o C
Albacore tuna: 14-23^o C
Big eye tuna: 11-28^o C
Yellow fin tuna: 17-31^o C
(please refer to tuna migration map)

Tuna migration map

At the Indian Ocean there are six types of tuna. Tuna has a very wide migration territory across tropical areas as well as cold-temperate areas during summer. Research has been done by attaching marks on tuna in Florida (United States) which later then known to have crossed the Atlantic and found at Gulf of Biscay. Pacific tuna which were marked around California have been catch in Japanese waters.

1. Thunnus maccoyii (blue fin tuna); Indon, tuna sirip biru
2. Thunnus alalunga (albacore); Indon. albakora
3. Thunnus obesus (big eye tuna); Indon. tuna matabesar
4. Thunnul albacares (yellow fin tuna); Indon. madidihang
5. Thunnus tonggol (long tail tuna); Indon. abu-abu
6. Thunnus thynnus (small eye)

It's not very clear why these tuna have to make such a long journey. Possibly some migrations are needed to complete their nutrient needs or to avoid creating too much damage by overgrazing some territories. As the main tropical fish, tuna will enter cold-temperate region only when the temperature reach 20^o C. At this temperature the cold-temperate region will be rich with nutrients. These fast swimmers take advantage of the nutrient wealth of these territories by just following the temperature.

Swimming layer of tuna based on months of the year.

Around California, raised up cold water brings a lot of food organisms, but tuna will only enter this region when the surface temperature reaches 20-21^o C. In cases of cold years, the surface temperature may never reached the preferred level, and this means that tuna will never migrate to that area.

However, not all tuna restricted only to warm waters. In the Atlantic, blue fin tuna regularly migrate to New Foundland during summer even though the temperature there is still under 20^o C. Tuna always going back to the tropics to breed and their young spend their time in tropical waters. Bigger size tuna live in groups of 20-60 fishes and stay at deeper layer of the ocean. The smaller tuna live nearer to the surface in much bigger groups of 600 to 1000 fishes.

As mentioned above, water temperature very much influence tuna distribution. Other factors include degree of salinity, deep ocean current, season, and availability of nutrients. Temperature does not influence the size of tuna found.

Sailing to High Seas by Only Using Bobbin

Sendang Biru pier. Seen here many sekoci (bobbins).

When you see a bigger ship with 18 meter length, designed flat without cabin for captain or any communication equipment, powered by two outboard motor and one reserve engine, then this the sekoci (bobbin), a vessel for tuna fishing. This bobbin can travel as far as 180 km to the open ocean.

No fishermen will dare to sail if any of the motor is in trouble. Sailing into the Indian Ocean is rough, a challenge to nature. When our team joined them for sailing, we were cautioned by an official of East Java Research Center, suggesting that the kind of vessel we're about to aboard to could be crashed only after six miles to the ocean. Fortunately it didn't happen. Different to other fishing ships, according to the bobbin seamen, this bobbin is actually derived from the phinisi (Bugis cargo boat) and the Bugis has been famous for their seamanship. In fact most of the crew are actually Bugis people and for them 100 miles to the open ocean is not extraordinary.

Even though sekoci can reach the rumpon, unexpected disaster could always happen. To reach a rumpon, a sekoci has too sail continuously for 20 hours day and night. Night time is most risky since logs from illegal logging activities could be the phantom of the sea. It's not uncommon that illegal loggers from Kalimantan unload their logs here to avoid being catch by the custom. These logs are invisible to the fishermen in the deep dark of the night in the middle of the ocean.

In 2005 several bobbins crashed against these logs and since there is no SAR team for these fishermen, they have to save their own life. There is seldom any survivor if accidents happen in the middle of Indian Ocean. Hallucination, no rescues boats, and worse no communication equipments are the main factors. They sail only rely on being dare to sail.

Fishermen are now have more concern on their own safety. They now tend to sail in groups since most accidents happened not because of the unfriendly nature of the ocean itself. Many Sendang Biru fishermen now turn from sekoci to payang boat, a vessel type which consumes a lot of  fuel and can only sail parallel to the coast.

More photos of bobbins and tuna fishing vessel >>

Locating the Rumpon

How could a sekoci can find a rumpon without any navigation system or communication? A sekoci will only have supply for seven days and enough fuel only to sail to the rumpon and sail back home.

With a simple bookkeeping, the fishermen cooperative provide everything needed. All sekoci provided with a GPS (Global Positioning System) device to locate position of a rumpon. In case a sekoci was dragged by water current then the difference won't be more than one circular mile. Rumpons usually visited by these sekoci are very simple type compared to the Japanese ones with their own lightings, radar reflector, and radio buoy.

Stark difference between Indonesian traditional rumpon with Japanese FAD.

A 3000 meter rope tied a rumpon to heavy object at the bottom of the ocean. The rumpon was carried from Sendang Biru to the middle of the ocean. After two weeks this traditional rumpon will be the home of the fishes. A rumpon could be lost due to being dragged by the strong Indian Ocean water current or stucked to the longline of bigger fishing vessels, in which case the rope was usually broken off. Long-line fishing is a commercial fishing technique that uses hundreds or even thousands of baited hooks hanging from a single line.

More than often these bigger fishing vessels also operate nearby the rumpons. These vessels equipped with ocean map and fishing map from satellite. If there are many fish in the rumpons, these are also shown by the satellite fishing map. They would then cracking nearby the rumpons, of which the traditional fishermen would be helpless. Different with their bigger fishing vessel counterpart, the traditional fishermen use pole and line fishing technique (A pole and line consists of a hooked line attached to a pole).

Ice for Preservation

To keep the catch fresh, fishermen need ice. Blocks of ice are first crushed into ice crumbs for storing the catch. Quality of water used for making ice is crucial to the persistence of the ice. Poor water quality would results to ice that more likely to liquefy. The Bugis fishermen usually use tamarind to preserve fishes. A lucrative but illegal short cut is using formaldehyde to preserve the catch. These illegally preserved fishes are usually come from unofficial unloading sites.

Ice for preservation of catch >>

Traditional Vessels and the Way They Operate

There are many kind of traditional Indonesian vessels which many of us not aware of. Each Indonesian territories have their own type of vessels with various sailing capabilities. Phinisi cargo boat is only one of them.

Phinisi ship always travel a long way and we never heard any of them crashed in the ocean. Even smaller Bugis Sandex sampan (small boat) was once used by Japanese explorer around the world. Traveling around the world is not uncommon for the Bugis. Does any of you still remember the Kontiki expedition crossing the Pacific from South America to Hawaii? It might also amuse you to learn that the name of Sasak tribe (in Lombok) is actually derived from the word sesek or bamboo raft. Their ancestors were actually used bamboo raft to sail from Java to Lombok.

Payang boat at Sendang Biru beach.

In the Southern coast of Java there are many types of vessel such as payang boat, sekoci (or bobbin which can reach the outer border of the Indonesian Exclusive Economic Zone), and jukung boat which usually used to catch groupers and shrimps.

There are many 18-meter long payang boat powered by a single outboard motor operate in Sendang Biru utilizing fishing nets. This kind of vessel could conduct 120 fishing trips a year, each trip with variable costs of 33 million Rupiahs and averagely generates 225 million Rupiahs (roughly equivalent to US$3,300 and US$22,500 respectively).

A jukung could conducts 160 trips a year with variable cost of 3.2 million Rupiahs each trip and averagely generates 12.8 million Rupiahs (US$320 and US$1,280 respectively).

The biggest earner are tuna fishing vessels which can conduct 25 trips in year with variable cost of 24.5 million Rupiahs and generates 175 million Rupiahs (US$2,450 and US$17,500 respectively). This would the the lowest estimate and in times a tuna fishing vessel could generate 80% revenue on top of the above mentioned.

The late father Logano inspecting his pursein boat construction.

The smaller ships are built in Java while the medium- and bigger-sized ones are from South Sulawesi (Bugis) or Kalimantan. There are many ship builders in Malang even though there is  no slipway (a ramp on the shore by which ships or boats can be moved to and from the water). The only exception is at the Perigi beach (southeast of Trenggalek, East Java) where the late Father Logano, the only Catholic priest in Indonesia who is also a fisherman himself, have his own slipway. He can build his own vessel which is properly built. His type of vessel is the pursein which sail parallel to the coast.

Indonesian Traditional vessels >>

How to Get to Sendang Biru

When you are in Malang you might want to travel further to the southern coastal area to Pondok Dadap which more popular known as Sendang Biru. While traveling you could buy fresh fishes which is securely consumable. You can amuse yourself by seeing how small ships could travel so far to the end of Indonesian Exclusive Economic Zone. Some people say only bigger vessels can do that,  but proof yourself!

Legends:
1. Licin beach, 2. Sipelot beach, 3. Wediawu gulf, 4. Legoksono beach, 5. Tambak Sari beach, 6. Tamban beach, 7. Sendang Biru beach, 8. Banyumati beach, 9. Wonorogo beach, 10. Balekambang beach, 11. Kondang Merak beach, 12. Kondang Iwak beach, 13. Bantol beach, 14. Ngeliyep beach, 15. Ngulurung beach, 16. Jonggring Saloko beach, 17. Menjangan beach, 18. Ngebros beach, 19. Mondangan beach.

This article is based on maritime research in 2002 conducted by Giga Maritime Team, rewritten to be published in Neotek print magazine and www.discoveryindonesia.com online magazine by Robert M. Erwinn - Giga Team.

Auctioning tuna at Sendang Biru >>
Understanding the Rumpon: Beyond Technology >>

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