Protected Resources

International Sea Turtle Activities

WWF Indonesia:
Research and Training for Mitigation of Sea turtle Interactions with Fisheries

NOAA Fisheries has provided funding to World Wildlife Fund-Indonesia (WWF) to support sea turtle conservation and management institutional capacity building in Indonesia. The focus is on commercial and traditional fisheries with significant sea turtle interactions. A key goal is to obtain baseline estimates of the impact of inshore small-scale coastal fisheries near two major leatherback turtle nesting beaches along the north coast of Papua through collection of interaction data by observers stationed in fishing villages. This project will also provide data on the characteristics and extent of sea turtle interactions with Indonesian longline and purse seine fisheries through implementation of a pilot observer program.

A high priority is placed on sensitizing the industry to the current declining status of turtle stocks throughout the Pacific and Indian Oceans, and the importance of minimizing mortality to sea turtles during fishing operations. The primary target audience is the fishing industry, specifically: fishing vessel captains and crews, shore-based supervisory and support personnel, as well as key government officials engaged in fishery management and development.

The project emphasizes participation of the industry on a voluntary basis and works closely with recognized industry groups, including the Indonesia Tuna Association (ASTUIN) and the Indonesia Tuna Longline Association (ATLI). To carry out the project's activities, a close working relationship has been developed with government tuna fishery officials engaged management and development, including individuals from the Research Centre for Capture Fisheries, the Research Institute for Marine Fisheries of the Ministry for Fisheries and Marine Affairs, and the Indonesian Institute of Sciences (LIPI).

Project activities include the collection and analysis of fisheries bycatch data by student observers from one of Indonesia's fishery training schools. An important component of the overall project is the planning for training of a small cadre of fishery observers to work full-time onboard vessels based in three major tuna ports: Benoa (Bali), Muara Baru (Jakarta), and Bitung (North Sulawesi). Observers and their respective coordinators will comprise a major link in information flow to target fleets on turtle bycatch mortality mitigation, and will enhance an already ongoing dialog between WWF, the fishing industry and government on the need for increased attention to appropriate management of the country's fisheries. Observer activities continue through 2006 with near gear trials, including circle hooks, scheduled for 2007.

Field observations of the trawl and longline fishery

From July 6-26 2005, several students of Udayana University conducted interviews of 106 boat captains and crew in Benoa fishing harbor in Bali. In addition, the Akademi Perikanan Sorong Sorong Fisheries Academy (APSOR) student observers collected data onboard twelve Sorong-based shrimp trawl vessels and eleven Benoa-based tuna longline vessels from March to June 2005.

On-board observations from shrimp trawl vessels in the Arafura Sea revealed sea turtles are often incidentally caught in trawls. Most sea turtles caught were hawksbill and green turtles, including occasional catches of loggerhead, olive ridley and leatherback turtles. These data suggest that the Arafura Sea and adjacent waters are important migratory or foraging grounds for sea turtles. Almost all incidentally caught sea turtles were released back to the sea (98.5%), and only 1.5% kept for consumption. Reasons given for release of turtles included: (1) crews were aware of the prohibition of sea turtle exploitation, (2) the size of sea turtles made it difficult to utilize or consume due to limited space, and (3) superstition that sea turtles onboard would reduce their fishing catch.

One reason for the high amount of sea turtle bycatch was the disincentive to install turtle excluder devices (TEDs) in trawls with the impression being that TEDs cause a decline in fish bycatch. Boat crews are usually entitled to any fish bycatch, which provided additional income typically larger than their monthly wages. Alternative solutions should be explored to reduce the economic impact to boat crews of using TEDs, bycatch excluder devices (BEDs), and juvenile turtle excluder devices (JTEDs). Before such solutions are established it would be very difficult for shrimp trawl industries to implement any national regulations.

From onboard observations, interviews, and frequent sightings of sea turtles during the operation of tuna longline vessels, it was discovered that the vessels' fishing grounds are also sea turtle migratory routes. Interview transcripts revealed that informants sighted sea turtles ten to 30 times per month.

From eleven longline vessels monitored, observers reported one loggerhead turtle incidentally caught. Interview transcripts informed that on average, one to three sea turtles were caught incidentally per month. Respondents claimed they released all sea turtles back to the sea, citing awareness of the regulation that prohibits catch or trade of sea turtles and also based on a superstition that having a sea turtle onboard would bring misfortune. The same superstition applied as well to vessels whose captains or owners were of East Asian origin or descent (Japan, China and Taiwan). Captains and owners prohibited the crew to fish for sea turtles. According to their beliefs, sea turtles are personifications of the God of long life, hence it is strictly forbidden to lift sea turtles onboard or kill them. Javanese crews held similar beliefs.

Study of sea turtle bycatch in the longline fishery

Sea turtle bycatch in tuna longline industries in Indonesia was surveyed from May to September 2005 in several fishing ports, i.e. Muara Baru (Jakarta), Cilacap (Central Java), Bitung (North Sulawesi), Kendari/Bau-bau (Southeast Sulawesi) and Makassar/Bone (South Sulawesi). Longline fishermen (boat captains and crews) and non-longline fishermen (i.e. those using gillnets and purse seine) were interviewed. Questions asked included: name, position, and work experience; vessel name and specifications; fishing ground and seasons; fishing gear, size, and methods, as well as fishing targets (main and bycatch). In addition, respondents were asked about their sea turtle bycatch, handling methods and reasons for releasing animals back to sea. A total of 163 respondents were interviewed, including 40 from Bitung, 50 from Muara Baru Jakarta, 23 from Cilacap, 30 from Kendari/Bau-Bau, and 20 from Makassar/Bone. A total of 70% respondents interviewed used tuna longline, while 30% of respondents used other fishing gear (gillnet, purse seine, hand hook and line, and other gear).

All Muara Baru and Cilacap based tuna longline vessels operate in Indian Ocean (west of Sumatra and south of Java). Bitung-based ships operate in north of Papua (Pacific Ocean) and Indian Ocean. Ships in Kendari/Bau-Bau and Makassar/Bone operate in inner Indonesian waters (Banda Sea, Flores, Maluku, Buru, and Seram). Tuna longline vessels operate throughout the year with three months duration per trip. Other fishing vessels operate during mild seasons (transitional seasons, good weather conditions without heavy swells).

These tuna longliners usually operate using 1,100-2,000 hooks per set, fished at either 60-75 meters depth, or shallower. Due to the shallow nature of this fishery, the probability of sea turtles interacting with the gear is higher than fisheries setting deeper (>100 meters). Primary species caught are yellowfin tuna, albacore, bigeye tuna, marlin, swordfish and sailfish. Bycatch includes sharks, rays and sea turtles. Most respondents (95%) acknowledged usually catching at least one sea turtle per month. With an estimated 1,600 Indonesian tuna longline vessels catching three sea turtles per trip (one trip takes three months on average), the average sea turtle bycatch is estimated to range from 6,400 to 19,200 animals per annum (p.a.). The most common sea turtle bycatch species in both the Indian and Pacific Oceans is loggerhead turtles. Leatherback turtles were also frequently caught in both oceans, although catch rates in the Pacific Ocean were higher. Indonesian tuna longline bycatch in the Pacific is estimated to be 256 to 768 animals p.a. for leatherback turtles and 768 to 2,304 animals p.a. for loggerhead turtles. In the Indian Ocean, bycatch for leatherback turtles is estimated to be 1,349 to 4,032 animals p.a., while bycatch for loggerhead turtles is 4,032 to 12,098 animals p.a. This Indian Ocean estimate exceeds Lewison's (2004) bycatch calculation for the year 2000, of 4,000 leatherback turtles and 6,000 loggerhead turtles, and confirms the importance of longline fisheries in bycatch issues in Indonesia.

Sea turtles caught in offshore oceanic waters were larger (carapace length > 50 cm), than those caught in inner waters (25-50 cm). Most respondents (98%) released the turtles by bringing them onboard (for smaller size) or cutting the line directly for larger turtles. All respondents were willing to release turtles because: (1) the animals were protected by national laws; (2) sea turtles onboard are considered taboo; (3) sea turtles cannot be sold; (4) compassion towards the animals; (5) boat captains and owners of Chinese origin or descent consider the sea turtle as a personification of a deity.

WWF Indonesia Marine Turtles webpage