Northern Irian Jaya coast, on the eastern perimeter of South Pacific Ocean, is inhabited by four marine turtle species: Leatherback (Dermochelys coriacea), Green (Chelonia mydas), Hawksbill (Eretmochelys imbricata) and Olive ridley (Lepidochelys olivacea). Leatherback turtle are distributed from Waigeo Island to Yapen Island (Tomascik et.al, 1997). Since the early 1990s, current development of human settlements and logging activities have resulted in a decline in the number leatherback nests on those beaches, except for Jamursba Medi beach. Petocz (1987) suggested that the other three turtle species are abundant in Cendrawasih Bay, Raja Ampat Islands, Yapen Island and Padaido Islands.

Up to date information on these turtle populations is lacking. The WWF Indonesia - Sahul Bioregion has only collected data from certain locations: Jamursba Medi beach, Cendrawasih Bay National Park and Jayapura Bay, which provide some insight into the current situation of these turtle populations. The data are summarised below, by location (simply click the WWF logo on Map).

Located on Bird Head Peninsula on the northern coast of Irian Jaya (0º20'-0º22' S and 132º25'-132º39'E, see Map), the beach is one of few remaining nesting beaches available for the turtles, particularly leatherbacks. The beach is unique in that it is pristine and undeveloped. Recently a company (PT. Multi Wahana Wijaya) was granted permission from the local government to conduct logging activity.

From May through October 1999, 3,408 adult females turtle of any species were counted on this beach and 3,244 turtle (about 92.5 percent) laid the eggs (See Table 1). During peak nesting season in July 1999, fieldworkers recorded 30 new leatherback nests every night, totaling about 1,103 nests during this period (Teguh, 2000).

Table 1. Number of nests by species recorded in Jamursba-Medi beach (May to October 1999)

Source: Teguh (2000)

Petocz (1987) assumed that the whole coast of northern Bird Head Peninsula and the north coast of Yapen Island are potential turtle nesting areas and surveys have revealed nests on all beaches in this area. However, extensive hunting and egg collection, in addition to rapid rural and urban development, have reduced nesting activities in these areas. Jamursba Medi is now one of the last harbors for these turtles lay their eggs.

Bhaskar and Bakarbessy (1984) in Bakarbessy (1999) stated that the main nesting beach was 17,9 km long and divided into three sections:

• Wembrak beach (approx. 8,2 km) with black sand substrate.

• Baturumah beach (approx. 5 km) with greyish white sand substrate.

• Warmamedi beach (approx. 4,8 km) with greyish white sand substrate.

Table 2. Data on Leatherback Turtle Nest Recorded in Jamursba-Medi (Teguh, 2000)

Notes:

1) 1985 data did not explain the monitoring date.

2) No detailed monitoring dates and number of monitoring days.

3) No detailed number by species and it is not clear whether data are include 2 olive Ridley turtle found or not.

4) No detailed number of monitoring days, but it is informed that it conducted between May to September.

5) Calculated from 25 percents of 13,360 nests.

6) Refer also to Suwelo et. al. (1994) in National Marine Fisheries Service and U.S. Fish and Wildlife Service (1998): Predicting about 2,600 female adult turtle during 1994 nesting season.

Numbers of nests appeared to be declining (See Table 2), and is probably related to increased coastal development for cultivation (coconut, cocoa and coffee), hunting, egg exploitation and trawl fishing (Petocz, 1987). The nests and hatchlings are also subject to predation by both dogs and feral pigs (Maturbongs, 1999). Other predators of hatchlings include the sea eagle (Halieathus leucogaster), crab and shark, not to mention hatchlings lost due to exhaustion while digging out the nests and swimming (Putrawidjaja, 1999).

Between 1984 to 1985, local egg exploitation was relatively intense. During the period, 4 to 5 boats visited the beach weekly and brought out 10,000-15,000 eggs per boat. This activity has been declined significantly since 1993 (Bakarbessy, 1999).

At present, the logging concessions are not restricted to the southern boundary of the nesting beach, which is gazette as limited production forest. The logging activities include lumber harvest and transportation, and the construction of a log pond and base camp. These activities potentially threaten the beach structure, due to changes to the physical environment, not to mention a potential threat of increased opportunity for poaching in the future. Logging and log transportation will likely cause erosion upstream of rivers and creeks that exit from the beach. Silting, which is likely can change the beach substrate, which are currently 78% coarse sand and 21% fine sand (Putrawidjaja, 1999). Turtle eggs require a proper substrate for development during incubation, and increased levels of silt and clay deposited on the beach can potentially reduce the hatching success of sea turtle eggs.

The use of the beach as an access for harvested lumber to log pond also has a direct impact on nesting turtles: the logs will block access to the beach by sea turtles. Human activities, both during logging and in the base camp, can disturb the turtles which are light and noise sensitive (Pritchard, 1971). High numbers of people on the beach can discourage turtles from emerging from the sea to lay nests, not to mention the possibility that the loggers will collect eggs. Chemicals used to treat the lumber have the potential to concentrate in the sand on the beach, which in turn may poison both adult turtles and developing embryos. Other wastes from the logging process, such as grease, oil, domestic wastes and sawdust potentially can pollute the water.

It is critical for the provincial government and the forestry agencies to be more proactive with respect this issue, or otherwise this unique asset will be lost. It is of utmost urgency that this beach is declared as protected area, especially for turtles. The district government of Sorong of Irian Jaya has already recommended that it receive wildlife reserve status under the Letter No. 522.5/1010, dated 8 November 1994, covering an area of 10.000 hectares. However, recommendation is not enough, and legal status must be issued. So far, the government has shown no signs of serious action or follow-up on this issue. To address the issue, WWF and Irian Jaya II Regional Nature Conservation Office held a workshop in December 1999 to gazette the beach as National Park, especially for turtle. The proposed National Park will cover an area of 465,543.45 hectares (WWF, 2000), including:

• Jamursba-Medi beach (278,75 hectares),

• Limited production forest in the southern boundary of the beach (74,855.50 hectares),

• Protected forest in the other part of the area (25,595.30 hectares),

• Northern Tamrau Mountain Nature Reserve (351,934.80 hectares) and

• Seas (12.515,10 hectares).

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Cendrawasih Bay

Cendrawasih Bay is the largest bay in Irian Jaya. The western part of the bay (1º43'-3º22' S and 134º06'-135º10' E, see Map) was declared as a Marine National Park on 2 September 1993 by the Decree of Ministry of Forestry No. 472/Kpts-II/1993 (See Map 1). The park occupies am area of 1,453,500 hectares of seas and islands. The park includes 80,000 hectares of coral reefs, 55,800 hectares of islands and 12,400 hectares of Northern Irian Jaya coastline (Reksodihardjo, 1993).

Cendrawasih Bay includes nesting habitat for green and hawksbill turtles. The leatherback and olive ridley turtles are known to feed in the bay. The islands of Nusambier, Iwari, Kuwom, Matas and Wairundi and several mainland beaches have been recorded as turtle nesting beaches.

Salm et.al (1982) recorded 169 turtles nested in the area (82 green, 52 hawksbill and 35 unidentified) and 88 discarded carapaces (20 green, 31 hawksbill and 17 unidentified), while other 33 turtles (21 green and 12 hawksbill) were detected in an aerial survey. Setyadi (1997) recorded turtle occurrences at several potential locations (See Table 3).

Table 3. Turtle Occurrences in Cendrawasih Bay

Table 2 shows that there is no significant change in the number of turtle populations in the area over the years. Most of the detected habitat is composed of coral islands, such as Kuwom, Rorebo, Kabuai and Tridacna Atoll.

Turtles in Cendrawasih Bay are significantly threatened by human predation. Turtles hunting and egg exploitation, which has been practised mostly by outside fishermen for centuries, are the main threats. Putrawidjaja (1997) reported the existence of trade in meat and egg in the local fish market of Nabire. Five turtle (average weight: 5 kg) are traded daily for Rp. 6,500-10,000 (US$ 0.85-1.30) per kilo. Most of the turtles that were offered for sale were hawksbill and green turtle, and were caught in the park. Other turtles caught are directly exported to Bali, the largest turtle market in Indonesia. Eggs are also sold for Rp. 10.000 (US$ 1.30) per 10-12 eggs. The trade also occurs in other major cities around the bay including Biak, Serui and Manokwari (Putrawidjaja, 1997).

According to WWF monitoring in 1999, olive ridley turtle often were seen feeding in the bays of Jayapura. In June 1999, many hawksbill and olive ridley turtle were seen nesting on Hamadi beach (Yos Sudarso Bay, see Map), close to the Indonesian Naval Base and local fish market. This was surprising since the area is highly populated and the sago swamp occupies some of the area.

Between 2-5 turtles (average weight: 5 kg) are traded daily in local fish market for of Rp. 15,000 (US$ 2) per kg. Eggs are also traded for the same price in Nabire. Local traders reported that approximately 500 eggs are traded in the market everyday.

Turtle populations and distribution in Irian Jaya is decreasing significantly due to predation of nests, both by natural and human predators. Turtle hunting and egg exploitation has occurred for centuries. Current development of industry and human settlement has accelerated the decrease.

Turtle exploitation, both in terms of meat and eggs, often occurs in Irian Jaya primarily due to a lack of awareness on the importance of turtle preservation, particularly among fisherman and local villagers. Management plans for turtle conservation is required to establish the protection of turtle nesting beaches and to should include the following:

• Training and education,

• Law enforcement, patrolling and monitoring,

• Development of alternative local economies, e.g. seaweed and sea cucumber culture.

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Literature Cited