Interview and Aerial Survey Data in Relation to Resource Management of the Dugong in Manus Province, Papua New Guinea

BULLETIN OF MARINE SCIENCE, 31(3): 662-672, 1981

INTERVIEW AND AERIAL SURVEY DATA IN RELATION TO RESOURCE MANAGEMENT OF THE DUGONG IN MANUS PROVINCE, PAPUA NEW GUINEA

Brydget E. T. Hudson

ABSTRACT Manus, the most northerly Province of Papua New Guinea, has a population of dugongs which is important to, and hunted by, the coastal people of the Province. Village patrols and aerial surveys have been conducted to assess the numbers of dugongs in the Province, the level of hunting carried out by the people, and their attitudes to the conservation of this vulnerable marine mammal. This paper outlines the results of this work, supplementary work to be done, and suggests conservation areas which the people might like to create for the dugong and other marine resources in Manus Province.

A postal survey conducted in 1973/1974 (Hudson, 1977) indicated that Manus Province, situated between longitude 146°00'W-148°30'W and latitude 01°45'8 and 04°00'8, our most northerly Province, had the second largest dugong population in Papua New Guinea. In response to this survey the people of Papua New Guinea, told of their concern that the numbers of dugongs were declining in our waters. The dugong was made a National Animal of Papua New Guinea, in 1976. This legislation is aimed at protecting the dugong but retaining it for village use, if caught by traditional methods. The Wildlife Division's "Dugong conservation, management and public edu- cation programme" was started in 1978 to find strategies suitable to Papua New Guinea, and its people, for the management of the dugong which is classified as a vulnerable marine mammal (IUCN, 1976). The collection of baseline data concerning the numbers of dugongs in the population, their distribution, reproductive strategies, hunting and other pressures on them, if any, must be found to imple- ment this aim. The reaction of local people to possible management guidelines must be assessed, and suitable action taken to ensure the survival of the dugong in Papua New Guinea coastal waters. In February 1977 a patrol (visit) was made to the islands of Lou, Rambutyo and Pak in the south-east of Manus Province, to collect information from the village people about the dugongs and other marine resources and the people's concerns about wildlife in the area. A patrol of the main island was not possible at that time because of very bad weather, but such a patrol was made in July 1979 when the islands previously visited with the exception of Lou Island were revisited and a visit was made to Baluan Island which had not been visited in 1977. (Fig. 1). From such village patrols anecdotal information was collected concerning dugong numbers and seasonality in the area, trends in the numbers of dugongs in the local population, calving areas, hunting pressure and other interesting information about the way of life of the dugong and the people's relationship to it. To obtain objectives counts of the population of dugongs other methods must be used. An aerial survey program of the Manus Province dugong resources was started in 1978. Such surveys have been conducted at least once a year since then, using

662 HUDSON: DUGONG SURVEY, MANUS, NEW GUINEA 663

147"30'

MASSONG ISLANDS aO 2'00'

BIPI-PAHI ~--, OrONG ISLAND 'I) °ill ISLAND ISLANDS

SAN MIGUEL ISLANDS ~~~ <>

BISMARCK SEA LOU ...- ~~ ISLAND~) RAM8UTYO 00 ISLAND M'aUKE ~V/) 17 ISLANDS ..' JOHNSTON ~ - " < ISLANDS / o 20 (n BALUAN ~ISLAND KM

Figure I. Places where dugongs are sighted and numbers hunted. Stippled areas indicate where dugongs are commonly seen (information from postal survey). Numerals within squares designate the numbers of dugongs killed per year (information from interviews during visits to villages around the coast of Manus Province).

methods as detailed in Hudson (in press) developed by the author as an adaption of the methods of Heinsohn et aI., 1976. Both sets of data have been discussed with the village people and the Provincial and local governments with suggestions as to management and conservation strategies which they might use for the management of the dugong resources of the Province.

METHODS The two methods of collecting information will be dealt with separately. Firstly, the village patrols and information collected and then the aerial surveys and their results will be discussed,

Village Patrols

In both 1977 and 1979 similar methods of conducting extension work in the villages of Manus Province and the community in Lorengau the capital of the Province, were used. Before the patrol, information concerning the proposed route and arrival times at villages was broadcast on the information program of the local radio station. Project staff were interviewed by this radio station to inform the local people about the aims of the patrol. Such interviews were also given when project staff visited the Province to conduct aerial surveys. During these interviews information was also given about a system of conservation and management areas called Wildlife Management Areas (WMAs), which is used widely in Papua New Guinea. These WMAs are areas of land or sea, which are set aside by the people for conservation, The landowners or people with hunting or fishing rights, make the rules they wish to use to run the Area and enforce these rules themselves. The Wildlife Division assists by having these rules published in the Government Gazette so that they are legally enforceable. The Division also assists the people to collect biological information on which sound management decisions can be made. Other forms of conservation areas such as national parks, sanctuaries or other forms of conservation areas are discussed with the village people during patrols. Project staff aim to stay at least one night at villages where we believe that we can obtain relevant information, so as to get to know the local people and assist them by supplying information about conservation and management strategies suitable for their wildlife. In the village, meetings are conducted in the lingua franca New Guinea pidgin, either in the late afternoon or early morning, so as not to inconvenience the people from their usual occupations. Such 664 BULLETIN OF MARINE SCIENCE. VOL. 31, NO.3, 1981

I /\ 147·00' 147"30' NARES HARBOUR i ~ ANORA ISLAND B c I PONAM ISLAND j PITYllU •• SORI ISLAND I ~ HUS ISLAND J •••• SSONG @ • HARBOUR / I 0 0 ISLANDS 0° 2"00' ill 8IPl-PAHI 'll 0 ISLANDS

I I I A I I BISMARCK SEA I RAMBUTYO I I ISL"ND I D I I I I 0 20

Figure 2. A comparison of aerial survey sightings to information concerning dugong numbers gathered during village patrols. Aerial Surveys: Area A 1978 (March) = 16, (July) = 1, 1979 (April) = 7, (July) = 1, 1980 (July) = 5; Area B 1978 (March) = 26, (July) = 14, 1979 (April) = 3, (July) = 13, 1980 (July) = 4; Area C 1978 (March) = 4, (July) = 3, 1979 (April) = 6, (July) = I, 1980 (July) = 4; Area D 1978 (March) = 3, (July) = 12, 1979 (April) = I, (July) = 12, 1980 (July) = 29. Village patrol information: numbers within circles show the location and number of dugongs reportedly seen regularly. The numbers within triangles show the total number of du£ongs reported in comparison to aerial survey areas A, B, C and D.

meetings usually last for about 2 hours and people with the most detailed knowledge are asked if we can talk with them after the meeting. Such detailed talks can take many hours. While in the village, talks are often given at the local school where extension materials, such as badges, posters and booklets are distributed. In the evening, films are shown of Wildlife Management Areas, the animals of Papua New Guinea, and other topics of interest. Preliminary habitat surveys are made and any other important data is collected concerning dugong and other marine and terrestrial wildlife, whilst we are on patrol. We feel that such extension work to collect and disseminate information is one of the most important aspects of our work. (Hudson, 1980). We therefore take great trouble to listen carefully and at length to what people have to tell us. We usually have an officer with us from the Province who is well known to the village people and we try and return to the village on a regular basis to develop rapport with the villagers. Such work cannot be rushed, and the attitude of the interviewer and knowledge of the local language is most important in this work. The Western Islands of the Province have not been visited as they reportedly do not have a population of dugongs, although one dugong is suppposed to live near a lagoon in the Ninigo Islands. Specific details of the patrol work can be found in Hudson (in prep.).

RESULTS OF VILLAGE PATROLS Below is a synthesis of interesting information collected on the patrols (Fig. 2), All the village people said that dugongs were two to three times more nu- merous before World War II than today. Years ago people had strong tradi- tionallaws about the protection of reef areas, on a clan basis. They could hunt dugongs for funeral, marriage or birth celebration feasts or other special occasions, on their own clan "owned" reefs. In recent years these laws have broken down and dugongs are now hunted opportunistically with spears instead of the traditional nets. Dynamite was used for fishing but the people soon realized the de- structiveness of this technique and now ban its use. HUDSON: DUGONG SURVEY, MANUS, NEW GUINEA 665

14 ·00'

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Figure 3. Aerial survey route 13 March ]978 (Dots indicate the survey route and triangles indicate the places where dugongs were sighted).

Lou IsLand.-The people of the island were converted to the Seventh Day Ad- ventist Mission in the 1930s. This "church" does not allow the eating of dugong, which they consider unclean meat. The people of Lou Island have stopped hunting dugongs, but people from other areas still come to hunt dugongs around the island. The people said that dugongs seem to be attracted to the fires they light on the beach at night. They have seen dugongs mate in shallow water near the village in January. Dugongs are said to congregate in the area in the south-east windy season from April to October; at this time the water can be cloudy. The islanders said that if a dugong is stranded in the shallow water by the

147'00' 147'30' NARES HARBOUR ANORA ISLAND • I PONAM ISLAND / PITYILU ISLAND SORI ISLAND...." j HUS ISLAND 1 ••••••••.•••••••••• " ••••••• A 0.... ,l~~AOL~R HARBOUR "' •• l"': •••• ~ - ~Q

•••••••• ~. LOS NEGROS 2 ISLAND o TONG BIPI-PAHI .~ .. ISLANO \l 0 PAK •• ISLANOS ISLAND ••••.A o a~. SAN MIGUEL

ISLANDSfJ ;. d) :

Q ••• ·BUKE ...... LOU RAMBUTYO BISMARCK SEA ••. ISLANDS _.;]'5: .•...... •...... \SLAN~:::... .. ISLAND () • jOHN"STON 2'30' ISLANDS ••• o 20 O;·BALUAN KM •••• ISLAND

Figure 4. Aerial survey route 27/28 July 1978; dots and triangles as in Figure 3. 666 BULLETIN OF MARINE SCIENCE. VOL. 31, NO.3, 1981

147-00' NARES HA RBOUR ANORA ISLAND PONAM ISLAND J PITYllU ISLAND MASSONG SORI ISLAND c::::a HUS ISLAND J c:. .~, ••••••••••••••••••••••••••••J ~ SEEAOLER HARBOUR ISLANDS a •• :oiI!:'- .••••••~••••• .,,: : '.' •...... LOS NEGROS BIPI-PAHI : ISLAND ISLANDS ••• •• .'. n •••• ISLAND .~:. :~'" PAK _. A··· .... ISLAND

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Figure 5, Aerial survey route 5 April 1979; dots and triangles as in Figure 3. receding tide, it will turn on its back and use two or three strokes of the tail fluke to propel itself over the reef into the deep water. The people said that the dugongs do this because the skin on their back is thicker than the belly skin. Marks seen on the backs of dugongs inspected during our carcass salvage operation in Daru is consistent with this information. Dugongs from Daru area also sometimes have parallel scars which are probably dugong tusk scars, These scars, which are fairly common on female dugongs, may be made during mating. Some large female dugongs from Daru also have fully erupted tusks which are equal in size to those of the males, If the people block a dugong's passage to return to the deep water with the

147"30'

MASSONO ISLANDSo'"

2'00'

OTONG BIPI-PillHI ~ ISLAND PAK ISLAND

floe:. SAN MIGUEL ISLA~DS

• BISMARCK SEA . J:2ISLAND I) • • M'BUKE (J ISLANDS '.' JOHNSTON 2'30' ISLANDS 0 20

Figure 6. Aerial survey route 16 July 1980; dots and triangles as in Figure 3. HUDSON: DUGONG SURVEY. MANUS. NEW GUINEA 667

146' 147' 148' SOUTH PACIFIC OCEAN

LOS REYES ISLAND I' x 2' Q

o ~, SA88EN ISLANDS : /"-.., RAM8UTYD LOU p::!..J ISLAND :. " ISLANDeS( BISMARCK SEA PAM

8ALUAN ISLAND

PURDY ISLANDS • o 20 40 X ALiM ISLAND KM

Figure 7. Proposed .marine management areas marked with X's. The proposed management areas do not have boundarIes marked as these will depend on the wishes of the local people. and will be made if and when the people wish to make these suggested areas into marine wildlife management areas.

tide, then the dugong may charge the canoe in an effort to return to the deep water. The people believe that dugongs will eat three kinds of short seagrasses and one long species which they call "mut" in Paun village (Sander, 1980). Whilst in Paun village a dugong was seen feeding a little way from the shore. We got in canoes to go close to the dugong which was surfacing every 1 minute. As it dived a large amount of the back was visible and the people said that this was a characteristic of young dugong. This animal appeared to be about 2 m long. Ramhutyo /s/and.-On the west coast of the island is a shallow area which has a depth of about 2 m. The dominant seagrass appears to be Enha/us acoroides which the people say is not a preferred food of the "kamendra" which is the name of the dugong in the local language. On the island the "Siliu" clan must not eat dugong meat. This is the third largest clan on the island. Such clan mem- bership is passed on matrilineally and the numbers of members of this clan, which appears to be based in Baluan, is decreasing. The people attribute the decline in dugong numbers to overhunting especially to the breakdown of traditional conservation laws. They said that in places where years ago 5 dugongs could be seen, today only one or two are seen. The people believe that if a baby is speared the mother will come to try and assist it to escape and that she will put her flipper around the baby and try and carry it away. They say that she will hold on so tightly that she can be pulled to the boat with the young dugong. Mokerang Village.-The best known hunter in the Province lives in this village. In 1977 he said that he had killed 107 dugongs in the previous 20 years. Dugong 668 BULLETIN OF MARINE SCIENCE, VOL. 31, NO.3, 1981

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00 t::: 00 00 N e t::: I 00 0- ;j:; '" N ~- t::: HUDSON: DUGONG SURVEY, MANUS, NEW GUINEA 669 hunting is a very prestigious occupation and like dugong hunters in other parts of the country, records of numbers killed are carefully kept by the hunters. Lucas said that of these dugongs, five were obviously pregnant and that he kills equal numbers of male and female dugongs. He said the largest group of dugongs he had ever seen was eight but groups of four or one or two were more usual inside Seeadler Harbour. He said that dugongs come into the Harbour, in the south-east wind season. Also that dugongs root in the seagrass like pigs on the land root for food in the soil. Andra Island.-The people said that dugongs feed most on the south coast of the island. The same information was received from Ponam Island where the dugong is not thought to be of great importance to the people (Carrier and Carrier, 1980). Tulu Village.-We were told that some years ago a dead dugong floated ashore near the village and the people thought that it had been killed by a stonefish or other poisonous animal. The people ate the meat and were not affected by it. The dugongs are thought to eat the white seacucumbers found in the area as well as seagrasses. Bundrahei Village.-The people said that they have a custom that the first born child of a family cannot eat dugong meat until a special feast has been made for the child. They said that often first born children never eat dugong meat. Timonai Village.-There are stands of Thalassodendron cilia/um near the village and the people said that dugong come and feed on these seagrasses which grow On a hard substrate often in a waveaction area. Pere Village.-We were told that men record their dugong hunting success on the houseposts in the village and that in the 1930s there had been a man in the village who had killed 130 dugongs. Baluan Island.-The people of the island were called "titons" and are related to people of Timonai, Tilienu, Moklen and Pere. They are seafaring people who appear to know more about the dugongs than people from other areas. The men keep records of the dugongs they kill On sago sticks, which they keep in their houses. Traditionally at a marriage the women's family had to provide a dugong for the feast. The people made dancing platforms for feasts called "chinal." These posts often had representations for dugongs and turtles on them, in pro- portion to the number of animals given at the feast. These chinal were kept in the men's houses and were often used at several feasts. Alim Island.-Alim Island has a great significance to the people of Baluan as do the six islands near Bipi Island to the people there. There are elaborate cere- monies related to going to the islands and behavior on the islands. Dugong are found and hunted around Alim Island. The Baluan people said that Pollot and Pam Islands are very important areas for dugongs in the south-east of Manus Province, as the dugong come there to shelter in the south-east wind season and the people who live on the island are not really seafaring people and do not hunt them very often. Pak Island.-We were told that the seagrass beds around the island are increasing and so are the number of dugong sightings. The people said that sometimes dugongs are seen around Tong Island but never around the Los Reys or Nauna Island. 670 BULLETIN OF MARINE SCIENCE, YOLo 31, NO.3, 1981

Plate 1. Village people discussing marine management areas.

Aerial Surveys As no small aircraft are based in Manus Province high winged aircraft have to be brought from the mainland or Rabaul to conduct surveys. This greatly in- creases costs and difficulties. The surveys are usually conducted at 300 m (1,000 ft) and 185 to 220 kmfh (100 to 120 kn) depending on conditions. Manus has been the subject of a testing of survey techniques in 1979, to compare numbers of dugong seen from fixed-wing airplanes and helicopters (Hudson, 1980; in prep.). The survey team usually consists of a survey leader and 2 observers (Hudson, in press; Heinsohn et al., 1976).

Management Proposals Following these patrols and aerial surveys discussions were held with the local and Provincial Governments. At these meetings it was suggested that Govern- ments consider a moratorium on dugong hunting for 5 to to years, to allow the number of dugongs to increase, hopefully to their former numbers. Specific areas such as Alim, and Pam-Pollot-Lou were also suggested as suitable management areas. It has also been suggested that an officer for the dugong programme of the Wildlife Division be posted to Manus Island to assist the Provincial Wildlife Officer with dugong and other marine management work. It has been also rec- ommended that aerial surveys of the dugong population be made at the end of 1980, March and November 1981 and 1982 to assess trends in the dugong population in different seasons and as a result of management techniques used. HUDSON: DUGONG SURVEY. MANUS. NEW GUINEA 671

DISCUSSION The postal survey of 1973/1974gave us information as to the Provinces and places of greatest interest where further investigations should be made. Village patrols conducted carefully and repeatedly give further specific information about places where dugong may be found regularly and about the people's attitudes and concerns about their resources. Such patrols can direct aerial survey efforts to areas where dugongs are most likely to be found. Aerial surveys are the only method available to give a direct count to dugongs in an area. Aerial surveys need to be conducted with great thoroughness so that the herds of dugong, such as the 24 + 4 sighted at Pam Island in 1980, are not overlooked. It is necessary to conduct the aerial surveys in suitable weather conditions (not possible in 1979), at the various seasons north-west and south- east, and with suitable intensity so as not to miss herds. Thus, aerial surveys give data on the specific places to direct research efforts with the dugongs themselves, calving rates in different years and possible migra- tion patterns locally and the use by the dugong of different areas. From the data it can be seen that the number dugong actually seen on aerial surveys is not as large as the estimate of population size given by the people. Our aerial surveys are not of such thoroughness as to enable us to say that they may be regarded as total counts (as could those of Brownell et aI. in Palau) but our surveys may be used as an index of the population. It is interesting to note that dugong are sighted where the people say that they may be found, and that dugong appear to favor some areas being almost always found in these locations. The numbers said to be hunted each year appears a little inflated, but it is hoped when we have an officer based in the Province, he will be able to collect more accurate information. A hunting rate of half that reported by the people would give rise to concern viewed in the light of the numbers of dugong being seen in the Province during aerial surveys. Drastic action must be taken if the people are to retain and manage their resource as they have said they wish to do. The dugong seem to be of particular importance to the titon group of people of the south of the Province but not of such great importance to the people of the north coast of the Island (Carrier and Carrier, 1980). With the cooperation of the people of Manus Island, the Provincial and the local Governments and officers of the Wildlife Division it is hoped that in the next few years more detailed information can be gathered about the dugong of Manus Province. Also that all the people of the area will assist to successfully manage this resource for the good of the people and the dugongs in Manus Prov- ince, Papua New Guinea.

ACKNOWLEDGMENTS

The author would like to thank all Wildlife Division and Department of Primary Industry staff who assisted on the patrols and aerial surveys. Also the people in the villages visited who gave us their hospitality and made working in their Province a pleasure and privilege. Thanks is also given to the Manus Provincial Government and Local Government Council and their officers who assisted us in every way.

LITERA TURE CITED

Brownell, R. J. P. K. Anderson, R. P. Owen, and K. Ralls. 1981. The status of dugongs at Palau, an isolated island group. The Dugong. Proceedings of a Seminar/Workshop held at James Cook University 8-13 May 1979. p. 19-43. Carrier, J., and A. Carrier. 1980. Dugongs of Ponam Island. Wildlife in Papua New Guinea 80116. Wildlife Division, P.O. Box 2585, Konedobu Papua New Guinea. 45 pp. 672 BULLETIN OF MARINESCIENCE, VOL. 31. NO.3, 1981

Heinsohn, G., A. V. Spain, and P. K. Anderson. 1976. Populations of dugongs (Mammailia: Sirenia): aerial survey over the inshore waters of tropical Australia, BioI. conserv. (9) p. 21-23. Hudson, B. E. T. 1977. Dugong distribution, hunting and cultural significance in Papua New Guinea. Wildlife in Papua New Guinea 77/16. Wildlife Division, P.O, Box 2585, Konedobu, P.N.G. 22 pp. ---. 1980. Dugongs in Papua New Guinea. Report 1978 to 1980 and Action Plan 1980 to 1982. Wildlife in Papua New Guinea, Wildlife Division, P.O. Box 2585, Konedobu, P.N.G. 102 pp. Sander, H. F. 1980. Dugong feeding habitats in Manus Province. Wildlife in Papua New Guinea. Wildlife Division, P.O. Box 2585, Konedobu. PNG. 31 pp.

DATE ACCEPTED: March 3, 1981.

ADDRESS: Dugong Project, Wildlife Division, P.O. Box 2585, Konedobu, Papua New Guinea.