NUMBER 14                                            OCTOBER 1990

 

 

IN THIS ISSUE:   -  NEW DUGONG PROJECT IN INDONESIA (p. 10)

 

                 -  PROGRESS IN MANATEE AGE DETERMINATION (p. 15)

 

 

    UNITED NATIONS CONFERENCE ON ENVIRONMENT AND DEVELOPMENT

                  RIO DE JANEIRO, BRAZIL, 1992

 

     A   United   Nations   conference   of   potentially   great significance  to the environment will be held in Rio de  Janeiro, June 1-12, 1992, coinciding with World Environment Day on June 5. This intergovernmental meeting, known as UNCED '92 or ECO '92, is being  planned  by  an UNCED Preparatory Committee  open  to  all member governments of the UN. Maurice Strong of Canada will serve as UNCED's Secretary-General. The UNCED Secretariat, with a staff of about 40,  is located in Geneva with additional small units in New York and Nairobi.

     The Preparatory Committee has two open-ended working groups, which  seek  to  arrive  in  1992  at  "specific  agreements  and commitments  by Governments and international  organizations  for defined  activities  on environment and  development,  specifying targets  and  timetables  and providing the  basis  for  concrete action  plans."  Issues  to  be dealt with  by  Working  Group  1 include,  among  others,  conservation of  biological  diversity; those  of Working Group 2 include protection of seas and  coastal areas and their living resources.


     The Preparatory Committee held its first substantive session in Nairobi in August 1990; three further substantive sessions are scheduled (in Geneva, Mar. 18-Apr. 5 and Aug. 12-30, 1991, and in New York in early 1992). Documents approved at these sessions can be  obtained directly from UNCED's offices in Geneva or from  the Centre  for Our Common Future (Palais Wilson,  52 rue des Paquis, CH-1201 Geneva;  tel.  022-732-7117, telex 27910 ch, FAX 022-738-5046).   The  UNCED Secretariat has also set up a series of read-only  electronic  "conferences"  or  databases  where  the   most important  documents in preparation for UNCED will be posted  for reading  and  downloading.  These  are  called  EN.UNCED.UPDATES, EN.UNCED.GENERAL, and some related ones not yet on line. They are accessible   through  any  of  the  Association  for  Progressive Communications  electronic networks  (Alternex,  Econet/Peacenet, The Web, GreenNet, Nicarao, FredsNaetet, Pegasus).

     National preparatory processes, resulting in the development of  national  reports,  are also to occur in all countries  under guidelines adopted by the Preparatory Committee.  There is also a series  of regional meetings:  regional conferences  for  Africa, Europe,  and  Asia  and  the Pacific have already  been  held,  a further  Asia-Pacific meeting is planned for February  1991,  and meetings for Latin America and the Caribbean and for Western Asia are also planned for early 1991.  A fund has been established  by the  UN to help the least developed countries participate in  the preparatory process.

     A  significant feature of the UNCED planning process is  the provision  for  participation  by  "Independent  Sectors."  These include non-governmental organizations (NGOs) having consultative status  with  the  UN,  all  environment  and  development  NGOs, business and industry,  trade unions,  professional associations, scientific  and  academic  institutions,  women's  organizations, youth groups, religious and spiritual groups, indigenous peoples' organizations, and other citizens' groups.

     A parallel meeting of the "Independent Sectors" will be held in  Rio at the same time as the main conference,  and a series of other  UN-sponsored  events  will take  place  throughout  Brazil during 1992. These will include an official ceremony for heads of state  and government in Manaus.  The "Independent Sectors"  also plan a wide range of preparatory,  participatory,  and  follow-up activities.

     Independent  sector organizations wishing to become involved in the '92 process can obtain information from the Centre for Our Common Future,  which has (among many other initiatives) begun to publish  a  monthly  review of  independent  sectors'  activities called  Network  '92.  NGOs and individuals are already  actively organizing  in many countries (including Brazil and the U.S.)  in order  to have an impact on the UNCED process and to  modify  the conference themes proposed by the UN.  For example,  the proposed themes  are  widely viewed as presenting a fragmented picture  of ecological and social issues;  as omitting some important issues; and  as improperly addressing topics such as the  eradication  of poverty  as isolated issues rather than as general principles for guidance of discussion on all themes.

     It  is important to realize that action must be taken in the next  few  weeks and months if it is to have any  effect  on  the final  outcome  of  UNCED.  By June 1992 the conclusions  of  the process  will have long since been effectively set  in  concrete. There  is  a need to ensure that the national reports  now  being formulated  address the issues as appropriately as possible,  and this will not be easy to achieve - especially in the U.S.,  where Administration policy remains completely and determinedly out  of step  with  the views of most other governments on  many  crucial environmental  issues.  Readers of  this  newsletter,  especially those  in developing countries,  now have a short-lived window of opportunity  to get involved in the UNCED process and affect  its outcome.  People  from all nations and all walks of life need  to mobilize on an unprecedented scale, and send their governments to Brazil  with  the weight of global public  expectation  on  their shoulders.  Only  this  will make the difference between  holding just another indecisive,  time-wasting intergovernmental  ritual, or moving the world measurably toward a sustainable future. - DPD

 

 

               NEW ADDRESS, PHONE, AND FAX NUMBERS

 

     Please  note the new addresses and numbers listed at the end of  this  issue  - especially those for the  manatee  project  in Manaus, Brazil, and for Sirenews.

     Also note that,  although most issues of Sirenews are mailed in  franked envelopes generously provided by the  U.S.  Fish  and Wildlife Service lab in Gainesville,  Florida,  they are produced in and mailed from Washington,  D.C.  All Sirenews correspondence should therefore be directed to Washington and not Gainesville.

 

 

                    RESEARCH FUNDS AVAILABLE

 

     The  Foundation  for Field Research is  looking  for  marine mammal  field projects to support.  Grants to  researchers  range from  US$1,000  to $25,000,  and are derived  from  share-of-cost contributions  by  volunteer participants on the research  teams. Contact them at P.O.  Box 2010,  Alpine,  Calif.  92001-0020 USA; telephone 619-445-9264.

 

                             LETTER

 

To Sirenews:

 

     The  editor  of Sirenews has recently proposed  the  slogan, "Never  underestimate a sirenian".  I suggest something  else,  a reminder  which  could  be tucked away for  ready  retrieval.  My slogan  is,  "Never  overestimate an artist." I'm  stimulated  to propose  this  bit  of  grafitti  as  a  result  of  too-frequent encounters   with  misrepresentations  (or  worse)  of   sirenian morphology.  To  date  I know of only one  artist,  a  delightful Britisher  named  Hubert Pepper,  who has produced  a  reasonably accurate dugong representation.

     The  latest  in  the  many offenses  that  lie  behind  this complaint appears in The Pilot (the Newsletter of the UNEP MArine Mammal Action Plan) [No.  4,  1989,  p.  13]. A reproduction of a Vanuatu  postage stamp purports to represent a dugong mother  and calf.  Mother  dugong's  muzzle and mouth are  truly  remarkable, strongly reminiscent of those of a St.  Bernard dog.  The partial view  of  junior's pectoral is  quite  manatee-like.  The  latter brings  to mind two occasions when I have picked up  coffee-table books  of  Australian  mammals in which the  impressive  "dugong" closeup showed an unmistakable West Indian manatee.

     Perhaps  I'm oversensitive,  having to routinely explain  to laymen  (and even fellow mammalogists) that dugongs and  manatees are,  taxonomically,  as different as dogs and cats, or sheep and goats.

     That  brings  up another pet peeve which is  relevant  here. Steller   described  the  pectorals  of  Hydrodamalis  gigas   as terminating  in hoof-like,  bristle-covered pads with  which  the animals  maintained position on surf-washed rocks while  cropping kelp. I've yet to see an illustration portraying this feature (as opposed   to   manatee  or  dugong-like   flippers).   Rise   up, sirenologists!   Let's  help  them  get  things  right!  

 

                                               Paul Anderson

 

[EDITOR'S  COMMENT:  A reconstruction of  Hydrodamalis,  done  by artist  Dugald  Stermer under my direction,  appeared  in  Oceans 13(5): 10-11, 1980. It attempted to show the flipper correctly. A new  poster  by Pieter Folkens,  also with my  advice,  seeks  to improve the depiction further. However, we'll probably never know if we've got it exactly right.]

 

 

                           LOCAL NEWS

 

AUSTRALIA

 

     Changes  to Fishing Regulations in  Southern  Queensland.  - Ever since the introduction of monofilament nylon nets, there has been  concern all over the world about the impact of gill nets on marine mammals,  including dugongs.  The only region in Australia where  management measures have been specifically  introduced  to minimize  this  problem  is the Great Barrier Reef  Marine  Park, where some important dugong areas have been closed to  commercial fishing.  This  response  is understandably very  unpopular  with fishermen.

     In  the  last  few  years,  there have  been  several  well-publicized incidents of animals drowning in commercial gill  nets set  in  Hervey  Bay in southeast Queensland.  This is  the  most important area for dugongs in Queensland south of Cape York,  and the area where fisheries and dugongs are most likely to  overlap. Most of the incidents have occurred in the winter,  when seasonal concentrations  of dugongs apparently occurred in the same  areas as similar concentrations of commercial fish, particularly school mackerel.  The numbers of dugongs drowned in some such  incidents are  high.  For  example,  the  local  Fisheries  Patrol  Officer informed me that at least seven and up to 14 dugongs drowned in a net  in August 1986.  The toll from this incident is greater than the   number  of  dugongs  caught  by  many   remote   Aboriginal communities in a year.

     The  impact  of commercial gill netting on dugong stocks  in southern  Queensland is unknown.  However,  this mortality is  of concern  to urban Aborigines and  Islanders,  who  understandably resent  their hunting being restricted when little has been  done about  the problem of incidental capture of dugongs in gill nets. This mortality is also used by recreational fishermen opposed  to commercial gill netting in an effort to close this fishery.

     The  commercial gill net fishermen who regularly operate  in southwestern Hervey Bay have reacted to this public opposition by using their local knowledge to develop strategies to minimize the chances of dugongs tangling in their nets.  These strategies have been  supported by the Queensland Fish Management Authority,  who have changed the regulations governing the fishery in key  dugong areas in Hervey Bay:  (1) the specifications of offshore set gill or  drift  nets  have  been changed to increase  the  chances  of dugongs escaping from the nets if incidentally captured; (2) each master fisherman can set only one net and must remain at that net at  all times to increase the chances of dugongs  being  released alive  after  accidental  capture;  (3) netting has  been  banned between 4pm and 4am in the months of July,  August, and September to reduce the chances of incidental capture.

     If  successful,  this approach may be a model for some other areas,  especially  those  from which it is impracticable to  ban commercial fishing.  -  Helene Marsh

 

     Dugong Pelvic Bones are Sexually Dimorphic. - During a visit to  Townsville this past summer,  I had the opportunity to  study the  large collection of dugong skeletal material that  has  been assembled by the James Cook University dugong project and that is now  kept  at  the Townsville branch of  the  Queensland  Museum. Thanks  to the voluminous and detailed data associated with  this unparalleled  collection,  it was possible to demonstrate for the first  time that dugong pelvic bones do vary systematically  with sex  and,  to  some degree,  age.  I studied pelvic bones  of  70 dugongs (41 males, 29 females), most of which had previously been aged by Marsh and her coworkers using growth layers in  tusks.  I constructed  a dichotomous key that was 93% accurate in placing a given  specimen in a category consistent with what was  known  of its sex, age, and sexual maturity.

     This  information  should prove useful to those  needing  to extract  data on sex and sexual maturity from  dugong  carcasses, especially  when  condition of the carcass precludes use of  more direct  indicators.  It may also prove  useful,  by  analogy,  in sexing  skeletons  of extinct dugongids.  A paper  reporting  the results  of  this  study has been submitted  for  publication  in Marine  Mammal Science.  Data will be welcome on  whether  pelvic variation in other parts of the range of Dugong dugon conforms to the pattern here documented for Queensland.  -  DPD

 

     Dugongs  Do Not Use Their Tusks For Feeding.  - Also in  the course  of my visit to Townsville,  I was able to examine stomach content  samples  from  many of the dugongs  in  the  James  Cook University  collection,  as  well  as ones collected  by  Brydget Hudson and her coworkers in Papua New Guinea.  As far as I  could determine,  there  was no difference between males and females in the amounts of seagrass rhizomes ingested (as opposed to leaves), nor  did  adult males appear to have eaten larger  rhizomes  than females.  This  suggests that the erupted tusks of males are  not used   in  feeding  (specifically,   to  harvest  rhizomes   more effectively  than can females),  and hence that previous  workers have  been correct in assuming that the sexually dimorphic  tusks of dugongs are used only in social interactions.

     There is,  however,  no evidence that extinct dugongids were similarly  dimorphic,  and  I am in the process  of  testing  the hypothesis  that many of these forms did use their tusks to  feed on  seagrass rhizomes [see abstract in this issue].  As one  such test,  I  used  plastic casts of four different kinds  of  fossil dugongid tusks,  plus an actual Dugong tusk,  as digging tools to extract  rhizomes  by  hand from seagrass beds at  two  sites  in northern Queensland.  With the help of Helene Marsh's statistical wizardry,  I was able to demonstrate that, whereas size and shape of  tusk  are  irrelevant  to ability  to  excavate  rhizomes  of Cymodocea  and  Halodule,  longer  and more bladelike  tusks  are significantly  better when the task is excavation of the  larger, tougher,  and more deeply buried Thalassia. This corroborates the hypothesis,  and may help to explain how three,  four,  five,  or even more species of dugongids were able to coexist sympatrically in the Caribbean region during the Miocene.

     I  also conferred with Tony Preen at James Cook  University, and visited Janet Lanyon at Monash University in Melbourne.  Both have  gathered  voluminous  and diverse data  on  dugong  feeding ecology for their nearly-completed doctoral dissertations,  and I venture  to predict that we are on the threshold of a significant new synthesis in our understanding of this topic.  I thank Helene and  Janet for their generous hospitality and help in  making  my Australian visit highly productive as well as enjoyable.  -  DPD

 

     Dugong  "Nose Valves".  - In the letter above,  I unburdened myself  of my frustration with artists' dugong  renditions.  Here I'd  like to point,  more briefly,  to a  frequent  misconception regarding dugong anatomy (one of which I suspect I've been guilty in  the  past).  On the basis of superficial observation one  can easily conclude that on submergence,  dugong nostrils are  closed by an anteriorly attached flap, and this erroneous impression has crept  into the popular literature.  The true situation is  quite different.  The openings are actually closed by means of cushion-like  pads in the floors of the nostrils.  It appears that in the relaxed  position  the floor of the passage is elevated  so  that this pad blocks the opening,  and that exhalation and  inhalation require  muscular retraction of the floor to open the air passage (see Domning,  1978,  Acta Amazonica 8,  Supl. 1, p. 57). It's an eminently sensible sirenian invention.  -  Paul Anderson

 

COLOMBIA

 

     New  Amazonian Manatee Project Planned.  - Antonio Villa  L. reports  that the Colombian natural resources service is planning a program for the conservation, research, and reproduction of the Amazonian manatee.  They are also trying to interest local people in  the  work  and educate them  about  manatees.  Some  research facilities  and related projects are already in existence at  the Amacayacu National Park.  This park, which comprises 3,000 square kilometers  and  was gazetted in 1975,  is located  in  the  most southern  territory  of  Colombia,  in close contact  with  human populations  along  the  Amazonas  and  Putumayo  rivers,   where manatees were abundant in the past.

     The project's planners are looking for help with references, suggestions,  and comments.  The contact address is:  J.  Antonio Villa L.,  Jefe, Parque Nacional Amacayacu, INDERENA, Apdo. Aereo 006, Leticia, Colombia.

 

FLORIDA

 

     Creative  Justice  Dept.  -  A boater caught speeding  in  a manatee  protection  zone  has  been sentenced  to  32  hours  of shouting warnings to other boaters along the Withlacoochee River.

     "It  seemed  a common-sense solution to a  problem,"  Citrus County  Judge  Gary  Graham said of the sentence he  gave  Al  L. Porter on June 19,  1990.  Porter,  working his community service under the Florida Marine Patrol,  will stand on the banks of  the Withlacoochee  and holler to speeding boaters to slow  down.  The judge  waived a fine and withheld a finding of guilt for  Porter, 19,  of Sebastian Inlet on Florida's east coast,  but ordered him to  carry a personal message to boaters on the  Withlacoochee  in west-central Florida.

     "If  they  have to come back for four or five  weekends  and work  to  solve the problem they are creating,  it will stick  in their minds," the judge added.  "We've got manatee zones designed to  protect  the  manatee and they  are  just  not  working.  The manatees continue to be killed."  -  Associated Press

 

     The  following information is excerpted from a recent report of  the  Marine Mammals Section,  Florida Department  of  Natural Resources.

 

     Manatee  Mortality.  - As of the end of  September,  manatee mortality in Florida in 1990 has soared to 176, already exceeding the  total  mortality  for  all of  last  year  by  ten  animals. Practically  all of the increase over 1989,  however,  is due  to last winter's heavy cold-related mortality;  mortality from other causes is tracking about evenly with the 1989 rates. Nonetheless, it's  getting  much  harder  to be uplifting as  we  continue  to experience new records in mortality.

 

     Manatee  Salvage/Research.  - The  emphasis of  the  salvage program over the last several months has been to achieve a higher standard  of  performance.  There have been  several  significant positive   changes.   We  have  capitalized  on   the   initially inconvenient   circumstance  whereby  the  Kissimmee   Diagnostic Laboratory abruptly discontinued its involvement in salvage. This necessitated  planning  for construction of a  centrally  located necropsy  facility  using funds from the U.S.  Fish and  Wildlife Service (USFWS).  A site for this facility is being secured,  and much  of  the  scientific  equipment  for  it  has  already  been purchased.  Ground-breaking  is expected later  this  fall.  Also integral  to  the operation of a central necropsy facility  is  a network  of refrigerated trailers to transport  carcasses;  these have  been  designed by Section staff and will be engineered  and manufactured by a national company.

     Research   funding   for  collaborative  projects   on   the pathogenesis  of clostridial organisms and genetic  relationships of captive manatees has been committed.  A request for  proposals on manatee acoustic research is in preparation.  Dr. Scott Wright is   supervising  the  research  project  of  a  student  at  the University  of  Central Florida concerning the  microanatomy  and dynamics of the manatee thyroid gland.  He is collaborating  with Dr.  Greg  Bossart  (Miami  Seaquarium) on  the  relationship  of circulating  levels  of  thyroxine  and  the  immunohistochemical staining of the thyroid in manatees.  Dr.  Wright is working with Mote  Marine  Laboratory to establish the incidence of  pulmonary anthracosis.

 

     Geographic   Information   System.   - The  GIS   has   been extensively  used  to create maps that accurately  represent  the proposed manatee protection zone boundaries. Protection zone maps are used along with maps showing manatee distribution as observed during  aerial surveys and locations of dead animals for  display during  public  hearings.  The maps are also used  by  management staff  reviewing  water-related projects to  determine  potential impacts to manatees.

     In  September,  new  digital base maps were  received  which bring  GIS  coverage  to the entire Florida  shoreline  with  the exception of Monroe County and Lake Okeechobee. These two missing pieces  should  be received from the  National  Ecology  Research Center  by  late  October.  The  available base  maps  have  been provided  to  other governmental GIS users including  the  USFWS, Everglades  National Park,  Florida Department  of  Environmental Regulation,  and  numerous county governments.  Digitized  aerial survey  data sets,  along with mortality data through 1989,  have also  been  distributed to agencies for their use  in  protection plans and permit reviews.

     The Marine Resources GIS (MRGIS), of which the Marine Mammal Section GIS is a part,  has purchased a new computer system which will  replace  the outdated system purchased  in  1982.  The  SUN fileserver  and associated workstations will run at speeds up  to 15  million instructions per second,  provide at least 4  billion bytes  of  on-line data,  and have graphic resolution four  times that of microcomputers currently used by Section  personnel.  The Section  has purchased a workstation to act as the Marine Mammals node into the MRGIS via an Ethernet network.  By the end of 1991, each marine mammals researcher and manager should have access  to the MRGIS through a menu-driven system on the network.  Until the network is complete, the Section's GIS personnel will continue to provide both researchers and managers with data and maps required to publish scientific papers and effect public presentations.

 

     Population  Assessment  and  Aerial  Surveys.   - Plans  are underway  for the Synoptic Survey,  a statewide aerial survey  of manatees  to  be conducted twice between December  15,  1990  and March 15,  1991,  after major cold fronts.  These surveys must be conducted  under  specific weather conditions to  be  meaningful. Each  survey will require about 25 airplane days and 50  observer days of effort.

     Twice-monthly  aerial surveys are currently being  conducted to  count manatees and dolphins in Tampa Bay and Collier  County. Another  aerial  survey is set to begin in St.  Lucie and  Martin counties.  Three cooperatively funded manatee aerial surveys  are also  ongoing or starting up in Cocoa Beach,  Palm Beach  County, and  Everglades  National Park.  An aerial survey  of  endangered right  whales on their calving grounds off northeast Florida will be conducted in the coming winter.

     Plans  are underway for an assessment of visibility bias  in John  Reynolds' winter aerial survey of manatees at power  plants in cooperation with the USFWS and Eckerd College.  The objectives of  the research are to estimate the reliability of  power  plant aerial  counts  and to establish a population index that  can  be used  to  determine whether the population is rising or  falling. The percentage of satellite- and radio-tagged animals seen during aerial  surveys  will  be used to estimate what  percent  of  all manatees present at the warm water discharges is observed.

     USFWS satellite telemetry locations have been processed  and added to our GIS system,  for data obtained between December 1986 and  June  1989.  These  data  are being used  as  an  additional indicator of manatee distribution for the development of  manatee protection  zones  and to better predict what weather  conditions will optimize aerial counts at power plants.

 

     Passive  Integrated  Transponder (PIT)  Tags.  - A  research project to investigate the potential to permanently mark manatees using PIT tags has recently been initiated.  PIT tags are  minute glass-encased microchips which have no power source of their own. An  external  power  source called a scanner  "reads"  the  tag's unique  12-digit  identification  code when passed close  to  the injection site.  Tags will be injected under the dermis,  at  two sites  on  each animal.  The first phase of the project is  being conducted  on fresh manatee carcasses to determine the best  site and  the best method of injection.  Work on this phase  began  in late August.  The second phase will be directed toward animals in captivity,  with  two animals being tagged initially at Homosassa Springs Nature World,  Sea World,  and Epcot.  Epcot Living  Seas contributed $6,000 toward this research. Ultimately, this project should  facilitate obtaining an accurate population estimate once it is applied to the wild population over several years.

 

     Telemetry.  - A three-year west coast telemetry project will be  begun in February 1991 by tagging up to five manatees at  the warm  water  discharges  of  power  plants  in  Tampa  Bay   with assistance from the USFWS Sirenia Project. Up to 90 manatees have been  counted at the Bay's thermal refuges in winter,  but aerial survey  counts  indicate that more than half leave  in  the  non-winter  seasons.  While aerial surveys have been used to map  the distribution  of animals throughout the Bay,  the telemetry study should  provide  additional data on  daily  movements,  migratory pathways,  and  reactions of tagged animals to  boating  traffic. Staff  for  the  telemetry project will be working  with  Sirenia Project  personnel this fall to assemble transmitters  and  build belts  necessary for tag attachment.  Telemetry project staff and staff members from Tequesta and Jacksonville will also assist  in tracking  manatees  tagged  on  the east  coast  by  the  Sirenia Project.

 

     Manatee  Protection  Zones.  - Manatee protection  zones  in Collier  and  Brevard  counties  were  adopted  in  June  by  the Governor and Cabinet.  Public hearings have been conducted on the zones  in  Palm Beach and Martin counties;  these zones  will  be presented for adoption at the November 15 meeting of the Governor and Cabinet.  The next rules to be drafted will contain the zones for Dade, Broward, and Duval counties.

     Protection in the vicinity of the Ft. Pierce power plant has recently  been  increased  to  year-round  status.  Sign  posting projects  are  planned or in progress in the Banana River and  in Brevard,  Palm  Beach,  and Martin counties.  The Florida  Inland Navigation  District  (FIND) was directed by the  Legislature  to take  over  from  the Department of Natural Resources  the  sign-posting activities for the 13 key manatee counties. FIND's fiscal year started on October 1,  with $700,000 budgeted for the  sign-posting projects.

 

INDONESIA

 

     New  Dugong  Project  in the Moluccas.  - In  April  1990  a project  was  initiated on dugong management and conservation  in the Maluku Province,  Indonesia. The project is a cooperative one between   the  Environmental  Study  Centre  of   the   Pattimura University  (UNPATTI) at Ambon and the Foundation Aid Environment at  Amsterdam;  it is financed by the Commission of the  European Economic Community. Participating Dutch research institutions are the Centre for Environmental Studies of the Leiden University and the Research Institute for Nature Management at Texel.

     The  major  objectives  of the program are  to  implement  a research  and monitoring program on dugong populations and  their habitat  in selected project areas in the Maluku Province and  to train UNPATTI staff in research methodology.

     Since  virtually no research on dugongs has been carried out in  Indonesia,  and very little information is available for  the Maluku Province, the project had to start with a very meager data base.

     Initially  the eastern part of the Aru Archipelago had  been selected as the major area for field studies. Nishiwaki and Marsh referred in 1985 to the Aru Islands as an area where "toward  the end  of 1979 dugongs were apparently still very  numerous".  This information  was  based on reports provided by Salm in  1984  and Compost in 1980, based in turn on a field survey during 1979.

     However,  since the visit by Compost in 1979 no more studies were reported from Aru. This lack of information is partly due to the   remoteness  of  the  Aru  Archipelago  and  the  logistical constraints  on  the implementation of major studies in  such  an area.

     Compost,  who  spent two months on Aru,  made mention  of  a serious  threat to dugong populations from the increasing use  of shark  nets  in shallow coastal areas.  Based on interviews  with local informants,  he estimated an annual catch of  approximately 1,000 animals in the main fishing zones.

     A  project  team visited eastern Aru during April  1990  and selected a suitable site for further research on the eastern side of  Kobroor  Island,  near  the  village  of  Balatan.  Based  on interviews  with  local  fishermen in seven villages  and  actual observations of dugong catches,  the estimated catch for  eastern Kobroor, in 1989, amounted to 20-40 dugongs. Compost estimated in 1979  an  annual catch of 80-200 dugongs for the fishing zone  of East Kobroor (Mairiri and surroundings), indicating a significant decline in the annual catches in this area.

     Although Compost reported in 1980 that harpooning of dugongs by specialized dugong hunters was still common in the  area,  the team observed in 1990 that this method had been abolished.  Local villagers  stated  that the major reasons for this were  depleted dugong  stocks  and  the increasing importance  of  pearl  oyster diving and shark netting as major sources of income.

     Dugongs were mainly reported as an accidental side catch  in the  shark  nets.  However,  dugong  meat  was  still  a  favored commodity,  and  dugong tusks and ribs were still traded for  the manufacture of cigarette holders, as reported by Compost in 1980.

     A  detailed  analysis  of dugong catches in the  village  of Balatan  from 1975 onwards revealed that harpooning was  a  major cause  of  dugong  mortality until 1981;  thereafter  shark  nets contributed almost exclusively to dugong  catches.  Incidentally, dugong  catches  were  reported in tidal traps (sero)  made  from wooden fences and placed close to the mangrove fringe.

     Based on this analysis,  it is concluded that shark  netting is  the  major cause of dugong mortality in the project  area  of eastern Kobroor.

     Within the framework of the project,  a plan was drafted for further  studies in the project area.  It was,  however,  decided that,  due  to  the archipelago's remoteness,  only part  of  the program would be implemented in Aru. Since the project team found feeding  tracks of dugongs in several intertidal seagrass meadows of   Halodule  uninervis  and  Cymodocea  rotundata   during   an additional  field  survey  in coastal areas  of  Ambon,  Saparua, Hairuku,  and  Nusa  Laut,  it was decided to focus part  of  the program on the area of Ambon and adjacent islands.

     Since  April  1990,   a  field  station  in  Aru  has   been permanently  staffed  by  scientists  and  students  of  UNPATTI, whereas  Dutch  students and scientists of the Leiden  University and  the Research Institute for Nature Management participate  in the research programs in both Ambon and Aru.

     A   major  theme  in  the  study  is   the   seagrass-dugong relationship.  The  team investigates in particular the  carrying capacity of littoral seagrass meadows,  recolonization of feeding tracks,  biomass  and growth of rhizomes and shoots,  and  dugong distribution. However, since scientific information on dugongs is very  scarce in Indonesia,  the project also covers dugong  catch statistics, dugong aerial surveys, processing of recovered dugong carcasses,  dugong  field observations (an observation tower  was constructed at Aru),  dugong behavior, and habitat mapping. Apart from  biological  and  ecological  aspects,   the  program  gives particular attention to the socioeconomic aspects.  Project funds have  been  allocated to give support for an  improved  community water supply and school facilities in the village of Balatan.

     A   public   awareness  and  information  campaign   is   in preparation,  to  inform local villagers about the importance  of dugong   conservation.   So  far  in  Indonesia,   no  particular conservation  measures  have been proposed  or  implemented  with respect to dugong populations. The team concluded in this respect that  the recently established Aru Tenggara National Marine  Park does  include  limited  areas suitable  as  dugong  habitat.  The project should,  therefore, eventually lead to recommendations on the  designation of appropriate conservation zones.   -  Hans  de Iongh

 

     School  Children  and  Dugongs.  - In order to  obtain  more information about the dugong,  but from another angle, the pupils in  a  number  of classes in Koijabi (Aru)  were  asked  to  make drawings  of  the  animal,   which  could  also  be  used  as  an interesting  basis for a discussion with them.  We expected  that the  drawings would give an indication of the familiarity of  the children with the animal. (On Aru there are no pictures, books or posters showing the animal.) The teacher,  a man from Kei, though clearly  instructed  about the aim of the  exercise,  wanted  his pupils  to make a good impression.  He presented his image of the animal to the children first,  though it was obvious that he  had never clearly observed the dugong.  He drew one like a fish. Some of the drawings of the pupils, however, clearly show a good image of  the  animal.  Interesting  in particular were  some  drawings showing a kind of "evolution" from the teacher's fish to the real animal [see illustration below].