NUMBER 14 OCTOBER 1990
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
NUMBER 14 OCTOBER 1990
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
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
NUMBER 14 OCTOBER 1990
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.
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. sirenolo2ists! Let's helD them 2et things ri2ht!
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[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.]
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
NUMBER 14 OCTOBER 1990
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,
NUMBER 14 OCTOBER 1990
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
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.
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
NUMBER 14 OCTOBER 1990
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." -
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
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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
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
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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.
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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
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
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
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
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
NUMBER 14 OCTOBER 1990
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 longh
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 (Am) 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
NUMBER 14 OCTOBER 1990
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].
All children had seen dugongs a number of times, even though in Koijabi some animals
might be caught, dragged ashore and consumed without being noticed. About 15 children
(out of 48) informed us that their father had ever caught a dugong, while all of them (except for
the boys of the Chinese shopkeeper) had eaten dugong meat. Attempts to learn frequencies of
dugong catches or consumption from the children proved to be very difficult and did not result in
very clear answers. Gerard Persoon
Madagascar has signed a treaty with Japan which opens several sensitive dugong habitats
to the Japanese [fishing] nets. It may spell the end for an already severely depleted [dugong]
NUMBER 14 OCTOBER 1990
stock in the Antongil and Ile Ste. Marie areas of eastern Madagascar. Pieter Folkens
Stranding Network Established. Antonio A. Mignucci Giannoni reports that a Red
Caribena de Varamientos (Caribbean Stranding Network) has been created in Puerto Rico to
assess mortality of and to rescue and rehabilitate stranded, sick or injured manatees, dolphins,
whales, and sea turtles. Participants in the Network are found so far in six Caribbean
countries (Puerto Rico, U.S. Virgin Islands, British Virgin Islands, Dominican Republic,
Colombia, and Venezuela), and more will be added as the organizers approach other countries
for traineeship and cooperative agreements. The Network's address is: Red Caribena de
Varamientos, c/o Departamento de Ciencias Marinas, Universidad de Puerto Rico, RUM,
Apartado 908, Lajas, Puerto Rico 00667-0908.
In order to attend emergency cases of sick or injured animals, a 24-hour-a-day phone
pager has been established. The number is (809) 782-8686, pager unit 124-3565.
Manatee Surveys. Buddy Powell, now based in Cameroon, reports that he conducted
some brief manatee surveys this past spring in Guinea-Bissau and Senegal, where the
governments are hoping to set up some reserves and management programs for manatees.
"The most interesting area", says Buddy, "was the Bijagos Archipelago, which lies off the
coast of Guinea-Bissau. There are about 50 islands and only 19 are inhabited. The outermost is
about 40 miles offshore. It appears that all of the larger islands have manatees. Orango
Island seems to have the largest population. On Orango there is very little hunting pressure.
However, on Formosa Island, where there also appear to be quite a few manatees, Senegalese
fishermen build platforms near freshwater seeps where they can harpoon the manatees when
they come to drink from the springs. On a 2 km stretch of river I counted six platforms. It
was at the end of the dry season, so only one seep was still flowing. I tested it with a salinity
meter sure enough, very fresh. Manatees seem to feed primarily on Rhizophora, but I also
found an extensive meadow of probably Zostera between Formosa and Carache islands. The
fishermen report that manatees are often seen feeding on the meadow.
"The Bijagos also has a sizable population of 'marine' hippos. They live in the mangrove
estuaries and can sometimes be seen in the ocean adjacent to beaches. We saw only one in the
mangroves, but also tracks on the beach."
Buddy also mentions that manatee meat is still openly sold in the fish market at Douala,
Cameroon, in fact, it has become fairly common lately. At least some of the manatees are
apparently taken in the Wouri River adjacent to Douala. He expects to do some satellite
tracking in Ivory Coast next spring to follow up on his earlier research and the current work
being done there by Akoi.
NUMBER 14 OCTOBER 1990
The following abstract is of a paper being presented at the IV Reunion de Trabajo de
Especialistas em Mamiferos Acuaticos de America del Sur, held in Valdivia, Chile, Nov. 12-15,
1990. It is here translated from the Portuguese.
Feeding Habits of the Amazonian Manatee (Trichechus inunguis) (I.G. Colares and R.
C. Best). Trichechus inunguis is the only sirenian endemic to the Amazon region and lives
exclusively in fresh water. It is a non-ruminant herbivore that feeds on a wide variety of
aquatic and semiaguatic plants. To determine its feeding habits, we used an indirect
method: comparison of epidermal tissue of plants found in the digestive tract and/or feces with
epidermal specimens of plants previously identified in the animal's habitat. Microscope slides
were made of specimens from digestive tracts of animals found dead and/or from feces found
floating in different regions of the Brazilian Amazon, with the objective of identifying the plants
in the diet. We identified 24 species of aquatic macrophytes in the digestive tracts and feces
analyzed. Among these, 15 species were of emergent plants, 6 of floating plants, and 3 of
submerged plants. The greatest number of plants (13 species) belonged to the family Gramineae,
of these, the animals preferred Paspalum repens and Echinochloa polystachya. The second most
frequent family was the Pontederiaceae, with Eichhornia crassipes. We observed variation from
1 to 7 plant species in each sample, with 2 to 3 species per animal being the most common
observation. Separating the samples by season (dry or flood), we found in each season the
same tendency of animals to have eaten predominantly 2 or 3 species of plants, except that
during the dry season 23 species were identified, while only 10 species had been consumed
during the flood season.
The following abstract is of a paper presented at the annual meeting of the Society of
Vertebrate Paleontology, Lawrence, Kansas, Oct. 13, 1990.
The Rytiodontine Radiation: Diverse Large-tusked Sirenians as Key Species in Cenozoic
Seagrass Communities (Daryl P. Domning). The chief discovery in sirenian paleontology in
the last five years is that Rytiodus, a rare and "aberrant" dugongid described in France in 1866,
was really the Old World tip of a New World iceberg. The Subfamily Rytiodontinae now
stands revealed as a major dugongid clade, probably Caribbean in origin, that radiated vigorously
in the Late Oligocene and Early Miocene and persisted into the Pliocene. It is so far known to
comprise at least five genera, most of which had large, bladelike, self-sharpening tusks.
I hypothesize that these animals specialized in excavating large, tough seagrass rhizomes,
thereby disrupting "climax" seagrass communities and increasing the latter's diversity and
productivity. This in turn could have helped create and maintain niche space for other
dugongids with smaller tusks and/or body size. This hypothesis, for which I have begun to
NUMBER 14 OCTOBER 1990
develop experimental tests, is an attempt to explain the fact (also newly discovered) that Miocene
Caribbean faunas included at least three and probably five or more sympatric dugongid
species a situation unparalleled in the modern world.
The following abstracts are of papers presented at the VIIIth Biennial Conference on the
Biology of Marine Mammals, held in Pacific Grove, California, Dec. 7-12, 1989.
Bajpai, S., M.P. Singh, and P. Singh. 1987. A new sirenian from the Miocene of Kachchh,
western India. Jour. Palaeont. Soc. India 32: 20-25. [Metaxytherium kachchhensis (sic), n. sp.1
Bonde, R.K., and C.A. Beck. 1990. How the Florida manatees fare today. Whalewatcher 24
Buckingham, C.A. 1990. An evaluation of manatee distribution patterns in response to
public use activities in Kings Bay, Crystal River, Florida. Florida Cooperative Fish &
Wildlife Research Unit (Univ. of Florida, Gainesville), Tech. Rept. No. 39: 1-49.
Chambers, M., and E. Bani. 1989. Vanuatu safe haven for the dugong. The Pilot (Nairobi,
IUCN & UNEP) No. 4: 13-14.
Chambers, M., and E. Bani? 1989? [Report of dugong survey in Vanuatu.1 South Pacific
Regional Environment Programme Topic Review No. 37.
Colmenero-R., L.C., and B.E. Zarate. 1990. Distribution, status and conservation of the West
Indian manatee in Quintana Roo, Mexico. Biol. Conserv. 52: 27-35.
Domning, D.P. 1990. Fossil Sirenia of the West Atlantic and Caribbean Region. IV.
Corystosiren varguezi, gen. et sp. nov. Jour. Vert. Paleo. 10(3): 361-371. [Spanish summary.]
Donovan, S.K., D.P. Domning, F.A. Garcia, and H.L. Dixon. 1990. A bone bed in the Eocene
of Jamaica. Jour. Paleo. 64(4): 660- 662. [Discovery of new specimen of Prorastomus
Fischer, M.S. 1990. Un trait unique de l'oreille des elephants et des sireniens (Mammalia): un
varadoxe phvlogeneticue. C. R. Acad. Sci. Paris (3)311(4): 157-162. [English summary.]
NUMBER 14 OCTOBER 1990
Geraads, D. 1989. Verte'bre's fossiles du mioce'ne supe'rieur du Diebel Krechem el
Artsouma (Tunisie centrale. Comparaisons biostratigraphigues. Ge'obios 22(6): 777-801.
[Describes a tooth of Metaxytherium sp.1
Hasegawa, H. 1988. Paradujardinia halicoris (Owen, 1833) (Nematoda: Ascarididae)
collected from a dugong, Dugong dugon, of Okinawa, Japan. Biol. Mag. Okinawa #26: 23-
25. [In Japanese; English summary.]
Ijiri, S., and N. Inuzuka. 1989. [Extinct Japanese giant
Shokan Publ. Co., Ltd.: 1-242. [In Japanese. Discusses
MacPhee, R.D.E., and A.R. Wyss. 1990. Oligo-Miocene vertebrates
a catalog of localities. Amer. Mus. Novitates 2965: 1-45.
Morgan, M.A., and G.W. Patton. 1990. Aerial studies of the West
(Trichechus manatus) on the west coast of Florida. Mote Marine
Tech. Rept. No. 167: iv + 21 + .
mammals.] Tokyo, Tsukiji-
desmostylians and North
from Puerto Rico, with
Lab. (Sarasota, Florida)
Mou Sue, L.L., D.H. Chen, R.K. Bonde, and T.J. O'Shea. 1990. Distribution and status of
manatees (Trichechus manatus) in Panama. Mar. Mamm. Sci. 6(3): 234-241.
Myroniuk, P. 1988. A survey of mammals on Hinchinbrook Island,
Austral. Zool. 25(1): 6-10.
Osakwe, M.E., A.J. Meduna, E.E. Kigbu, and P.D. Ishaya. 1988. Management of pigmy
hippopotamus and West African manatee in Jos Wildlife Park. Nigerian Field 53(4): 175-178.
Paterson, R.A. 1990. Effects of long-term anti-shark measures on target and non-target
species in Queensland, Australia. Biol. Conserv. 52(2): 147-159.
Patton, G.W., H.F. Anderson, and A. McAllister. 1989. Port of the Islands manatee habitat
characterization: final report. Mote Marine Lab. (Sarasota, Florida) Tech. Rept. No. 148: i + 8
Reep, R.L., J.I. Johnson, R.C. Switzer, and W.I. Welker. 1989. Manatee cerebral cortex:
cytoarchitecture of the frontal region in Trichechus manatus latirostris. Brain Behav. Evol.
NUMBER 14 OCTOBER 1990
Reep, R.L., and T.J. O'Shea. 1990. Regional brain morphometry and
Sirenia. Brain Behav. Evol. 35(4): 185-
Satoh, A., K. Hashimoto, and Y. Hasegawa. Early Miocene
Goyasu Formation, Iwaki City, Fukushima Prefecture, Japan.
Natl. Univ., Sec. II (Biol. & Geol.), No. 36: 57-70. [In Japanese;
Vazzana, A. 1988. Sirenidi del Miocene in Calabria. Not. Mineral.
Wang Z. 1989. Manatee, an ugly treasure. Nature (Beijing) No. 37:
lissencephaly in the
desmostylid skull from
Sci. Repts. Yokohama
Paleont. #56: 27-29. [In
46-47. [In Chinese.]
CHANGES OF ADDRESS
Ioni G. Colares, Laboratorio de Mamiferos Aquaticos, INPA, C.P. 478, 69011 Manaus -
AM, BRASIL; FAX NUMBER: 092-236-0255 [= Brazilian manatee project address]
Hans H. de Iongh, Centre for Environmental Studies, Leiden
P.O. Box 9518, 2300 RA Leiden, THE NETHERLANDS
University, Garenmarkt la,
Daryl P. Domning, Sirenews, Dept. of Anatomy, Howard University, Washington, D.C.
20059 USA; NEW FAX NUMBER: 202-806-5523; NEW TELEPHONE NUMBER: 202-
Tony Preen, Zoology Dept., James Cook University, Townsville,
Qiu You-xiang, Dept. of Zoology, Univ. of Florida, Gainesville,
Pat M. Rose, Florida Dept. of Natural Resources, 3900 Cor
Tallahassee, Fla. 32399 USA
Essam Samson, Ingenieur des Eaux, Fore^ts et Chasses, Ministere du
Qld. 4811, AUSTRALIA
Fla. 32611 USA
NUMBER 14 OCTOBER 1990
Jeheskel Shoshani, Elephant Interest Group, 106 East Hickory Grove Road, Bloomfield
Hills, Mich. 48304 USA
U. S. Marine Mammal Commission, 1825 Connecticut Ave. NW, Suite 512, Washington, D.
C. 20009 USA
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