NUMBER 6
OCTOBER 1986
LOCAL NEWS
BORNEO
During a
visit to Sabah, Malaysia, from 28 June through 10 July 1986
I spoke to several people familiar
with wildlife conservation in
Kota Kinabalu and Sandakan. Fishermen report few, if any, sightings of dugongs, which are considered
very rare, or possibly extirpated, along
the coast in Sabah. The last animal reported from the Sandakan area was butchered and
eaten in 1984. I also spoke to a biologist studying proboscis
monkeys in the mangrove forests of Sarawak, Malaysia.
Dugongs also are thought to
be rare or extirpated in this region
of Borneo. Intense fishing and the introduction of nylon fishing nets
probably are related to the decline in
dugong numbers in northern Borneo.
- Galen B.
Rathbun (U.S. Fish & Wildlife Service)
BRAZIL
Manatee
Research at INPA. - While Robin Best
is working on his doctoral degree at Cambridge, England,
manatee research at the
Instituto Nacional de
Pesquisas da Amazo^nia
in Manaus continues under the interim supervision of Elton Pinto Colares. He reports on recent activities as
follows:
The objective
of the aquatic mammal project at INPA is
to study the distribution, exploitation,
and ecology of aquatic mammals in order to better understand
their role in the ecosystem and their importance to the human population along
the rivers of Amazonia. The
project also seeks to study
the basic biology, feeding habits, growth,
behavior, etc., of aquatic mammals, and on this
basis to develop plans
for their conservation
and rational utilization and
techniques for raising
them in captivity. To
these ends we are carrying out the following investigations on
the Amazonian manatee:
food preferences; feeding habits;
annual variation in aquatic macrophytes and their nutritional
constituents; daily food consumption; digestibility of food and passage time
through the digestive tract; anatomy of
the digestive tract and sites of nutrient
absorption; optimum
composition of milk formula for development of manatee calves; endocrinology; cytogenetics; and age
determination.
New Manatee Legislation. - Robin Best reports that, as a
result of new legislation (Portaria No.
011 of Feb. 21, 1986), the
Brazilian federal fisheries agency SUDEPE now has authority to protect manatees, small
cetaceans, and seals. This should mean that wardens of either IBDF (the federal
forestry agency, which has
traditionally had jurisdiction over manatees and most other wildlife) or
SUDEPE can now protect these
animals. Robin had suggested and supported this action, and Sirenews
is glad to hear that it has been taken.
New West
Indian Manatee Project.
- The Environmental Department of
IBDF has recently begun a project on the biology of Trichechus manatus in Brazil. This will center around a radio-tracking study,
and is based at a field
station at Barra
de Mamanguape in Paraiba. The project is headed by Mo^nica Borobia, a
former student of the manatee project in Manaus. Because of
the station's remoteness from libraries,
she would like very much to receive
reprints on marine mammals. Her mailing
address is: Mo^nica Borobia, a/c Dr. Henry Matthews, ESAM, C.P. 137,
Mossoro', RN 59.600, Brasil.
INDIA
Can a
Saw-fish (Pristis sp.) Kill a Dugong? - On 15.4.86
a male dugong 2.73 m
in length was found floating near
Manoli Island in the Gulf of
Mannar. The animal was towed to the
shore and examined. There were many deep
gashing wounds on the ventral side of the dugong. Some of the wounds were as long as 50 cm and
2 cm deep. The flippers were perforated by the injury. The animal had just died,
as indicated by the fresh blood in the
viscera. The local fishermen say
that saw-fish (Pristis sp.),
which are common in the
area, attack dugongs, and similar cases have been seen by them. According to them the saw-fish, which lies buried in the
sand, gets provoked when the dugong
goes near them browsing the sea-grass. The shadow of
the dugong provokes them to attack. The
fishermen also seem to be cut by the Pristis sp. in these
areas. Dr. Francis Day (1878), the well-known author on Indian fishes, also
has reported such attacks on fishermen by the saw-fish. Further,
two Echenies naucrates (sucker-fish)
were found attached near the armpit of the dugong.
I would appreciate knowing if any dugongs
attacked by saw-fish have
been reported by
earlier workers. Comments
from sirenian workers on these observations are welcome. - R.
S. Lal Mohan (Research Centre of CMFRI, West
Hill, Calicut 673005, India)
DEVELOPMENT OF
DUGONG TELEMETRY GEAR - A PROGRESS REPORT
Several years
ago Helene Marsh of James Cook
University inquired if personnel of the U.S. Fish and Wildlife Service's Sirenia Research
Project could apply
the radio-tracking
techniques used on manatees in Florida
to dugongs in Australia. James Reid
and I agreed
to develop the
belt, tether and transmitter housing for dugongs, based on our
experience with manatees
(Rathbun, G.B., J.P.
Reid, and J.B. Bourassa. 1986. Design and
construction of a
tethered, floating radio-tag assembly for manatees. Unpubl. MS.,
U.S. Fish & Wildlife Service, Gainesville,
Fla.). Using morphometrics
and a cast
of the peduncle and fluke region
of a dugong, a prototype peduncle belt
was designed and built at the Service's
Gainesville Research Station in
Florida. The VHF transmitter housing used on the
manatees was used as a model for an improved version for dugongs. The tether
developed for manatees
has remained essentially unchanged. In order to test and further develop the new
assembly Helene Marsh and I applied for
a Marine Technology and Science Grant from the Australian Government, which was approved in late 1985.
The first
step in developing the prototype harness was to test
it on captive dugongs, which are
found only in Japan and Indonesia. The Japanese did not want
their animals disturbed, but the manager of the Jaya Ancol Oceanarium in
Jakarta, Mr. Tas'an, agreed to let us work with the two dugongs under his
care. With the help of Tas'an, a
research proposal to test the attachment on the
dugongs in Jakarta was approved by the Indonesian Government in January
1986. Helene Marsh, Anthony Preen from the Meteorology and Environmental
Protection Administration of Saudi
Arabia, Andrew Smith, a postgraduate student of Marsh's, and I met at
the Oceanarium in Jakarta on 11 June
1986. The two captive dugongs were
fitted with peduncle belts, tethers,
and dummy floating transmitter
housings and these were monitored for 16
days, when they were
removed. During this time several
modifications to the belts were made in order to reduce the possibility
of abrading the dugongs' skin.
Additional
funding from UNEP has been promised,
which will allow us
to test the new attachment
on free-ranging dugongs. These tests
are due to be completed in late
1986 in northern Queensland. - Galen B. Rathbun
HAVE YOU
ANY EDUCATIONAL MATERIAL ON SIRENIANS?
It has
been suggested that the IUCN Sirenia
Action Plan, currently under review [?], be expanded to include conservation [?] and
education as well as research options.
For this purpose it would
be useful to have a list of educational
and public awareness material
on sirenians that is currently available
in different languages and parts
of the world. This would include audiovisual materials (films, slides,
records, etc.), posters,
buttons, stickers, leaflets, pamphlets,
and teachers' guides, as well as popular and review articles. Please send
to Sirenews examples, copies,
or a description
(with prices, ordering information, and
conditions for reproduction
or use where possible) of any such materials that
are available in your area. (Hopefully
you are already making Sirenews aware of any published articles, popular
or technical, that come to
your attention!) If the materials cannot
be purchased, please let us know of their existence all the same;
they may provide examples for others to emulate. UNEP is already preparing a catalogue of such
items for marine mammals in general, but
it would be worthwhile to develop a more specialized one that could be appended
to our Action Plan in order
to provide a
basis for the
development of more specifically appropriate materials for
sirenians.
SIRENIAN CROSSWORD PUZZLE
No newspaper
is complete without one! Test your knowledge of sirenian trivia. Solution in
the next issue. (Sirenews
thanks the Aquatic Weed Program, University of Florida, Gainesville, and its
computer for assembling these words into a puzzle for us.)
REVIEWS
Judith
Delaney, Wendy Hale,
and Renee Stone,
Manatees: An Educator's Guide
to the Natural History, Habitat, Problems, and Conservation of the Order
Sirenia. 28-page booklet, 2 leaflets, and 17" x 22" poster. Florida Department of Natural Resources, Tallahassee. (Available
on request from the
Florida Audubon Society, 1101
Audubon Way, Maitland, Fla. 32751 USA.)
The schoolteacher
in search of material
for a biology lesson, the student needing information for a class
project, the researcher besieged by schoolchildren's requests for "everything you have on manatees" - all can now
relax; salvation has come. Florida's Save the Manatee Committee, sponsored by the Florida Audubon Society,
has produced an
envelope stuffed full
of attractively presented, up-to-date information on manatees and their
relatives, designed for primary
and secondary schools in Florida but
marvellously useful wherever teachers,
students, and the general public want to know something about
seacows. The heart of the package is a booklet filled with information
on manatee biology, manatee
conservation and regulatory
laws in Florida, aquatic ecology, marine mammals in general,
and sources of further information. All this is interspersed with puzzles, suggested activities, and ideas for helping manatee conservation
efforts. Four pages are designed to be
duplicated for individual students;
copy and distribution
of all the
material are encouraged. As the authors state, the "activities
can be adapted to suit the special needs,
ages, and abilities of your
students and are designed for multidisciplinary study areas."
"While this guide focuses on
the West Indian manatee, the importance of interdependencies within the whole ecosystem
and the role the manatee plays" are stressed throughout. However,
a lot more stress could have been placed on human population growth in
Florida as the root cause of the manatee's problems. This
is touched on in the suggested activities on pages 19 and 20, which are
good as far as they go; but
please - let's take off the kid gloves
and put the finger on the real issue, even
if it is unpopular in certain circles. Why not a graph of Florida's human
population growth, for
comparison with the graph of
manatee mortality? Why not
some discussion questions
explicitly challenging the belief that increase in our population is
a good thing? Come
on, teachers, the
kids aren't going to get the message if you don't have the courage to
tell them!
The booklet
is supplemented by a pair of leaflets comprising a concise "manatee fact sheet" of
basic natural history data; a list of
resource agencies and organizations in Florida
concerned with manatees; and
two solid pages of references
to recent popular and semipopular articles on sirenians, reference books, "books especially for
young readers", and available audiovisual aids. Also
included is an attractive four-color wall poster by Mary Ruth Sprankel portraying the
"Sirenians of the World", with
a map of their distribution. The manatee
and dugong pictures are quite true-to-life (something never to be taken for
granted), and even the one of Steller's sea cow is better than most
you will see in the literature.
Throughout, editorial and
typographical errors are few, and the facts are accurate. And there's more:
"Also available as part of the overall package is a 23 minute video tape
program, 'Silent Sirens: Manatees in
Peril,' available in either 1/2"
or 3/4" format from your
district media centers. Written
permission must be obtained from the
Florida Audubon Society before
duplicating this video cassette in part or in its entirety."
I am
impressed. Together with the authors, I
hope "that the use of this guide will result in informed decisions, responsible behavior, and constructive actions towards the protection
of the manatee and its habitat in Florida." It should also
serve as a model to
be emulated by public awareness
programs in other countries. If
it doesn't, it won't be the fault of those who created this excellent and unique
resource. - DPD
Mary Unterbrink, Manatees: Gentle Giants in Peril.
St. Petersburg (Fla.), Great Outdoors
Publ. Co., 1984: 1-47. Illus. (Softbound; ISBN
0-8200-9914-7. Order from Great
Outdoors Publishing Co., 4747
28th St. North, St.
Petersburg, Fla. 33714 USA.
Price US$2.95 + $1.00
postage & handling [$2.00
for orders over $10.00]; Florida residents add 5% sales
tax.)
This little
book gives a thorough and readable
introduction to the problems faced by the manatee in
Florida. Suitable for students
in grade school or above, or
anyone interested in manatees,
it covers the
last two decades
of research and conservation efforts in an anecdotal style, well seasoned
with up-to-date facts on the
manatee's life history. Several active manatee researchers contributed
information and helped ensure the book's accuracy. The illustrative sketches of manatees by
Robert G. Cannon are reasonably true to
life, though the drawing of a dugong
reflects the fact that most
wildlife artists still have little grasp
of sirenian anatomy, especially facial anatomy.
Emphasis is
properly placed on the various threats posed
by man's activities, and
the book gives
the Manatee Hotline telephone number
and the locations
of the various
manatee sanctuaries in Florida.
But it could usefully have included more explicit instructions
on what boaters, divers,
and would-be manatee watchers
should and should not do, in
accordance with present knowledge and
applicable laws. For example, the various degrees of
limitation on boat
speeds in and
near manatee sanctuaries should
have been described, and the
restrictions on contact of
manatees by divers should
have been more
clearly explained. Readers would also have welcomed advice on when and where
to see wild manatees
without disturbing them.
It is important for
the public to have some background
knowledge of what manatees are
and how they live, but it is equally
important to give them detailed guidance on minimizing the
problems we humans create.
The ultimate and most insidious source of these
problems is human population
growth, yet nowhere does the author
hint that Florida's explosive growth in
people, boats, marinas, and general busyness is the real issue. The lesson to be driven home is that most
wildlife management is really people management. Despite the book's stress
on the manatee's present peril, that
lesson could have been made still clearer, and this book accurately reflects how far
public comprehension of it has yet to go.
Although this
booklet does not completely meet the need
for a reliable popular
work on manatees, it makes
a worthwhile contribution, and
I hope it
will be used
by schools and conservation groups
as the convenient resource that it
is. An improved and
expanded edition would go
even further toward filling the need, and growing market, for nontechnical sirenian literature. - DPD
ABSTRACTS
Lung Structure
and Mechanics of the West Indian
Manatee (Trichechus manatus)
(Michael R. Bergey). - Marine mammals are capable of
exchanging lung air
very rapidly compared
with similarly sized terrestrial
mammals. This capability has
been attributed to the great
stiffness of marine mammal airway walls, which reduces flow-induced restriction
of the lumen during rapid
exhalations. In this
study, manatee lung morphology and flow mechanics were investigated using
specimens harvested from dead,
stranded animals. Airway
dimensions were measured
from vinyl acetate lung casts,
direct dissection, and histological sections. Static volume-pressure relationships were recorded
by measuring lung volume changes while
pressure on the lung surface was varied to simulate chest wall movements. Maximum expiratory flow-volume data were
obtained by venting inflated
lungs rapidly into an evacuated
chamber while recording
instantaneous lung volume changes.
Manatee lung airways differed greatly from the terrestrial pattern by
possessing cartilage plaques at
the level of the
respiratory bronchioles, and unbroken
rings within the walls of all larger
airways. The excised lungs changed volume greatly with small changes in
inflation pressure, and demonstrated
very small residual volumes when inflation pressure was reduced to
zero. Maximum expiratory flow
rates for manatees followed the pattern
of other marine mammals, in which flow
rates at all lung volumes exceeded
predictions based on
terrestrial mammals. This
is consistent with the observed
high degree of airway reinforcement in
manatee lung airways,
which may stabilize
airway wall dimensions, preventing flow-induced restriction. [Abstract of a master's thesis
in Biological Oceanography submitted
to the University of Miami,
Florida, in June 1986 and supervised by D.K. Odell.]
RECENT LITERATURE
Anderson, P.K.
1986. Dugongs of Shark Bay, Australia -- seasonal migration, water temperature, and forage. Natl. Geographic Research .... [Autumn 1986]
Bayliss, P. 1986.
Factors affecting aerial surveys
of marine fauna,
and their relationship to a census of dugongs in the coastal waters of the Northern Territory
[Australia]. Aust. Wildl. Res. 13(1): 27-38.
Caldwell,
D.K., and M.C. Caldwell. 1985. Manatees - Trichechus manatus, Trichechus senegalensis, and Trichechus inunguis. In: S.H. Ridgway and R.J. Harrison, eds.,
Handbook of Marine Mammals. Vol.
3: The Sirenians and Baleen Whales. Academic Press, London: __-__.
Domning,
D.P., and L.C.
Hayek. 1986. Interspecific
and intraspecific
morphological variation in manatees
(Sirenia: Trichechus).
Marine Mammal Science 2(2): 87-144.
Domning,
D.P., C.E. Ray,
and M.C. McKenna.
1986. Two new
Oligocene desmostylians and a discussion of
tethytherian systematics. Smithsonian Contrib. Paleobiol. 59: iii + 56.
Frailey, C.D.
1986. Late Miocene and Holocene mammals, exclusive of
the Notoungulata, of
the Rio Acre
region, western Amazonia
[Brazil]. Nat. Hist.
Mus. Los Angeles
County Contrib. Sci. No. 374:
1-46. [Fossil Trichechidae]
Gallivan, G.J.,
J.W. Kanwisher, and R.C. Best. 1986. Heart rates and
gas exchange in
the Amazonian manatee
(Trichechus inunguis) in
relation to diving. J.
Comp. Physiol. B.
Biochem. Syst. Environ. Physiol. 156(3): 415-424.
Halstead, L.B. 1985.
On the posture
of desmostylians: a
discussion of Inuzuka's
"herpetiform mammals". Mem.
Fac. Sci. Kyoto Univ., Ser.
Biol. 10(2): 137-144.
Hanitsch, R. 1908.
Guide to the Zoological Collections of
the Raffles Museum, Singapore.
Singapore, Straits Times Press,
Ltd.: 112 pp. [P. 13 mentions a
captive dugong exhibited at the
Museum for a few weeks in 1895. Bob Brownell thinks this was
the earliest instance
of a dugong
being kept in
captivity. Can anybody beat that record?]
Hudson, B.E.T. 1986. Dugongs and People. Oceanus 29(2):
100-106.
Inuzuka, N. 1985.
Are "herpetiform mammals" really impossible? A reply to Halstead's discussion. Mem. Fac. Sci. Kyoto Univ., Ser. Biol. 10(2): 145-150.
Kamiya, T., P. Pirlot, and Y. Hasegawa. 1985. Comparative
brain morphology of miocene and
recent sirenians. Fortschritte der
Zool. 30: 541-544.
[Comparison of a brain of Dugong
with endocasts of the desmostylian Paleoparadoxia.]
Marsh, H. 1986.
'Dugong is Number One Tucker.' Oceanus
29(2): 102.
Nishiwaki, M.,
and H. Marsh. 1985. Dugong, Dugong dugon (Mu"ller, 1776). In: S.H. Ridgway and R.J.
Harrison, eds., Handbook of
Marine Mammals. Vol.
3: The Sirenians and Baleen
Whales. Academic Press, London:
1-31.
Ono, K., and
T. Uyeno. 1985.
Tertiary vertebrates from Sado
Island, Niigata Prefecture, central Japan. Mem. Natl. Sci. Mus.
(Tokyo) No. 18: 65-72. [In
Japanese; English summary. Paleoparadoxia.]
Pervaiz, S., and K. Brew. 1986. Purification and
characterization of the major whey
proteins from the milks of the
bottlenose dolphin (Tursiops truncatus), and
Florida manatee (Trichechus manatus
latirostris) and the
beagle (Canis familiaris). Arch. Biochem. Biophys.
246(2): 846-854.
Pervesler, P.,
and F. Steininger. 1986. Die Seekuh Metaxytherium krahuletzi: Skelett
eines 22 Millionen
Jahre alten Meeressa"ugetieres aus Ku"hnring. Katalogreihe des Krahuletz- Museums [Eggenburg, Austria] Nr. 7: 12 pp. [Museum pamphlet on
the excavation and
exhibition of an
Early Miocene sirenian skeleton.]
Rathbun, G.B.,
and P.B. Best. 1986. [Review of] S.H. Ridgway and R.J. Harrison, eds., Handbook of Marine
Mammals. Vol. 3: The Sirenians and
Baleen Whales. Mar. Mamm. Sci. 2(3):
236-239. [Rathbun reviews Nishiwaki & Marsh, 1985,
and Caldwell & Caldwell, 1985, cited above.]
Rowlatt, U., and
H. Marsh. 1985. The heart of the dugong (Dugong dugon) and
the West Indian manatee (Trichechus manatus) (Sirenia). J. Morphol. 186(1): 95-106.
Shoshani,
J. 1986. Mammalian
phylogeny: comparison of
morphological and molecular results.
Molec. Biol. & Evol. 3(3):
222-242. [Relationships of Sirenia and Desmostylia within "Paenungulata".]
Takahashi, S., D.
Domning, and T. Saito. 1986. Dusisiren dewana, n.
sp. (Mammalia: Sirenia), a new ancestor of Steller's sea cow
from the Upper
Miocene of Yamagata
Prefecture, northeastern
Japan. Trans. Proc. Palaeont. Soc. Japan, N.S., No. 141: 296-321.
CHANGES OF ADDRESS
Dr. K. Radway
Allen, 20/8 Waratah Street, Cronulla, N.S.W. 2230, Australia
Barbara J.
Bernier, Miami Seaquarium, 4400 Rickenbacker Cswy., Key Biscayne, Fla. 33149
Dr. R. S.
Lal Mohan, Research
Centre of CMFRI, West Hill,
Calicut 673005, India
Dr. Thomas E.
Lovejoy, World Wildlife
Fund, 1255 23rd St. NW,
Washington, D.C. 20037
A NOTE TO OUR READERS
Please notify us if your address changes or if
the address we are
using is incorrect. If you no
longer wish to
receive Sirenews, please send us a postcard to let us know so
that we can save on costs of printing and mailing. On the other hand, if you find Sirenews useful in your work, we'd also like to hear from you - in the form of reports of your
sirenian-related activities, and copies of
any publications on
sirenians (popular or technical) that you produce. Several of you are listed in our
file as
heads of sirenian research projects in your respective countries, but in
many cases we have received no news
of your projects, whether
they are enjoying success or
otherwise. The purpose of Sirenews
is to foster communication among sirenian workers everywhere, and just as you have benefitted from hearing
news of other projects in these
pages, others will benefit from hearing
about what you are doing. So please write!
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