Sirenews (ISSN 1017-3439) appears twice a year
in April and October and is
edited by Daryl P. Domning,
Department of Anatomy, Howard
University, Washington, D.C. 20059 USA
(fax: 1-202-265-7055). It is
supported by the U.S. Marine Mammal Commission
and Sea World, Inc.
NUMBER 24 OCTOBER 1995
IN THIS ISSUE: - U.S. SIRENIA
PROJECT THREATENED WITH
EXTINCTION
(p. 11)
- DUGONGS DECLINING IN QUEENSLAND (p. 5)
- LARGE-SCALE
POACHING IN BELIZE
AND UNITED ARAB
EMIRATES
(pp. 7, 11)
- ADVENTUROUS FLORIDA MANATEE EXTENDS
SPECIES'
RANGE TO NEW ENGLAND (p. 9)
DEATHS REPORTED
Tammy Dominguez and Amaury Villalba
Last January,
Tammy Dominguez, her colleague,
Amaury Villalba, and
their pilot were killed when
their plane went down during a manatee survey off Barahona on the southern
coast of the Dominican Republic. A third colleague, José Ottenwalder, was
injured but made a miraculous
escape, and is doing fine. We
first started to correspond with Tammy
shortly before the 1994
First International Manatee and Dugong
Research Conference, which
she attended. She was also an
active participant in the Manatee and Dugong Research Workshop which followed
the conference. Tammy was very dedicated to the conservation of sea
turtles and marine mammals,
especially manatees. She is greatly
missed by all of her colleagues.
- Lynn
Lefebvre (Sirenia Project)
MANATEE AERIAL SURVEY SAFETY RULES
Manatee aerial surveys
present special hazards to survey biologists because of the small planes that
are typically used (they can easily be overloaded), the relatively low
flight level (generally 500 feet), the tight turns that are
frequently made to count manatees (possibility
of stalling), and flight paths over water. At times, the dedication of the surveyors may become a hazard,
if their determination to complete a mission interferes with their
judgment concerning weather conditions,
the qualifications of their pilot, and the condition of the aircraft.
Listed below are some
"common sense" rules for manatee aerial survey personnel. They
are not intended to
be all-inclusive, but represent the highlights of regulations provided
by the Office of
Aircraft Services (OAS), which all Department of Interior (DOI)
employees in the U.S. must follow when participating in work-related aviation.
Ms. Burma Campbell, U.S. Fish and Wildlife
Service, is gratefully acknowledged for
providing information used to develop
these rules, for reviewing them, and for her
continued interest and encouragement.
_ The Cessna 172 aircraft is underpowered for low-level flying
(less than 500 feet). During low-level missions, aircraft cannot operate lawfully
at a higher certified load (aircraft,
passengers, fuel, cargo) than that recommended by the manufacturer. If more than two observers are planned, then
a Cessna 182, 185, or 206 is recommended.
_ Surveys should never be
flown at an altitude lower than 500 feet.
Many survey biologists
prefer an altitude of about 750 feet for circling and counting of manatees
in groups. Under
DOI Aviation Policy, aircrew members may not fly below
500 feet without special training and personal
protective equipment.
_ Know your pilot's qualifications. How many hours of flight experience
does he or she have in
the aircraft in which you will be a passenger? OAS regulations
require 1000 hours of flying
time in order to certify a pilot.
_ Know your plane's
service record. DOI Aviation Policy
requires servicing and inspection of a
plane after every 100 hours of flying time.
_ Prepare a GO/NO GO checklist that you go through
before every flight. While the
pilot has the final say in the decision to GO, remember YOU always have
the final say in the decision to cancel
a flight. If you have any doubts about
the weather, the pilot, or the plane,
cancel the flight. You are much more
important than a missed survey! Also,
all surveys should be conducted
under optimal weather conditions to ensure some comparability across survey dates; questionable weather means
questionable survey results. If
changes occur in the weather or pilot
or observer mental or physical
condition, the observer should call off the mission and request the
pilot to return to home base, or to
land at the nearest suitable location, depending upon the severity of the
change in flight conditions.
_ Prepare a flight plan and give it to ground personnel
at the airfield(s) where your
flight originates and ends. The person(s) to whom you give it will be
responsible for flight following and will institute search
and rescue procedures if your aircraft does not reach its destination within
one hour of its estimated time of arrival.
_ Only cargo and passengers which are essential to a mission
should be on the aircraft. Not
only does this eliminate the possibility of an accident from something
that should not have been onboard, but it keeps the weight of the aircraft at
a minimum, thereby using less fuel
and minimizing costs. Survey biologists should be
careful to secure
such routinely used objects as:
pencils and pens; camera lenses, lens covers, film canisters, small tape recorders, palm counters, etc.
_ DOI Policy requires the pilot be present to supervise the
type, quantity and quality of fuel used
in the aircraft when refueling. There have been misfueling mishaps in the U.S.,
in which jet fuel has accidentally been put into reciprocating-engined
aircraft.
_ If a single-engine aircraft is to be used beyond power-off gliding distance to shore,
the aircraft should be float-equipped and all persons onboard should
have personal flotation devices.
_ Biologists who fly regular missions can benefit from a flight
familiarization course consisting of 4
hours of ground school and 4 hours of flight training (cost is approximately $500). It is intended to give passengers limited
knowledge of how to operate aircraft controls, radios, etc., and land
the plane in the event of a pilot-incapacitated emergency.
Your comments
on these rules are welcome. If
you would like to help by translating them into Spanish or other languages, please contact me. If you would like examples of a
GO/NO GO checklist or a flight plan, or information on the
flight familiarization course, please contact: Dr. Lynn Lefebvre,
Sirenia Project, National Biological Service, 412 NE 16th Ave., Rm 250, Gainesville, FL 32601 USA; phone:
904-372-2572; Fax: 904-374-8080; Internet: sirenia@nervm.nerdc.ufl.edu. - Lynn Lefebvre
DEATH REPORTED
Mauricio Prieto
A pioneer
in field research
and conservation of
aquatic mammals in
Colombia, Mauricio Prieto died
from cancer in
Bogotá on 1
April 1995, at
age 39. He
worked extensively with
cetaceans, and in 1987 he launched a study of the ecology of the manatee
in the Río San Jorge area, where he perfected his singular competence in
environmental education at the
community level. He later turned his attention to marine mammal-fisheries interactions on the Pacific coast. With his death, the South
American aquatic mammal community has
lost a spiritual leader and a genuine conservationist. (Excerpted from an obituary by Koen Van Waerebeek and Daniel Palacios in the Marine Mammal Society Newsletter 3(3):
3, Sept. 1995.)
INTERNATIONAL DUGONG SYMPOSIUM
An International Symposium
on the Dugong will be held at the Toba Aquarium, Toba, Japan, 15-17 November 1995. Oral presentations (both
submitted and invited) will be given on dugong
biology, paleontology,
conservation, rescue, and husbandry.
Investigators, students, and
other interested people are encouraged to attend. A proceedings volume will be
distributed at the meeting.
For further details,
contact Mr. Hiroshi
Maeda, Planning Office,
Toba Aquarium, Toba 3-3-6, Mie
Prefecture, 517 Japan; phone: 81-599-25-2801;
fax: 81-599-26-3608; E-mail:
LDN03052@niftyserve.or.jp; Compuserve: 100463,3176
SIRENIA SPECIALIST GROUP MEMBERSHIP
The following people have agreed to serve as
members of the IUCN Sirenia Specialist
Group for the 1994-1996 Triennium:
Prof. Helene MARSH (Co-Chair), Dept. of Tropical Environment Studies
& Geography, James Cook
Univ., Townsville, Qld. 4811, AUSTRALIA (ph. +61-77-814325, fax
+61-77-815581, e-mail HELENE@CATHAR.JCU.EDU.AU)
Dr. Miriam MARMONTEL (Co-Chair),
Wildlife Biologist, Sociedade Civil Mamirauá,
C.P. 0001, 69470-000 Tefé
AM, BRAZIL (ph.
& fax +55-92-7432736, e-mail MANATI@NERVM.NERDC.UFL.EDU)
Dr. Vic COCKCROFT, Curator of
Marine Mammals, Port
Elizabeth Museum, P.O.
Box 13147, Humewood 6013,
SOUTH AFRICA (ph.
+27-41-561051, fax +27-41-562175, e-mail PEMVGC@ZOO.UPE.AC.ZA)
Mr. Hans DE IONGH,
Ecologist/Director,
International Cooperation, Centre
for Environmental Science, P.O.
Box 603, 6700 AP Wageningen, THE
NETHERLANDS (ph. +31-71-275642, fax +31-71-277496)
Prof. Daryl DOMNING (Newsletter Editor), Dept. of
Anatomy, Howard Univ., Washington, DC 20059, USA (ph.
+1-202-806-6026, fax +1-202-265-7055)
Dr. William FREELAND, Principal
Wildlife Research Officer,
Wildlife Division,
Conservation Commission of the Northern
Territory, P.O. Box 496,
Palmerston, NT 0831, AUSTRALIA
(ph. +61-089-894400, fax +61-089-894524)
Dr. Toshio KASUYA, Director, Offshore Marine Resources,
National Institute of Research on
Far Seas Fisheries, 5-7-1 Orido,
Shimizu, Shizuoka, 424 JAPAN (ph.
+81-543-340715, fax +81-543-359642)
Dr. Janet LANYON, Dept.
of Zoology, Univ.
of Queensland, Brisbane,
Qld. 4072, AUSTRALIA (ph. +61-7-3654416,
fax +61-7-3651655)
Dr. Lynn LEFEBVRE, Sirenia
Project Leader, National Biological
Service, 412 NE 16th
Ave., Room 250, Gainesville, FL 32601,
USA (ph. +1-904-372-2571, fax +1-904-374-8080, e-mail
SIRENIA@NERVM.NERDC.UFL.EDU)
Ms. Nicole LEOTAUD, Biologist, WIldlife Section, Forestry Division, 15
Monteverde Th., Morne Coco Road, Petit
Valley, Trinidad, TRINIDAD & TOBAGO (ph. +1-809-662-5114, fax
+1-809-645-4288)
Dr. Antonio MIGNUCCI-GIANNONI, Scientific Coordinator, Red Caribeña de
Varamientos, P.O. Box 38030, San Juan,
PUERTO RICO 00937-1030 (ph. +1-809-899-2048,
fax +1-809-899-5500)
Dr. Thomas O'SHEA, Assistant
Director, Midcontinent Ecological Science Center, National Biological
Service, 4512 McMurry Ave., Fort Collins, CO 80525-3400,
USA (ph. +1-303-226-9397, fax
+1-303-226-9230)
Dr. James POWELL, c/o Dr. David
Vousden, UNDP/GEF Coastal Zone Management
Unit, Fisheries Dept., P.O. Box 148, Belize City, BELIZE (ph. 501-2-30719, fax 501-2-35738, e-mail
DAVID.VOUSDEN@UNDP-ORG)
Dr. Anthony PREEN, Research Fellow, Dept. of Tropical Environment Studies
& Geography, James Cook Univ., Townsville, Qld. 4811, AUSTRALIA
(ph. +61-77-815575, fax +61-77-814020, e-mail
ANTHONY.PREEN@JCU.EDU.AU)
Dr. Galen RATHBUN, Research Biologist, National Biological
Service, P.O. Box 70, San Simeon, CA 93452-0070, USA (ph.
+1-805-927-3893, fax +1-805-927-3308)
Mr. Ismu Sutanto SUWELO,
Senior Instructor, Centre
for Education and
Training of Forestry Personnel,
Jalan Gunung Batu, P.O. Box 141, Bogor
16001, INDONESIA (ph. 0251-312841/0251-323565,
fax 0251-240566)
MANATEE RESEARCH OPPORTUNITY
The Save the Manatee Club (SMC) is issuing a
request for proposals from researchers
interested in conducting aerial surveys
to determine manatee abundance and distribution in west Volusia and Brevard counties, Florida, over the next two
years. Interested parties should
call or e-mail Patti Thompson at
SMC for further information.
Phone: 1-800-432-5646; e-mail: manatee@america.com
THANKS, SEA WORLD!
Sirenews is pleased to
acknowledge an unrestricted donation of $500 from Sea World, Inc. to help defray printing and mailing expenses. We
thank Sea World and Dan Odell for this
generous gesture of support.
LOCAL NEWS
AUSTRALIA
Hardening Evidence for Dugong Decline Along the More
Developed Regions of the
Coast of Queensland, Australia. - The Great
Barrier Reef stretches for some 2000 km
along the eastern coast of
Queensland. The northern region along the coast of
Cape York Peninsula is a remote area with a very low human population
density and little development. In
contrast, much of the area south of Cape York Peninsula
is undergoing very rapid
coastal development. This southern
region was surveyed
for dugongs from the air in 1987
and 1992. The estimated number of dugongs present in
the region in 1992 was 1857 ±
s.e. 292, much less than the 1987 estimate of 3479 ±
s.e. 459 dugongs. When
differences in survey conditions are taken into
account in the analyses, the difference
approaches significance (a=0.06),
suggesting that dugong numbers have declined in this
region.
The aerial
survey was repeated
in November 1994 with the aim of evaluating
whether this observed decline was
a real trend or
an artifact of sighting
conditions, which were slightly worse in 1992 than in 1987.
The population estimate resulting
from the 1994 survey was
1750 ± 257 dugongs, supporting the findings of the 1992 survey. Parallel declines were not
recorded in the estimates of turtles
or cetaceans which were recorded in the same surveys.
The
reasons for this decline in dugong numbers
are probably complex
and may include habitat loss, traditional hunting, and incidental drowning of dugongs in
commercial gillnets. Parallel
declines have not been recorded in
repeat surveys of more remote regions in the dugong's range
in Australia where traditional hunting and incidental drowning in gillnets are the
major anthropogenic impacts. - Helene Marsh
Dugong Adopts Offshore Oil Platform as Focal Point for Activity.
- During March-April 1995,
workers on the production
platform Vicksburg (21°07'
S, 115°06' E) on the South Pepper oilfield (North West Shelf of Western
Australia), noticed the presence of a dugong which appeared to
have adopted the platform as its home base.
Unfortunately, nobody
recorded the exact date
when this dugong arrived at
the platform, but its continued presence warranted entry of a report in the operations log
of the Vicksburg on 14 April 1995.
No further log entries
were made over
the next four weeks,
until platform worker
Martin Rawlings was
prompted to report the
dugong's apparent extended stay to the Western Australian Museum.
Dr. Ric How
referred the report to R. I. T.
Prince.
Daily log reports of further sightings of this dugong were entered from
12 through 26 May 1995. Photographic
recording of the dugong was requested
on 25 May, as none of the platform
personnel were known to have previously attempted this. The prints
subsequently obtained included
portions of the platform supports, and numbers
of large long-toms (needlefish,
Family Belonidae), as well as the
resident dugong.
The dugong
apparently deserted the rig
between 26 and 27 May. The last
three relevant log entries, for 27 and 28 May and 1 June, record the absence of further sightings of the animal.
One
dugong only was seen around the Vicksburg at all times from arrival until
just before desertion. The
observers believe that they saw the same animal each time. Noting the
uncertain time of
arrival, this dugong centered its activities
around the Vicksburg structure for a minimum of 8-10 weeks, and possibly more than 12 weeks.
Circumstances of arrival and fixation of this dugong
on the platform are not known, but several probably
significant events preceded
its disappearance. Another two or three dugongs appeared
around the Vicksburg about this
time, and a
drop in ambient water
temperature of ca. 2-3°C is also
reported to have occurred between
26 and 27 May. It is possible
that an associated change in water circulation over the Barrow Islands Shoals to the north of
the Vicksburg mobilized
other dugongs in that
area, and that the former
platform resident subsequently followed its new-found associates as they moved on.
The photographs of the Vicksburg
dugong suggest that it was
a juvenile. The larger species of long-toms of the North
West Shelf waters can
grow to lengths
of 1.3-1.5m, but most seen would average
around 1m (Barry Hutchins,
Western Australian Museum, pers. commun.). Scaling from the photographs, using this knowledge
and that of the visible platform support
dimensions, suggests that this
dugong was most probably <_1.5m in
length. It certainly was
not more than 2m.
Sex could not
be determined, because all
observations were made from the
platform deck (18m above water).
Apart from
the photography mentioned
above, some other
more detailed observations of
behavior patterns were planned for the dugong's
later period of residence around the Vicksburg. Unfortunately, the animal's
disappearance prevented this. However, it was noted to spend a lot of time suspended inactive below the surface
in the upper water
column. At other times it was seen
rolling about; the observers
considered this may have been "playing".
On other
occasions it disappeared from the observers' view, during
some of which times
it could have drifted under the platform out of sight. It might also
have been diving to feed, although the 17m water depth around the Vicksburg
is at the deeper extreme of known dugong feeding range. Still, the observers did not think the dugong
had lost body condition
during its time at the
platform.
One other
lone Western Australian dugong is known to have
associated for about 7 days in
mid-January 1989 with
a large (29.8m, 372-tonne)
moored tugboat, the Pilbara
Sun, in Dampier Harbour (20°39' S,
116°42' E). Water temperatures in Dampier Harbour during this period were reported
to have varied between 26 and 31°C.
The
Pilbara Sun dugong was certainly
a young, unweaned calf (photo
estimate, ca. 1.1m in
length). Its mother,
which had apparently been
feeding on a seagrass
bed directly behind the boat pen, had been killed beforehand by the
same tug when reversing from its
mooring for work. The carcass was
unsalvageable, being mutilated beyond recognition by the propeller impact.
Unfortunately, formal
reporting of this fatal
collision, and the subsequent orphan calf/tug
association, was not
made until a week
after the event. The
movements that had been observed meanwhile of the orphan back and forth alongside the tug
suggested it was seeking
milk. Nothing further
was learned from this association because the calf disappeared
overnight almost immediately after the report was
made. Starvation or shark
attack may have
caused its disappearance. - Robert I. T. Prince
(Wildlife Research Centre, Dept.
of Conservation and Land Management, P.
O. Box 51, Wanneroo 6065), Martin
Rawlings (c/o Atwood Oceanics Australia Pty. Ltd., 35 Peel
Road, O'Connor 6163), and
Roberta Selleck (Western
Mining Corporation Ltd.,
P. O. Box 7660, Perth 6850,
Western Australia).
BELIZE
Manatee
Butchering Sites in Port Honduras. - In the tranquil
waters of southern Belize,
there lies a serious threat to the existence of the manatee. Fishermen in Port Honduras are killing manatees at an alarming rate. This activity was recently made public through reports generated by
the Belize Center for Environmental Studies. Last year four
manatee skeletons were discovered
in the area of Deep Creek, in the Toledo
District of Belize. At that time
it was suspected that some
opportunistic butchering was taking
place;
however, the magnitude of the
recent killing was not apparent until now.
With funding graciously provided by the
Smithsonian Institution Biodiversity Program, we
went to Belize in late August and early September 1995 to conduct
dolphin and manatee research. While
there, we were able to fly several
aerial surveys and counted 109 manatees
at selected survey sites. The total
number of manatees in
Belize is not known,
but is assumed to be
around 200 animals. During
an aerial survey
of Port Honduras we counted 4 manatees. There
is excellent habitat for a local population in the protected cays, adjacent Deep Creek and Rio Hondo
rivers, and Icacos Lagoon.
A large number of
manatees were observed to
the north in nearby Placencia
Lagoon where 37 individuals were
counted. The presence of this large
group of manatees
in the north could be responsible for migratory animals
occasionally moving south
into Port Honduras.
These animals could easily
become victims of the illicit poaching operation.
During
boat surveys of Port Honduras with
local fishermen, we
discovered 11 separate butchering sites, which contained a minimum of 35 manatee carcasses. Twenty-four skeletons were classified as adults, and the remaining 11
were either juveniles
or calves. Detailed studies of
the skeletal material collected from
each site will be conducted. Evidence
of recent butchering was apparent, and we were watched by hungry John Crows
(vultures) as they
sat in the nearby trees. Some
of the decaying flesh was still
attached to the
bones. One site
was known to be two to three
years old, while at least two
of the sites were active
and had been used within the
last month.
Many of
the skulls examined
had large, deep cut marks in the cranial bones. It was
apparent that the manatees were
either shot, harpooned, or
chased until exhausted, then brought close to the boat and dispatched with heavy machete blows
to the
head and nose. Carcasses would then be taken to
the nearest dry land site, and
under the cover of heavy vegetation or
nightfall, the meat would be
removed. It would
then be taken
to market and illegally sold.
No manatee
meat was observed
in markets in Belize; however, there are several rumors that the meat
can occasionally be purchased in Guatemala.
It is likely that fishermen from Guatemala are coming into Belize, killing the manatees, and
taking the meat back
to Guatemala to
sell. Manatees are protected in both Belize and Guatemala,
but there is little or no enforcement of
existing laws. The direct impact
that this poaching is having on the
local population in south Belize is not known, but the magnitude of this
activity clearly puts
excessive pressure on
this population. Immediate
measures need to be taken to
enforce existing laws
protecting manatees, and ensure that all poaching activities are stopped
as soon as possible.
Additional
information regarding this
investigation can be obtained
by contacting either the
Fisheries or Forestry Departments,
Belize City, Belize, or the
Sirenia Project,
Gainesville, Florida, USA.
- Robert K. Bonde (Sirenia
Project) and Charley Potter (Smithsonian Institution)
DOMINICAN REPUBLIC
Stranded Manatee Calf Rescued.
- In late March
1995, a manatee
calf was stranded alive
at Barahona, Dominican Republic, after fishermen killed its
mother. The dehydrated and
anemic 70-pound calf was discovered by Tropescar Sur, a
nonprofit animal-welfare organization,
and rescued by a team
from the Acuario Nacional
in Santo Domingo, led by Enrique
Pugibet and Mo'nica Vega. Antonio
Mignucci from the Caribbean Stranding
Network in Puerto Rico was called in
for expert advice, and the baby manatee
is now doing well on a diet of
goat's milk and soy milk.
The calf was christened Tamaury
in memory of Tammy Dominguez and
Amaury Villalba, who were recently killed in a plane crash during a
manatee survey (see notice in this
issue).
The fishermen who killed the mother were caught and fined, but the applicable
law dates from 1960 and the amount
of the
fine was inconsequential. -
(source: Alerta Neptuno [Caribbean Stranding Network]
2(2), June 1995.)
EAST AFRICA AND MADAGASCAR
Aerial Survey in Kenya Finds Few Dugongs. -
From 17-24 November, the Kenya Wildlife Service, in
collaboration with UNEP OCA/PAC, IUCN's
Regional Office for Eastern Africa, and Eden Wildlife Trust carried out an intensive aerial survey of 500 km of Kenya's
shoreline to determine
the distribution of sea turtles,
dugongs, whales, dolphins, and
whale sharks. Five
aircraft were used over
a period of seven days.
A total of 254
hours were spent
in the air, doing 1 km-wide transects out to the 30 m
depth contour.
Sea turtles,
dolphins, and whale sharks were found to be evenly
distributed along the coast
within a depth
of 20 m. Dugongs were found
only in Ungwana Bay and Manda Bay in Lamu, however, and only 16
animals were sighted,
indicating a very small
population. Survey participant Vic Cockcroft estimates a population of about 50 dugongs
for the whole of Kenya; and based mainly on anecdotal data from
interviews, he doubts that there are more than 2000 dugongs in the
western Indian Ocean,
excluding the Arabian Gulf.
"Our results
demonstrated that sea turtles and dugongs are the
most vulnerable of the
animals covered," reports
George Wamukoya, a marine botanist with the Kenya Wildlife Service.
"This is probably the result
of habitat destruction and human
activities such as poaching
and disposal of
plastic wastes. If we are to
conserve these species, we need to protect key turtle
nesting areas in Ras Tenewi
and Shella, and
the known dugong habitats
in Ungwana and
Manda bays."
On related topics, Vic Cockcroft reports that he has just obtained funding from WWF International for a coastal zone assessment for Madagascar, including a comprehensive assessment of dugong status there. He is now seeking money for a compr