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Sirenews (ISSN 1017-3439) appears twice a year


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: 202-265-7055). It is supported by the U.S. Marine Mammal Commission.



NUMBER 23 APRIL 1995


IN THIS ISSUE: MANATEE SURVEYS AND RELEASES IN
BRAZIL (p. 4)

DUGONG CONSERVATION
RECOMMENDATIONS FOR
INDONESIA (p. 5)

RADIOTAGGING MANATEES IN
MEXICO (p. 6)


EDITORIAL: FLORIDA MANATEE FISHERY
ACHIEVES NEW RECORD TAKE

The annual harvest of manatees in Florida last year scored an all-time high total of
animals taken, according to figures compiled by the state's Department of Environmental
Protection. The 1994 summary of manatee mortality lists a total of 70 deaths attributable to
human-related causes (watercraft collisions, floodgates/canal locks, and other), the largest
number since record-keeping began in 1974. The number of watercraft-related deaths (49) was
the third highest on record (after 53 in 1991 and 50 in 1989), and the total number of deaths
(192) was second only to the maximum of 206 reached in 1990. These numbers represent an
annual mortality of about 10% of the Florida manatee population, based on the current
population estimate of around 2,000. (Population models indicate that, even given a low rate of
mortality, a sirenian population is capable of increasing at a rate of only about 5-6% per year.)
After showing rapid growth in the late 1980's that peaked in 1991, the harvest went
into a two-year slump that many have attributed to poor economic conditions which
discouraged growth in boating. The 1994 statistics indicate that recovery from this slump is
now complete, and with human population growth and boat registrations in Florida surging to




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new highs, it is safe to anticipate the most successful manatee harvest ever in '95.
Despite this continued strong growth in the manatee fishery, however, there is cause for
concern over its future in the longer run. This is because of its unusual nature in
comparison with other forms of resource use. Typical commercial harvests of living resources
obey the ecological laws of predator-prey relationships, because the harvesters' direct
nutritional or economic dependence on the harvest creates a negative feedback loop. If the prey
are overexploited, the yield diminishes and eventually forces a corresponding diminution of the
harvesting effort: the predators either die, go out of business, or start exploiting other
resources. This is also true of purely recreational fisheries, since the fishing effort is at least
partly a function of the take. The Florida manatee fishery, in contrast, is exempt from this
kind of natural regulation, because it constitutes an incidental take that mostly occurs in the
absence of any intent or even consciousness on the part of those causing the mortality.
Moreover, the carcasses of the harvested animals are not put to any commercial or even
recreational use whose loss might be felt. Therefore, not even total extinction of the manatee
stock would cause the harvesting effort (e.g., power boating) to diminish.
This lack of natural regulation, then, predicts that the manatee harvest will eventually
collapse, owing to practical extinction of the manatee stock. (Indeed, the Potential Biological
Removal [PBR] level calculated for this stock by the U.S. Fish and Wildlife Service is already
zero individuals per year.) The basic problem we must acknowledge is that the manatee-fishing
fleet is already heavily overcapitalized, with too much investment in expensive and overly-
efficient fishing gear (hulls and high-powered engines). In the absence of natural feedback to
control the accelerating growth of this already too large and efficient fleet, artificial regulation by
government (e.g., limits on boat speeds and numbers of launching ramps) is an unfortunate
necessity if we are to get the manatee PBR level back up where it belongs and enjoy a healthy
harvest of manatees into the next century.
An ominous aspect of this situation, however, is the fact that excess fishing capacity
inevitably generates political pressures to increase fishery quotas in this case, upward from
the present PBR of zero. Therefore, without reduction in the human population whose growth is
ultimately driving the expansion of this and every other fishing fleet, there is little hope of
rebuilding the manatee stock to a safely exploitable level.
One cause for optimism, on the other hand, is the heavy involvement of the Florida
state government in manatee conservation. This contrasts with the situation in (for example)
Hawaii, where the Hawaiian monk seal recovery effort has been almost entirely the work of
federal agencies. When the federal budget is tight, as it has been for years, there is no
effective state program with an independent mandate and funding source to take up the slack.
The result of this essentially single-source funding base is that the monk seal program has been
chronically underfunded and essential recovery tasks have been left undone, to the extent that
the Hawaiian monk seal is now seriously in danger of being the world's first managed species
of marine mammal to face biological extinction. Florida, in contrast, was willing and able to
shoulder an increasing share of the manatee program as the federal involvement diminished




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over the past decade. As a result, the manatee's status (despite continuing cause for concern) is
much less precarious than the monk seal's.
It is, in principle, a healthier and more stable situation when the people of a state claim
ownership of, and accept the responsibility for, a local conservation program, rather than
leaving Washington (read: the taxpayers of all the other states) to carry the entire burden. It is
to be hoped that the Florida state government will continue to recognize the historic
importance of its role and responsibility for protecting the manatee in U.S. waters. Much has
already been done to fulfill this responsibility, but the greatest and most urgent challenge still
lies ahead: to rein in the reckless growth and activity of our own species. DPD




FUNDS AVAILABLE FOR MANATEE RESEARCH

Save the Manatee Club (SMC) is interested in research projects involving the West Indian
manatee in the wild. SMC is specifically interested in projects that are prioritized in the
Florida Manatee Recovery Plan and are therefore considered important for the recovery of the
Florida manatee. The deadline for receipt of proposals for funding in 1996 is 15 September
1995. Interested individuals should submit a letter of inquiry (no more than two pages) stating
explicitly how the proposed research project relates to the goals of the Florida Manatee
Recovery Plan and an estimate of cost. (Note: SMC does not pay overhead or similar charges.)
The average cost of research projects funded in recent years is approximately $6000 in the U.
S. and about $1550 out of country. Research proposals involving unforeseen, critical events may
be submitted any time. Investigators should determine whether an Endangered Species Permit
is required for the proposed work. Contact Patti Thompson, Save the Manatee Club, 500 N.
Maitland Ave., Suite 210, Maitland, FL 32751 for further information and instructions for
submitting full proposals. Phone 1-800-432-5646.


SUMMER SCHOOL ON ZOO ANIMAL BEHAVIOR AND WELFARE

Edinburgh Zoo, in conjunction with the University of Edinburgh, is offering a two-
week summer school from 17 to 28 July 1995 on Zoo Animal Behaviour and Welfare. It is
designed for all those involved in management and husbandry of captive animal populations
(zoos, safari parks, rear-and-release schemes, etc.), and will update participants on the latest
scientific theory and its practical implementation. Edinburgh Zoo's research has resulted in
changes in enclosure design and marked reduction in stereotyped behavior and general
boredom. The tuition cost is 750 (add-on accommodation package, 140); registration
deadline is 31 May 1995. For information, contact Hamish Macandrew, UnivEd Technologies




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Ltd., Abden House, 1 Marchhall Crescent, Edinburgh EH16 5HP, UK; tel.: 0131-650-3475; fax:
0131-650-3474.


SIRENEWS AND OTHER MANATEE INFORMATION ON THE INTERNET

The Florida Department of Environmental Protection (DEP) now makes several sources
of manatee-related information available on the Internet. This includes the contents of
brochures on basic manatee biology, protective measures, and safe boating practices in
manatee areas. Manatee mortality statistics will also be posted in the future. You can reach this
service at the following address: www.dep.state.fl.us (this provides access to DEP's Internet
node; the manatee information can then be obtained by choosing the option "Protected Species
Management").
Beginning with this issue, Sirenews will also be accessible via this service. This may not
have happened by the time you receive this issue, but it is in the works for the near future.
READERS PLEASE NOTE: In the event that you find this new way of receiving
Sirenews sufficient for your needs and you no longer wish to receive the hard-copy version,
please notify me of this by fax or regular mail (NOT via e-mail) so that our printing and
mailing costs can be kept down. Thanks! DPD


ABSTRACTS OF PUBLISHED PAPERS IN SIRENEWS?

A reader has inquired whether it would be possible for Sirenews to print abstracts from
published papers in addition to those from unpublished presentations and theses. I do not have
the time to do the necessary typing, which would be extremely burdensome (and take up an
inordinate amount of space) if I attempted to include all the new papers cited in each issue.
However, if authors submit abstracts of their new papers on diskette, I am willing to include
them on a space-available basis. Indeed, I would appreciate it if all submissions were made on
diskette, preferably in WordStar or ASCII IBM-compatible format. I'll even return your
diskettes! DPD


LOCAL NEWS

BRAZIL

Preliminary Studies of Manatee
(Trichechus manatus) Distribution and
Status and Conservation Efforts on the




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Northern Coast of Brazil. Continuing the
work of the "IgarakuF" mobile unit of
IBAMA's National Center for Conservation
and Management of Sirenians (Centro Peixe-
Boi), preliminary studies have been carried
out on manatee distribution and status on the
northern coast of Brazil.
The study area was approximately 2600
km of coastline, comprising the states of
Maranhao, Para, and Amapa, including also
Maraj6 Island and the mouths of the Amazon
River. Between 20 March and 11 September
1992, researchers conducted 136 interviews
at 74 localities along the coast of Maranhao,
which was divided into five regions: (I) the
mouth of the Paraiba River; (II) "Leng6is
Maranhenses"; (III) Tubarao Bay; (IV)
"Golfao Maranhense"; and (V) "Reentrancias
Maranhenses".
Manatees were found to occur in regions
III, IV, and V, with region III the most
important. They are absent from large areas.
The total population of the Maranhao coast
appears to be little more than 100 animals,
occupying areas of mangroves and
"paturd" (Spartina sp.). Harpoon hunting
occurs rarely; fishing nets seem to be the
main way of capturing manatees in the region.
Between June and August 1993, the Pard
coast, Maraj6 Island, the Amazon mouths
and the Amapd coast were surveyed. In Pard,
85 interviews were done and 55 localities
visited, in Amapd, 44 interviews and 29
localities. The presence of manatees was
recorded in the Gurupi River estuary (the
boundary between Pard and Maranhao). They
have disappeared from almost the entire Pard
coast, but manatees of unknown species (T.
manatus or T. inunguis) are present near the
mouth of Maraj6 Bay. In the inner portion of




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the bay, on the mainland as far as Bel6m, we
found evidence only of T inunguis, but in
the part close to Maraj6 Island (Soure,
Pesqueiro) we found indications of the
occurrence of both species. In the entire
area of the Pard River surrounding the island
as far as Macapa, as well as on the coasts
of the island and the adjacent archipelago,
in the Amazon mouths, and in the area of
Lake Piratuba (Amapa), we found evidence
of the continuous occurrence of T. inunguis.
Along the Amapa coast from Maraj6 Island
to the Oiapoque River (the boundary between
Brazil and French Guiana), the species present
is T. manatuls.
Many harpoon hunters are still actively
killing both species. In Amapa they use an
interesting method employing a "muta", a
platform on which the hunter waits with his
harpoon when the tide rises and the manatees
come to feed on the surrounding submerged
vegetation.
Through this work the Centro Peixe-Boi
has surveyed the range of T. manatus along
the entire coast of Brazil a four-year study
in ten states, involving 862 interviews and
visits to 357 localities. In each locality
conservation efforts were developed with
the community, through dissemination of
information and ongoing participation of
the population. Regis Pinto de Lima
(Centro Peixe-Boi, IBAMA, Paripueira,
Alagoas)

First Reintroduction of Manatees into
the Wild in Northeastern Brazil. On 10
October 1994, two 3-year-old manatees
(Trichechus m. manatus), rescued as
orphaned calves in 1991 and kept in
captivity since then, were transported from




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the facilities of IBAMA 's National Center for
Conservation and Management of Sirenians
(Itamaraca Island) to Paripueira Beach in
Alagoas State, where a circular wooden pen
15 m in diameter was constructed to
enclose the animals, providing for gradual
readaptation to the natural environment and
also for behavioral studies.
The animals, Astro (male) and Lua
(female), traveled to Paripueira aboard a
truck in a fiberglass tank half filled with
water and with its bottom covered with
polyurethane-sponge cushioning. After a 210-
mile trip lasting more than 10 hours, they
were placed, one at a time, in a stretcher to
be moved to an inflatable boat that took them
to the pen, approximately 800 m from the
beach.
Immediately after the transport, Astro and
Lua showed the same pattern of behavior that
they used to have in captivity, eating,
playing, and resting. During the very first
hours they were observed eating algae
(Ulva sp.) and seagrass (Halodule sp.) that
grew inside the pen.
Their diet gradually came to include a
higher percentage of seagrass and algae
collected in the vicinity of the pen. They
always welcomed the seagrass (having been
fed Halodule in captivity), but accepted only
a few species of algae. Their feces were
collected for future analysis.
Astro and Lua showed very dependent
behavior and extensive interactions, even
nursing on each other frequently. A
bioacoustic study was done to correlate their
behavior and vocalizations.
During their first week in the pen, they
received a visit from a group of three wild
manatees, one adult, one young, and one




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calf, which remained around the pen for over
two hours and then left. No other wild
manatees were reported close to the pen.
After 70 days, both animals were judged
ready for release. In December they were
marked with PTT/VHF transmitters in a
cooperative effort between the technicians of
the Centro Peixe-Boi and James Reid of the
U.S. National Biological Service's Sirenia
Project. The animals were then measured, in
order to verify any loss of weight after
release.
On 15 December, after a short period of
training, both animals were accompanied by
a diver to the area outside the pen. This
procedure was continued for five days, each
time going further away but always returning
to the pen, until the release day, when the
gate was opened and the animals went out by
themselves.
Prior to the release, efforts were made to
inform all coastal communities of the
important role they would play in the
release, reporting any sightings of the
marked animals or the transmitters. This was
done through informal conversations,
distribution of posters, TV, and radio, and as
a result many calls were received from all
along the coast reporting sightings of Astro,
Lua, and wild manatees.
Astro and Lua have been radio-tracked
since their release with approximately 10
hours of observation every day. In the first
weeks they gradually expanded their range
north and south, always using the pen as a
reference point. Both animals have lost their
transmitters at least twice, but were always
retagged. They have now been observed in
areas used by wild manatees. They have not
lost any considerable amount of weight, and




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are always observed in shallow waters,
feeding, playing, traveling, and resting.
Also worth noting is another first: the
creation of the Paripueira Municipal Marine
Park, the first marine park of its kind in
Latin America, which hopefully will help
raise the environmental consciousness of
local communities as well as provide
additional protection to the manatees' habitat
in Alagoas. RWgis Pinto de Lima (Centro
Peixe-Boi, IBAMA, Paripueira, Alagoas)
(Mario Antonio de Mello, Municipal
Secretary for the Environment, Paripueira,
also contributed to this report.)

INDONESIA

Indonesia-Netherlands Dugong
Research Project Makes Conservation
Recommendations. The joint research
project being carried out by Pattimura
University (Indonesia) and Leiden
University (The Netherlands) considers the
dugong a flagship species for coastal
conservation in Indonesia. There and
throughout coastal Asia, habitats are
threatened by unsustainable fishing (e.g., with
dynamite or cyanide) and land-based
activities causing erosion and sedimentation
in seagrass beds. Our observations are based
on a small area and thus should be
interpreted with care, but since the situation in
the Lease islands is representative of many
tropical small-island ecosystems outside
Australia, our results should be of interest
to those working in similar ecosystems.
Since 1990 we have studied seagrass
dynamics, the impact of dugong feeding, and
dugong movements and behavior in Haruku
Strait, between Ambon and Haruku. Aerial




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surveys (1990-91) indicated a minimum
population of 22-37 dugongs. Satellite-
tracking of a subadult male showed that these
animals interact with a larger population
around Ceram Island to the north.
The available seagrass meadows are
confined to a coastal shelf no more than 500
m wide, and all are situated in front of
coastal villages. Most of the dugongs
consistently foraged on only 2-3 "core areas";
cultivation grazing was common and
small (presumably family) groups of
dugongs returned regularly to the same
feeding plots. Dugongs adapted their feeding
strategy to the characteristics of individual
meadows. An intertidal meadow showed
feeding peaks only during August-October
(at the end of the rainy season), when total
organic carbon in the below-ground
biomass is maximal in these Halodule-
dominated meadows. In a single subtidal
meadow, on the other hand, peak feeding
occurred in October-November, when standing
crop was maximal. Grazing on the whole was
infrequent or absent from January to May,
when rhizome/root biomass is low, and
frequent from June to December, during and
after the onset of the wet monsoon, when
rhizome/root biomass is high. There are
strong indications that (as in Australia)
calving takes place mainly when high rhizome/
root biomass is available.
We have concluded that the existing marine
reserve in Pulau Pombo is insignificant for
dugong conservation because of its
relatively sparse seagrass beds, and have
recommended to the local government the
establishment of dugong sanctuaries in
Haruku Strait, Saparua Bay, and Piru.
Dugong conservation and management in the




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Moluccas will in general require enforcement
of existing international and national laws
respecting dugong catches and trade in
dugong products; continued research on
dugong migration, distribution, and
reproduction; promotion of community-based
conservation; and implementation of a coastal-
zone management plan that includes dugong
protection. Our specific recommendations are
as follows:
a. Enforcement of existing regulations
protecting dugongs in East Ambon.
b. Creation of the dugong sanctuaries
mentioned above. Declaration of these
sanctuaries should coincide with
enforcement and enhancement of
traditional conservation systems, like the
local "sasi laut".
c. Restriction of gillnet fishing during
periods of high rhizome-root biomass of
Halodule in sanctuary areas, to prevent
incidental catch of neonates.
d. Training of Pattimura University
students in dugong and seagrass research
methods, so that they can take over this
research in the future.
e. Production and distribution of dugong
posters, leaflets, and T-shirts among
government offices, village leaders,
schoolteachers, pupils, and households in
the project area. This should be done in close
cooperation with the Asian Wetland Bureau,
PHPS, WWF Jakarta, Oceanarium Ancol in
Jakarta, and the Yayasan Hualopy in Ambon.
- Hans de longh

MEXICO

Manatee Research in Mexico. Belize
and the Mexican state of Quintana Roo share




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one of the larger populations of West Indian
manatees outside Florida. Resource managers
from both countries are concerned that the
current and future development plans for the
region may endanger the manatees, but more
information on their habitat needs is required
to develop protection plans. Biologists from
Quintana Roo and Belize initiated a study of
the manatees in the region, including a
population assessment using aerial surveys. A
radio-tracking study has also been started to
determine movement patterns and habitat use
of the manatees in Chetumal Bay.
The radio-tracking project is led by
Benjamin Morales Vela, a marine
mammalogist with the Centro de
Investigaciones de Quintana Roo (CIQRO) in
the city of Chetumal. Because this is one of
the first radio-tracking studies of West
Indian manatees outside Florida, CIQRO
biologists David Olivera Gomez and Gerardo
Rivas Hernandez spent a week in Florida
during late October 1994 learning how to
construct the specialized radio-tags. In
addition, two biologists from the United
States National Biological Service, Bob
Bonde from the Sirenia Project in
Gainesville, Florida, and Galen Rathbun from
the Piedras Blancas Research Station in San
Simeon, California, traveled to Chetumal to
give advice and assistance with the initial
phase of the project. The objectives of this
initial phase were to develop capture methods
for manatees in the Chetumal Bay area, and
train Mexican and Belizian biologists in the
techniques of radio-tagging and tracking
manatees.
Between 8 and 18 November 1994,
Mexican, American, and Belizian biologists
worked at capturing and radio-tagging two




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manatees, under a permit issued by the
Mexican government to CIQRO. Bob Bonde
brought capture nets from Florida, with the
hope of finding some animals in a suitable
canal or lagoon where the nets would be
effective. Galen Rathbun brought equipment
to try and capture manatees in open water
with hand-held hoop-nets, a technique that he
helped develop for dugongs in Australia.
Both techniques, however, failed.
Manatees were not found in any narrow canals
or channels in November, and thus the
nets were of little use. The capture team
also failed to hoop-net any manatees in
open water, although some were "almost"
captured. The escape behavior of manatees
is very different from that of dugongs. Even
when fleeing at nearly full-speed, as soon as
the manatees sensed a net or noose near their
head they tucked and rolled out of the net
with incredible speed and agility.
In the end, a chase-and-tire capture
method that Mexican fishermen traditionally
used in the region was used. In contrast to
the fishermen's method, however, an airplane
was used to find manatees in good capture
locations. At the end of an aerial search, the
pilot would drop a map in a plastic bottle to
the waiting capture boats, and with this
information the capture team efficiently
located manatees in clear, shallow water. The
boats were used to continually, but gently,
chase and herd the same manatee until it tired
after 1-2 hours. At this point swimmers
entered the water and slipped a rope noose
over the head and onto the peduncle. The
first manatee captured, named Carmen, was
easily brought alongside the boats, where it
was sexed, measured, and radio-tagged while
surrounded by swimmers standing in chest-




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deep water. The second manatee, named
Gabriela, was captured in deeper water,
which gave the opportunity to test a modified
inflatable boat to cradle her while she was
moved to water where swimmers could stand;
it all worked perfectly.
The chase-and-tire technique worked very
well in Chetumal Bay, but probably has
limited use in other areas where the water is
deeper and more turbid. Unless an individual
manatee can be followed for one or two
hours until it tires, there is little chance of
approaching it with nets or nooses.
The two female manatees have been
radio-located one or more times a week since
they were tagged. During December and
January neither moved more than about 9 km
from their capture locations. With the
experience and success gained from capturing
and radio-tagging these two manatees, plans
are being developed to tag up to 10 more
individuals in the next two years. However,
this plan must now be reassessed in terms of
the dynamics of the Mexican peso. -
Benjamin Morales Vela, Galen B.
Rathbun, and David Olivera Gomez

PALAU

Palauan Dugongs Once More
"Officially" Endangered. What one
bureaucratic oversight does, another can
sometimes undo. Thus it came to pass that
way back in 1970, when the U.S. Fish and
Wildlife Service listed the dugong as
endangered under the Endangered Species
Conservation Act of 1969, separate lists of
foreign and domestic protected species were
being maintained, and the dugong was placed
only on the foreign list although the




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Palauan population was then under U.S.
jurisdiction.
This slip-up was seemingly rectified when
the 1969 act was superseded by the
Endangered Species Act (ESA) of 1973 and
the separate lists were merged into a single
one. The dugong was included on this list as
endangered throughout its range including,
implicitly and for the first time under U.S.
law, Palau.
In 1988, however, the Service belatedly
discovered that this inclusion of the
Palauan dugong population had been made
without the required public notice. Contrary
to the ESA's provisions, the Trust Territory of
the Pacific Islands had not been notified of the
proposed change in listing and invited to
comment on it. Upon discovering this second
procedural oversight, the Service then deleted
the Palauan dugongs from the list. This left
them outside the protection of both the ESA
and the Marine Mammal Protection Act
(which never applied to the Trust Territory),
and thus protected only by inadequately-
enforced Palauan law.
Not until August 1993 did the Service finally
publish a proposed rule to re-list the Palauan
population as endangered. Also in that
year, at the instigation of the U.S. Marine
Mammal Commission, the drafting of a
recovery plan for the population was
begun. Both efforts were still underway on 1
October 1994, when Palau became fully
independent and the Service's management
authority over Palauan dugongs ended.
So where does that leave the dugongs, rule-
wise? In the view of sources in the U.S.
government, Palauan independence has now
rendered the issue moot, because the 1988
listing applied to the dugong's entire range




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"except USA." Now that dugongs no longer
exist in the USA, the Palauan population is,
by default, once again considered
endangered, with no further legal action
required.
Meanwhile, the Palauan population
continues its decline, and the recovery plan
(which will be turned over to the Palauan
Government when completed) cannot be
implemented too soon. (based in part on
the Marine Mammal Commission Annual
Reports to Congress, 1993 and 1994)

UNITED ARAB EMIRATES

Dugong Surveys Planned in the Arabian
Gulf. Recent wildlife surveys in UAE
waters of the southern Arabian Gulf by the
Abu Dhabi-based National Avian Research
Center have pinpointed specific areas
apparently used regularly by herds of
dugongs. Although precise population
estimates are still lacking, anecdotal evidence
gleaned from local fishermen suggests that
significant numbers remain.
The rather piecemeal observations
achieved to date are hopefully to be replaced
by systematic aerial surveys and quarterly
monitoring flights (during which turtles will
also be censused) from late 1995 onward. A
proposal to satellite-tag one or more animals
is a possibility, with research on the
distribution and productivity of seagrass
beds also likely. Such work is to be a
collaborative venture involving several
organizations.
Attempts are presently underway by an
independent film company to record the
everyday life of dugongs in Abu Dhabi. This
will have an educational and scientific value




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and highlight the threats faced.
It is nine years since an aerial survey
conducted by the Meteorological and
Environmental Protection Agency of Saudi
Arabia estimated 73001302 individuals
in the entire western Arabian Gulf (Kuwait-
UAE). The time is thus right for a repeat
survey. Development pressures and seabed
reclamation have certainly increased and
some harvesting continues. An international
effort will be required to effectively manage
and conserve Gulf stocks. Simon
Aspinall (National Avian Research Center, P.
0. Box 45553, Abu Dhabi)

WASHINGTON, D.C.

Progress on Publication of Sirenian
Bibliography. Domning's Bibliography
and Index of the Sirenia and Desmostylia is
now approximately at the page-proof stage. It
will appear as No. 80 in the series
Smithsonian Contributions to
Paleobiology. Its progress has been slowed
by personnel shortages at the Smithsonian
Press, but they say it will definitely be out in
1995, probably in early fall. Ordering
information should therefore be available
(with luck!) in the October issue of Sirenews.
- DPD

ABSTRACTS

Water flux and osmoregulatory physiology of the West Indian manatee (Trichechus
manatis) (Rudy Martin Ortiz). This study provides the first comprehensive analysis
addressing the questions of water balance and osmoregulatory physiology in any sirenian
species. Water turnover estimations using deuterium oxide dilution were conducted on captive
manatees in fresh and salt water. Animals kept under freshwater conditions actively
consumed large volumes of water in addition to obtaining relatively large quantities of
preformed water in their lettuce diet (about 92% water). As for the lone captive saltwater




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animal, turnover trials performed on him strongly suggested a lack of mariposia. Four animals
temporarily exposed to salt water before being returned to fresh water also did not provide any
evidence for active salt water consumption. Further analyses of their osmoregulatory responses
to a hypo-and hyperosmotic environment reveal the capability of these animals to maintain
appropriate water balance. Regardless of the habitat, animals were able to maintain osmolarity
and electrolyte homeostasis by regulating both parameters within narrow ranges similar to other
terrestrial and marine mammals. Dehydration was not apparent in any of the animals in salt
water. This is not surprising, however, since preformed water obtained in lettuce was
substantial. Analysis of PRA-aldosterone profiles reveals that sympathetic stimulation of beta
receptor induced-renin release was exhibited and that a functional RAA axis is present in these
animals, typical of other terrestrial and marine mammals.
Urine samples were only obtained during the switched salinity experiment. Urinalysis
strongly suggested a lack of dehydration in animals during the salt water phase, however,
exposure to this habitat was sufficient to significantly elevate pNa+ and pCl- and to noticeably
increase pOsm.
A comparison of plasma osmolarity, electrolyte, and hormone levels provided evidence that
free-ranging animals exposed to a hyperosmotic environment have the osmoregulatory
mechanisms to deal with the osmotic challenge. There was also no significant variation in the
measured parameters between representatives of the Florida and Antillean subspecies when
exposed to similar conditions. [Abstract of a thesis for the degree of Master of Science in
Wildlife and Fisheries Science, submitted to Texas A&M University in 1994.1

__Aspects of the chemical ecology of the West Indian manatee, Trichechus nianaitus (Audra
L. Ames). Liver, kidney, and blubber tissues from the West Indian manatee were analyzed
using gas chromatography and combined gas chromatograph/mass spectrometry for a variety of
chlorinated hydrocarbons. The tissues were also examined for petroleum hydrocarbons, but
none was found. Due to the low frequency of observed pesticides, their concentrations could
not be related to age, sex, length, or the geographic location where the manatee carcass was
recovered. Pesticides (o,p-DDT, o,p-DDD, hexachlorobenzene and lindane) were detected in all
three tissues, but found most frequently in the liver and kidney.
The sloughed skin from three captive manatees at Lowry Park Zoological Garden was
examined over a period of one year to determine its stable carbon isotopic composition. The
foods consumed by these manatees were also sampled and their d13C values determined. The
sloughed skin d13C values from the captive manatees were found to be 1.28 to 7.25 per mil
greater than the lettuce they consumed. The skin was 0.67 to 3.55 per mil greater than the
wheat sprouts, and the difference between the skin and carrots was -1.45 to 4.26 per mil. d13C
values of the skin could be related to changes in the manatees' diet.
Finally, d13C values for internal tissues (liver, kidney, and blubber) and skin from dead
manatees were also determined. These values were compared to values of vegetation that
manatees are known to eat in the wild. The d13C values of the internal tissues and skin of wild




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manatees fell in the range of dl3C values of their expected diet. [Abstract of a thesis for the
degree of Master of Science in Marine Science, submitted to the University of South Florida in
1994 and supervised by Edward S. Van Vleet.]



RECENT LITERATURE

Agudo, A.I. 1994. Primer catalog general de sirenios recientes depositados en
museos y colecciones biol6gicas venezolanas (Mammalia: Sirenia: Trichechidae).
Anartia (Zulia, Venezuela, Mus. Biol. Univ. del Zulia) No. 7: 1-8.

Anderson, I. 1994. Resort plans stuck in the mud. New Scientist 144(1953): 7.
[Concerns a proposed resort in dugong habitat at Oyster Point, Queensland, Australia.]

Anderson, P.K. 1994. Dugong distribution, the seagrass Halophila spinulosa, and
thermal environment in winter in deeper waters of eastern Shark Bay, Western Australia.
Wildl. Res. 21(4): 381-388.

Aragones, L.V. 1994. Observations on dugongs at Calauit Island, Busuanga,
Palawan, Philippines. Wildl. Res. 21(6): 709-717.

Aragones i Valls, E. 1994. Descobriment i excavacio6 del sireni fossil de Vilafranca
(holotip de Metaxytherium catalaunicum Pilleri). Batalleria 4: 45-47. [In Catalan;
Spanish & Engl. summs.]

Barry, F.P., P.J. Neame, J. Sasse, and D. Pearson. 1994. Length variation in the
keratin sulfate domain of mammalian aggrecan. Matrix Biology 14(4): 323-328.

Carr, T. 1994. The manatees and dolphins of the Miskito Coast Protected Area,
Nicaragua. Natl. Technical Information Service (Springfield, Virginia 22161 USA)
Document No. PB 94-170354: iv + 19.

Converse, L.J., P.J. Fernandes, P.S. Macwilliams, and G.D. Bossart. 1994.
Hematology, serum chemistry, and morphometric reference values for Antillean
manatees (Trichechus manatus manatus). Jour. Zoo & Wildl. Med. 25(3): 423-431.

Court, N. 1994. The periotic of Moeritherium (Mammalia, Proboscidea): homology
or homoplasy in the ear region of Tethytheria McKenna, 1975? Zool. Jour. Linn. Soc.
112(1-2): 13-28.




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Dennis, J. 1994. The call of the mermaid. Wildl. Conserv. 97(5): 70-72. [Mermaid
legends and sirenians.]

Domning, D.P., and P.D. Gingerich. 1994. Protosiren smithae, new species
(Mammalia, Sirenia), from the late Middle Eocene of Wadi Hitan, Egypt. Contrib. Mus.
Pal. Univ. Michigan 29(3): 69-87.

Domning, D.P., P.D. Gingerich, E.L. Simons, and F.A. Ankel-Simons. 1994. A new
Early Oligocene dugongid (Mammalia, Sirenia) from Fayum Province, Egypt. Contrib.
Mus. Pal. Univ. Michigan 29(4): 89-108. [Eosiren imenti, new species]

Faure, M., C. Guerin, and M. Raimbault. 1993. L'exploitation des sireniens a travers
le temps. In: J. Desse & F. Audoin-Rouzeau (eds.), Exploitation des animaux savages a
travers le temps. Juan-les-Pins: 307-317.

Freess, W.B. 1991. Beitrage zur Kenntnis von Fauna und Flora des marine
Mitteloligozans bei Leipzig. Altenburger Naturwiss. Forsch. 6: 1-74. [Mentions
Halitherium schinzii.]


Garrott, R.A., B.B. Ackerman, J.R. Cary, D.M. Heisey, J.E. Reynolds III, P.M. Rose, and
J.R. Wilcox. 1994. Trends in counts of Florida manatees at winter aggregation sites.
Jour. Wildl. Manage. 58(4): 642-654.

Gerstein, E.R. 1994. The manatee mind: discrimination training for sensory perception
testing of West Indian manatees (Trichechus manatus). Marine Mammals: Public
Display & Research 1(1): 10-21.

Gingerich, P.D., D.P. Domning, C.E. Blane, and M.D. Uhen. 1994. Cranial morphology
of Protosiren fraasi (Mammalia, Sirenia) from the Middle Eocene of Egypt: a new study
using computed tomography. Contrib. Mus. Pal. Univ. Michigan 29(2): 41-67.

Irwin, D.M., and U. Arnason. 1994. Cytochrome b gene of marine mammals: phylogeny
and evolution. Jour. Mamm. Evol. 2(1): 37-55.

Kemper, C., P. Gibbs, D. Obendorf, S. Marvanek, and C. Lenghaus. 1994. A review
of heavy metal and organochlorine levels in marine mammals in Australia. Science of the
Total Environment 154: 129-139.




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Livermore, B. 1994. Tracking the elusive manatee. Sea Frontiers 40(6): 40-47, 54-55.

Marshall, C.D., and R.L. Reep. 1995. Cytoarchitecture of the caudal cerebral cortex in
the Florida manatee (Trichechus manatus latirostris). Brain Behav. Evol. 45: 1-18.

Matthies, E. 1994. Vom "lachenden" Manati zu einigen bemerkenswerten,
historischen Sirenendarstellungen. Milu (Berlin) 8(2): 186-193.

Pfretzschner, H. U. 1994. Biomechanik der Schmelzmikrostruktur in den Backenzdhnen
von Grossdugern. Biomechanics of the enamel microstructure of large mammals.
Palaeontographica Abt. A, 234(1-3): 1-88. [In German; Engl. summ.]

Ponte, F., H. Marsh, and R. Jackson. 1994. Indigenous hunting rights:
ecological sustainability and the reconciliation process in Queensland. Search 25(9): 258-
261.

Preen, A.R. 1995. Diet of dugongs: are they omnivores? Jour. Mamm. 76(1): 163-171.

Reynolds, J.E., III, W.A. Szelistowski, and M.A. Le6n. 1995. Status and conservation of
manatees Trichechus manatus manatus in Costa Rica. Biol. Conserv. 71(2): 193-196.

Ross, A. 1994. Traditional Aboriginal hunting in Australia: a cultural heritage issue.
Cultural Survival Quarterly 18(2, 3): 22-26.

Shimada, K., and N. Inuzuka. 1994. Desmostylian tooth remains from the Miocene
Tokigawa Group at Kuzubukuro, Saitama, Japan. Trans. Proc. Pal. Soc. Japan, N.S., No.
175: 553-577.

Vallee, J.D. 1994. Manatees and boats a collision course. Florida Naturalist 67(4): 15-
17.

Zoehfeld, K. W. 1994. Manatee winter. Norwalk (Connecticut), Trudy Management Corp.
& Smithsonian Inst. (Soundprints series; Smithsonian Oceanic Collection): 1-30. $14.95.
[Book for young children. Available with companion read-along audiocassette tape and
stuffed toy.]


CHANGES OF ADDRESS




Sirenews (ISSN 1017-3439) appears twice a year


Jessica Kadel Koelsch, Mote Marine Laboratory, 1600 Thompson Pkwy., Sarasota, FL
34236 USA

Leslee Parr, 15608 N.E. 29th, Vancouver, WA 98686 USA






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