NUMBER 39 APRIL 2003
IN
THIS ISSUE: - HAND-RAISED DUGONG
FAILS TO THRIVE IN THE WILD
(p. 3)
- RED TIDE AGAIN STRIKES
INTERNATIONAL SIRENIAN WORKSHOP TO BE HELD IN DECEMBER
A
workshop to discuss sirenian conservation issues has been proposed to be held
in conjunction with the 15th Biennial Conference on the Biology of Marine
Mammals,
Registration
for the workshop will be awarded on a first-come-first-served basis and will be
free to those who sign up beforehand. Another announcement with more specific
information on exact time and location of the workshop will be made in the next
issue of Sirenews. Mark your
calendars now!
For
additional information please contact Nicole.
- Nicole Adimey (USFWS) and Bob
Bonde (USGS). (Nicole Adimey,
Fish and Wildlife Manatee Biologist,
Fish and Wildlife Service,
EDITOR'S NOTE
With
our next issue, Sirenews will
complete an astonishing (to me!) 20 years of continuous publication. This is an
appropriate time for stocktaking, and the workshop announced above will provide
a convenient venue. I ask you, the readers of this newsletter, to consider
whether it has been meeting your needs as a source of sirenian-related
information in support of your efforts in research and conservation. How can it
be improved? How should it be changed? In view of the recent establishment of
the SIRENIAN listserv and the Sirenian International website by Caryn Self
Sullivan and her collaborators, as well as other on-line resources, is a
hard-copy newsletter now redundant? Or is it still relied upon by some,
especially workers in developing countries without easy Internet access?
Since
I lack the leisure to pursue investigative reporting, Sirenews has always relied on your contributions of news and
opinion; and for your two decades of support in this fashion, I am extremely
grateful. During that time it has been a pleasure to witness the geographic
spread of sirenian research and the involvement of new people. Twenty years ago
the major sirenian research centers were in
However, in recent years I
have also noticed that I am drawing more and more on news services and other
published sources, for lack of exclusive first-person reports volunteered by
you, the active workers directly involved in the study of sirenians. It is your
contributions that have always been the main strength of Sirenews, and made it unique. If you have not sent us any news
lately, is it because there is too little happening in your neighborhood, or
too much happening but with too little time to report it? If Sirenews is to be worth your while to
read, it must contain timely information from your colleagues -- and vice
versa.
I
earnestly solicit your thoughts on these issues, at any time up to and
including the December workshop, where I hope a formal discussion of this topic
can be included on the agenda. The publication of Sirenews is an extremely time-consuming task. I want to make sure
that my energies are being applied in the most productive direction, and (if
this newsletter is to continue) that it genuinely serves the needs of the
sirenian research and conservation community.
- DPD
LOCAL NEWS
Hand-Raised Dugong
Recap-tured. - The male dugong calf hand-raised from a neonate (Sirenews No. 31, April 1999 and No. 33,
April 2000), and released into Moreton Bay in Queensland on March 12, 2002 (Sirenews No. 37, April 2002), was
recaptured in poor condition on November 9, 2002 and returned to Sea World (Australia)
after 8 months in the wild. At 145.5 kg, "the pig" - whose identity
was unequivocally confirmed only after capture - had lost 52.0 kg (26.3%) of
his release body weight, and had been severely beaten up by another, presumably
male, dugong.
He was recaptured in shallow
water in Days Gutter, along the south-western aspect of
The pig's recuperation is
proving to be a continuously challenging process. He proceeded to lose another
8.5 kg off his already frighteningly lean physique in the first four days after
return to Sea World. After erratic gains and losses, his weight was down to
136.0 kg by the end of the fifth week - a staggering 61.5 kg (31.1%) lighter
than his weight at release. When one considers the relatively greater
contribution of the heavy sirenian skeleton to total body weight compared to
that in terrestrial mammals, this probably represents an even more alarming
percentage of his soft tissue mass.
Since mid-December, however,
the pig has demonstrated a gradual improvement in health and body condition.
The combination of abundant salad vegetables, supplementary milk paste, various
medications, worming, restoration of intestinal bacteria, a heated pool, and
lots of TLC have seen his weight creep upwards, albeit somewhat erratically, to
a maximum of 156.0 kg in late February 2003.
While understandably
disap-pointed by his failure to thrive in the wild, we consider ourselves
extremely fortunate to have been able to recapture him in spite of the
premature detachment of his tracking device. Positive aspects of his attempted
release include his surviving for 8 months (through winter), avoiding predation
and boat strike, and apparently mastering the vagaries of tides and currents
(Days Gutter is an area of relatively heavy boat traffic and strong currents).
Any decisions about his
long-term future will continue to be made in consultation with the other key
stakeholders in this ongoing 4-year rescue and rehabilitation process, viz.,
the
Pitchford and his team
perform necropsies on virtually every manatee carcass found in the state. “We
suspect red tide in these animals because of circumstantial and gross
findings,” Pitchford said. “The circumstantial is that they all came from red
tide bloom areas. The gross findings are consistent with red tide poisoning:
swollen, congested kidneys, froth in the airways of the lungs, blood that
doesn’t coagulate when you cut into the animal, hemorrhaging in the eyes,
bloody froth in the nose. As we get tissues tested, we’ll move them from
suspect to confirmed.”
The largest red tide manatee
die-off ever recorded was in 1996, when 149 died between March 5 and April 27
in
Last year, red tide killed
35 manatees; before 1996, the largest suspected red tide manatee die-off was in
1982, when 39 died over 11 weeks in
“We’ve essentially had an
event every year since 1996,” Pitchford said. “We undoubtedly had them before,
but they probably went unrecognized because of the small numbers involved and
the lack of a test.”
Scientists chalked the 1996
die-off up to a confluence of events. As area water started warming up,
manatees that had spent the winter in warm-water areas, such as the Florida
Power & Light power plant on the
This year’s event is a
little different. Red tide has been in
Some manatees have survived
the algae's toxin, which becomes airborne and causes respiratory irritation in
humans as well. Once away from the toxin produced by red tide, the manatees
usually recover, scientists said.
“Certainly we don’t know all
there is to know about manatees and the effects of red tide,” Pitchford said.
“One thing is painfully clear: When red tide is in manatee habitat, manatees
are going to die.” - Kevin Lollar (from The News-Press [
Status of
Staff at FWC's Florida
Marine Research Institute prepared a biological status review of the
*[ED. NOTE: For a critique of the State of
O.J. Simpson Pays Fine. - O.J. Simpson has paid a
US$130 fine for speeding through a manatee
zone in a powerboat. Patricia Jones, Simpson's attorney, paid the fine on
Nov. 22. The former football star didn't
come to the courthouse. Simpson, 55, had been ticketed July 4 for creating a
wake in a manatee zone while driving
a 30-foot powerboat near downtown
Judge Ana Maria Pando had
earlier issued a bench warrant for Simpson after he and his attorney both
missed a court hearing. The warrant meant Simpson could have been arrested if
stopped by police. The warrant was withdrawn hours later after Simpson's
primary attorney, Yale Galanter, explained he didn't attend because of a
scheduling mix-up.
Simpson was acquitted of
murder charges in the 1994 slayings of his ex-wife and her friend. A civil jury
later held Simpson liable for the killings and ordered him to pay the victims'
survivors US$33.5 million. He hasn't worked since. Any money he makes could be
seized to satisfy that judgment, which remains largely unpaid. He continues to
maintain his innocence in the killings.
- (Source: Associated Press
Online,
Fate is Against Us. - A
Q: Will docks or manatees disappear?
A: Boat owners are going to
win over manatees. Money generally
rules. And with evolution, our animals are changing. In about five years,
manatees will be extinct. Destiny
wants them extinct. I'm not blaming the boat owners. - (Source:
The News-Press [
Manatee Born in
The Singapore Zoo started
with three adult manatees (T. m. manatus)
from
New
Manatee Research and Conservation Program. - We are pleased to inform
you that a long-term research and conservation program on the West African
manatee will be undertaken in October 2003 (planned for a minimum of 3 years).
This program, part of a new-born French and international NGO (devoted to
education, research and conservation), will focus on 3 main objectives :
1. Study of the West African
manatee's distribution and repartition in the Niger Inner Delta (
2. Study of the manatee's
biology - 3 years of field observations planned.
3. Population genetics studies
(species comparisons, genetic variability, population viability, etc.).
More details will be published and issued in October
2003 (NGO website, official research program, contact addresses, etc.). In the
meantime, we welcome contacts with other biologists, sirenologists and
research/conservation organizations. Contact Frederic G. Speyser at our temporary e-mail address: <t.senegalensis@netcourrier.com>.
ABSTRACTS
The following abstracts are of presentations at
the 10th
Reunion de Trabajo de Especialistas en Mamíferos Acuaticos de America
Anatomical and Histological
Characteristics of Female Reproductive Tract of Trichechus inunguis (Natterer, 1883) (Mammalia: Sirenia).
Fernanda Rosa Rodrigues & Vera Maria
Ferreira da Silva
Instituto
Nacional de Pesquisas da Amazônia (INPA); Laboratório de Mamíferos Aquáticos –
LMA; Av. André Araújo,
2936; Petrópolis; Manaus-AM; Brasil.
The
Amazonian manatee (Trichechus inunguis),
like other representatives of the Order Sirenia, is uniparous with possesses
slow reproduction, considering the interval between birth and long gestation
interval. Another aggravating factor to its population growth is that hunting
of the species continues, although prohibited by law. The reproductive tract’s
macroscopic and histological study, especially of the ovaries, supplies
important information about the life history and on the female’s reproductive
state. In this study, anatomical and histological descriptions of the female
reproductive tract and mammary glands were made for the first time for T. inunguis. Three specimens were
utilized, and the collected material was fixed in buffered formalin at 10%.
After the biometry and anatomic description, tissue samples of the female
reproductive apparatus were removed and prepared for histological sections.
Histochemistry and immunohistochemistry techniques were used. The results
revealed that the external genitalia, mainly the clitoris and the labia majora, present numerous nervous
ganglions and tactile sensitive corpuscles in the dermis, important for sexual
stimulation. The vaginal epithelium is columnar, mucus-secreting, varying from
simple to pseudostratified. In mammals in general, the epithelium is stratified
squamous non-glandular keratinised. This keratinization is related to the
degree of friction to which the epithelium is subjected. The hymen has two
vaginal openings, tied by a short segment, and it separates the vagina from the
vestibule. These openings, possibly, become a single opening during sexual
intercourse. The shortage of elastic fibers corroborates this hypothesis,
reducing the possibility of complacency of the hymen. In one of the specimens
in this study, whose endometrial glands didn't present maximum development, no
placental scars were observed in the uterus. In this same individual the
presence of hemorragic body and Graafian follicles in the right ovary, besides
corpora albicantia, was recorded, suggesting that T. inunguis goes through infertile cycles, in order to reach sexual
maturity, before the first gestation. Macroscopically, the cicatricial body
counts were difficult because of their small diameter. It is not possible to
differentiate the cicatricial bodies resulting from the follicles’ rupture
(corpora albicantia) from those of non-ruptured follicles. It was
histologically observed, through the technique of Picrosirius - modified for
confocal, that the cicatricial bodies can be differentiated among corpora
albicantia and those resulting from non-ruptured follicles by the variation of
the organization and density of the collagen fibers of these structures. The
presence of corpora albicantia in the
right and left ovaries of one of the specimens in this study suggests bilateral
function of the ovaries in T. inunguis. [Master's
Thesis in Aquatic Biology and Interior Fisheries,
Phylogeography of Trichechus
inunguis (Natterer, 1883) (Mammalia: Sirenia) in Brazilian Amazon.
Andréa Martins Cantanhede1; Vera
Maria Ferreira da Silva1 & José A. Alves-Gomes2
1-Laboratório de
Mamíferos Aquáticos – LMA; Instituto Nacional de Pesquisas da Amazônia (INPA);
Av. André Araújo, 2936; Petrópolis; Manaus-AM; Brasil.
2-Laboratório
Temático de Biologia Molecular; Instituto Nacional de Pesquisas da Amazônia
(INPA); Av. André Araújo,
2936; Petrópolis; Manaus-AM; Brasil.
The Amazonian manatee is endemic to the
The Apparent Period of Pregnancy in Amazonian Manatee (Trichechus inunguis) Females Kept in
Captivity, Based on Plasmatic Levels of Progesterone.
Claudia Carvalho do Nascimento1,
Cláudio Alvarenga de Oliveira1, Vera Maria Ferreira da Silva2,
Érika Cristiane Gutierrez Felippe1, José Anselmo d´Affonseca Neto.
1Laboratório de Dosagens Hormonais - Faculdade de Medicina Veterinária e
Zootecnia - Universidade de São Paulo (LDH-FMVZ-USP). Av Prof. Dr. Orlando
Marques de Paiva, 87. CEP 05508-000. Cidade Universitária - Butantã. SP/SP
Brasil. E-mail: claucn@hotmail.com
2 Laboratório de Mamíferos Aquáticos- Instituto Nacional de Pesquisas da
Amazônia. CP478 Manaus-AM Brasil CEP 69011-970. E-mail: tucuxi@inpa.gov.br
The Amazonian manatee is the only
sirenian which lives in the
The following abstract is of
a doctoral dissertation submitted to the Centro de Investigación Científica y
de Educación Superior de Ensenada, CICESE,
Habitat factors that determine the distribution of Antillean manatees
(Trichechus manatus manatus) in the northern portion of
León David Olivera-Gómez.
The West Indian manatee (Trichechus manatus, Mammalia: Sirenia)
and the Antillean subspecies (Trichechus
m. manatus) are considered endangered by the Mexican and many international
environmental laws, for three main reasons: its reduced population size (a
result of the intensive hunting of this species since the arrival of Europeans
to the New World), the poor knowledge about many regional populations because
of their low densities and the difficulty of studying manatees in cryptic
habitats, and the human impact and modification of the rivers, estuaries and
coastal zone, where these mammals live. A large part of the studies about this
species referred to their general conservation and to the distribution of some
of their populations. In these studies, researchers indicated the need of
studying the principal characteristics of the habitat of the manatee. Those
studies had recognized some elements of the habitat, but few had explored
quantitatively the relationship of these characteristics with the use by the
manatees at a medium spatial scale. In this research, I accomplished a field
study to test the correlations between functional characteristics of the
habitat and the use by the manatee of small spatial units, of 0.02 km2,
within Bahia de Chetumal, located on the
The habitat characteristics evaluated were: distance to sources of freshwater, submerged vegetation coverage, depth, slope of the bottom, shelter from wind and surf, salinity and water temperature. I counted the manatees and sampled the habitat characteristics concurrently, between November of 1998 and April of 2000. I registered the location and the number of manatees through 17 aerial surveys with a light aircraft, in four sampling periods along a series of fixed transects on the northern coasts of the bays. Throughout these transects I established the study units. I built surface maps with the data of the habitat characteristics, and from these maps I assigned the corresponding values to each unit. I calculated the frequency of occurrence of manatees inside each unit, and finally, I calculated the Spearman’s correlation coefficients between each habitat variable and the occurrence of manatees and between each pair of habitat variables. I accomplished the same analysis for the data of the east and west coasts separately. Furthermore, to observe the multivariate relationships among habitat characteristics and manatee data, I carried out three types of analysis: Poisson regression, logistics regression and discriminate functions analysis. With the exception of the shelter from the wind and surf, all the analyzed variables presented a significant correlation with the frequency of occurrence of manatees. The global correlation was influenced by the data of the west coast, since the manatee occurrence on the east coast presented correlation only with the distance to freshwater sources. In the multivariate approaches, the distance to the sources of freshwater and the depth were the variables that contributed more to the models of regression and classification. In this study, I confirmed the association of the habitat variables proposed to explain the differential use of sites by the manatees at a small spatial scale. My data emphasize the influence of the distance to freshwater sources on habitat models.
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SIRENIAN WEBSITE DIRECTORY