'?kwsletter of the JUCW7/SSC
IN THIS ISSUE:
-USE OF SONAR TO DETECT MANATEES IN BRAZIL AND
HONDURAS (p. 11, 18)
-A NEW BOOK ON FLORIDA MANATEE CONSERVATION
A TRIBUTE TO JUDITH VALLEE, EXECUTIVE DIRECTOR OF
SAVE THE MANATEE CLUB
After 21 years serving as Save the Manatee Club's executive director, Judith
Vallee has decided to step down so she can pursue some of her other many talents and
interests. Judith's dedication and self sacrifices on behalf of manatees is unequaled and
there is no question that Save the Manatee Club could not have been nearly so successful
without her. I remember when I first spoke to Judith in 1984 as she was organizing a
manatee protection and awareness event in Broward County. I was immediately struck
with her unwillingness to take "no" as an answer when it came to furthering manatee
protection. Just a short time later I had the honor as Vice Chairman of Save the Manatee
Club to interview and hire Judith as the Club's Director. To this day I can think of no
other person that could have lead Save the Manatee Club so successfully through the
many challenges and pitfalls the future had in store for both the Club and the manatees.
UNION INTERNATIONAL POUR LA CONSERVATION DE LA NATURE ET DE SES RESOURCES
INTERNATIONAL UNION FOR CONSERVATION OF NATURE AND NATURAL RESOURCES
U IC N Commission de la sauvegarde des especes-Species Survival Commission
u.i MJ.uip..NIa_ Sirenews (ISSN 1017-3439) appears twice a year
in April and October and is edited by Cynthia R. Taylor and James A. Powell,
Wildlife Trust, 1601 3rd Street S., Suite F, St. Petersburg, FL 33701 USA.
It is currently supported by the U.S. Marine Mammal Commission.
The Save the Manatee license plate is an example of both Judith's great foresight
and willingness to sacrifice for the cause of manatee protection and recovery. Although
the license plate was Judith's idea as a fundraising tool for Save the Manatee Club, she
was willing to sacrifice for the Club in order to help insure that the state of Florida's
manatee program could be expanded to meet the challenges manatees were facing
statewide. Even though this made Judith's job of growing the Club's resources much
more difficult, without this sacrifice Florida's manatee research and protection programs
would never have been so successful. Her commitment to state and federal efforts did
not stop there as she regularly looked for other opportunities for the Club to fund both
state and federal research and rescue programs on behalf of manatees.
Fortunately for Save the Manatee Club Judith has graciously agreed to work part
time as the Club's Director of Development while she takes a little more well-deserved
and overdue time for herself. -Pat Rose
Thank you, Judith, for your past and continuing dedication to saving manatees and their
The Florida Manatee: Biology and Conservation, by Roger L. Reep and Robert K.
Bonde. A new book on the Florida manatee released by University Press of Florida.
"With a depth that comes from decades of working on manatee research in both the field
and laboratory, Roger Reep and Bob Bonde lead readers on a journey into the world of
this unique and endangered marine mammal. This journey reveals new discoveries about
manatee brains and behavior, delves into current controversies surrounding manatee
conservation, and is told from the perspectives of the authors' personal experiences and
the individuals who have made a difference in the field."--Charles Deutsch, Florida Fish
and Wildlife Research Institute
"A must-read for anyone with an interest in the conservation of this important species."--
Jim Valade, U.S. Fish and Wildlife Services Manatee Recovery Activities
In the field of marine biology, there is a uniqueness to manatee research, and in this
book, Roger Reep and Robert Bonde make clear both its rewards and challenges. Veteran
researchers with 45 years' experience between them, they have created an instantly
engaging, accessible tale of this mysterious creature for professionals and interested lay
Having played integral roles in many of the research efforts discussed in the book,
Reep and Bonde humanize the sometimes difficult-to-grasp characteristics of manatee
biology, their relation to the environment, and the biopolitics that result from the
intersection of science and wildlife management. They weave fact with real-life scenarios
to explain what science has learned about this unusual animal--from microorganisms that
cause manatee die-offs during red tide blooms to the complexity of long-distance
migrations to the curiosities of manatee physiology. The evolutionary basis of the
sirenian language (how manatees communicate with each other) is also revealed.
Sirenews No. 45
Technological innovations and conservation efforts since the landmark protection
legislation of the early 1970s are also central to the manatee story. Captive rehabilitation,
radio tracking, and advanced boating regulations are discussed as methods to ensure
manatee survival. Reep and Bonde argue that increasing interaction between man and
manatee, most notably through the shared use of waterways, makes ongoing scientific
research essential if successful coexistence is to be possible.
Roger Reep is a neuroscientist and professor in the College of Veterinary Medicine at
the University of Florida. Bob Bonde is a biologist with the U.S. Geological Survey
Sirenia Project. The book is available through Amazon.com and other major book stores.
Marine Mammals Ashore: A Field Guide for Strandings (J.R. Geraci & V.J.
Lounsbury) in the hardcover format is back!
A comprehensive manual for understanding and dealing with a stranded seal,
manatee, dolphin, whale, or sea otter, this book contains information for the interested
beach dweller or student and for the scientist or marine resource manager.
Marine Mammals Ashore describes rescue operations, how to organize a response
team, and how to deal with the media and the public. It includes basic information on
marine mammal biology, life history and health, and an extensive bibliography.
The book also provides stranding network participants with practical guidelines for
collecting data and specimens to better understand the biology and behavior of marine
animals and the condition of their environment.
All chapters have been updated and expanded, with emphasis on topics that include:
* Enhancing network organization, public education, and media relations.
* Natural and human-related mortality in each major marine mammal group.
* Recognizing, responding to, and investigating unusual mortality events.
* New or updated protocols for specimen and data collection (e.g., samples for PCR
analysis; basic guidelines for investigating possible noise-related strandings; collecting
environmental data and samples; and a detailed protocol for examining marine mammals
for signs of human interactions).
* Zoonoses and other public health issues.
* Updated overview of marine mammal stranding frequency and distribution in North
America, with coverage extended to Canada and Mexico.
* Overview of special topics provided by invited authors: disentanglement (Peter
Howorth, Santa Barbara Marine Mammal Center, Santa Barbara, CA); tagging and
monitoring (Anthony Martin, British Antarctic Survey); and GIS applications (Greg
Early, A.I.S., Inc., New Bedford, MA).
* Close to 600 new references (and a few new carcass disposal stories!).
The 372-page second edition features water- and tear-resistant paper, a vinyl cover
and durable plastic coil binding.
Cost =$38 U.S. plus shipping and handling. Total with shipping and handling =
* U.S. or Canada $44
* Other countries (surface, 4-8 weeks) $47
* Other countries (airmail, 7-12 days) $54
Sirenews No. 45
For more information or to order, please visit
A review of this book is provided below.
2005 MARINE MAMMAL CONFERENCE
The 16th Biennial Conference on the Biology of Marine Mammals was held in
San Diego, California, USA, 12-16 Dec. 2005. Numerous papers and posters were
devoted to sirenians. Unfortunately, copies of the abstract volume are sold out.
J.R. Geraci and V.J. Lounsbury. 2005. Marine Mammals Ashore: A Field Guide for
Strandings, Second Edition. National Aquarium in Baltimore, Baltimore, MD. 371 pp.
Back in the Dark Ages before the original version of Marine Mammals Ashore
was published, students, biologists, veterinarians and anyone else who wanted to
understand what to do about a stranded marine mammal mostly had to rely on
information passed down from one person to another which, as we all know, can
sometimes be good information, and sometimes a horrible lesson in what not to try again.
Thus, with the publication of the first volume in 1993, it immediately became recognized
as a wonderful general resource with good descriptions and standardized techniques
written in a way that was user-friendly for everyone in the field.
This new edition of the original volume has been updated and greatly improved
with the addition of almost 600 new, well-researched references, special topics including
chapters on Disentanglement, Tagging and Monitoring (although this does not include
manatees), and GIS Applications, as well as updated protocols and sample forms. There
has also been some good reorganization; for example, the Guide to Marine Mammals of
North America has been consolidated into one chapter, rather than descriptions
interspersed throughout the book. Another highlight for many readers (because a
requirement for most people who deal with carcasses is a healthy sense of humor) will be
the chapter on Carcass Disposal which includes several wonderful new anecdotes, and
the funny but enlightening cartoons all through the book.
The manatee chapter (which one might assume Sirenews readers will be most
interested in!) has been expanded to give a general introduction to all four sirenian
species, a new map detailing West Indian manatee range, and updated information about
subjects such as causes of mortality and rescue equipment needs. The only unfortunate
aspect of the chapter is that some drawings were not updated and show techniques that
are either outdated (Florida manatees are not usually transported in a box resembling a
coffin) or dangerous (rescue crews pull netted manatees to shore head first to avoid
drowning, not tail first as shown in the picture). Additional good information for
manatees can be found in the Specimen and Data Collection chapter, which has very
detailed descriptions and drawings of techniques for manatee blood draws and necropsy
Sirenews No. 45
All chapters have been expanded with emphasis on topics including network
organization, media relations, recognizing unusual mortality events, zoonoses and other
pubic health issues. In short, topics that have become increasingly important as more
people become involved and respond to standings. The hard plastic cover, plastic coil
binding and waterproof pages make Marine Mammals Ashore durable and field-worthy,
and there are blank pages for notes at the end of each chapter. I am certain this book will
continue to be a useful resource for the stranding network community for many years to
come. Lucy Keith (email@example.com).
Language Matters in Dugong Conservation. The Great Barrier Reef region in
northeastern Australia, covering an area of 344,400 square kilometres, is the largest
World Heritage Area in the world. The Great Barrier Reef World Heritage Area
(GBRWHA) is also the feeding and breeding ground for many threatened species
including the dugong. The GBRWHA is functionally divisible into two regions: the
remote region off Cape York (Northern Great Barrier Reef) and the urban coast. Marsh et
al. (2002) estimate that the coastal waters of Cape York support about ten thousand
dugongs, some 10 percent of the Australian dugong population.
The land bordering the GBRWHA is also home to 70 Indigenous traditional
owner groups (approximately 11,000 Indigenous people), many of whom continue to
harvest dugongs as a traditional right, and for whom hunting continues to be of high
cultural and dietary value (Baldwin 1985). Indigenous hunting of dugong however is an
activity that has historically polarized communities living along the GBRWHA.
Population models indicate that the current Indigenous harvest levels of dugongs are
unsustainable both within the northern Great Barrier Reef Region and neighboring Torres
In the last twenty years the Great Barrier Reef has worked in various ways with
Indigenous peoples to manage traditional hunting practice. Specifically, Hope Vale
Aboriginal community, located within the Northern reef section, has had an ongoing
dialogue with Management Agencies and worked towards effective management of
Indigenous dugong hunting activities. These management initiatives have included (i) the
implementation of the first permit system within the reef, (ii) development of a Turtle
and Dugong Hunting Management Plan (the first in Australia), and most recently (iii) the
establishment of Traditional Use Marine Resource Agreements (TUMRAs) with the
Great Barrier Reef Marine Park Authority (GBRMPA).
Our research has focused on the relationship between Management Agencies and
the Hope Vale community in relation to management of dugong hunting. Using a
discourse approach, our research, funded by the James Cook University, the CRC Reef
Research and the Pew Foundation via Professor Helene Marsh, aimed to identify whether
or not differences between linguistic understandings of Indigenous hunting, planning and
management had any effect within on the ground management initiatives, such as the
Hope Vale Plan.
A key finding of our research was that significant linguistic differences exist
between Management Agencies and Hope Vale Community about dugong hunting,
Sirenews No. 45
planning and management. Management Agency staff, for example when talking about
dugong management, prioritized this need in the context of biodiversity protection, while
Indigenous members viewed dugong management primarily as a mechanism that would
address cultural survival objectives. In this context, Management Agency staff prioritized
the production of a plan, whereas Hope Vale prioritized planning processes, a priority
reflected in their respective discourses about planning and management.
Further, while the same terminology was used throughout the management
process, our research revealed core differences in understanding between Hope Vale and
Management Agency personnel. 'Equity', for example, was a term employed by Hope
Vale community members within dialogue about Indigenous rights. For Indigenous
people, hunting was seen as a value-laden activity and therefore an equity issue. Terms
used to describe the rights held by the community included: (i) who had the right to hunt;
(ii) who had access to permits; (iii) who had the right to speak with Management
Agencies; and (iv) who had the right to manage hunting activities. Achieving equity was
understood then as achieving parity within this rights framework. Management Agency
staff, by contrast, discussed the term equity in a far broader context. Management Agency
staff employed the term equity to explain the problem of reconciling Indigenous interests
with those of non-Indigenous groups (including scientific and conservation) in
management. This concern reflects the wider community perception that Indigenous
people received preferential treatment in relation to Indigenous harvesting of Green
turtles and dugongs in the GBRWHA. This difference in understanding offers an
important insight into how negotiations over dugong management can end up at cross-
purposes because the fundamental concepts and actions being discussed are understood
Many other examples could be discussed. Overall, however, our research revealed
that how language is used and interpreted within resource management does matter because
different linguistic interpretations within such programs have a direct impact on their
efficacy. In this case, the ebb and flow between the different discourses and their impacts
on the ground, were a significant contributing factor that explained the difficulties in
implementing the Hope Vale Plan.
The research highlights that species such as the dugong, which are so vulnerable,
need to be protected by management regimes that address both social justice and
biodiversity objectives, in ways that are politically feasible, socially just and economically
viable. The research calls for the establishment of a small integrated group, led by an
Indigenous person, to provide a briefing to the Commonwealth of Australia on how to
achieve a national 'Caring for Country and Culture' scheme that will ensure both species
protection and respect Indigenous rights to hunt. Melissa Nursey-Bray and Helene
Marsh (for further information you can contact: Melissa Nursey-Bray, Australian Maritime
College on firstname.lastname@example.org or Professor Helene Marsh, James Cook
University on Helene.Marsh@jcu.edu.au).
Update on Captive Dugong in Australia. -More than three years have passed since Pig,
the male dugong hand-raised at Sea World (Australia) and released in March 2002, was
recaptured in extremely poor body condition after spending eight months in the wild
(Sirenews No. 39, April 2003). Over that period, numerous tests were done to try to
pinpoint the reasons) that he failed to regain the good health he had shown prior to release,
Sirenews No. 45
but there was no clear indication of why he now failed to thrive. For 18 months prior to
release he had flourished when housed outdoors, where water temperatures reached a
minimum of 17C during winter. Now, in his emaciated (and therefore poorly-insulated)
post-recapture state, it seemed that he could be compromised by water temperatures
somewhere around the mid-200C's or perhaps even higher. For this reason, he has had to
be maintained in a specially heated rehabilitation pool adjacent to the Veterinary
Quarantine Centre (VQC) since his return to Sea World.
Many months into his recuperation, consensus grew amongst various stakeholders
that it would be unjustifiable to contemplate any future attempt at re-release of this
particular individual. Eventually, in August 2004, Sea World made a formal application to
the Queensland Environmental Protection Agency (QEPA) to transfer Pig off the Rescue
Permit under which he was hand-raised and released, and on to Sea World's Wildlife
Exhibitor's License. Permission to do so was granted in October 2004. Plans were made
to house Pig where he could be seen by the public in a dedicated area with a heated pool
which allowed underwater viewing. Demolition and refurbishment of the interior of the
building that had once been the World of the Sea Theatre began. Photographs, video
footage, object galleries, and several interactive stations were utilised, in addition to
standard textual graphics with a strong emphasis on dugongs and dugong conservation in
general (as well as lots of specific information about Pig and his story), to increase the
educational impact of this interpretive material. The new exhibit "Dugong Discovery"
opened on Boxing Day 2004.
In addition to Pig's unique contribution to raising public awareness of dugongs and
threats to their survival, the hand-raising techniques developed during his original
rehabilitation have already proven useful, after the January 2005 stranding of yet another
baby dugong in central Queensland. This female calf is currently making steady progress
at Sea World after being rescued from a beach at Emu Park (between Rockhampton and
Yeppoon) by Rosslyn Bay Marine Parks rangers and an elder of the local Darumbal
community. She has been named "Wuru", a Darumbal word meaning 'young child'. As
Wuru continued to thrive, in July 2005 we sought QEPA permission to move her into
Dugong Discovery where she could be seen by the public in lieu of Pig. Wuru is currently
housed in the 3.9m deep Dugong Discovery tank, an environment she shares with various
species of fish, small benthic sharks (grey carpet sharks, epaulette sharks) and stingrays.
She still gains most of her nourishment from bottle-feeds of milk, but will be weaned
gradually over the next six months.
Pig was taken off display and back to his rehabilitation pool adjacent to the VQC,
where it was more practical to closely monitor changes in his body weight, blood values,
food intake and faecal output. Subsequently, staff came back to revisit the idea that the
bacterial flora in Pig's intestine, essential to allow him to digest a herbivorous diet, was
somehow not up to scratch. Within the first couple of months of his recapture, re-
inoculation of his gut with faeces from wild dugongs was attempted on two occasions, but
in retrospect it was felt that for various reasons this process might not have been
successful. In September and October 2005, more freshly-passed faeces was collected in
the vicinity of feeding dugong herds in Moreton Bay, and efficiently delivered to Pig (and,
as he was going through yet another downturn in his appetite and body weight, a number of
medications were also administered around the same time). Since then he has rallied and
begun to eat very well, regaining a great deal of lost condition and, for the first time since
Sirenews No. 45
his recapture, is steadily closing in on his release weight. -Wendy Blanshard (Sea World,
P.O. Box 190, Surfers Paradise, Queensland 4217 Australia; tel.: +61-7-5588-2222; fax:
+61-7-5588-2266; e-mail: ).
Dry Season Manatee Captures in Belize March 2006. -Wildlife Trust's Manatee
Project in Belize began in late 1996; the first manatee, an adult male, was captured in
November 1997. This past March made the 16th time we have assembled a crew from
Belize and abroad to catch manatees in the Southern Lagoon, a 9000 ac Wildlife
Sanctuary in the heart of Belize's coast. Our schedule is now to capture animals once in
the dry season and once in the wet season.
Starting on March 18, we had three priority animals to catch; specifically those
that had satellite (PTT) tags. The first attempt was an adult male originally captured and
tagged with a PTT tag in November 2005 within the marine environment of the Drowned
Cays. As the PTT component stopped functioning in February, and we were
unsuccessful in detecting a signal from the VHF component of the tag, we were unable to
find the animal to catch.
The team then moved to the more reliable waters of the Southern Lagoon, a
brackish estuarine system, where we track between 5-10 manatees throughout the year.
We caught four new males, and one new female in the Lagoon. We were able to capture
and change the tag of a female originally caught in 1997 as a calf, and who we have been
tracking since November 2004. We are awaiting signs of the first mating or pregnancy
from this female named "Morgan".
The most challenging task was to catch "Super-K", one of the priority three, a
large adult male (424 kg) originally tagged in November 2005. "Super-K" had moved
out of the Lagoon, southward along the coast to a small lagoon area about 10km away, as
identified by the satellite reading. Our efforts resulted in receiving the tag's VHF signal,
which was only two to three beeps every 10 minutes; we were therefore unable to locate
its exact position.
Serendipitously, while tracking for "Super-K", we picked up the signal for a
female, "Ellie" who we were looking for since we began the week's captures. "Ellie"
was another target adult that we have been tracking since April 2003; the PTT component
of her tag was no longer functioning and therefore needed to be retrieved. Sitting within
a mile of our boat in about 4.5 meters deep water, she was with a group of about 10 other
manatees. Through the great skill from the team and some luck, we were able to retrieve
the tag and catch her for a medical examination.
Within the last three years we have been tagging mother and calf pairs to observe
weaning and subsequent calving by the adult. In some cases we also tag the weaned calf
to monitor long-term reproductive patterns (as we did with "Morgan".) This capture we
had targeted a mother and female calf pair originally tagged in November 2005, as the
mother lost her tag (the belt broke off). Unfortunately we missed that pair in the process
of the capture and the calf too lost her tag. Fortunately, all animals we capture are tagged
with two unique microchips (PIT tags) so we can identify them if caught in the future.
For this capture event, all animals were considered in "excellent" body condition,
save "Ellie" who was classified as "good" she had new scars and appeared a little thin.
Sirenews No. 45
Two were previously caught animals, and six of the eight had boat scars. Until the next
capture in the wet season (October), we will be tracking eight manatees in Southern
Lagoon and one in the offshore cayes. We collect positional data, basic physical water
quality data, and behavioral data of the manatees we monitor. Nicole E. Auil (Belize
Program Manager / Conservation Biologist, Wildlife Trust; email@example.com).
Some recent records of manatees in the great Belim area, on the north coast of
Brazil. -The distribution and occurrence of manatees (Trichechus spp.) is poorly
understood in the surroundings of Belem, Para State capital, as well the Maraj6 Island
and nearby coastline in Brazil. The high hunting pressure in the past has decimated most
of the existing populations but apparently some small groups are thriving. Also important
is the fact that both species can coexist, and hybrids have been recorded in the mouth of
the Amazon River and the great Belem area. Due to these facts we strongly recommend
further investigation of their conservation status.
There is an increasing interest in their occurrence by biologists and as a
consequence their presence is being reported from several localities. Additionally
manatees and cetaceans were included as a key topic and will be investigated by the staff
of Projeto Piatam (Potenciais Impactos Ambientais do Transporte de Petr6oleo e
Derivados na Zona Costeira Amaz6nica) Mar supported by PETROBRAS-Brazil Oil
Company. Major institutions from the northern Brazilian coast are involved in the
project such as Museu Paraense Emilio Goeldi (MPEG) and Universidade Federal do
Recent manatee records are known from Cameta (02 14' 54"S; 490 30' 12" W)
and the Salgado region. The Cameta specimen was found on February 1 2006 with
several wounds inflicted from a probable hunter. It was a 2 m long pregnant Amazonian
manatee. The latter was a confiscated specimen found during a routine patrol by local
authorities. Additional records include two specimens found in 2005 from the localities
of Soure and Salvaterra, Maraj6 Island. The skull from the latter specimen is deposited at
MPEG and represents an important confirmed record for the area.
We thank Rosalia F. C. Souza (UFRA/IBAMA/CEPNOR/PIATAM Mar) for
providing information on the specimen from the Salgado region. S. Siciliano and N.
Renata Lima have received support for field studies from Projeto Piatam Mar and Projeto
Piatam Oceano/Cenpes/Petrobras. Salvatore Siciliano1, Neusa Renata E. de Lima2,
Adriana C. Colosio3, and Josd de Sousa e Silva Jr.4. (1Grupo de Estudos de Mamiferos
Marinhos da Regido dos Lagos (GEMM-Lagos), Laborat6rio de Ecologia, Depto. de
Endemias Samuel Pessoa, Escola Nacional de Saude Piblica/FIOCRUZ. Rua Leopoldo
Bulh6es, 1480-terreo, Manguinhos, Rio de Janeiro, RJ 21041-210 Brasil; 2Universidade
Federal do Para, Depto. de Biologia, Laborat6rio de Ornitologia e Bioacistica; 3Novos
Curupiras, Soure, Ilha do Maraj6, PA; 4Museu Paraense Emilio Goeldi, Coordenacgo de
Zoologia (CZO), Av. Perimetral, 1901, Terra Firme, Belem, PA 66077-530).
Amazonian Manatee Project Brazil. -The Amazonian manatee is one of the aquatic
mammals belonging to the Sirenia family and is one of the biggest species of this type. It
can reach 2.8 meters in length and it can weigh up to 500 kg. Its color varies from dark
gray to black, with many animals having white or pinkish patches on their bellies.
Sirenews No. 45
This species is endemic to the Amazon basin and is categorized on IUCN's Red
List as "Vulnerable" (facing a high risk of extinction in the wild in the medium-term
future) and is on the Brazilian official list of species as threatened (Instituto Brasiliero do
Meio Ambiente e dos Recursos Naturais Renovaveis IBAMA). It is also included in
Appendix I of the Convention for International Trade of Endangered Species (CITES)
that addresses threatened species.
Our greatest long-term challenge is for this species to be protected enough to be
removed from the list of threatened species in Brazil and to guarantee the survival of the
manatee population, especially the population in the Anavilhanas Ecological Station
(350,018 hectares), one of the largest fluvial archipelagos in the world, composed of
more than 400 islands in the Rio Negro region where this project is being carried out.
Both governmental and non-governmental agencies and the riverine communities are
involved in this conservation program.
The general objectives of this research are to determine relative habitat use and
movement patterns of manatees and design management plans for the species and its
wetlands habitat, and to implement environmental education for local people in order to
raise their awareness about the importance of conservation.
The ecological studies will require the radio-tagging of at least two manatees per
year. Temporal and spatial habitat maps with descriptions for manatees in each area will
be developed, along with reports of threats to manatees and wetland habitats. This
information and results will be compiled and presented by our project staff in the form of
recommendations and for mitigation of threats. Furthermore, the information gathered
through this study will be used to develop a Manatee Management Plan for the Amazon
Basin, together with other researchers from Amazonas. During the next few years, we
will hopefully be able to obtain the necessary data for a manatee population viability
analysis, which will ultimately provide the tools for the implementation of a management
program for the Amazonian manatee.
We began project activities in 2003 interviewing workers from IBAMA and
hunters from the region, and making expeditions on the lakes and paranas (arm of a large
river separated by an island from the main course) of Anavilhanas Ecological Station in
areas where we had been told that the Amazonian manatee (Trichechus inunguis) could
be sighted. The places where the manatees were seen were documented with GIS and
plotted on a map. We explored the lakes and paranas to find incidence of the following
aquatic plants that compose the manatee diet. We identified 19 species of aquatic plants
whose young leaves had been fed upon by the manatees: "feijoarana" (Puerasia
phaseolades), "cip6-icica", "maracarana" (Coccoloba densifrans), "feijoarana"
(Phaseolum pilosus), "melanciarana" (Cayaponia sp.), "batatarana" (Ipomaea
squamosa), "cararana" (Passiflora pohlii), "arroz-bravo" (Oryza perennis), "embauba"
(Cecropia sp.), and others.
On the morning of June 18 2004 the first sighting of a manatee was made
approximately 300 meters from the boat while the animal was submerging, exposing its
rounded fluke. The location of the sighting was the river arm known as "parana do Siriri"
which passes through the lake. We did see manatees at other times, including feeding on
the leaves of"embauba" and "feijoarana" near Prato Lake, and a manatee feeding in the
Siriri Lake 20 meters from the boat. That animal was probably feeding on wild rice
(Oryzaperennis), which at this time is found at the bottom of the lake. We followed its
Sirenews No. 45
activity for 45 minutes when it moved and went into the Siriri Channel, where it was
possible to see its entire body. Manatees were sighted in Araga Lake at different points.
In most of the sightings only the nostrils were visible, as it is rare for the Amazonian
manatee to expose its backside (dorsal) or face out of the water.
In 2003, we also began environmental education activities directed towards
students and teachers of public schools. These activities were executed during the
traditional celebration in the municipality of Novo Airao known as the Manatee Eco-
festival. During this festival the entire municipality of Novo Airao takes part in festivities
in honor of the Amazonian manatee. The environmental education activities resulted in
the "Mini Eco-festival of Student's Art and Culture for the Manatee". The purpose of this
activity was to transmit the importance of conservation of the Amazonian manatee and
also to honor the students' creative work.
Teachers from two state schools (Balbina Mestrinho and Danilo Mattos Areosa),
three municipal schools (Bandeirantes, Arist6teles Freire Arnoud and Violeta Cardoso
Alves de Mattos Areosa), Agape Foundation, and the Program to Eradicate Child Labor
(PETI) participated in the workshops. As a result, the teachers presented work developed
in the classroom, involving around 3,000 students where their creativity was widely
applied and expressed in works of theater, dance, folders, music and poetry. This event
occurs in the schools in October, since 2003. In June, another important event
commemorating Environment Week occurs in the schools from Novo Airao. The purpose
of this event is to work on questions related to biodiversity, environment and its
importance to the maintenance of life in the world.
These environmental education activities count on the support of other
institutions, including the Almerinda Malaquias Foundation (FAM), IBAMA/AM and the
Center for the Preservation and Research of Aquatic Mammals ("Centro de Preservagao e
Pesquisa de Mamiferos Aquaticos" CPPMA), strengthening and stimulating
partnerships in the township of Novo Airao.
We are aware that we have established a relationship of trust with the community
of Novo Airao and also with the communities located in the area surrounding
Anavilhanas and that this involvement allows us to work in partnership with the diverse
players in region: teachers, students, the public sector and with other NGOs active in the
region. We believe that our action in the region will result in the successful execution of
activities and programs both for scientific research and community involvement and in
building credibility for IPE's work in Amazonia. Clarice Bassi (Researcher / Biologist,
M. Sc. in Ecology, IPE Instituto de Pesquisas Ecol6gicas -Institute for Ecological
Creative ways to see and count manatees in murky waters. -One of the biggest
questions about Amazonian manatees is: how many are there? The answer is often
frustrating we don't know. And we don't have a baseline number for populations in the
past. All that is available is a minimum number of culled animals during the years of the
commercial harvest. The reason for such a situation is three-fold: the Amazon is a huge
area, most waters where manatees occur are sediment-laden in nature and consequently
coffee-and-milk in appearance, and the beast is just "fino", a local expression to convey
the idea that the animal is shy, secretive and very witty. In an attempt to overcome such
handicaps, Mamiraua Institute's Aquatic mammal research group has been using
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alternative ways to "see" and count animals. Following a lead by the Natutama group
from Colombia (previously with Omacha Foundation), we used the help of local hunters
during the height of the past dry season to attempt a community-based Amazonian
manatee estimate of manatees concentrated in deep holes in the Amana lake, a manatee
refuge during the dry-water period. Although we concluded the number of counters was
too small and the survey time too short considering the extent of the lake (40 km long by
3 km wide), it was an interesting experiment which will help us plan better for the next
A novel way we intend to obtain an index of abundance of Amazonian manatees
is by setting up an imaging sonar device to see them under turbid water conditions. The
device, a bit more sophisticated than the commonly-used fish finders, operates at
frequencies ranging from 310 kHz to 1 MHz, well above manatee hearing range. The
equipment can be set to work either as a rotary sonar (covering anywhere from 1 to 360)
or a single side-scanning sonar, and is capable of recording all the images on disk. The
sonar is being tested in clear water springs in Florida during this winter season, in
cooperation with USGS' Sirenia Project, which shall allow for calibration of the
signature obtained in the sonar record. The tests have been very promising, and most of
the manatees seen in the wild have been captured on record, especially up to a 40-m
range. During the next receding-water period the equipment will be set up such as to
create an acoustic fence across one of the well travelled channels by manatees during
their yearly migration in the Amazon, in order to estimate the number of animals using
the Amana lake. In addition, we are planning to use a hydrophone in the same floating
station as the sonar, to record manatee sounds as they move by. -Miriam Marmontel
Manatees and the 2005-2006 water cycle in the Brazilian Amazon. -Manatee life down
in the Amazon is intimately linked to water level variations. In the year 2005 the state of
Amazonas underwent one of the most dramatic climatic phenomena in the last few
decades. Significant reduction in the rain levels in the months of May, June and July
relative to previous years caused a very rapid and severe drought. Most water bodies
became reduced in extent, communities became isolated and a large number of fish died.
The rigorous decrease in water levels allowed researchers to observe with relative ease
the footprints that reveal the presence of manatees in lakes and canals. The bad news was
that this improved the chance of detection, increasing the vulnerability of animals
gathering in certain restricted areas, and resulted in local hunters catching a large number
of manatees along the Amazon basin. Stories appeared frequently in the media about
culls in different towns, notably Coari and Codajas. Several orphaned calves were
rescued by environmental agencies and taken to rehab centers (Manaus and Balbina)
already filled to their capacity. The Mamiraua Institute's aquatic mammal research group
confirmed three manatee deaths due to hunters in the Tefe Lake (700 km west of
Manaus), although the real number may have exceeded 10. In the Amana Lake (within
the Amana Sustainable Development Reserve, 100 km west of Tefe), on the other hand,
greatly due to the work conducted with the local hunters, it is believed that the animals
were relatively safe in their refuge, which may not have been true in the nearby Castanho
Lake and channel, and adjacent areas in the Amana reserve.
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During 2005, funding from Petrobras, the Brazilian oil company, allowed us to
conduct a new manatee capture in the Amana Reserve. Due to the extreme drought, the
deployment of the large nets had to be adapted to use in the large blackwater Amana
Lake rather than the usual capture site on the narrow Castanho channel. Two males of
over 240 cm total length were fitted with belt-mounted VHF transmitters and their
movements have been monitored since the time of release. Due to La Nina conditions in
the tropical Pacific, the Amazon basin has been receiving a lot of rain since early this
year, and the flood is being predicted as one of the largest in the century. By mid-
December 2005, at least two months earlier than expected, the animals started moving
out of the deep water lake back to the floodplain areas. Miriam Marmontel
Florida Manatee Recovery and Implementation Team Update. -The Florida Manatee
Recovery and Implementation Team was re-convened in 2003. Its purpose is to oversee
and facilitate the implementation of recovery actions as outlined in the third revision of
the Florida Manatee Recovery Plan and to make recommendations for revised
implementation actions to include in the next revision of the recovery plan. The team
currently has over 100 members, representing 60 agencies and organizations. It is led by
a 7-member Steering Committee and has 10 officially-appointed Working Groups and
The Recovery Team Steering Committee serves in a liaison capacity between
recovery team members and the U.S. Fish and Wildlife Service. Its role is to foster
communication among Team members and provide guidance and direction to the
Working Groups and Task Forces on recovery priorities. The Steering Committee
identifies recovery tasks needing to be accomplished, and monitors progress on
The Working Groups and Task Forces are responsible for the implementation of
specific recovery actions according to the four objectives outlined in the recovery plan.
Some of these groups were already in existence prior to 2003 and actively engaged in
manatee conservation activities before being incorporated under the umbrella of the
recovery team. Others were newly created for specific recovery efforts. The following is
a brief summary of their activities and accomplishments.
Protection Working Group Provides guidance on ways to reduce threats to
manatees. This group is reviewing current manatee protection strategies and
evaluating potential new methods of protection. They have developed draft guidance
on the marking of manatee protection areas, and will prepare recommendations to
help reduce manatee harassment.
Regulatory Working Group Recommends ways to improve regulatory and
permitting programs affecting manatees and their habitat. This group's efforts
include reviewing and evaluating relevant science as it relates to regulatory programs,
evaluating manatee regulatory programs and decision-making criteria, and identifying
information needs for improved regulatory decision-making. Their first
accomplishment was to educate stakeholders on the state and federal permitting
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Population Status Working Group Provides an assessment of the current status of
the manatee population. They provide advice on manatee demographic criteria,
interpret and review information and data relevant to population biology, and make
recommendations on potential research needs and methods. They recently completed
a biological population assessment of the Florida Manatee that will be useful for the
Service's 5-year review of the species. They are currently evaluating manatee habitat
carrying capacity, assessing the scientific justification for the designation of the four
manatee subpopulationss," reviewing manatee mortality information, and providing
refinements to population survey methodology and estimation procedures.
Habitat Working Group Identifies threats to manatee habitat and develops
strategies to reduce those threats. They are addressing broad, habitat-related issues
such as water quality, freshwater sources, foraging habitat, resting and calving areas,
and migration and travel corridors. They advocate the protection of springs, and are
addressing minimum flows and levels. In 2004, they helped host a Manatee Habitat
Workshop. They are currently working on an assessment methodology for important
manatee wintering sites. This assessment process will be used to evaluate habitats
throughout Florida and may be used to estimate winter foraging carrying capacity.
Warm Water Task Force Develops and implements strategies to ensure safe and
dependable warm-water refuges for manatees. This Task Force is developing a
conceptual plan for a long-term network of warm-water refuges throughout Florida.
They are prioritizing the importance of individual springs and identifying warm-water
enhancement opportunities for spring systems. They are also developing a plan to
reduce the potential loss of manatees in the event that a power plant goes off-line,
either permanently or for an extended period, and exploring potential new sources of
artificial warm water. They helped host the Manatee Habitat Workshop and are
working with the Population Status Working Group to assess warm water manatee
carrying capacity in Florida.
Education Working Group Facilitates manatee recovery through public awareness
and education and through coordination with other Working Groups and Task Forces.
In 2005, this group awarded a contract for a statewide inventory and preliminary
assessment of existing manatee education materials and programs. This assessment is
expected to be completed this year. The results will help us to better understand what
types of information has been most effective for reaching the public and improving
our understanding and awareness of manatee conservation.
Rescue, Rehabilitation, Release Partnership Assists distressed manatees and
reintroduces them back into the wild. In 2005, an estimated 65 manatees were
rescued. Thirty of these animals were subsequently released (15 died as a result of
their injuries or illnesses). Manatee rescues, captive manatees, and manatee releases
draw attention to the manatee and their associated threats. As a result, this
partnership is also an extremely important outreach tool for promoting manatee
conservation. The media heavily publicize rescues and releases, and more than
10,000,000 visitors a year see manatees at critical and long-term care facilities. The
facilities do an outstanding job of interpreting the challenges that manatees face and
promoting recovery efforts.
Entanglement Working Group Decreases and eliminates manatee entanglements
in fishing gear through education and outreach efforts, gear recovery and clean-up,
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data collection protocols, entanglement research, and potential technique/gear
modifications. This group has a number of successes to report, particularly with
regard to monofilament recycling efforts around the state. They produced an
entanglement brochure and created an educational video on the impacts of improperly
discarded monofilament for education and outreach purposes; they routinely conduct
derelict crab trap removals and assist other organizations in initiating such efforts;
and they tag and monitor formerly entangled manatees to better understand how
manatees become entangled and cope with entanglements. In 2005, approximately 16
manatees were rescued from entanglements in fishing gear.
Water Control Structures Task Force Eliminates manatee deaths and
entrapments due to the operation of major flood control structures, navigation locks
and drainage structures. This interagency partnership has successfully worked to
have a majority of water control structures and navigation locks retrofitted to ensure
manatee protection throughout the state. This effort has been an incredible asset
toward eliminating this threat to the manatee population in Florida.
CERP Interagency Task Force Assures that the implementation of the
Cooperative Everglades Restoration Plan avoids and minimizes manatee conflicts.
Task Force members conduct site visits and evaluate canal systems used by manatees.
They prepared an issue paper that recommends that manatees be precluded from the
Everglades portion of the Central and Southern Florida (C&SF) canal network.
The recovery team has made significant progress in overseeing the implementation of
recovery actions as outlined in the recovery plan. The Working Groups and Task Forces
have addressed some of the highest priority issues, and they are currently identifying
additional recovery actions necessary to address specific threats to the Florida manatee.
It is anticipated that the recovery implementation schedule will be updated later this year.
The current Florida Manatee Recovery Plan can be viewed online at the FWS North
Florida Ecological Services Field Office website at:
-Dawn Jennings, Jim Valade (U.S. Fish and Wildlife Service).
Update on Manatee Forum. In July 2004 the Florida Fish and Wildlife
Conservation Commission (FWC) and the U.S. Fish and Wildlife Service (USFWS)
initiated the "Manatee Forum." The purpose of this 22 member group is to provide a
forum where stakeholders can meet to discuss manatee issues, better understand
competing views, and hopefully resolve conflicts. Manatee conservation in Florida had
become increasing polarized in recent years with stakeholder groups focusing on
litigation and Legislative fixes rather than engaging in productive dialogue. Conflicts
range from environmental organizations who believe the agencies aren't doing enough to
protect manatees to boating interest advocates who believe there is too much regulation
in Florida because of manatees. The Forum is held quarterly, typically for two days, and
is professionally facilitated. Funding for the Forum is provided by FWC & USFWS.
Each has focused on a different topic. The first Forum was used to determine the best
course of action to address the conflicts and to establish the willingness of participants to
engage in on-going dialogue. Forum II was devoted to developing a governance
framework. Forums III and IV focused on research topics. Both included highly
interactive discussions between researchers and the Forum participants. Forum V
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combined presentation of information with conflict resolution efforts while Forum VI
focused solely on conflict resolution.
The Manatee Forum has been a useful venue for stakeholders to express their
concerns and communicate directly to the management agencies. There has been open
dialogue which gives participants insight into various perspectives about the issues and
allows for clarification of misinformation by the agencies. One of the most important
outcomes has been the interactive dialogue between scientists and stakeholders which has
made manatee research more transparent and has quelled many suspicions held by
stakeholders relating to the science. However, the communication of scientific data and
research results remains challenging, as Forum members will have varying interpretations
of the same research. The Forum has fostered better communication between the
agencies and stakeholders; whether it will facilitate conflict resolution remains to be seen.
-Kipp Frohlich (kipp.frohlich@MyFWC.com).
Pregnancy Diagnostic for Sirenians. -Researchers at the University of Florida's College
of Veterinary Medicine are interested in collaborating with manatee and dugong
biologists worldwide, to assist in the validation of a progesterone-based pregnancy
diagnostic for sirenians. Preliminary trials with Florida manatees have shown great
promise for the detection of pregnancy, particularly in the first six months of gestation,
when pregnancy cannot be detected visually.
Serum is required for this high sensitivity assay and should be banked in one
milliliter (ImL) aliquots. Five milliliters of serum per animal is requested though not
required. The minimum sample requirement is 0.5 ml serum (no anticoagulant added).
Samples from females being bred in captivity, with known gestation, are of particular
interest. Monthly sampling would be optimal for these pregnant females. For further
information, please contact Katie Tripp (firstname.lastname@example.org).
Are the Threats to Florida Manatee Changing Over Time? -Manatees and dugongs
have long been threatened by human activities such as hunting, loss of habitat and boat
strikes or collisions. The vast number of Florida manatees being seriously injured or
killed by these boat strikes or collisions has resulted in strong legislation, numerous
public awareness and education programs and the implementation of watercraft speed
limits. However, since the implementation of these new programs or legislation, the
population of the Florida manatee has not substantially increased. We were interested in
exploring what other factors may be playing a role in preventing the population of the
Florida manatee from increasing.
Looking at a 10 year period, from 1995 to 2004, data obtained from the Florida
Fish and Wildlife Conservation Commission was examined pertaining to Florida manatee
population numbers and their causes of death. Synoptic survey data and annual numbers
of carcasses were examined to verify the causes of their deaths. The following
information is expressed as the absolute number of manatee deaths, a percentage of the
total number of manatee deaths, and a percentage of the absolute numbers of the causes
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Absolute numbers of Manatee deaths
1995 1996 1997
canal lock 8
Other human 5
Cold stress 0
1998 1999 2000 2001 2002 2003 2004
66 82 78 81 95 73 69
As it can be expected the number of deaths over the 10 years has variability but
certain conclusions can be made. Despite having regulations and public awareness
programs, the number of watercraft deaths have increased from 42 (1995) to 69 (2004)
with a maximum number of deaths of 95 in 2002. Perinatal deaths gradually rose from 56
(1995) to a high of 72 (2004) and cold stress had a dramatic rise from 0 (1995) to 50 in
2004. Other causes have dropped substantially such as flood gate/locks- 8 (1995) to 3
(2004)- and natural- 35 (1995) to 24 (2004).
The Causes of Death as Percentages of the Total of Deaths for Each Year
1995 1996 1997 1998 1999 2000 2001 2002
Watercraft 20.9 14.5 22.3 28.4 30.5 28.7 24.9 31.1
When looking at the causes of death as a percentage of the deaths within the same
year, it can be seen that certain causes form the majority of the deaths. For instance,
watercraft (20.9%), perinatal (27.8%) and undetermined causes (26.4%) formed the
majority of deaths and were over 20% in each case. However, in 2004, watercraft rose to
25%, perinatal stayed the same at 26.1% and undetermined caused dropped to 18.5%. All
other causes had drops in percentages except for cold stress which went from 0% (1995)
to 18.1% (2004).
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The Causes of Death as a Percentage of Change Between 1995 and 2004
1995 2004 Percentage Change
Water-craft 42 69 +39
canal lock 8 3 -63
Other human 5 4 -20
Perinatal 56 72 +22
Cold stress 0 50 +100
Natural 35 24 -32
Undetermined 53 51 -4
Unrecovered 2 3 +50
TOTAL 201 276
When comparing the causes of deaths as a percentage of change in only the first and
last year, it is observed that the watercraft (+39%), perinatal (22%) and cold stress (100%)
deaths had dramatic increases. Death due to other causes such as natural, flood gate/lock and
other human causes had large percentage decreases.
From these results, it is clear that Florida manatees are still facing both human and
environmental stresses whose relative impact has changed over time. Watercraft related
mortalities continue to play a role in manatee deaths but other causes such as perinatal
mortality and cold stress have risen to become significant contributors. Further research
should focus on these specific causes (perinatal and cold stress) of death if we are to have a
significant and favorable impact on Florida manatee conservation. Michael Belanger,
Amanda MacNeill, Nesime Askin, Carin Wittnich (Oceanographic Environmental Research
Society, 12 Burton Ave., Barrie, Ontario Canada L4N2R2; tel. 1-416-978-0505;
Status and Distribution ofAntillean Manatees (Trichechus manatus manatus) on the
North Coast of Honduras: Preliminary Report From the Field. -On March 29, 30, 31
and April 2,3, and 4, 2006 aerial surveys were conducted on the North Coast of Honduras
from the Rio Aguan (west of Trujillo) to the Laguna El Diamante (east of Tela). Flights
were flown at 700ft and at a speed of 80kt in a Cessna 206. Three observers were located
on the right side of the aircraft (front right data recorder, middle right secondary
observer, and back right primary observer). Surveys were flown with the doors
removed to improve visibility. I led the team of three biologists as part of my Master's
program at Loma Linda University. The rest of the team included Saul Flores (Museum
curator and professor of biology at the National University of Honduras, Tegucigalpa)
and Cyndi Taylor (Senior Research Scientist with Wildlife Trust, FL).
This area of Honduras has not been extensively surveyed for manatees since
Rathbun et al. (1983). During that survey they observed manatees at a rate of 0.8 per
survey hour over the entire coast and at 13.3 per survey hour from Zambuco to El
Porvenir on the North Coast. They also observed manatees in the coastal areas as well as
the rivers and lagoons along the coast. Finally, during their March surveys of 1979 they
detected 4 calves (17%) on the North Coast.
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The end of March was chosen to conduct these surveys so that we could directly
compare them with the surveys completed in 1979-80 by Rathbun et al. March
represents the dry season and the water conditions are most favorable.
We averaged 3 animals per survey with a detection rate of 1.31 animals per
survey hour. This was significantly lower than that in 1979-80. Our survey time ranged
from 2 hrs 10 min to 2 hrs 40 min per survey. In all we sighted manatees 18 times during
a total of 13 hrs 43 min of survey time. Interestingly, we never observed a manatee along
the coast but rather always saw them within the rivers and lagoons. In addition, we only
observed adults. This also marks a significant difference from the sightings in 1979-80.
Finally, we sighted manatees in the Rio Chapagua and Rio Aguan and the lagoon
Laguna de Guaimoreto, all of which had no previous record of manatees in the literature
other then anecdotally. The rest of the sightings were within Cuero y Salado Wildlife
Refuge similar to those in 1979-80. Most of our sightings were in Cuero y Salado
Wildlife Refuge (11), although a significant amount were clustered in both the Rio Aguan
and Rio Chapagua (5), which may represent a new important area for the remaining
manatees of the North Coast of Honduras. More detailed information will be provided in
an up coming publication.
I would like to thank Cyndi Taylor and Saul Flores for participating in these aerial
surveys. I would also like to thank Chuck Schroll for being such a cooperative pilot and
LightHawk (Michele Gangaware) for providing the plane and pilot. I would like to thank
Jose Herrero for assisting in attaining permits to fly in Honduras. This project was
funded by a grant from USAID-MIRA. Daniel Gonzalez-Socoloske (for more info
contact Daniel at email@example.com).
Rathbun, G. B., Powell, J. A., Cruz, G. (1983). Status of the West Indian Manatee in
Honduras. Biological Conservation. 26, 301-308.
The use of side scan sonar to detect and study West Indian Manatees (Trichechus
manatus). -Estuaries, lagoons and turbid rivers have long been complicated study
locations for aquatic fauna, particularly in locations with dangerous animals. In the late
1970's, experiments were conducted using conventional sonar to detect manatees in
Florida. These experiments did not have very positive results partially due to the large
amounts of oxygen released by submerged vegetation in the clear waterways in Florida
(Rathbun, personal communication).
Sonar technology has greatly improved since then and unlike the conventional
sonar used in the 1970's, I used a side scan sonar, which provides a surface image of the
bottom. I also targeted locations that had little or no submerged vegetation. The sonar
unit that I used was released in January of 2005 by Hummingbird and is the first side
scan sonar that is directly mounted on the back of a boat. Traditionally side scan sonar
has been used for search and rescue of sunken ships or by oceanographers to study ocean
and lake bottoms topology. This new unit represents the first time side scan sonar is used
to detect aquatic fauna. Objects create a characteristic shadow which can be used to
determine the shape.
To test whether large aquatic animals can be detected by side scan sonar I
experimented with the unit for 10 hours in the dark turbid (tannin stained) rivers and
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canals of Cuero y Salado Wildlife Refuge, on the North Coast of Honduras during July
21-23, 2005. I found that I was able to clearly distinguish large aquatic animals within
the water column. Cuero y Salado Wildlife Refuge is home to both crocodiles
(Crocodylus acutus) and caiman (Caiman crocodiles chiapasius) as well as the Antillean
manatee (Trichechus manatus manatus) (personal observation, Rathbun et. al 1983). In
addition, there are smaller animals such as sliders and river otters (personal observation),
which I suspect are too fast and rare to represent the signals that were detected.
Due to the turbidity of the water and the extreme shyness of both crocodiles and
manatees in the area, I was not able to confirm which animal I was detecting. Judging by
the relative size of the response, the time of day, and the location in which I detected
them, I suspect the signals to be from manatees.
To test whether the responses were indeed manatees I subsequently experimented
with the side scan sonar in Crystal River, Florida on January 29 and 31, 2006 with the
help of Bob Bonde (USGS Sirenia Project). Crystal River provides freshwater springs
which are warmer than the ambient water temperature during the cool winter months.
Manatees aggregate at these springs to survive. I took advantage of the aggregation and
experimented with the sonar in late January when the manatees begin to move out of the
springs (Bonde, personal communication).
I also chose Crystal River because, as its name implies, the water clarity is very
good. This way we could compare what the sonar detected with what was actually in the
water. After confirming that manatees can be detected by the side scan sonar I conducted
14 "blind" transects in which I would note the number of manatees I detected by only
looking at the side scan sonar and Bob Bonde would confirm it by visual detection. We
only worked with the left side of the sonar because the large outboard motor was causing
too much interference. In addition to number of animals, I also noted how far from the
boat (laterally) the animal was. Out of 60 animals detected visually (by Bonde), I was
able to detect 44 with the side scan sonar (73.33%). All of the detections matched the
approximate distance from the boat. When corrected for manatees that were further then
30 ft from the boat (laterally) and calves that were behind the mothers parallel to the
sonar, the number of animals detected visually drops to 46, resulting in 95.65% sonar
detection. The range I set to "see" laterally was 30ft so animals at that distance could
have been missed. We saw no indication that the sonar could be heard by the manatees as
was expected because the frequency of the sonar falls outside of their hearing range.
Finally on March 22-23, 2006 I tested the unit in the Laguna de las Ilusiones,
Tabasco, Mexico with the help of Dr. Leon David Olivera-Gomez. This lagoon, which
lies right in the middle of the city of Villahermosa, is home to at least 9 manatees
(Olivera-Gomez, personal communication). This location was chosen because it provides
water conditions similar to those found throughout Mesoamerica (dark and turbid). In
addition, this location was chosen because the resident manatees are landlocked and can
be detected by a trail of bubbles that they create by "walking" on the bottom substrate.
I conducted 29 "blind" transects with Olivera-Gomez similar to what was done in
Florida. This time I used both sides of the sonar and I extended the range to 40ft on each
side. Of 27 animals visually detected (by the bubble trails) on the right side I detected 24
with the side scan sonar (88.88%), and out of 15 animals visually detected on the left side
I detected 15 with the side scan sonar (100%). The average of both sides was 92.86%.
All of the detections matched the side where the animal was, its distance from the boat
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and the number of animals. The relative size of the animal was also detected in the case
of a mother and young calf.
This new technique aims at providing scientists and conservationists with a new
tool for studying manatees in these complicated waterways. This technology could be
applied to the other manatee species as well as dugongs in locations where the water
conditions do not allow for visual confirmation. More information will be provided in
I would like to thank my adviser Dr. Robert Ford for purchasing the sonar unit
with his ESSE 21 grant. I would like to thank Mark Gibson (Hummingbird Inc.) for
helping me understand how the sonar works and Galen Rathbun for historical use of
sonar to detect manatees in Florida. I would like to also thank Bob Bonde, Miriam
Marmontel, and Cathy Beck; Leon David Olivera-Gomez; Jose Paz, and Justo Carcamo
for logistical support in Florida, Mexico, and Honduras respectively. Daniel Gonzalez-
Socoloske (for more info contact Daniel at firstname.lastname@example.org).
Rathbun, G. B., Powell, J. A., Cruz, G. (1983). Status of the West Indian Manatee in
Honduras. Biological Conservation. 26, 301-308.
Recent developments in dugong research in Balikpapan Bay, East Kalimantan,
Indonesia. During 2005 our research team studied dugong-seagrass interactions in
Balikpapan Bay, situated at the East coast of the Indonesian part of Borneo. Balikpapan
Bay, a major industrial port located in East Kalimantan, is a large bay covering 16,000 ha
that drains a watershed of 194,443 ha, bordering both rural and urban/industrial areas.
The coastal and marine biodiversity resources in Balikpapan Bay form part of East
Kalimantan's Megaa diversity" in ecosystems that nowadays are still productive and
support the livelihoods of the bordering communities. However, there is also a
devastating degradation of coastal and marine resources that possibly affects, directly and
indirectly, seagrass and dugongs in Balikpapan bay.
De Bruijn (2002) had studied dugong- seagrass interactions in Balikpapan Bay
during 2001, and she spotted at one location (Kariangau) mostly single individuals some
15 times. On one occasion the presence of three individuals was recorded. Since we
discovered large surfaces of seagrass maintained ungrazed, we do not believe that the
amount of seagrass is the limiting factor in Balikpapan Bay, but that the quality of the
seagrass, especially in terms of available carbohydrates (sugars and starch), is the main
limiting factor (De Iongh et al. 1995,De Iongh 1996). During our research we selected six
intertidal mono-specific (Halodule univervis) seagrass meadows in Balikpapan Bay for
regular monitoring of above and below ground biomass and the intensity of dugong
Once per month during 2005 we surveyed the selected seagrass beds in order to
collect data for the biomass analysis and to determine the quality of the seagrass above
and below ground. The seagrass beds were visited at the end of each month when the
tide was most suitable to carry out the survey. In each survey 5 random samples were
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collected per seagrass meadow with a plastic corer (15, 8 cm diameter and 15 cm deep)
and gathered in plastic bags marked with date and location for the next process. At the
location where each sample was taken, the percentage coverage was estimated based on
the seagrass presence in a 40 x 40cm square and the location was marked with GPS. In
The Netherlands at the lab of the Resource Ecology group (University of Wageningen),
digestibility was determined using the method of Tilley and Terry (1963). This method is
based on the simulation of the first two stages of digestion of ruminants. Using this
method the proportion of digested material can be calculated and hence the quality of the
seagrass bed can be estimated. For N, P, Ca, Mg and Na, a modified Kjeldahl destruction
method was used. Dissolved nitrogen and phosphor concentrations were measured
colorimetrically using a continuous-flow analyser and sodium and potassium
concentrations were measured by using an Atomic Spectrophotometer. In addition we
determined the ratio between Dry Weight (DW) and Ash Free Dry Weight (AFDW),
which is a measure for the amount of carbohydrates (sugar and starch) in the seagrass
below ground and above ground biomass.
During April and May very few dugong grazing tracks were found in the
intertidal segarass meadows, but this started to change in May 2005. Especially inside
the meadow of Kariangau the presence of dugongs was confirmed by many new grazing
tracks between May and June. In addition another seagrass bed, Petrosea, was grazed
intensively in the same period. Dugong grazing continued in these two seagrass beds
during July until December. The other four seagrass beds did not show any confirmation
for the presence of dugongs during May and June, but in August and September dugong
grazing also occurred in the Balang segarass bed. Dugong grazing always started when
the ratio of DW to AFDW of the below ground fraction was above 70%. Below this level
almost no grazing tracks were found. No such relationship could be established with total
N in the seagrass below ground and above ground fractions.
Dugong grazing is presumably mostly done at night. During the daytime only
three individual dugongs were spotted during the whole study period. From the
interviews it becomes clear that dugongs have been spotted in those locations over the
four month period. In comparison with the former study by De Bruijn (2002), who
spotted 15 individual dugongs during daylight hours, it can be concluded that during
2005 fewer individuals have been observed during daytime in the bay. On the other hand,
the high number of new grazing tracks from May to December implies that there is night
grazing and/or rotational grazing by at least five dugongs in Balikpapan Bay.
During interviews with fishermen it was determined that during 2005 two dugongs
had been killed, one by the propeller of a speed boat and another was caught in a fishing
trap. Dugong mortality was also reported during previous years, including dugongs killed
by boat propellers. If this mortality continues, it may become a serious threat to the survival
of this small population of dugongs. We have recommended that the local authorities
consider the establishment of a dugong sanctuary at the Kariangau meadow, which is the
most important seagrass bed for the surviving dugong population in Balikpapan Bay.
Sirenews No. 45
De Iongh, H.H., Wenno B. and Meelis E. (1995). Seagrass Distribution and Seasonal
Biomass Changes in Relation to Dugong Grazing in the Moluccas, Indonesia. Aquatic
Botany 50: 1-19
De Iongh, H.H. (1996). Plant-Herbivore Interactions between Seagrasses and Dugongs in
a Tropical Small Island Ecosystem. PhD Thesis, Katholieke Universiteit Nijmegen.
De Bruijn, P., (2002). Population ecology of a recently discovered Dugong population,
Dugong dugon in Balikpapan Bay, East Kalimantan, Indonesia. Final report at Institute
of Environmental Sciences, Leiden University.
Tilley, J.M.A. and Terry, R.A., (1963). A two-stage technique for the in vitro digestion
of forage crops. Journal of the British Grassland Society 18, 104-111
-Hans de Ionghl, Willem van Esch' and Eva Cruz1 (Institute of Environmental
Sciences, Department of Environment and Development, POB 9518, 2300 RA Leiden,
The Netherlands, tel +31-71-5277431, fax +31-71-5277496, e-mail corresponding author:
An informative international symposium was held on 11-12 February 2006 in Okinawa,
Japan. The symposium was entitled Recent Advances in Cetology and Sirenology and
was hosted by the Okinawa Churaumi Aquarium under the direction of Dr. Senzo
Uchida. Representatives from Brazil, Mexico, Taiwan, Australia, Denmark, and the
United States complemented expertise provided by Japanese scientists. Primary topics
included taxonomy, emerging diseases, strandings, feeding mechanisms, placentation,
conservation, whaling, physiology, captive handling, and natural history. Proceedings
will be forthcoming.
West African Manatee Conservation. -The Regional Conservation Project for
the West African Manatee (Trichechus senegalensis) led by Wetlands International
(Dakar) in collaboration with PRCM, IUCN, WWF, FIBA and CSRP, is developing its
A series of field surveys, initiated in August 2005 and continuing through
November 2006, have made it possible to collect information on the status of the manatee
in the PRCM area (Mauritania, Senegal, The Gambia, Guinea Bissau and Guinea). This
fieldwork has, in particular, enabled us to characterise the threats to the species. Our
team, placed in the field by our regional network, has explored the deltas of Senegal and
Saloum Rivers, some coastal wetlands in The Gambia, Lower Casamance, Guinea Bissau
and Guinea. Fieldwork was recently initiated in Sierra Leone, the next PRCM guest. This
Sirenews No. 45
regional survey on the manatee, which includes Senegal and Mauritania (via the Senegal
Delta), The Gambia and Senegal (via the Niumi Saloum), and the South Guinea coast
near Sierra Leone, sets the tone of a project that aims to be transboundary.
This investigative work has made it possible to organise National Forums, which
are participatory assemblies that bring together the field participants in each of the survey
areas. The Forums act to validate the field experience and focus on priority manatee
actions to be developed. The Saint Louis (Senegal), Saloum, Ziguinchor, Bissau and
Conakry Forums have made it possible to develop recommendations on the scientific
monitoring of the species, the conservation of its habitat, increasing awareness, and
economic support to communities, while conserving the species and its habitat. New
recommendations should be made at the Banjul and Freetown Forums, to be held very
soon. These Forums are in preparation for the Dakar Regional Forum planned in fall
The Programme calls for collaboration between Wetlands International, the
United Nations Environment Programme (UNEP/RSP "Regional Seas Programme"), the
Convention for Co-operation in the Protection and Development of the Marine and
Coastal Environment (Abidjan Convention, 1984), and the Secretariat of the Convention
on Migrant Species (CMS). With support from the Government of Monaco, these
institutions will join their efforts to develop a manatee conservation strategy
encompassing all countries in which the species occurs. This collaboration will result in
a regional scientific publication on the manatee. It is represents the extension of the
manatee conservation programme to about twenty countries in West Africa.
The first results of our surveys show that the West African manatee is still an
endangered species in the PRCM area, largely due to loss of habitat. The degradation of
mangroves, the manatee's main habitat in this part of West Africa, has resulted from
climatic changes and overexploitation (fuelwood, building materials, etc.). Incidental
catch in fishing nets represents the second major threat (Saloum, The Gambia, Guinea
and mainly Guinea Bissau). These initial results, refined and completed, should make it
possible to develop a relevant conservation strategy in the PRCM area and eventually
throughout West Africa. The West African manatee, Trichechus senegalensis, remains a
highly threatened manatee species. Mame Dagou Diop (Wetlands International
Manatee Conservation Project Officer, email@example.com).
The following abstract is from the Annual Meeting of the American Association for the
Advancement of Science, Feb. 16-19, 2006 in St. Louis, MO:
Red Tides and Sirens: Brevetoxicosis in the Endangered Florida Manatee
Gregory D. Bossart, VMD, PhD
Recent often unprecedented endangered Florida manatee (Trichechus manatus
latirostris) epizootics have been associated with potent marine neurotoxins known as
brevetoxins, which are produced by the 'red tide' dinoflagellate Karenia brevis.
Brevetoxins are known to kill large numbers of fish and cause illness in humans who
ingest toxic filter-feeding shellfish neurotoxicc shellfish poisoning) or inhale toxic
aerosols. The pathogenesis of manatee brevetoxicosis is suspected to involve direct
Sirenews No. 45
inhalation of toxins and/or ingestion of toxins in food sources. Important new data
indicate that brevetoxin vectors such as seagrasses can result in delayed or remote
manatee exposure causing intoxication in the absence of toxin-producing dinoflagelates.
Thus, unexpected toxin vectors may account for manatee deaths long after or remote
from a dinoflagellate bloom. Diagnosis of brevetoxicosis in manatees is typically by
exclusion and may be based on pathologic findings and postmortem demonstration of the
toxins in fluids and tissues. The pathologic findings of inhalational brevetoxicosis in
manatees are catarrhal rhinitis, pulmonary hemorrhage and edema, multiorgan
hemosiderosis and nonsuppurative leptomeningitis. Immunohistochemical staining is
used to determine the presence, abundance and distribution of brevetoxins in tissues. The
present data suggest that manatee mortality resulting from brevetoxicosis may not
necessarily be acute but occur after chronic inhalation and/or ingestion and involve the
release of inflammatory mediators that result in fatal toxic shock. The inhalational route
of brevetoxin exposure appears to be unique in marine mammals but shared with humans.
Increases in human pulmonary emergency room diagnoses are temporally related to 'red
tide' occurrences, which may be increasing in frequency along Florida coastlines.
Vianna, J.A., R.K. Bonde, S. Caballero, J.P. Giraldo, R.P. Lima, A. Clark, M.
Marmontel, B. Morales-Vela, A.A. Mignucci-Giannoni, J.A. Powell, and F. R. Santos.
2006. Phylogeography, phylogeny and hybridization in trichecid sirenians: implications
for manatee conservation. Molecular Ecology 15(2): 433-447.
The three living species of manatees, West Indian (Trichechus manatus),
Amazonian (Trichechus inunguis) and West African (Trichechus senegalensis), are
distributed across the shallow tropical and subtropical waters of America and the western
coast of Africa. We have sequenced the mitochondrial DNA control region in 330
Trichechus to compare their phylogeographic patterns. In T manatus we observed a
marked population structure with the identifications of three haplotype clusters showing a
distinct spatial distribution. A geographic barrier represented by the continuity of the
Lesser Antilles to Trinidad Island, near the mouth of the Orinoco River in Venezuela,
appears to have restricted the gene flow historically in T. manatus. However, for T
inunguis we observed a single expanding population cluster, with a high diversity of very
closely related haplotypes. A marked geographic population structure is likely present in
T. senegalensis with at least two distinct clusters. Phylogenetic analyses with the mtDNA
cytochrome b gene suggest a clade of the marine Trichechus species, with T inunguis as
the most basal trichechid. This is in agreement with previous morphological analyses.
Mitochondrial DNA, autosomal microsatellites and cytogenetic analyses d the presence
of hybrids between the T manatus and T. inunguis species at the mouth of the Amazon
River in Brazil, extending to the Guyanas and probably as far as the mouth of the
Orinoco River. Future conservation strategies should consider the distinct population
structure of manatee species, as well as the historical barriers to gene flow and likely
occurrence of interspecific hybridization.
Dos Santos Lima, D., J. E. Vergara-Parente, R. J. Young, and E. Paszkiewicz. 2005.
Training of Antillean manatee, Trichechus manatus manatus (Linnaeus, 1758), as a
Sirenews No. 45
management technique for individual welfare. Latin American Journal ofAquatic
Laist, D.W. and C. Shaw. 2006. Preliminary evidence that boat speed restrictions reduce
deaths of Florida manatees. Marine Mammal Science 22(2): 472-479.
Larkin, I. L. V., T. S. Gross and R. L. Reep. 2005. Use of faecal testosterone
concentrations to monitor male Florida manatee (Trichechus manatus latirostris)
reproductive status. Aquatic Mammals 31(1):52-61.
Natiello, M. and D. Samuelson. 2005. Three-dimensional reconstruction of the
angioarchitecture of the ciliary body of the West Indian manatee (Trichechus manatus).
Veterinary Ophthalmology 8(6):367-373.
Natiello, M., P. Lewis, and D. Samuelson. 2005. Comparative anatomy of the ciliary
body of the West Indian manatee (Trichechus manatus) and selected species. Veterinary
Mann, D. A., D. E. Colbert, J. C. Gaspard, B. M. Casper, M. L. H. Cook, R. L. Reep, and
G. B. Bauer. 2005. Temporal resolution of the Florida manatee (Trichechus manatus
latirostris) auditory system. Journal of Comparative Physiology A: Sensory, Neural and
behavioral Physiology 191(10):903-908.
Spiegelberger, T. and U. Ganslosser. 2005. Habitat analysis and exclusive bank feeding
of the Antillean manatee (Trichechus manatus manatus L. 1758) in the Coswine Swamps
of French Guiana, South America. Tropical Zoology 18(1):1-12.
Sweat, J. M., C. M. Johnson, Y. Marikar, and E. P. Gibbs. 2005. Characterization of
surface interleukin-2 receptor expression on gated populations of peripheral blood
mononuclear cells from manatees, Trichechus manatus latirostris. Veterinary
Immunology and Immunopathology 108(3-4):269-283.
Vianna, J.A., R. K. Bonde, S. Caballero, J. P. Giraldo, R. P. Lima, A. Clark, M.
Marmontel, B. Morales-Vela, M. J. De Souza, L. Parr, M. A. Rodriguez-Lopez, A. A.
Mignucci-Giannoni, J. A. Powell, and F. R. Santos. 2006. Phylogeography, phylogeny
and hybridization in trichechid sirenians: Implications for manatee conservation.
Molecular Ecology 15(2):433-447.
Woodruff, R. A., R. K. Bonde, J. A. Bonilla and C. H. Romero. 2005. Molecular
identification of a papilloma virus from cutaneous lesions of captive and free-ranging
Florida manatees. Journal of Wildlife Diseases 41(2):437-441.
SIRENIAN WEBSITE DIRECTORY
(NOTE: Not all of these sites have been visited recently by your Editor, and some may
no longer be active, or their addresses may have changed.)
Sirenews No. 45
The Call of the Siren (Caryn Self Sullivan):
Caribbean Environment Programme, Regional Management Plan for the West Indian
Caribbean Stranding Network:
Columbus (Ohio) Zoo manatee exhibit:
Dugong necropsy manual (available for downloading):
Florida Fish and Wildlife Conservation Commission, Bureau of Protected Species
Florida Fish and Wildlife Conservation Commission, Florida Marine Research Institute
(Florida manatee mortality data):
Friends of the Manatee Association, Manaus & Balbina, Brazil:
dopeixe-boi.org.br/english/Ing_index2.htm> [Includes a bibliography of INPA aquatic
mammal project publications and abstracts]
Fundaci6n Salvemos al Manati de Costa Rica:
Great Barrier Reef dugongs:
IBAMA manatee project, Brazil:
Jacksonville University (Florida) Manatee Research Center Online:
"Manatee Watchers" Internet discussion list:
News clippings on Florida manatees:
Philippines Dugong Research and Conservation Project:
Sirenews No. 45
Save the Manatee Club:
Sea World of Florida:
SEMARNAP, Secretaria de Medio Ambiente, Recursos Naturales y Pesca, Mexico:
Sirenews (texts of current and recent issues):
snews.htm>; (for archive of most older
Sirenia Project, U.S. Geological Survey: or
Sirenian International, Inc.: [Includes a bibliography of
sirenian literature, and an archive of Sirenews issues.]
Smithsonian Institution sirenian bibliography:
nmnh/sirenia.htm> [This is a relatively short bibliography, compiled by Joy Gold, that
provides a very good introduction to both the technical and the popular literature.]
Steller's sea cow: < http://www.hans-rothauscher.de/steller/steller.htm>. This site also
includes a searchable database of museum collections worldwide that contain bones of
Hydrodamalis gigas: . See
also the website [in Finnish] of Dr. Ari Lampinen, Univ. of Jyvaskyla, Finland:
Trichechus senegalensis skull:
senegalensis/>. [CT imagery of an African manatee skull and mandible, viewable as
individual thin slices, 3-D rotational movies, and slice movies. Excellent detail!]
West African manatee in Chad (Jonathan H. Salkind):
Xavier University manatee web site (Midwest Manatee Research Program; Chuck
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