Sirenews (ISSN 1017-3439) appears twice a year

in April and October and is edited by Daryl P. Domning,

Department of Anatomy, Howard University, Washington, D.C. 20059 USA

(fax: 1-202-265-7055). It is supported by the U.S. Marine Mammal Commission

and Sea World, Inc.

NUMBER 24 OCTOBER 1995

IN THIS ISSUE: - U.S. SIRENIA PROJECT THREATENED WITH EXTINCTION

(p. 11)

- DUGONGS DECLINING IN QUEENSLAND (p. 5)

- LARGE-SCALE POACHING IN BELIZE AND UNITED ARAB

EMIRATES (pp. 7, 11)

- ADVENTUROUS FLORIDA MANATEE EXTENDS SPECIES'

RANGE TO NEW ENGLAND (p. 9)

DEATHS REPORTED

Tammy Dominguez and Amaury Villalba

Last January, Tammy Dominguez, her colleague, Amaury Villalba, and their pilot were killed when their plane went down during a manatee survey off Barahona on the southern coast of the Dominican Republic. A third colleague, José Ottenwalder, was injured but made a miraculous escape, and is doing fine. We first started to correspond with Tammy shortly before the 1994 First International Manatee and Dugong Research Conference, which she attended. She was also an active participant in the Manatee and Dugong Research Workshop which followed the conference. Tammy was very dedicated to the conservation of sea turtles and marine mammals, especially manatees. She is greatly missed by all of her colleagues.

- Lynn Lefebvre (Sirenia Project)

MANATEE AERIAL SURVEY SAFETY RULES

Manatee aerial surveys present special hazards to survey biologists because of the small planes that are typically used (they can easily be overloaded), the relatively low flight level (generally 500 feet), the tight turns that are frequently made to count manatees (possibility of stalling), and flight paths over water. At times, the dedication of the surveyors may become a hazard, if their determination to complete a mission interferes with their judgment concerning weather conditions, the qualifications of their pilot, and the condition of the aircraft.

Listed below are some "common sense" rules for manatee aerial survey personnel. They are not intended to be all-inclusive, but represent the highlights of regulations provided by the Office of Aircraft Services (OAS), which all Department of Interior (DOI) employees in the U.S. must follow when participating in work-related aviation.

Ms. Burma Campbell, U.S. Fish and Wildlife Service, is gratefully acknowledged for providing information used to develop these rules, for reviewing them, and for her continued interest and encouragement.

_ The Cessna 172 aircraft is underpowered for low-level flying (less than 500 feet). During low-level missions, aircraft cannot operate lawfully at a higher certified load (aircraft, passengers, fuel, cargo) than that recommended by the manufacturer. If more than two observers are planned, then a Cessna 182, 185, or 206 is recommended.

_ Surveys should never be flown at an altitude lower than 500 feet. Many survey biologists prefer an altitude of about 750 feet for circling and counting of manatees in groups. Under DOI Aviation Policy, aircrew members may not fly below 500 feet without special training and personal protective equipment.

_ Know your pilot's qualifications. How many hours of flight experience does he or she have in the aircraft in which you will be a passenger? OAS regulations require 1000 hours of flying time in order to certify a pilot.

_ Know your plane's service record. DOI Aviation Policy requires servicing and inspection of a plane after every 100 hours of flying time.

_ Prepare a GO/NO GO checklist that you go through before every flight. While the pilot has the final say in the decision to GO, remember YOU always have the final say in the decision to cancel a flight. If you have any doubts about the weather, the pilot, or the plane, cancel the flight. You are much more important than a missed survey! Also, all surveys should be conducted under optimal weather conditions to ensure some comparability across survey dates; questionable weather means questionable survey results. If changes occur in the weather or pilot or observer mental or physical condition, the observer should call off the mission and request the pilot to return to home base, or to land at the nearest suitable location, depending upon the severity of the change in flight conditions.

_ Prepare a flight plan and give it to ground personnel at the airfield(s) where your flight originates and ends. The person(s) to whom you give it will be responsible for flight following and will institute search and rescue procedures if your aircraft does not reach its destination within one hour of its estimated time of arrival.

_ Only cargo and passengers which are essential to a mission should be on the aircraft. Not only does this eliminate the possibility of an accident from something that should not have been onboard, but it keeps the weight of the aircraft at a minimum, thereby using less fuel and minimizing costs. Survey biologists should be careful to secure such routinely used objects as: pencils and pens; camera lenses, lens covers, film canisters, small tape recorders, palm counters, etc.

_ DOI Policy requires the pilot be present to supervise the type, quantity and quality of fuel used in the aircraft when refueling. There have been misfueling mishaps in the U.S., in which jet fuel has accidentally been put into reciprocating-engined aircraft.

_ If a single-engine aircraft is to be used beyond power-off gliding distance to shore, the aircraft should be float-equipped and all persons onboard should have personal flotation devices.

_ Biologists who fly regular missions can benefit from a flight familiarization course consisting of 4 hours of ground school and 4 hours of flight training (cost is approximately $500). It is intended to give passengers limited knowledge of how to operate aircraft controls, radios, etc., and land the plane in the event of a pilot-incapacitated emergency.

Your comments on these rules are welcome. If you would like to help by translating them into Spanish or other languages, please contact me. If you would like examples of a GO/NO GO checklist or a flight plan, or information on the flight familiarization course, please contact: Dr. Lynn Lefebvre, Sirenia Project, National Biological Service, 412 NE 16th Ave., Rm 250, Gainesville, FL 32601 USA; phone: 904-372-2572; Fax: 904-374-8080; Internet: sirenia@nervm.nerdc.ufl.edu. - Lynn Lefebvre

DEATH REPORTED

Mauricio Prieto

A pioneer in field research and conservation of aquatic mammals in Colombia, Mauricio Prieto died from cancer in Bogotá on 1 April 1995, at age 39. He worked extensively with cetaceans, and in 1987 he launched a study of the ecology of the manatee in the Río San Jorge area, where he perfected his singular competence in environmental education at the community level. He later turned his attention to marine mammal-fisheries interactions on the Pacific coast. With his death, the South American aquatic mammal community has lost a spiritual leader and a genuine conservationist. (Excerpted from an obituary by Koen Van Waerebeek and Daniel Palacios in the Marine Mammal Society Newsletter 3(3): 3, Sept. 1995.)

INTERNATIONAL DUGONG SYMPOSIUM

An International Symposium on the Dugong will be held at the Toba Aquarium, Toba, Japan, 15-17 November 1995. Oral presentations (both submitted and invited) will be given on dugong biology, paleontology, conservation, rescue, and husbandry. Investigators, students, and other interested people are encouraged to attend. A proceedings volume will be distributed at the meeting. For further details, contact Mr. Hiroshi Maeda, Planning Office, Toba Aquarium, Toba 3-3-6, Mie Prefecture, 517 Japan; phone: 81-599-25-2801; fax: 81-599-26-3608; E-mail: LDN03052@niftyserve.or.jp; Compuserve: 100463,3176

SIRENIA SPECIALIST GROUP MEMBERSHIP

The following people have agreed to serve as members of the IUCN Sirenia Specialist Group for the 1994-1996 Triennium:

Prof. Helene MARSH (Co-Chair), Dept. of Tropical Environment Studies & Geography, James Cook Univ., Townsville, Qld. 4811, AUSTRALIA (ph. +61-77-814325, fax +61-77-815581, e-mail HELENE@CATHAR.JCU.EDU.AU)

Dr. Miriam MARMONTEL (Co-Chair), Wildlife Biologist, Sociedade Civil Mamirauá, C.P. 0001, 69470-000 Tefé AM, BRAZIL (ph. & fax +55-92-7432736, e-mail MANATI@NERVM.NERDC.UFL.EDU)

Dr. Vic COCKCROFT, Curator of Marine Mammals, Port Elizabeth Museum, P.O. Box 13147, Humewood 6013, SOUTH AFRICA (ph. +27-41-561051, fax +27-41-562175, e-mail PEMVGC@ZOO.UPE.AC.ZA)

Mr. Hans DE IONGH, Ecologist/Director, International Cooperation, Centre for Environmental Science, P.O. Box 603, 6700 AP Wageningen, THE NETHERLANDS (ph. +31-71-275642, fax +31-71-277496)

Prof. Daryl DOMNING (Newsletter Editor), Dept. of Anatomy, Howard Univ., Washington, DC 20059, USA (ph. +1-202-806-6026, fax +1-202-265-7055)

Dr. William FREELAND, Principal Wildlife Research Officer, Wildlife Division, Conservation Commission of the Northern Territory, P.O. Box 496, Palmerston, NT 0831, AUSTRALIA (ph. +61-089-894400, fax +61-089-894524)

Dr. Toshio KASUYA, Director, Offshore Marine Resources, National Institute of Research on Far Seas Fisheries, 5-7-1 Orido, Shimizu, Shizuoka, 424 JAPAN (ph. +81-543-340715, fax +81-543-359642)

Dr. Janet LANYON, Dept. of Zoology, Univ. of Queensland, Brisbane, Qld. 4072, AUSTRALIA (ph. +61-7-3654416, fax +61-7-3651655)

Dr. Lynn LEFEBVRE, Sirenia Project Leader, National Biological Service, 412 NE 16th Ave., Room 250, Gainesville, FL 32601, USA (ph. +1-904-372-2571, fax +1-904-374-8080, e-mail SIRENIA@NERVM.NERDC.UFL.EDU)

Ms. Nicole LEOTAUD, Biologist, WIldlife Section, Forestry Division, 15 Monteverde Th., Morne Coco Road, Petit Valley, Trinidad, TRINIDAD & TOBAGO (ph. +1-809-662-5114, fax +1-809-645-4288)

Dr. Antonio MIGNUCCI-GIANNONI, Scientific Coordinator, Red Caribeña de Varamientos, P.O. Box 38030, San Juan, PUERTO RICO 00937-1030 (ph. +1-809-899-2048, fax +1-809-899-5500)

Dr. Thomas O'SHEA, Assistant Director, Midcontinent Ecological Science Center, National Biological Service, 4512 McMurry Ave., Fort Collins, CO 80525-3400, USA (ph. +1-303-226-9397, fax +1-303-226-9230)

Dr. James POWELL, c/o Dr. David Vousden, UNDP/GEF Coastal Zone Management Unit, Fisheries Dept., P.O. Box 148, Belize City, BELIZE (ph. 501-2-30719, fax 501-2-35738, e-mail DAVID.VOUSDEN@UNDP-ORG)

Dr. Anthony PREEN, Research Fellow, Dept. of Tropical Environment Studies & Geography, James Cook Univ., Townsville, Qld. 4811, AUSTRALIA (ph. +61-77-815575, fax +61-77-814020, e-mail ANTHONY.PREEN@JCU.EDU.AU)

Dr. Galen RATHBUN, Research Biologist, National Biological Service, P.O. Box 70, San Simeon, CA 93452-0070, USA (ph. +1-805-927-3893, fax +1-805-927-3308)

Mr. Ismu Sutanto SUWELO, Senior Instructor, Centre for Education and Training of Forestry Personnel, Jalan Gunung Batu, P.O. Box 141, Bogor 16001, INDONESIA (ph. 0251-312841/0251-323565, fax 0251-240566)

MANATEE RESEARCH OPPORTUNITY

The Save the Manatee Club (SMC) is issuing a request for proposals from researchers interested in conducting aerial surveys to determine manatee abundance and distribution in west Volusia and Brevard counties, Florida, over the next two years. Interested parties should call or e-mail Patti Thompson at SMC for further information. Phone: 1-800-432-5646; e-mail: manatee@america.com

THANKS, SEA WORLD!

Sirenews is pleased to acknowledge an unrestricted donation of $500 from Sea World, Inc. to help defray printing and mailing expenses. We thank Sea World and Dan Odell for this generous gesture of support.

LOCAL NEWS

AUSTRALIA

Hardening Evidence for Dugong Decline Along the More Developed Regions of the Coast of Queensland, Australia. - The Great Barrier Reef stretches for some 2000 km along the eastern coast of Queensland. The northern region along the coast of Cape York Peninsula is a remote area with a very low human population density and little development. In contrast, much of the area south of Cape York Peninsula is undergoing very rapid coastal development. This southern region was surveyed for dugongs from the air in 1987 and 1992. The estimated number of dugongs present in the region in 1992 was 1857 ± s.e. 292, much less than the 1987 estimate of 3479 ± s.e. 459 dugongs. When differences in survey conditions are taken into account in the analyses, the difference approaches significance (a=0.06), suggesting that dugong numbers have declined in this region.

The aerial survey was repeated in November 1994 with the aim of evaluating whether this observed decline was a real trend or an artifact of sighting conditions, which were slightly worse in 1992 than in 1987.

The population estimate resulting from the 1994 survey was 1750 ± 257 dugongs, supporting the findings of the 1992 survey. Parallel declines were not recorded in the estimates of turtles or cetaceans which were recorded in the same surveys.

The reasons for this decline in dugong numbers are probably complex and may include habitat loss, traditional hunting, and incidental drowning of dugongs in commercial gillnets. Parallel declines have not been recorded in repeat surveys of more remote regions in the dugong's range in Australia where traditional hunting and incidental drowning in gillnets are the major anthropogenic impacts. - Helene Marsh

Dugong Adopts Offshore Oil Platform as Focal Point for Activity. - During March-April 1995, workers on the production platform Vicksburg (21°07' S, 115°06' E) on the South Pepper oilfield (North West Shelf of Western Australia), noticed the presence of a dugong which appeared to have adopted the platform as its home base.

Unfortunately, nobody recorded the exact date when this dugong arrived at the platform, but its continued presence warranted entry of a report in the operations log of the Vicksburg on 14 April 1995. No further log entries were made over the next four weeks, until platform worker Martin Rawlings was prompted to report the dugong's apparent extended stay to the Western Australian Museum. Dr. Ric How referred the report to R. I. T. Prince.

Daily log reports of further sightings of this dugong were entered from 12 through 26 May 1995. Photographic recording of the dugong was requested on 25 May, as none of the platform personnel were known to have previously attempted this. The prints subsequently obtained included portions of the platform supports, and numbers of large long-toms (needlefish, Family Belonidae), as well as the resident dugong.

The dugong apparently deserted the rig between 26 and 27 May. The last three relevant log entries, for 27 and 28 May and 1 June, record the absence of further sightings of the animal.

One dugong only was seen around the Vicksburg at all times from arrival until just before desertion. The observers believe that they saw the same animal each time. Noting the uncertain time of arrival, this dugong centered its activities around the Vicksburg structure for a minimum of 8-10 weeks, and possibly more than 12 weeks.

Circumstances of arrival and fixation of this dugong on the platform are not known, but several probably significant events preceded its disappearance. Another two or three dugongs appeared around the Vicksburg about this time, and a drop in ambient water temperature of ca. 2-3°C is also reported to have occurred between 26 and 27 May. It is possible that an associated change in water circulation over the Barrow Islands Shoals to the north of the Vicksburg mobilized other dugongs in that area, and that the former platform resident subsequently followed its new-found associates as they moved on.

The photographs of the Vicksburg dugong suggest that it was a juvenile. The larger species of long-toms of the North West Shelf waters can grow to lengths of 1.3-1.5m, but most seen would average around 1m (Barry Hutchins, Western Australian Museum, pers. commun.). Scaling from the photographs, using this knowledge and that of the visible platform support dimensions, suggests that this dugong was most probably <_1.5m in length. It certainly was not more than 2m. Sex could not be determined, because all observations were made from the platform deck (18m above water).

Apart from the photography mentioned above, some other more detailed observations of behavior patterns were planned for the dugong's later period of residence around the Vicksburg. Unfortunately, the animal's disappearance prevented this. However, it was noted to spend a lot of time suspended inactive below the surface in the upper water column. At other times it was seen rolling about; the observers considered this may have been "playing".

On other occasions it disappeared from the observers' view, during some of which times it could have drifted under the platform out of sight. It might also have been diving to feed, although the 17m water depth around the Vicksburg is at the deeper extreme of known dugong feeding range. Still, the observers did not think the dugong had lost body condition during its time at the platform.

One other lone Western Australian dugong is known to have associated for about 7 days in mid-January 1989 with a large (29.8m, 372-tonne) moored tugboat, the Pilbara Sun, in Dampier Harbour (20°39' S, 116°42' E). Water temperatures in Dampier Harbour during this period were reported to have varied between 26 and 31°C.

The Pilbara Sun dugong was certainly a young, unweaned calf (photo estimate, ca. 1.1m in length). Its mother, which had apparently been feeding on a seagrass bed directly behind the boat pen, had been killed beforehand by the same tug when reversing from its mooring for work. The carcass was unsalvageable, being mutilated beyond recognition by the propeller impact.

Unfortunately, formal reporting of this fatal collision, and the subsequent orphan calf/tug association, was not made until a week after the event. The movements that had been observed meanwhile of the orphan back and forth alongside the tug suggested it was seeking milk. Nothing further was learned from this association because the calf disappeared overnight almost immediately after the report was made. Starvation or shark attack may have caused its disappearance. - Robert I. T. Prince (Wildlife Research Centre, Dept. of Conservation and Land Management, P. O. Box 51, Wanneroo 6065), Martin Rawlings (c/o Atwood Oceanics Australia Pty. Ltd., 35 Peel Road, O'Connor 6163), and Roberta Selleck (Western Mining Corporation Ltd., P. O. Box 7660, Perth 6850, Western Australia).

BELIZE

Manatee Butchering Sites in Port Honduras. - In the tranquil waters of southern Belize, there lies a serious threat to the existence of the manatee. Fishermen in Port Honduras are killing manatees at an alarming rate. This activity was recently made public through reports generated by the Belize Center for Environmental Studies. Last year four manatee skeletons were discovered in the area of Deep Creek, in the Toledo District of Belize. At that time it was suspected that some opportunistic butchering was taking

place; however, the magnitude of the recent killing was not apparent until now.

With funding graciously provided by the Smithsonian Institution Biodiversity Program, we went to Belize in late August and early September 1995 to conduct dolphin and manatee research. While there, we were able to fly several aerial surveys and counted 109 manatees at selected survey sites. The total number of manatees in Belize is not known, but is assumed to be around 200 animals. During an aerial survey of Port Honduras we counted 4 manatees. There is excellent habitat for a local population in the protected cays, adjacent Deep Creek and Rio Hondo rivers, and Icacos Lagoon. A large number of manatees were observed to the north in nearby Placencia Lagoon where 37 individuals were counted. The presence of this large group of manatees in the north could be responsible for migratory animals occasionally moving south into Port Honduras. These animals could easily become victims of the illicit poaching operation.

During boat surveys of Port Honduras with local fishermen, we discovered 11 separate butchering sites, which contained a minimum of 35 manatee carcasses. Twenty-four skeletons were classified as adults, and the remaining 11 were either juveniles or calves. Detailed studies of the skeletal material collected from each site will be conducted. Evidence of recent butchering was apparent, and we were watched by hungry John Crows (vultures) as they sat in the nearby trees. Some of the decaying flesh was still attached to the bones. One site was known to be two to three years old, while at least two of the sites were active and had been used within the last month.

Many of the skulls examined had large, deep cut marks in the cranial bones. It was apparent that the manatees were either shot, harpooned, or chased until exhausted, then brought close to the boat and dispatched with heavy machete blows to the head and nose. Carcasses would then be taken to the nearest dry land site, and under the cover of heavy vegetation or nightfall, the meat would be removed. It would then be taken to market and illegally sold.

No manatee meat was observed in markets in Belize; however, there are several rumors that the meat can occasionally be purchased in Guatemala. It is likely that fishermen from Guatemala are coming into Belize, killing the manatees, and taking the meat back to Guatemala to sell. Manatees are protected in both Belize and Guatemala, but there is little or no enforcement of existing laws. The direct impact that this poaching is having on the local population in south Belize is not known, but the magnitude of this activity clearly puts excessive pressure on this population. Immediate measures need to be taken to enforce existing laws protecting manatees, and ensure that all poaching activities are stopped as soon as possible.

Additional information regarding this investigation can be obtained by contacting either the Fisheries or Forestry Departments, Belize City, Belize, or the Sirenia Project, Gainesville, Florida, USA. - Robert K. Bonde (Sirenia Project) and Charley Potter (Smithsonian Institution)

DOMINICAN REPUBLIC

Stranded Manatee Calf Rescued. - In late March 1995, a manatee calf was stranded alive at Barahona, Dominican Republic, after fishermen killed its mother. The dehydrated and anemic 70-pound calf was discovered by Tropescar Sur, a nonprofit animal-welfare organization, and rescued by a team from the Acuario Nacional in Santo Domingo, led by Enrique Pugibet and Mo'nica Vega. Antonio Mignucci from the Caribbean Stranding Network in Puerto Rico was called in for expert advice, and the baby manatee is now doing well on a diet of goat's milk and soy milk.

The calf was christened Tamaury in memory of Tammy Dominguez and Amaury Villalba, who were recently killed in a plane crash during a manatee survey (see notice in this issue).

The fishermen who killed the mother were caught and fined, but the applicable law dates from 1960 and the amount of the fine was inconsequential. - (source: Alerta Neptuno [Caribbean Stranding Network] 2(2), June 1995.)

EAST AFRICA AND MADAGASCAR

Aerial Survey in Kenya Finds Few Dugongs. - From 17-24 November, the Kenya Wildlife Service, in collaboration with UNEP OCA/PAC, IUCN's Regional Office for Eastern Africa, and Eden Wildlife Trust carried out an intensive aerial survey of 500 km of Kenya's shoreline to determine the distribution of sea turtles, dugongs, whales, dolphins, and whale sharks. Five aircraft were used over a period of seven days. A total of 254 hours were spent in the air, doing 1 km-wide transects out to the 30 m depth contour.

Sea turtles, dolphins, and whale sharks were found to be evenly distributed along the coast within a depth of 20 m. Dugongs were found only in Ungwana Bay and Manda Bay in Lamu, however, and only 16 animals were sighted, indicating a very small population. Survey participant Vic Cockcroft estimates a population of about 50 dugongs for the whole of Kenya; and based mainly on anecdotal data from interviews, he doubts that there are more than 2000 dugongs in the western Indian Ocean, excluding the Arabian Gulf.

"Our results demonstrated that sea turtles and dugongs are the most vulnerable of the animals covered," reports George Wamukoya, a marine botanist with the Kenya Wildlife Service. "This is probably the result of habitat destruction and human activities such as poaching and disposal of plastic wastes. If we are to conserve these species, we need to protect key turtle nesting areas in Ras Tenewi and Shella, and the known dugong habitats in Ungwana and Manda bays."

On related topics, Vic Cockcroft reports that he has just obtained funding from WWF International for a coastal zone assessment for Madagascar, including a comprehensive assessment of dugong status there. He is now seeking money for a compr