Environmentally Sensitive Species: The West Indian Manatee (Trichechus manatus manatus)

Environmentally Sensitive Species:
                      The West Indian Manatee
                      (Trichechus manatus manatus)
                            Trinidad and Tobago

Introduction
The Environmental Management Authority (EMA), a statutory authority of the
Government of the Republic of Trinidad and Tobago, was formally established in
June 1995 as a result of the enactment of the Environment Management Act
in March of that year. Through its Environmentally Sensitive Species Rules,
2001 (ESS Rules 2001), the EMA has been declaring species of Trinidad
and Tobago to be protected according to criteria set out in the ESS Rules.

The designation of a species as “environmentally sensitive” is to meet one
or more of three general categories of objectives:
(a) conservation of biological diversity and protection of the environment
(b) sustainable economic and human development
(c) logistic support, e.g., environmental education, information sharing, etc.

An Environmentally Sensitive Species (ESS) is any species:
• that is indigenous to Trinidad and Tobago or, although not indigenous to
Trinidad and Tobago, is present in Trinidad and Tobago for a part of its life or
reproductive cycle
• that throughout all or a part of its range is, or is likely to become, in danger of
extinction and whose survival is unlikely if the factors jeopardising it continue
to operate
• that is required to be protected for the purpose of meeting the Government’s
international obligations

Fig. 1: Map - Habitat range of the West Indian Manatee in Trinidad

Taxonomy
Kingdom       ANIMALIA
Phylum        CHORDATA
Class		       MAMMALIA
Order		       SIRENIA
Family		      TRICHECHIDAE
Species       Trichechus manatus manatus
Local names   Manatee, lamantin, sea cow

Description
An adult West Indian Manatee is approximately 3m long and can weigh
approximately 450 kg. Newborn calves generally range from 80 to 160 cm
long and weigh approximately 30 kg. The West Indian Manatee has a spindle-
-like shaped body, horizontally flattened fluke, and no obvious neck crease.
The skin is rough and generally gray to brown in colour, although colour varies
with age (newborns are darker) and the amount and type of epiphytic growth
(e.g., barnacles or algae). The eyes are small and no external ear is present.
Their snout has bristles on the upper and lower lip pads, and a muscular, flexible
lip is used, in conjunction with the forelimbs, to manipulate food. Six (6) to
eight (8) molars occur in each side of the upper and lower jaws, situated to-
ward the rear of the mouth. They are continuously replaced from back to front
after wearing and throughout the life of the manatee. Nostrils are located on
the tip of the snout, and muscular valves open and close them as the animal
surfaces and dives. Manatees have paddle-like, flexible forelimbs with nails
on the dorsal side. The flexibility of the forelimbs allows animals to walk along
the substrate. The animals possess no dorsal fin.

(a)                                                   (b)

                                    Fig. 2 a – b: Manatees

Status
The West Indian Manatee is recorded under the Red List of the World
Conservation Union (IUCN) as a vulnerable species, which means that it
has a great chance of becoming extinct in the wild. Trinidad has a small
resident population that has been conservatively estimated at approximately
thirty (30) individuals. Historically, this species has been hunted mainly
for food. The West Indian Manatee is the largest wild mammal inhabiting
the rivers and wetland areas of the east coast of Trinidad. In addition to
the Environmentally Sensitive Species Rules, 2001 it is also protected
under the Conservation of Wildlife Act, Chapter 67:01. This Act prohibits
the hunting of the species and possession of any part of it.

Trinidad and Tobago is a signatory to the Convention on International
Trade in Endangered Species of Wild Flora and Fauna (CITES). This convention
lists the West Indian Manatee on Appendix 1 which restricts the trade of
species due to the their vulnerability to extinction. Under the Convention of
Wetlands (Ramsar), the Nariva Swamp which serves locally as the
manatees’ main habitat is listed as a Ramsar site of international
i m p o r t a n c e . T h e a r e a i s a l s o d e s i g n a t e d a s a Pr o h i b i t e d
Area under the Forests Act, Chapter 66:01 and as an Environmentally Sensitive
Area under the Environmentally Sensitive Areas Rules, 2001. Together,
these laws regulate entry and activities within the area.

Habitat and Location
Locally, the main habitat of the West Indian Manatee population is the Nariva
Swamp, which is located on the east coast of Trinidad. The historical distribution
of manatees in Trinidad ranged from the eastern, southern, and western coastal
swamps, rivers, bays, and islets of the island. Their current range appears to
be the coast along the Ortoire River mouth, Cocos-Manzanilla Bay coastline,
Mayaro Bay, within the Nariva Swamp in the region of the Nariva River, Cocal
Lagoon and L’Embranche River, the Charamel River, Balandra River and Bay,
Salibia River and Bay, the Matura River, and the North Oropouche River. The
West Indian Manatee is currently extirpated from the island of Tobago. The
historical distribution of manatees in Tobago included the leeward coast and
the Buccoo Reef-lagoon Complex. Preferred habitat of the manatee is that of
sheltered coastal areas, slow moving riverine systems and other systems with
assemblages of aquatic vegetation such as estuarine areas of larger rivers
with abundant mangrove in the lower reaches and lined with grasses. Where
river levels fluctuate seasonally, the preferred areas are those with access to
deep pools or connecting lakes for dry-season refuge.

        (a)                                                     (b)

              Fig. 3 a-b: Habitat of the West Indian Manatee

Threats
Hunting: continues to pose a significant threat to the manatee population by
further reducing the critically low numbers of locally existing manatees.
Fishing gear entanglement: manatees can become tangled in nets and fish-
ing lines, resulting in drowning from an inability to free themselves to surface
in order to breathe.

Boating accidents: the use of motorized vessels within the manatees’
habitat poses a significant threat as the manatees are unable to respond
quickly enough to evade the path of such vessels. In addition, due to the
poor visibility of the manatees’ habitat, the users of motorized vessels are
unlikely to see submerged manatees.

Habitat destruction and manipulation:
Long-term development plans and their heavy impact on the hydrology
and ecology of the Nariva area threaten the manatee population. Such
impacts include swamp and wetland drainage, dam construction, pesticide
runoff, aquatic pollution, felling of mangroves, quarrying, dredging, and
timber cutting. Sluice gate and canal construction in the river systems can
block access to food resources and can cause fragmentation of subgroups
of the local manatee population. The Nariva Swamp, which is the major
manatee habitat locally, is also subject to the perennial problem of fires,
which are set mainly by farmers, hunters, and fishermen to clear vegetation.
Fires can often become uncontrollable due to strong coastal winds, thus
destroying the valuable habitat.

Management Recommendations
Manage, protect and monitor Manatee habitat:
• Identify essential manatee habitat and extent of range
• Develop habitat/range specific management protocols
• Improve enforcement of existing legislation
• Provide continuous monitoring of manatee habitat
• Promote restoration of degraded manatee areas
•Promote training for local personnel in the area of coastal area management
and conservation

Manage, protect and monitor status of the species:
• Promote research on local manatee population to address information gaps
• Create protected areas and sanctuaries for manatees
• Evaluate the effectiveness of law enforcement
• Promote co-operation and exchange of information on manatee conservation
at national and regional levels
• Support and create regional treaties promoting manatee conservation

Education and awareness:
• Promote greater co-operation and synergies amongst governmental and
non-governmental agencies in conservation of the species
• Build the capacity of local community groups to execute various aspects of
manatee research and monitoring
• Improve the level of manatee awareness within the country
• Develop and promote manatee ecotourism ventures
• Develop and distribute education and awareness material on the manatee

References
Nathai-Gyan & Boodoo, Manatee Conservation Trust. 2002. Trinidad and Tobago Manatee
Recovery Plan. UNEP

UNEP: Regional Management Plan for the West Indian Manatee (Trichechus manatus) compiled
by Ester Quintana-Rizzo and John Reynolds III. CEP Technical Report No. 48. UNEP

Caribbean Environment Programme, Kingston, Jamaica. 2010
Khan, J. 2002. Status of the West Indian manatee in Trinidad and Tobago. Unpublished

Environmental Management Authority. 2005. Legal Notice No. 123. Legal Supplement Part
B. Vol. 44. No. 98. pp. 399-402

For further information
The Environmental Management Authority
#8 Elizabeth Street, St. Clair, Port of Spain
Tele: (868) 628-8042 / 8044-5; Fax: (868) 628-9122
Email: ema@ema.co.tt
Website: ema.co.tt