Nariva Swamp

Transcription

Nariva Swamp
Environmentally Sensitive Area:
Nariva Swamp Managed Resource Protected Area
Environmental Management Authority
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 Areas,
2001 (ESA Rules 2001), the EMA has been declaring areas of Trinidad and
Tobago to be protected according to criteria set out in these ESA Rules.
The designation of an area as “environmentally sensitive” is to meet one or
more of three general categories of objectives:
(a) conservation of natural resources and protection of the environment
(b) sustainable economic and human development
(c) logistic support e.g. environmental education, information sharing
An Environmentally Sensitive Area (ESA) is an area that is:
• A good representation of a naturally-occurring ecological system of type
• Critically important to the survival or recovery of endangered, endemic or
vulnerable species/communities of plants or animals
• Special in value as a habitat for plants or animals at a critical stage of their
life cycle
To date the following Areas have been declared:
• Aripo Strict Scientific Reserve;
• Matura National Park;
• Nariva Swamp Managed Resource Protected Area
Fig. 1: MAP - Nariva Swamp Environmentally Sensitive Area
Description
Nariva Swamp is the largest, most diverse wetland ecosystem in Trinidad
and Tobago. It is located on the east coast of Trinidad between 10 °30- N
and 10° 22- N latitude and 61° 01- W and 61° 06- W longitude. The Nariva
Swamp Environmentally Sensitive Area covers an area of approximately
11343 hectares. The biodiversity within the system is extremely high owing to a
varied mosaic of distinct vegetation communities of swamp forest, upland forest
and grass savanna/marshes and is the habitat of a number of sensitive plants
and animals. It is an important area for waterfowl including migratory species and is
also a critical habitat for some endangered reptiles and mammals. Nariva is
the main habitat for the locally and globally endangered West Indian
Manatee. It is also the habitat for the locally extinct Blue and Gold Macaw,
which was recently reintroduced into the wild, and the Giant Anaconda.
The swamp has many interesting plants such as orchids, wild Cashmir, a
wild sugar apple favoured by monkeys and Montrichardia, which is a freshwater herbaceous plant of the Aroid family. The system contains a number
of commercially important aquatic species and is an important eco-tourism
and conservation site.
(a)
(b)
Fig. 2 a-b: Vegetation in Nariva Swamp
Vegetative Communities of Nariva Swamp
Marsh
Bacon et al (1979) recorded four types of marshes. Cyperus marsh which
took up one-third of the swamp basin, Phragmites which occurred in low lying
areas of the swamp, and Montrichardia a floating marsh which inhabited the
freshwater areas of Nariva.
Littoral Woodland
Most of this vegetation was removed, particularly at the east of the swamp,
as the area was used to cultivate crops such as watermelon and vegetables,
and as pasture for cattle. The littoral woodland is characterized by species
such as Sea Grape (Coccoloba uvifera), Tropical/Sea Almond (Terminalia
catappa), Pariti tileaceum and Chrysobalanus icaco.
Evergreen Seasonal Forest
In addition to the wetland plant communities previously mentioned, Nariva
Swamp contains evergreen seasonal forest which consists primarily of hardwood trees. This forest is categorised by the presence of Crappo-Guatecare association (Carapa guianensis – Eschweilera subglandulosa). Trees
such as Mahoe (Sterculia caribaea), Silk Cotton (Ceiba pentandra), Balata
(Anilkara bidentata), and Hog Plum (Spondias mombin) are found within the
swamp. Lianas, epiphytes and palms are also typical within the understory
of the forest.
Swamp Forest
This community is composed of mangal, swamp wood and palm swamp
forests. Mangroves make up the majority of this community in this brackish
water system. Mangroves were restricted to the eastern side of the swamp
particularly along the Nariva River. The Palm swamp communities are made
up of species such as Royal/Palmiste palm (Roystonea oleracea), Moriche
Palm (Mauritia setigera) and Bactris sp. that exist mainly in the southern
half of the swamp. Freshwater swampwood communities occur inland from
the mangrove forest and are the second most abundant type of community
after freshwater marsh. This community is categorised by species such as
Swamp Bloodwood (Pterocarpus officianalis), Cajuca/Wild Nutmeg (Virola
surinamensis), Yellow Mangue (Symphonia globuifera) and Swamp Immortelle
(Erythrina fusca).
(a)
(b)
Fig. 3 a-b: Fauna in Nariva Swamp
Fauna
Nariva Swamp is home to approximately 45 mammalian species, 39 reptile
species, 33 fish species, 204 bird species, 19 frog species, 213 insect species,
15 molluscs species and several species of arachnid, protozoa and crustacean.
Status
The significance of Nariva Swamp and its biodiversity has been recognized
for many years, leading to part of it being declared as a Wildlife Sanctuary
and Windbelt Reserve in 1968. The Nariva Swamp was listed as a Wetland of
International Importance and its entry into the Montreux record as a RAMSAR
site in 1993, signalled international recognition of the importance (RAMSAR
Convention, 1971). Subsequently, Nariva Swamp was recognised and prioritised
in a national planning project in the mid to late 1990’s and a management plan
for the area was developed.
These milestones set the pace for the conservation actions that were previously
undertaken with respect to the swamp and lead to the designation of the
Swamp in 2002 as an Environmentally Sensitive Area.
Threats
Historically the area has been severely impacted by human induced alterations
both within and outside of its boundaries. The most devastating of these impacts
have been illegal agricultural activities within its boundaries, which occurred in
the mid 1980’s and continued into the early 1990’s. Large sections of forest
and marsh in the central and western sections of the system were removed
to facilitate large-scale rice cultivation. In other parts of the system small
vegetable farmers illegally occupied state owned land, primarily in its southern
sector. These two activities resulted in the removal of large areas of forest
and alterations to the hydrology of the system.
Subsequently, there has been a change in the distribution and extent of the
vegetative communities, the hydrology of the swamp has been adversely
affected, and the water quality has been negatively impacted. Thus, there is a
compelling need for protection and restoration of these wetlands for biodiversity
conservation. The issues facing the management of Nariva Swamp
are essentially those related to environmental quality, resource exploitation,
and institutional and organisational frameworks to implement government
policies. The system is currently managed by multiple organisations, both
government and private, and efforts have been successful for a variety of
reasons. However, inadequate and ineffective legislation, as well as limited
human and financial resources are among the constraints.
Conservation and Management
The Environmental Management Authority in collaboration with the
University of the West Indies, the Forestry Division and other CBOs are in
the process of executing a Nariva Swamp Restoration Project (NSRP). This
project is in keeping with the principles of the National Environmental Policy
and International conventions including the Ramsar Convention on Wetlands
and the Convention on Biodiversity, Climate Change and Desertification.
The NSRP represents the first phase of implementation of the
Management Plan for the Nariva Swamp (IMA 1999).
This plan called for the restoration of the marsh swamp forest, the vegetation
that has been affected greatest by the clearing of lands for rice farming, in
an area referred to as Block B. In addition to this management plan, the
project implementation is also guided by a series of studies conducted for
the area including a Reforestation Scheme, a Social Impact Assessment, a
Water Resources Management Plan, and an Historical Change Detection
Analysis. The specific objective of the NSRP is to restore and conserve
the Nariva wetlands, through the recognition of the services it provides as a
carbon sink and a biodiverse ecosystem.
References
Institute of Marine Affairs. 1999. Final Report. The Formulation of a Management Plan for
the Nariva Swamp. Ministry of Agriculture Land and Marine Resources
Environmental Management Authority. 2006. The Administrative Record for the
Environmentally Sensitive Area: Nariva Swamp Managed Resource Protected Area.
Environmental Management Authority. 2006. Legal Notice No. 334. Legal Supplement Part
B. Vol. 45. No. 204. pp. 1489 -1497
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