MESOAMERICANA - Sociedad Mesoamericana para la Biología y la ...

Mesoamericana 13 (1) Agosto de 2009
MATERIAL AND METHODS
Cayo Coco is one of the islands of the Sabana-Camagüey
Archipelago and the fourth largest island within the
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Cuban archipelago, with an extension of 370 km . It is
located offshore the northern coast of Ciego de Avila
province; historically separated by a shallow interior sea
known as “Bahía de Los Perros”, but connected to the isle
of Cuba by a 17 km long causeway since 1989, the
beginning of the tourism development in this insular
region. Its climate is characterized by a moderate and
stable thermal regime, with an annual average temperature
of 25.6 ºC and the sea water temperature ranging from
17.7 to 33 ºC. Easterly winds of an average of 16 km/h
prevailing all along the year and the annual average
precipitation are of 1076 mm.
Laguna Larga is located on the northern-central
coast of Cayo Coco, (22º32'14” N, 78º21'25” W) (Fig. 1), it
has a long and narrow shape with an extension of 0.22
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km , and has just one exit to the open sea through a 6 m
wide channel in its easternmost point. Local tides exhibit a
synodic regular
s e m i d i u r n a l
pattern, with a
maximum average
amplitude of 0.74
m (Zúñiga and
González, 2000)
generating a flow
ranging between 0.8
3
and 1.2 m /s at the
exchange channel.
The natural
evolution of this
coastal wetland has
been influenced by
the growth of Rhizophora mangle (red mangrove) towards
the exit to the open sea, bringing about a continuous
decreasing of water exchange with the rest of the lagoon.
In addition, tourist resorts built during the 90´s have
altered its physical-chemical conditions due to dredging,
stuffing and temporal damping. Bathymetry and sediment
have been also altered by the accumulation of building
debris, and eutrophication conditions have been caused
by the occurrence of solid and liquid wastes spills.
Based on the current known geographical
distribution of R. maritima in Cuba according to Urquiola
and Cabrera (2000), its main dispersion means cited by
Kantrud (1991) were casuistically analyzed (hydrochory,
endozoochory by fishes and birds). In order to make a
checklist of the bird species consuming R. maritima
present in Cayo Coco: (1) several technical reports, papers
and inventory lists from surveys conducted in Cayo Coco
and neighbouring islets wetlands for the last 30 yr were
revised (Garrido, 1976; ACC e ICGC, 1990; López and
Martínez, 1995; Socarrás et al., 1995; Kirkconnell, 1998;
Sánchez and Rodríguez, 2001; Morgado, 2002; Parada et
al., 2006); (2) the initial bird list was consecutively
narrowed down based on the following criteria: bird
migratory behaviour (migratory corridors having an effect
on the study area) according to González (2002), ecomorphology,
abundance and permanence status of
aquatic bird species (Llanes et al., 2002), waterbirds habitat
preference described in Cayo Coco according to Parada et
al. (2006); and (3) dietary importance of R. maritima
drupelets in waterfowls species inhabiting the study area
classified as high, moderate and low, according to the
criteria of Kantrud (1991).
RESULTS
Figure 1. Location of Laguna Larga in the north-central area of Cayo Coco,
Sabana-Camaguey Archipelago, Cuba.
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The feasibility of a probable occurrence of hydrochory
and fish-mediated
endozoochory in
Laguna Larga were
ruled out by taking
into consideration
both geographical
d i s t a n c e a n d
hydrological patterns
in the archipelago as
well as the occurrence
a n d m o v e m e n t
patterns of Ruppiac
o n s u m i n g f i s h
ecosystems in the study area.
species inhabiting the
coastal and estuarine
On the other hand, bird-mediated endozoochory
was considered the most plausible way of dispersion
explaining the occurrence of the angiosperm in the
coastal wetlands of Cayo Coco, in which a group of
migratory waterfowl species became the most effective
dispersers. In this regard, 22 migratory waterbirds
consuming this wigeongrass were identified in our study
area, and 10 of them are dabbling ducks (Anas spp.).
Within this latter species grouping, Anas discors, A.
americana and A. clypeata were identified as the “best”
dispersers based on the criteria of the abundance and
permanence, the importance of drupelets in the diet, bill
eco-morphology, and the habitat preference in the