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International Journal of Marine Science 2014, Vol.4, No.14: 134-142
http://ijms.sophiapublisher.com
139
species displacement has been reported in Florida, but
mussels densities are up to thousand individuals per
square meter (Baker et al., 2002; Baker et al., 2007;
McGuire and Stevely, 2009). A similar situation has
been described for Venezuela, where this species has
become in a fishery product (Penchaszadeh and Vélez,
1996; Segnini et al., 1998; García et al., 2005).
Obviously, if there is not statistical comparison
between invaded and non-invaded areas, and if there is
not routine monitoring, then there is no way to ensure if
and how those associated species were affected by
mussel presence. Nevertheless, the present study
contributes to create a base line on that topic and helps
to identify objectives for future studies.
3 Materials and Methods
Cienfuegos Bay is located in the central part of the
southern coast of Cuba. Its centre is nearby at
22°08´04.5´´ N and 80°28´50.4´´ W. The total surface
area is 88.46 km
2
and a mean depth of 9.5 m, which
determine a mean volume of 810 millions of m
3
. The
Bay is oriented from NW to SW, with a maximum
longitude of 19 km, and a maximum wide of 7.5 km. It
is naturally divided in two lobules, commonly known
as North and South lobules (Muñoz-Caravaca et al.,
2008; Seisdedo and Moreira, 2007). To collect the
associated epifauna, mussels were extracted from four
sites registered as those with greatest relative density
(Lopeztegui - Castillo et al., 2014), they were all
situated in the North lobule of the Bay (Figure 4).
Sampling was carried out on February, May and
November, 2011. Those months are characteristic of
dry season (February) and rainy season (May) while
November is a transition month between these two
main seasons in our country. Besides, Temperature,
Dissolved Oxygen and salinity for Cienfuego´s Bay
was previously reported for that period (Garcés et al.,
2012). The collection of Asian green mussels was made
manually by free or autonomous (SCUBA) diving. At
Pablo Guzmán (PG) and Siete Cuadras (M7) the
substrate consisted of a series of metallic pilings. At
Punta Las Cuevas Wharf (PC) the pilings of the wharf
are made of concrete. Mussels at these three sites were
collected from pilings, between 1-3 meters of depth.
The BH site was a sunk metal boat at a depth of 1.5
meters; mussels were colleted form the hull of the boat.
At PG, M7 and BH the existent plain surfaces allowed
the use of a quadrat of 25 × 25 cm (0.0625 m
2
) as unit
sample. It was placed randomly three times at the same
depth and specimens inside were collected each time.
In PC sampling was done from piles. In that case,
specimens of three different piles were extracted each
time. The epifauna associated to each mussel was
collected by scraping the shell surface (valves). The
obtained sample was fixed in neutralized formaldehyde
solution (4%) and stored in plastic bags previously
tagged. Visual monitoring around
P. viridis
was also
considered.
Epifauna were collected from a total of 577 individuals
as it is shown in Table 3. The organisms (those
classified as megabenthos, > 4 mm) were identified
under the stereoscopic microscope with the help of
taxonomic literature (Abbott, 1974; Williams, 1984;
De Jong and Coomans, 1988; Espinosa et al., 1994;
Mikkelsen and Bieler, 2008) and taking in account the
criteria of different specialists.
Table 3 Number of
Perna viridis
collected each month at each
sampling site.
Sites
February May
November Total
PG
67
83
39
189
M7
38
62
37
137
PC
101
68
49
218
BH
13
12
8
33
Total
219
225
133
577
The species richness values (S=number of species) was
estimated for Asian green mussels epifauna associated,
by sites and for the bay. Wet biomass values were also
determined, by using a technical balance (±0.01 g). In
every case they were normalized by mussel quantity
and were expressed as grams of biomass per mussel
(g/m). Those values were compared among sites and
months by a unifactorial ANOVA, using
post-hoc
Fisher LSD test (F, p≤0.05) in order to know between
which pairs significant differences were established.
Acknowledgements
The authors want to thank Gema Hidalgo, Norberto Capetillo, José Espinosa
and Carlos Varela for their help identifying organisms. Also we want to
express our gratitude to colleagues from Fishery of Cienfuegos (EPICIEN)
because of the logistic support for sampling and to Johanna Fernández for the
supplied literature. We really appreciate the helpful comments of anonymous
reviewers that improved the quality of the manuscript.
Authors’ contributions
ALC conceived and design the study. Also collected the mussels, classified
most of the species and drafted the manuscript with AAV. YGR, NCG and
AAV processed and analyzed the data. RCB collected and conserved the
epifauna, and made biomass determinations. All authors took action in cruises
and also all of them read and approved the final manuscript.