International Journal of Marine Science, 2017, Vol.7, No.33, 316-343
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demographic growth of nesting populations in the WC rookeries (Mortimer and Donnelly, 2007) whose juveniles
use the JR corridor as a transitory route to other feeding grounds. In fact, the haplotype Q, best represented in the
largest WC rookery (Las Coloradas), is more frequent in non-adult turtles from JR between 2004 and 2006 than
the adult ones (Table 1), which was reflected in the increasing contributions from this source (Table 1; Figure 2).
Two immature individuals from JR with haplotypes EiA01 and EiA11 were identified as pubescent in a previous
study on sexual maturation in the marine area of the present study (Pérez-Bermúdez et al., 2010). The presence of
spermatozoa in these specimens indicated that they would reach the ability to copulate in
ca.
two months. In
addition, these pubescent males had similar SCL classes to those of adult ones of the same fishing aggregation,
which is relatively far from the WC breeding areas. Thus, these individuals would possibly complete their
maturation during this migration reinforcing JR as a migratory corridor, in this case of first breeders taking this
route to regional breeding grounds.
Although the present study incorporates in general
E. imbricata
rookeries and aggregations of the WC using 740
bp sequences, the MSAoa still results in wide confidence intervals due to the fact that haplotypes A/EiA01,
F/EiA011 and Q are highly frequent and shared among WC rookeries (Leroux et al., 2012). Hence, the current
MCMC model still has limitations that cannot process all the ecological complexity encrypted in the original data.
Other factors that may contribute towards uncertainty are the moderate and sometimes limited sample sizes in
some rookeries and aggregations; the quality and sampling frequency in both entities (Bowen et al., 2007); the
genetic similarity of some rookeries, given that they are isolated reproductively-speaking (Browne et al., 2010;
Leroux et al., 2012; Carreras et al., 2013); and the limited number of aggregations. This last one is present when
adult aggregations are analyzed in our study whose number is a small fraction of the real number of adult
aggregations in the WC. Consequently, these results could be biased and indicate the urgency to sample other
adult aggregations to improve the inferences and to clarify of better way on the connectivity among these breeding,
foraging and corridor grounds and the rookeries.
Furthermore, there are assumptions that can bias the results. For example, many studies have grouped the Cuban
fishing aggregations (Cuba A, B and D) as a single entity, perhaps because these belong to the same political
jurisdiction (Troëng et al., 2005; Blumenthal et al., 2009a; Browne et al., 2010). However, this is inappropriate
since these Cuban aggregations are separated by hundreds of kilometers and differ structurally, as well as in the
proportion of the maturation stages present (Carrillo et al., 1999). Consequently, we found marked differences
between the MSAs of both maturation categories in each fishing aggregation, probably reflecting a maturation
category-specific dispersal behavior. In addition, the MSAs of the present study using 740 bp still represent
unrealistic scenarios since 1) there are few aggregations characterized with this sequence, 2) there are haplotypes
that are frequent but orphaned (
i.e.
EiA24), and 3) the Belize rookery is only characterized for 384 bp. For
example, the contribution of the ME rookery to non-adult and adult aggregations for JR between 2004 and 2006
with 384 bp is slightly higher than that with 740 bp (Figure 1; Figure 3). In the latter, individuals with the orphan
haplotype EiA24 (N = 4) are excluded from the MSA with 740 bp, reinforcing the contributions of the BaL
rookery. The importance of selecting the data in rookeries and aggregations as well as the assumptions to execute
the MSA is more evident when our initial data are contrasted with these of other studies. For example, our
approach excluded the cumulative haplotype frequencies in rookeries and aggregations as well as the Texas
pelagic individuals from Bowen et al. (2007) and the Mona Island ―new recruits of platform‖ individuals from
Velez-Zuazo et al. (2008). These assumptions and data are used by subsequent authors to infer contributions
(Blumenthal et al., 2009a; Monzón-Argüello et al., 2010; Vilaça et al., 2013; Proietti et al., 2014). Likewise, the
Brazilian and Eastern Atlantic rookeries and aggregations used in Monzón-Argüello et al. (2010; 2011), Vilaça et
al. (2013), Proietti et al. (2014), Putman et al. (2014) and the recent publication of Cazabon-Mannette et al. (2016)
are excluded from our initial data. This partially explains that Doce Leguas rookery has been important for Tobago
aggregations because Cazabon-Mannette et al. (2016) also took the corresponding population size from Mortimer
and Donnelly (2007). This Nr is six times higher than that selected by us from Moncada et al. (2010), which is
better estimated because came from the more systematic and recent surveys (nesting seasons from 1997/1998 to
2008-2009) in that archipelago.
