Seasonal factors affecting sea turtle nesting in the Southeastern Caribbean Sea (Gulf of Paria, Venezuela)

Abstract

The nesting characteristics (number of nests and eggs, time of year, nesting initiation, and nesting length) of leatherback (Dermochelys coriacea) and hawksbill (Eretmochelys imbricata) sea turtles of the southern Caribbean Sea (specifically in the Gulf of Paria in Venezuela), were examined in association with weekly precipitation averages and number of rainy days per week during the period between 2009 and 2018. We hypothesized about the influence of rainfall intensity and patterns as the main abiotic factor for sea turtle nesting. On average, leatherbacks preferred nesting during the drier season of each year (March, April, and May), while hawksbills nested during the rainy season (June to September). For both species, we found few significant correlations between the number of nests or clutch size (number of eggs per nest) and weekly averages of seasonal precipitation rates in the region. Average hawksbill clutch sizes were not correlated with average precipitation rates but were positively correlated with the number of rainy days per week (r=0.66, P≤0.05). Average hawksbill clutch sizes decreased each year on average (-3.3 eggs/year, r=-0.88, P≤0.001), which coincided with a negative long-term trend in the number of rainy days (-0.11 rainy days/week, r=-0.69, P≤0.05). During the study period, nesting activities for both leatherback and hawksbills started progressively later (0.9 and 0.6 weeks/year, respectively p≤0.05) and were shorter (-0.9 and -0.8 weeks /year, P≤0.1 and P≤0.05, respectively).

Preliminary analysis of microplastics from the main continental nesting beach of the hawksbill sea turtle (Eretmochelys imbricata) in Venezuela

“…Marine turtles are ecologically important and charismatic mega-fauna of the oceans; they inhabit almost all oceans but only nest over tropical and subtropical sandy beaches (Bolten 2003). These endangered species are affected by many threats, especially from anthropogenic origins like fisheries bycatch (Alio et al 2010, Alfaro-Shigueto et al 2011, Putman et al 2020) and nesting habitat degradation (Maison et al 2010, Veelenturf et al 2020, Balladares & Barrios-Garrido 2021). An emerging concern is the impact of plastic debris, which they ingest during all their life stages (Bugoni et al 2001, Wedemeyer-Strombel et al 2015, Wilcox et al 2018.…”

Marine megafauna catch in Thai small‐scale fisheries

“…Marine megafauna (cetaceans, dugongs, sea turtles, and elasmobranchs) are threatened by a range of anthropogenic activities including: fisheries catch (i.e. catch and by-catch) (Reeves, McClellan & Werner, 2013;Dulvy et al, 2014;Burgess et al, 2018), habitat destruction (Muir et al, 2003;Karczmarski et al, 2017;Balladares & Barrios-Garrido, 2021;Dulvy et al, 2021), and vesselbased tourism (Christiansen & Lusseau, 2014;Schofield et al, 2015;Healy et al, 2020). Catch and by-catch in fisheries (hereafter referred to as 'catch') represent the greatest threat to marine megafauna (Read, Drinker & Northridge, 2006;Lewison et al, 2014;Dulvy et al, 2021) currently threatening a number of populations and species with extirpation and extinction (Brownell et al, 2019).…”