2021 journal article
Beached Sargassum alters sand thermal environments: Implications for incubating sea turtle eggs
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 546.
author keywords: Marine turtle; Thermal tolerance; Temperature-dependent sex determination; Hawksbill; Climate change; Macroalgae
TL;DR:
Impacts on sea turtle nesting ecology are described, with a focus on the below-ground thermal environment for incubating eggs of Sargassum spp, where these thermal changes can significantly impact developmental outcomes for sea turtle embryos.
(via Semantic Scholar)
open access via doi.org (publisher)
UN Sustainable Development Goal Categories
13. Climate Action
(Web of Science)
14. Life Below Water
(OpenAlex)
15. Life on Land
(Web of Science)
Source: Web Of Science
Added: November 8, 2021
Global environmental change has featured a rise in macroalgae blooms. These events generate immense amounts of biomass that can subsequently arrive on shorelines. Such a scenario has been playing out since 2011 in the tropical and subtropical Atlantic, where Sargassum spp. have been causing periodic ‘golden tides’ in coastal habitats. Here we describe impacts on sea turtle nesting ecology, with a focus on the below-ground thermal environment for incubating eggs. Sargassum may blanket the surface of beaches due to natural wave or wind energy and can be redistributed via anthropogenic beach cleaning. When it covers egg clutches, it may alter incubation temperatures and therefore affect both embryonic survival and primary sex ratios. To evaluate the thermal impacts of Sargassum, we measured sand temperatures with data loggers buried under Sargassum cover treatments on a beach in Antigua, West Indies. Our split-plot experiment also tested for effects from shade, season (summer versus autumn), and high rainfall events. We modeled temperatures with a mixed-effects model and, surprisingly, our most compelling finding suggested that Sargassum's effects on below-ground temperatures were contingent on season. Greater Sargassum cover was associated with a cooling effect in the summer but warming in the autumn. We assume that the model term for season integrates several climate-related factors that vary seasonally in the Eastern Caribbean and modulate Sargassum's impact, including windspeeds. Comparing estimated marginal means for the high-cover treatments versus the controls, Sargassum cover led to a 0.21 °C increase in the autumn and a 0.17 °C decrease in the summer; these thermal changes can significantly impact developmental outcomes for sea turtle embryos. Atlantic nesting beach managers should monitor this macroalgal phenomenon and can use these data to begin to infer impacts on sea turtle populations and develop potential management strategies.