Biology subjects

Elorriaga-Verplancken, F. R.

Publications and source records attributed to Elorriaga-Verplancken, F. R..

2 recordsLinked to original sources

bioRxiv2020

The demographic decline of a sea lion population followed multi-decadal sea surface warming

BackgroundThe population growth of top predators depends largely on environmental conditions suitable for aggregating sufficient and high-quality prey. We reconstructed numerically the population size dynamics of a resident population of California sea lions in the Gulf of California during 1978 - 2019, and its relation with the gulfs multi-decadal sea surface temperature trend. This are the first long-term insights to the oceanic environment of the Gulf of California and to the population trend of one of its major predators. ResultsOur results indicate that a three-decade sustained warming explains statistically the populations trend, including a [~]65% decline between 1991 - 2019, accounting for 92% of the variance. Long-term warming conditions started in the late 80s, followed by the populations decline, from a peak of 43,834 animals (range: 34,080 - 58,274) in 1991 to only 15,291 (range: range: 11,861 - 20,316) in 2019. The models suggested a century-scale optimum sea surface habitat for the population occurring in mildly temperate waters, from 0.18 to 0.39{degrees}C above the 100- year mean of 22.24{degrees}C. ConclusionsThe negative relation of the population size with warming sea surface conditions was evident, and the predictability of the former from the sea surface temperature 100-year anomalies was high. The mechanistic links of this relation are still untested, but an apparent diversification of pelagic fish catches suggests a reduction of high quality prey. We propose that this sea lion population should be considered as vulnerable to any disturbance that could add to the negative effects of the current sea surface warming conditions in the Gulf of California.

ecology↗

bioRxiv2019

Early sexual dimorphism in the developing gut microbiome of northern elephant seals

The gut microbiome is an integral part of a species ecology, but we know little about how host characteristics impact its development in wild populations. Here, we explored the role of such intrinsic factors in shaping the gut microbiome of northern elephant seals during a critical developmental window of six weeks after weaning, when the pups stay ashore without feeding. We show that the early-life gut microbiome is already substantially different in male and female pups, even though males and females cannot yet be distinguished morphologically. Sex and age both explain around 15% of the variation in gut microbial beta diversity, while microbial communities sampled from the same individual show high levels of similarity across time, explaining another 40% of the variation. Only a small proportion of the variation in beta diversity is explained by health status, but healthy individuals have a greater microbial alpha diversity than their non-healthy peers. Across the post-weaning period, the elephant seal gut microbiome is highly dynamic. We found evidence for several colonisation and extinction events as well as a decline in Bacteriodes and an increase in Prevotella, a pattern that has previously been associated with the transition from nursing to solid food. Lastly, we show that genetic relatedness is correlated with gut microbiome similarity in males but not females, again reflecting substantial early sex-differences. Our study represents a naturally diet-controlled and longitudinal investigation of how intrinsic factors shape the early gut microbiome in a species with extreme sex differences in morphology and life history.

molecular biology↗