Biology subjects

Correa, M.

Publications and source records attributed to Correa, M..

4 recordsLinked to original sources

bioRxiv2025

Drone Survey Reveals a Severe Chinstrap Penguin Decline and a Novel Gentoo Colony in an Antarctic Specially Protected Area

Seabird populations in Antarctica are sensitive indicators of environmental change and understanding their dynamics is crucial for assessing the health and future of the Antarctic ecosystems. This study provides an updated population assessment for three key seabird species - the Antarctic Shag (Leucocarbo bransfieldensis), Gentoo Penguin (Pygoscelis papua), and Chinstrap Penguin (P. antarcticus) - within the Antarctic Specially Protected Area (ASPA) 133 on Nelson Island. Using drone-based imagery and photogrammetric analysis, we conducted comprehensive nest counts to evaluate current population size in comparison with historical data. Our results reveal a pronounced 57% decline in the Chinstrap Penguin population at Harmony Point since the 1990s, with 38,080 nests counted compared to historical estimates of nearly 90,000. In contrast, Gentoo Penguin numbers at Harmony Point (3,659 nests) appear stable following a previously documented increase. We also provide the first population estimate for a large Gentoo Penguin colony located on a small peninsula south of Harmony Point, known as the Toe, where 4,641 nests were recorded. Additionally, we report an 84% increase in Antarctic Shags, with 127 nests recorded at Harmony Point. These findings are consistent with regional species-level trends and provide critical baseline data for monitoring the impacts of rapid environmental change on Antarctic seabird communities.

ecology↗

bioRxiv2025

Skuas mortalities linked to positives HPAIV A/H5 beyond Polar Antarctic Circle

The ongoing extinction crisis, driven by human activity, poses a significant threat to seabirds and its especially relevant in highly valuable environments such as Antarctica. Among these threats, seabirds face the risk of local extinctions due to emerging infectious diseases like the Highly Pathogenic Avian Influenza Virus (HPAIV).Progressive spread of HPAIV A/H5N1 outbreaks across South America and the sub-Antarctic islands have been detected, reaching the northern regions of the West Antarctic Peninsula (WAP) during the 2023-2024 season. Here we conducted a comprehensive epidemiological survey conducted on sixteen seabird nesting localities along the WAP from November 2024 to January 2025 to assess the health status of the Antarctic seabirds and detect the presence of HPAIV. We observed unusual mortalities among nesting populations of skuas, with a total of 35 deaths skuas recorded along the WAP and beyond the Antarctic Polar Circle, including Important bird breeding areas around Margarita Bay. HPAIV A/H5 was confirmed in all dead skuas sampled (n=11), from six different locations. This finding represents the southernmost record of seabird mortality in Antarctica related to HPAIV to date. The expansion of HPAIV observed here raises concerns about further spread of avian flu out the Antarctic Peninsula, potentially leading to increased mortality rates in the Antarctic bird populations. These findings are relevant for the assessment of the general health status of Antarctic seabird populations and provide a baseline for the continuous monitoring of the HPAIV spread in avian species during the next breeding seasons.

ecology↗

bioRxiv2022

Plant-PLMview: a database for identifying cis-regulatory sequences with preferential positions in gene-proximal regions of plants

BackgroundEstablishing relationships between transcription factors and target genes is essential for understanding the mechanisms regulating gene expression, which play a fundamental role in plant adaptation to the local environment. Despite the importance of this research area and the tremendous progress in sequencing methods such as ChIP-seq and DAP-seq, we are still far from a complete reconstruction of the cis-regulatory landscape. Only a small number of transcription factors can be assessed from experimental data to identify their cis-regulatory binding sites. This highlights the role that in silico approaches can play to complement experimental data. ResultsWe have developed Plant-PLMview, a web-accessible database for detecting preferentially cis-regulatory sequences in the gene-proximal regions of 20 plant species. Users of Plant-PLMview can (i) access the proximal regions of controlled genes from 20 plant species, (ii) query their own DNA motifs or access 840 cis-regulatory sequences from various plant resources, and (iii) use a tool called PLMdetect to search for preferentially located motifs in the gene-proximal regions of a list of genes. Results are displayed via a web interface with a list of DNA motifs preferentially located in a region near the start or end of genes, the distribution of these motifs and associated annotations. In addition, a graphical map of the preferential locations of the motifs in the 5 and 3-proximal regions of genes provides an overview of all motifs and genes examined. ConclusionPlant-PLMview provides the opportunity to study the proximal landscape of gene regulation in 20 plant genomes. The originality of the database lies in its ease of use thanks to the curated data (cis-regulatory sequences and proximal regions of genes) and the possibility to search through PLMdetect in the 5-gene-proximal region, but also in the 3-gene-proximal region, which is rarely explored. The web interface provides numerous graphical views that allow the users to get an overview and interpret the results more easily.

bioinformatics↗

bioRxiv2018

Natural enemies of armored scales (Hemiptera: Diaspididae) and soft scales (Hemiptera: Coccoidae) in Chile: molecular and morphological identification

Scale insects (Hemiptera: Coccoidea) are key pests of agricultural crops and ornamental plants worldwide. Their populations are difficult to control, even with insecticides, due to their cryptic habits. Moreover, there is growing concern over the use of synthetic pesticides for their control, due to deleterious environmental effects and the emergence of resistant populations of target pests. In this context, biological control may be an effective and sustainable approach. Hymenoptera Chalcidoidea includes natural enemies of scale insects that have been successfully used in many biological control programs. However, the correct identification of pest scale species and their natural enemies is particularly challenging because these insects are very small and highly specialized. Integrative taxonomy, coupling DNA barcoding and morphological analysis, has been successfully used to characterize pests and natural enemy species. In this study, we performed a survey of parasitoids and predators of armored and soft scales in Chile, based on 28S and COI barcodes. Fifty-three populations of Diaspididae and 79 populations of Coccidae were sampled over the entire length of the country, from Arica (18{degrees}S) to Frutillar (41{degrees}S), between January 2015 and February 2016. The phylogenetic relationships obtained by Bayesian inference from multilocus haplotypes revealed 40 putative species of Chalcidoidea, five Coccinellidae and three Neuroptera. In Chalcidoidea, 22 species were identified morphologically, resulting in new COI barcodes for 12 species and new 28S barcodes for 14 species. Two predator species (Rhyzobius lophantae and Coccidophilus transandinus) were identified morphologically, and two parasitoid species, Chartocerus niger and Signiphora bifasciata, were recorded for the first time in Chile.

molecular biology↗