Biology subjects

Samaniego, H.

Publications and source records attributed to Samaniego, H..

3 recordsLinked to original sources

bioRxiv2025

Socioeconomic Segregation and Park Greenness: Insights Across a Strong Latitudinal Gradient

Green Urban Areas (GUAs) in urban environments offer numerous benefits, including temperature regulation, air pollution reduction, climate event mitigation, and mental health improvement. Consequently, various organi zations worldwide emphasize the importance of equitable access to quality public green infrastructure to enhance urban quality of life. Despite these efforts, global trends indicate an unequal spatial distribution of greenness and GUAs, often favoring more affluent populations. In Chile, green infrastructure availability is similarly uneven, with greener GUAs typically found in higher socioeconomic neighborhoods. Our review of the evidence reveals that this inequity exists not only between cities with different investment capacities but also within the same administrations. However, most studies focus on the Metropolitan Region and primarily consider exposure and access to greenness. This study examines the greenness of GUAs in six Chilean conurbations, spanning a wide latitudinal gradient from Antofagasta to Puerto Montt, and compares it with socio-material segregation indicators. We calculated the mean NDVI of each green area using remote sensing data from Landsat 8. Socio-material characterization was conducted in two ways: stratifying the environment of each park using a socio-material index (ISMT) and analyzing the socioeconomic segregation of park visitors throughout the day using eXtended Call Detail Registries (XDR) from anonymized users of a major mobile telephone company (Movistar). Our findings indicate segregation in both dimensions, with greenness inequitably distributed among different ISMT categories. Additionally, the socio-material entropy of park visitors aligns with literature trends, showing higher segregation during times when people are at home and in more peripheral and socioeconomically vulnerable areas. We discuss the need for more granular and scaled analyses and highlight the studys relevance in addressing statistical issues such as the Modifiable Areal Unit Problem (MAUP).

ecology↗

bioRxiv2023

Spatial and temporal representation of marine fish occurrences available online

Despite the 243,000 species of marine species described by 2022, our knowledge about the biodiversity in the oceans is still incomplete. This may have dreaded and detrimental effect for the conservation of marine ecosystems under the current anthropization of our biota and the fast pacing climate and global change scenario. However, a large number of online repositories cataloging, storing and distributing biodiversity information hosting taxonomic information and species occurrence data have emerged recently. FishBase, the Global Biodiversity Information Facility (GBIF) and the Ocean Biodiversity Information System (OBIS) are part of these publicly available repositories representing a variety of sources that have exploded in number. However, despite the incredible accumulation of biodiversity records, not all the information is really useful, nor does it represent any new knowledge regarding global species richness patterns. In this study we evaluated the spatial and temporal representativeness of the records of marine fishes (order Actinopterygii) available in the GBIF and OBIS global repositories. We provide a methodological framework based on a set of non-parametric estimators to calculate species richness from incidence data, using hexagonal grids as sampling units overlapped on the marine bioregions worldwide. Using standard ecological and spatial analysis tools, we identify regions that are adequately represented in terms of available records and therefore have more reliable data, as well as regions with few records that do not represent current species richness. We overlap these results with the location of marine protected areas and fishing exploitation zones to understand the anthropogenic effect on marine ichthyofauna. We additionally evaluate hypotheses regarding the taxonomic, geographic, and temporal distribution of information biases to deepen our current understanding of public records of species occurrences worldwide. Considering that more than 40 years of information was analyzed, the results showed that on a global scale, the primary data on marine fish available on GBIF and OBIS platforms are still far from being representative and complete. Only 1.14% of the records were useful for our analyses. In addition, we found that the information seems to be biased towards coastal areas, regions close to developed countries and areas where there is a large fishing activity. Finally, the best represented species and families are those with a small body size, which use shallow habitats and have commercial cultural value.

ecology↗

bioRxiv2017

Otolith microchemistry identifies diadromous populations of Patagonian river fishes

Compliance with Ethical StandardsOtolith analysis was funded by a RAC grant from the University of New Mexico, USA. The Government of Chile supported the drafting of this document with a CONICYT Doctoral Fellowship to D. Alo in 2015 and to C. Correa through grants CONICYT-PAI N{degrees}82130009, and FONDECYT-Iniciacion en la Investigacion N{degrees}11150990.\n\nAll applicable international, national, and/or institutional guidelines for the care and use of animals were followed. Specimens were collected under permits No. 3587, 29 December 2006, and No. 2886, 4 November 2008 (amendment No. 602, 12 February 2009) granted by the Chilean Subsecretary of Fishing to C. Correa. The McGill University Animal Care Committee (UACC), Animal Use Protocol No. 5291, approved use and handling of animals.\n\nAbstractCoastal habitats in Chile are hypothesized to support a number of diadromous fishes. The objective of this study was to document migratory life histories of native galaxiids and introduced salmonids from a wide latitudinal range in Chilean Patagonia (39-48{degrees}S). Otolith microchemistry data were analysed using a recursive partitioning approach to test for diadromy. Based on annular analysis of Sr:Ca ratios, a diadromous life history was detected for populations of native Aplochiton taeniatus, A. marinus, and Galaxias maculatus. Lifetime residency in freshwater was suggested for populations of A. zebra and G. platei. Among introduced salmonids, populations of Oncorhynchus tshawytscha and O. kisutch exhibited anadromous migratory patterns, whereas the population of O. mykiss screened appeared restricted to freshwater. Salmo trutta exhibited variable habitat use consistent with establishment of an ocean-type life history in some populations. The capacity and geographic scope of hydropower development is increasing and may disrupt migratory routes of diadromous fishes. Identification of diadromous species is a critical first step for preventing their loss due to hydropower development.

ecology↗