View in EDS

Marine trophic architecture and hidden ecological connections in the Strait of Magellan: keystone species and ecosystem resilience.

Saved in:
Bibliographic Details
Title: Marine trophic architecture and hidden ecological connections in the Strait of Magellan: keystone species and ecosystem resilience.
Authors: Andrade, Claudia D.1 (AUTHOR) claudia.andrade@umag.cl, Sepúlveda, Taryn1 (AUTHOR), Rivera, Cristóbal1 (AUTHOR), Aldea, Cristian1,2,3 (AUTHOR), Marina, Tomás I.4 (AUTHOR)
Source: Oikos. Nov2025, p1. 21p. 7 Illustrations.
Subject Terms: *KEYSTONE species, *ECOLOGICAL resilience, *FOOD chains, *PREDATION, *BIODIVERSITY, *COEXISTENCE of species
Geographic Terms: STRAIT of Magellan (Chile & Argentina), PATAGONIA (Argentina & Chile)
Abstract: Understanding the ecological implications of species coexistence is central to biodiversity studies and to identify environmental and anthropogenic drivers of ecosystem dynamics, where ecological network analysis offers valuable insights. This study examines the complexity, structure, and potential responses to disturbances of the Strait of Magellan's topological food web. Based on a dataset of 438 predator–prey interactions among 139 trophic species (nodes), the food web was characterized using a two‐scale approach. At the network level, descriptors including connectance, degree distribution, and small‐world pattern, were used to evaluate overall architecture. At the node level, species' roles were assessed using degree, betweenness, closeness, condensed in a novel Keystone Species Index (KSI), and topological role. Potential resilience to ongoing perturbations was inferred by relating these network‐ and node‐level properties. Overall, the network exhibits low connectance and an asymmetrical degree distribution, with a few species concentrating most interactions. Its small‐world pattern, characterized by high clustering and short path lengths, suggests that local disturbances could propagate rapidly. More than half of the species are omnivorous, potentially buffering the system against fluctuations in prey availability. According to the KSI antopological role results, polychaetes, Fuegian sprat Sprattus fuegensis ‘sardina fueguina', and Patagonian blenny Eleginops maclovinus ‘róbalo patagónico', act as central conduits for matter and energy flow, linking benthic and pelagic production to higher trophic levels. The combination of low connectance, an asymmetric degree distribution, and small‐world properties suggests that the food web is fragile to perturbations affecting highly connected species, with the potential to trigger trophic cascades. These findings highlight the importance of understanding trophic interactions for effective conservation and ecosystem management and provide new insights for the Strait of Magellan's ecosystem. [ABSTRACT FROM AUTHOR]
Database: Academic Search Index
Description
Abstract:Understanding the ecological implications of species coexistence is central to biodiversity studies and to identify environmental and anthropogenic drivers of ecosystem dynamics, where ecological network analysis offers valuable insights. This study examines the complexity, structure, and potential responses to disturbances of the Strait of Magellan's topological food web. Based on a dataset of 438 predator–prey interactions among 139 trophic species (nodes), the food web was characterized using a two‐scale approach. At the network level, descriptors including connectance, degree distribution, and small‐world pattern, were used to evaluate overall architecture. At the node level, species' roles were assessed using degree, betweenness, closeness, condensed in a novel Keystone Species Index (KSI), and topological role. Potential resilience to ongoing perturbations was inferred by relating these network‐ and node‐level properties. Overall, the network exhibits low connectance and an asymmetrical degree distribution, with a few species concentrating most interactions. Its small‐world pattern, characterized by high clustering and short path lengths, suggests that local disturbances could propagate rapidly. More than half of the species are omnivorous, potentially buffering the system against fluctuations in prey availability. According to the KSI antopological role results, polychaetes, Fuegian sprat <italic>Sprattus fuegensis</italic> ‘sardina fueguina', and Patagonian blenny <italic>Eleginops maclovinus</italic> ‘róbalo patagónico', act as central conduits for matter and energy flow, linking benthic and pelagic production to higher trophic levels. The combination of low connectance, an asymmetric degree distribution, and small‐world properties suggests that the food web is fragile to perturbations affecting highly connected species, with the potential to trigger trophic cascades. These findings highlight the importance of understanding trophic interactions for effective conservation and ecosystem management and provide new insights for the Strait of Magellan's ecosystem. [ABSTRACT FROM AUTHOR]
ISSN:00301299
DOI:10.1002/oik.11711