Significance: Multiple anthropogenic disturbances affect the structure and functioning of communities. Recent evidence highlighted that, after pulse disturbance, the functioning a community performs may be recovered fast due to functional redundancy, whereas community multivariate composition needs a longer time. Yet, the mechanisms that drive the different community recovery times have not been quantified empirically. We use quantitative food-web analysis to assess the influence of species interactions on community recovery. We found species-interactions strength to be the main mechanism driving differences between structural and functional recovery. Additionally, we show that interactions between multiple disturbances appear in the long term only when both species-interaction strength and food-web architecture change significantly.

The search for general properties in network structure has been a central issue for food web studies in recent years. One such property is the small-world topology that combines a high clustering and a small distance between nodes of the network. This property may increase food web resilience but make them more sensitive to the extinction of connected species. Food web theory has been developed principally from freshwater and terrestrial ecosystems, largely omitting marine habitats. If theory needs to be modified to accommodate observations from marine ecosystems, based on major differences in several topological characteristics is still on debate. Here we investigated if the small-world topology is a common structural pattern in marine food webs. We developed a novel, simple and statistically rigorous method to examine the largest set of complex marine food webs to date. More than half of the analyzed marine networks exhibited a similar or lower characteristic path length than the random expectation, whereas 39% of the webs presented a significantly higher clustering than its random counterpart. Our method proved that 5 out of 28 networks fulfilled both features of the small-world topology: short path length and high clustering. This work represents the first rigorous analysis of the small-world topology and its associated features in high-quality marine networks. We conclude that such topology is a structural pattern that is not maximized in marine food webs; thus it is probably not an effective model to study robustness, stability and feasibility of marine ecosystems.

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.