A comparison between traditional kernel-based methods and network analysis: an example from two nearshore shark species

Lédée, Elodie J. I.; Heupel, Michelle R.; Tobin, Andrew J.; Knip, Danielle M.; Simpfendorfer, Colin A.

doi:10.1016/j.anbehav.2015.01.039

Cited by 44 publications

(33 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As analytic tools may influence ecological interpretation, future exploration will evaluate age-0 Rose Muskellunge and Northern Pike captured in 2015 using network analysis to provide a more comprehensive picture of young esocid movement (i.e. bidirectional through vegetative corridors; Lédée, Heupel, Tobin, Knip, & Simpfendorfer, 2015), relative to physical habitat features.…”

Section: Discussionmentioning

confidence: 99%

Spatiotemporal ecology of juvenile Muskellunge (Esox masquinongy) and Northern Pike (Esox lucius) in upper St. Lawrence River nursery bays during their inaugural fall and winter

Walton‐Rabideau

Lédée

Leblanc

et al. 2019

Ecology of Freshwater Fish

Self Cite

View full text Add to dashboard Cite

Understanding the spatial ecology of juvenile freshwater fish beyond summer months is an essential component of their life history puzzle. To this end, declines in the natural populations of sympatric Muskellunge (Esox masquinongy) and Northern Pike (Esox lucius) in the upper St. Lawrence River prompted study of spatiotemporal patterns and habitat requirements associated with earlier life stages of these congeneric, freshwater predators in fall and overwinter periods. Over 75 age‐0 esocids were tagged and passively monitored using acoustic telemetry in four nursery embayments in fall and winter months from 2015 and 2017 months to elucidate spatiotemporal ecology and test hypotheses related to emigration. Presence, residency, space and habitat use were assessed and modelled against key environmental (i.e. water temperature and level) and biological (total length) covariates using mixed effect models. Muskellunge were found to spend more time in deeper, littoral regions with canopy‐forming, submerged aquatic vegetation while Northern Pike aggregated in the deepest, highly vegetated region of their nursery embayment. Results suggest fish may exhibit transitionary movements in fall months and may span outwards into nearshore regions along the main river channel. Studies informing coastal restoration initiatives to increase Muskellunge production are encouraged to assess sympatric habitat use relative to prominent embayment structures and further explore depth partitioning by these young predators. With a substantial influence from water‐level regulation on use of nursery habitat, future studies must work in concert with management plans aimed at producing more natural riverine cycles and thus increased recruitment of Esox species.

show abstract

Section: Discussionmentioning

confidence: 99%

Spatiotemporal ecology of juvenile Muskellunge (Esox masquinongy) and Northern Pike (Esox lucius) in upper St. Lawrence River nursery bays during their inaugural fall and winter

Walton‐Rabideau

Lédée

Leblanc

et al. 2019

Ecology of Freshwater Fish

Self Cite

View full text Add to dashboard Cite

show abstract

“…Several quantitative metrics were calculated from the interconnected network to describe the local and global network structure (19): (i) number of edges, (ii) number of vertices, (iii) degree of centrality and (iv) density. The density defined as the proportion of edges actually present in the network among all possible edges in the data (19). The degree of centrality defined as the overall level of connectedness within the network.…”

Section: Methodsmentioning

confidence: 99%

“…The NA was based on movements between receiver locations, where the size of the node represented the degree centrality (19). To determine the relative importance of each node within the marine reserves, we calculated the eigenvalues, defining the centrality of each node as a proportion to the sum of the centralities of those nodes to the ones which are connected.…”

Section: Methodsmentioning

confidence: 99%

“…The definition of the extent and occurrence of long-range movements and population connectivity are necessary for a full understanding of the ecology of a species and hence for designing effective conservation action (18). By assessing movement frequency, Network Analysis (NA) can be used to identify important movement corridors between core habitats of a species (6, 19). NA provides a new insight into the connectivity of specific habitats and the animals moving between them.…”

Section: Introductionmentioning

confidence: 99%

“…NA provides a new insight into the connectivity of specific habitats and the animals moving between them. It also proves valuable in revealing important information on distinct spatial and temporal changes in animal movements (6, 19). For example, an area with a high degree of centrality would suggest strong site fidelity by wide-ranging animals, hence the animals may return to the same location from many different areas (6).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Shark movements in the Revillagigedo Archipelago and connectivity with the Eastern Tropical Pacific

Lara-Lizardi

Hoyos-Padilla

Hearn

et al. 2020

Preprint

View full text Add to dashboard Cite

Long-distance movements of sharks within and between islands pose substantial challenges for resource managers working with highly migratory species. When no-take zones do not cover the critical areas that sharks use as part of their lifecycle, exposure to fishing activities can be significant. Shark movements between the Marine Protected Areas (MPAs) of the Eastern Tropical Pacific (ETP) have been studied for several years, however little is known about the strength of connectivity between these islands. We analyzed the extensive MigraMar ultrasonic telemetry dataset to assess how Galapagos sharks (Carcharhinus galapagensis) and silky sharks (Carcharhinus falciformis) use different islands as stepping-stones during their migrations within the Revillagigedo National Park and other ETP islands. Of the 66 sharks monitored, 63.5% moved within the same island, 25.4% between two islands or more and only 10.1% across different MPAs. A C. falciformis tagged in Roca Partida Island, Revillagigedo, travelled to Clipperton Atoll and another one tagged in Darwin Island travelled to the atoll on two different years. The largest movement of C. galapagensis was accomplished by a shark tagged at Socorro Island, Revillagigedo, later detected at Clipperton and finally recorded in Darwin Island, Galapagos. This last path was in fact, one of the longest movements ever recorded for the species. Although long-distance dispersion was not common, our results highlight the need for co-operation between different countries to ensure adequate protection for sharks in the form of swimways and other conservation tools in the ETP.

show abstract

Dynamic use of coastal areas by bull sharks and the conciliation of conservation and management of negative human–wildlife interactions

Mourier

Soria

Blaison

et al. 2021

Aquatic Conservation

View full text Add to dashboard Cite

Knowledge about spatial and temporal variability in the distribution and abundance of predators is necessary to adapt measures to mitigate human–wildlife interactions. Acoustic telemetry and network analyses were used to investigate the spatial ecology of bull sharks, the species responsible for most shark bites in Reunion Island, one of the world's shark bite hotspots. The west coast of the island was not used uniformly by every individual, with size predicting the movements of sharks along the coast. Node‐based metrics – closeness, node strength, and cumulated continuous residency times – derived from up to 181 monthly movement networks from 20 individuals, revealed that smaller sharks (<250 cm total length) primarily used the south‐west coast while larger individuals spent most of their time in the northern region with regular visits to multiple areas along the coast. This study provides essential knowledge on bull shark behaviour and central areas used at different periods of the year, which correlates well with the dynamics of observed shark bites. Our approach provides a non‐invasive alternative to help predicting and anticipating human–shark conflicts and avoid shark culling programmes detrimental to the conservation of large predators such as sharks.

show abstract

A comparison between traditional kernel-based methods and network analysis: an example from two nearshore shark species

Cited by 44 publications

References 30 publications

Spatiotemporal ecology of juvenile Muskellunge (Esox masquinongy) and Northern Pike (Esox lucius) in upper St. Lawrence River nursery bays during their inaugural fall and winter

Spatiotemporal ecology of juvenile Muskellunge (Esox masquinongy) and Northern Pike (Esox lucius) in upper St. Lawrence River nursery bays during their inaugural fall and winter

Shark movements in the Revillagigedo Archipelago and connectivity with the Eastern Tropical Pacific

Dynamic use of coastal areas by bull sharks and the conciliation of conservation and management of negative human–wildlife interactions

Contact Info

Product

Resources

About