Space use patterns of sharks in relation to boat activity in an urbanized coastal waterway. (December 2021)

• Record Type: Journal Article
• Authors: Rider, Mitchell J.; Kirsebom, Oliver S.; Gallagher, Austin J.; Staaterman, Erica; Ault, Jerald S.; Sasso, Christopher R.; Jackson, Tom; Browder, Joan A.; Hammerschlag, Neil
• Is Part Of: Marine environmental research. Volume 172(2021)
• Publication Date: 2021-12
• Subjects: Urbanization -- Movement ecology -- Global change -- Acoustic telemetry -- Elasmobranch -- Coastal waters -- Vessel traffic; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2021.105489
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: Aquatic ecosystems face numerous anthropogenic threats associated with coastal urbanization, with boat activity being among the most prevalent. The present study aimed to evaluate a potential relationship between boat activity and shark space use in Biscayne Bay, Florida (USA), a coastal waterway exposed to high levels of boating. Spatiotemporal patterns in boat density and traffic were determined from aerial surveys and underwater acoustic recorders, respectively. These data were then compared with residency patterns of bull ( Carcharhinus leucas ), nurse ( Ginglymostoma cirratum ) and great hammerhead ( Sphyrna mokarran ) sharks quantified through passive acoustic telemetry. Results were mixed, with no detectable relationship between boat density and shark residency for any of the species. Hourly presence of G. cirratum decreased with increasing boat traffic, a relationship not seen in the other two species. Explanations for these results include habituation of sharks to the high levels of chronic boat activity in the study area and interspecific differences in hearing sensitivity. Highlights: Spatiotemporal patterns of boat activity compared to space use of 3 shark species. Boat activity measured via aerial surveys and passive acoustic monitoring. No relationship detected between boat densities and daily shark residencies. Hourly nurse shark presence was negatively related to boat traffic. Findings provide insights into effects of urbanization on marine predators.