Long-term acoustic monitoring of bottlenose dolphins, Tursiops truncatus, in marine protected areas in the Spanish Mediterranean Sea

Castellote, Manuel; Brotons, José María; Chicote, Carla A.; Gazo, Manel; Cerdà, Margalida

doi:10.1016/j.ocecoaman.2015.05.017

Cited by 13 publications

(17 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At a larger scale, Castellote et al . (2015) also found contrasting diel patterns in occurrence of bottlenose dolphins within Mediterranean MPAs located 90 km apart 38 . Our results highlight that site-specific variability in both tidal and diel behaviour persists at much smaller spatial scales (13.5 km).…”

Section: Discussionmentioning

confidence: 95%

“…This study highlights the importance of understanding temporal variation in behaviour to underpin more dynamic management of Marine Protected Areas. Although nocturnal activity has been detected in many studies of these animals 23,38,63 , visual methods are still widely used to study their distribution 64,65 . Visual surveys only provide data during daylight hours and may be underestimating the importance of certain locations during the night 23 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Fine scale spatial variability in the influence of environmental cycles on the occurrence of dolphins at coastal sites

Fernandez-Betelu

Graham

Cornulier

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Environmental cycles often influence the presence of animals, creating patterns at different temporal scales, which may mean that their effects overlap and/or interact. Interactions between diel and seasonal cycles have been reported to influence fish behaviour but little is known about such interactions in marine top predators. Here, we studied the combined effect of seasonal, tidal and diel cycles on the occurrence of bottlenose dolphins ( Tursiops truncatus ) within a Marine Protected Area in Scotland. Our analyses were based on echolocation detections from passive acoustic devices (CPODs) deployed at three coastal sites between 2010 and 2016. We described patterns of dolphins’ occurrence using circular statistics and then used generalised additive mixed models to explore the relative importance of each cycle and any interactions between them. We found site-specific cyclical patterns of presence that remained constant across years. There was a highly significant interaction between seasonal and diel cycles at two sites around deep channels, where occurrence was diurnal in summer but became nocturnal in autumn. The study demonstrates the highly plastic behaviour of bottlenose dolphins and shows a previously unreported behaviour that has management implications for this and other marine protected areas.

show abstract

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Fine scale spatial variability in the influence of environmental cycles on the occurrence of dolphins at coastal sites

Fernandez-Betelu

Graham

Cornulier

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…These may have important implications in understanding dolphin habitat-use, however, hours or seasons with lower detection rates may simply indicate reduced movement into the study area, fewer individuals, or transitory occupancy potentially determined by changes in foraging opportunities [54]. Diel patterns are reported in several studies, which revealed that dolphin acoustic activity generally decreases during daytime [26,32,55] and is greater during nighttime, when possibly foraging [29,[56][57][58]. However, whistle detection rate outcomes from around the world are heterogeneous, showing in some areas an absence of temporal trends, while elsewhere a general decrease during daytime [26,32,57].…”

Section: Discussionmentioning

confidence: 98%

“…Today, the majority of long-term acoustic studies focused on dolphin clicks, whose presence effectively revealed their daily and seasonal occurrence in an area, due to their consistent use by echolocating individuals [27][28][29][30][31]. Tonal sounds, on the contrary, being prevalently emitted during social context, have an emission rate lower than clicks, used as biosonar, and so far, their temporal trends have been explored prevalently in deep waters [30,32,33].…”

Section: Introductionmentioning

confidence: 99%

“…Passive Acoustic Monitoring has been considered as a useful and cost-effective method to acquire information about the acoustic occurrence of dolphin populations on the longterm temporal scales [34,35], and to integrate information during nighttime and in bad weather conditions [36]. Moreover, long time series of data are crucial for studying circadian and seasonal rhythms in dolphins' acoustic activity [26,29]. Nevertheless, automatic sound detection from vast acoustic datasets could be challenging: in the last years, several methods were proposed [37] and efforts were made also to better describe [38] and discriminate dolphin vocalizations from other biological and anthropogenic sounds [39].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Acoustic Presence of Dolphins through Whistles Detection in Mediterranean Shallow Waters

Gregorietti

Papale

Ceraulo

et al. 2021

JMSE

View full text Add to dashboard Cite

The evaluation of acoustic temporal rhythms in wide-ranging cetaceans can reveal patterns in animal spatial presence and the occurrence of periodical phenomena. Here, we aimed at assessing the temporal patterns of dolphin’s acoustic presence in a shallow-water area in the Sicily Strait (Mediterranean Sea). Whistles were collected continuously for 14 months from an acoustic monitoring station installed aboard of an elastic seamark. Over a total of 6955 h of recording, 14,048 signals were identified using both automatic and visual methods. Three parameters were analyzed: hourly presence (HP), used as a proxy of the presence of dolphins in the area; detection rate (DR), indicating the acoustic activity rate of dolphins measured per hour in the entire dataset; and detection rate in presence of dolphins (DRD), indicating the acoustic activity rate of dolphins considering only the hours when whistles were recorded. The highest values of both HP and DR were reached during the night, and the Autumn and Winter months, suggesting an increase in the dolphin’s occurrence and a possible moving away and towards the monitoring station potentially following prey. DRD, instead, showed an almost uniform distribution throughout the day implying that when the animals are close to the monitoring station, the acoustic activity does not show any pattern. However, possible changes in the communication exchange along the seasons were suggested. This study complements other work on this subject, improving the knowledge of dolphins’ acoustic activity in the area.

show abstract

Interactions between air-breathing marine megafauna and artisanal fisheries in Southern Iberian Atlantic waters: Results from an interview survey to fishers

et al. 2022

View full text Add to dashboard Cite

Long-term acoustic monitoring of bottlenose dolphins, Tursiops truncatus, in marine protected areas in the Spanish Mediterranean Sea

Cited by 13 publications

References 50 publications

Fine scale spatial variability in the influence of environmental cycles on the occurrence of dolphins at coastal sites

Fine scale spatial variability in the influence of environmental cycles on the occurrence of dolphins at coastal sites

Acoustic Presence of Dolphins through Whistles Detection in Mediterranean Shallow Waters

Interactions between air-breathing marine megafauna and artisanal fisheries in Southern Iberian Atlantic waters: Results from an interview survey to fishers

Contact Info

Product

Resources

About