scholarly journals Visualizing habitat use and behavior of whale sharks using the open tag, applications for ecotourism regulation.

2013 ◽  
Author(s):  
Jacob J Levenson ◽  
Robert Cooper ◽  
Colin Ware ◽  
Jacqueline Sly ◽  
David Wise ◽  
...  
Keyword(s):  
Habitat Use ◽  
Open Source ◽  
High Speed ◽  
Sensor Data ◽  
Measurement Unit ◽  
Release Time ◽  
Whale Shark ◽  
Fine Scale ◽  
Whale Sharks ◽  
And Behavior

Background. The rapidly decreasing cost of components and growing open source electronics industry has enabled access to improved tools for monitoring the behavior of aquatic species on a fine scale never before achieved. We use the new Open Tag as a novel approach to visualizing feeding behavior of whale sharks. Methods. The Open Tag is a Arduino compatible open-source inertial measurement unit for recording high speed motion sensor data to a microSD memory card. A three dimensional gyroscope, accelerometer, and magnetometer allow for calculating pitch, yaw, and heading, while depth and temperature sample continuously. The rechargeable lithium battery allows for deployments up to 7 days sampling at 100Hz. The Open Tag is placed in a hydrodynamic syntactic foam float, with a band that stretches around the dorsal fin. A galvanic release incorporated into the tag allows for a release time to be programmed and a VHF tag (ATS) aids in recovery. Results. An Open Tag was successfully deployed on a whale shark for 101 hours in August of 2013 in Yucatan Mexico. Behaviors noted included frequent surface intervals, even during the night when previously believed whale sharks were normally in deeper waters. A maximum depth of 49 meters was observed, with dives to 25 meters recorded regularly. We were able to identify possible harassment at the surface and defecation events. Conclusion. The Open Tag fills a unique niche in whale shark studies as a useful tool to better understanding of fine scale habitat use and behavior. By incorporating these data into Trackplot with data on the position of ecotour vessels, we can visualize behavior and investigate potential erratic changes in depth, heading and lateral movement amplitude indicative of harassment

scholarly journals Visualizing habitat use and behavior of whale sharks using the open tag, applications for ecotourism regulation.

2013 ◽  
Author(s):  
Jacob J Levenson ◽  
Robert Cooper ◽  
Colin Ware ◽  
Jacqueline Sly ◽  
David Wise ◽  
...  
Keyword(s):  
Habitat Use ◽  
Open Source ◽  
High Speed ◽  
Sensor Data ◽  
Measurement Unit ◽  
Release Time ◽  
Whale Shark ◽  
Fine Scale ◽  
Whale Sharks ◽  
And Behavior

Background. The rapidly decreasing cost of components and growing open source electronics industry has enabled access to improved tools for monitoring the behavior of aquatic species on a fine scale never before achieved. We use the new Open Tag as a novel approach to visualizing feeding behavior of whale sharks. Methods. The Open Tag is a Arduino compatible open-source inertial measurement unit for recording high speed motion sensor data to a microSD memory card. A three dimensional gyroscope, accelerometer, and magnetometer allow for calculating pitch, yaw, and heading, while depth and temperature sample continuously. The rechargeable lithium battery allows for deployments up to 7 days sampling at 100Hz. The Open Tag is placed in a hydrodynamic syntactic foam float, with a band that stretches around the dorsal fin. A galvanic release incorporated into the tag allows for a release time to be programmed and a VHF tag (ATS) aids in recovery. Results. An Open Tag was successfully deployed on a whale shark for 101 hours in August of 2013 in Yucatan Mexico. Behaviors noted included frequent surface intervals, even during the night when previously believed whale sharks were normally in deeper waters. A maximum depth of 49 meters was observed, with dives to 25 meters recorded regularly. We were able to identify possible harassment at the surface and defecation events. Conclusion. The Open Tag fills a unique niche in whale shark studies as a useful tool to better understanding of fine scale habitat use and behavior. By incorporating these data into Trackplot with data on the position of ecotour vessels, we can visualize behavior and investigate potential erratic changes in depth, heading and lateral movement amplitude indicative of harassment

scholarly journals Seasonal habitat use of whale sharks in the northern Gulf of Mexico, USA 2003 - 2013

2013 ◽  
Author(s):  
Jennifer A McKinney ◽  
Eric R Hoffmayer ◽  
Jim S Franks ◽  
Jill M Hendon ◽  
William B Driggers
Keyword(s):  
Home Range ◽  
Gulf Of Mexico ◽  
Habitat Use ◽  
Whale Shark ◽  
Shelf Edge ◽  
Northern Gulf Of Mexico ◽  
Use Patterns ◽  
Core Habitat ◽  
Whale Sharks ◽  
Satellite Tagging

Background: Reports of whale sharks (Rhincodon typus) in the northern Gulf of Mexico (GOM) date back to the 1930s. In 2003, the Northern Gulf of Mexico Whale Shark Research Program was established and began making directed efforts to document the regional occurrence, seasonal distribution and habitat preferences of whale sharks. Methods: Whale shark sightings data (WSS: 1989 – present; n=644) and tagging geoposition data (TD: 2009-2012; n=450) were used in seasonal kernel density (KD) analyses to delineate home range (95%) and core habitat (50%) use areas in the northern GOM. Kernel density estimation of distribution is a statistically robust manner of handling data sources with differing sampling designs (anecdotal vs. directed). Habitat use patterns from the two datasets were used to identify critical use areas. Results: In the study area, whale shark home range was 276,000 km2 (WSS) to 369,000 km2 (TD) in size, with 52,000 km2 (WSS) to 62,000 km2 (TD) being core habitat. Whale shark habitat use varied seasonally, with the largest home range occurring during summer (WSS: 213,000 km2) and fall (TD: 221,000 km2). Tag data revealed more winter habitat (75,000 km2) than the sightings dataset (41,000 km2), which was shifted further offshore to slope waters. Significant use patterns occurred along the continental shelf-edge, encompassing shelf-edge banks south of Louisiana, and near the mouth of the Mississippi River. Conclusions: The combination of sightings data and satellite tagging data represents an effective methodology for assessing seasonality of occurrence, distribution, and habitat use of whale sharks. Shelf-edge bank habitats were most commonly used by whale sharks in the region. Satellite tagging data provided additional evidence of connectivity between multiple jurisdictions, which lends support for international management of the species.

scholarly journals Movements and habitat use of satellite-tagged whale sharks off western Madagascar

2018 ◽  
Author(s):  
Stella Diamant ◽  
Christoph A Rohner ◽  
Jeremy J Kiszka ◽  
Arthur Guillemain d’Echon ◽  
Tanguy Guillemain d’Echon ◽  
...  
Keyword(s):  
Habitat Use ◽  
Marine Protected Areas ◽  
Small Proportion ◽  
Kernel Density ◽  
Local Economy ◽  
Northwest Coast ◽  
Whale Shark ◽  
Rhincodon Typus ◽  
Whale Sharks ◽  
Main Activity

Whale sharks Rhincodon typus, the world’s largest fish, are routinely sighted off the northwest coast of Madagascar, particularly off the island of Nosy Be. Dedicated whale shark tourism has been developing in the area since 2011. During our first dedicated survey, from September-December 2016, we photo-identified 85 individual whale sharks, ranging from 3.5–8 m in total length (all juveniles). None had been previously identified from other known whale shark aggregations. We tagged eight sharks with tethered SPOT5 tags in October 2016, with tracking durations of 9–199 days. Kernel density plots showed that the main activity hotspot for tagged sharks was around the Nosy Be area. Three individuals were resighted back at Nosy Be in late 2017, after having lost their tags. A secondary hotspot was identified off Pointe d’Analalava, 180 km southeast of Nosy Be. Five sharks swam off the shelf into the northeastern Mozambique Channel, between Madagascar and Mayotte, and one of these continued to near the Comoros islands. Two sharks swam to southern Madagascar, with minimum track distances of 3414 km and 4275 km. The species is presently unprotected in Madagascar, although a small proportion of the high-use area we identified in this study is encompassed within two marine protected areas adjacent to Nosy Be. Whale sharks are globally endangered, and valuable to the local economy, so there is a clear rationale to identify and mitigate impacts on the sharks within the two hotspots identified here.

scholarly journals Changes in diving behaviour and habitat use of provisioned whale sharks: implications for management

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gonzalo Araujo ◽  
Jessica Labaja ◽  
Sally Snow ◽  
Charlie Huveneers ◽  
Alessandro Ponzo
Keyword(s):  
Endangered Species ◽  
Habitat Use ◽  
Metabolic Rate ◽  
Sustainable Tourism ◽  
Diving Behaviour ◽  
Whale Shark ◽  
Rhincodon Typus ◽  
The World ◽  
Whale Sharks ◽  
Temperature Depth

Abstract Whale shark (Rhincodon typus) tourism is increasingly popular at predictable aggregations around the world, but only a few use provisioning to ensure close interactions. Understanding the effects of provisioning on the behaviour of this endangered species is critical to manage this growing industry. We recorded the diving behaviour and habitat use of juvenile whale sharks (n = 4) for a mean of 49.5 provisioned and 33.8 non-provisioned days using temperature-depth-recorders. We found that time spent at the surface (< 2 m) between 6 am and 1 pm increased ~ sixfold, while timing of deep dives shifted from 4–10 am to 10 am–2 pm, i.e. near or at the end of the provisioning activities. The shift might be related to a need to thermoregulate following a prolonged period of time in warmer water. These changes could have fitness implications for individuals frequently visiting the provisioning site. Based on recorded amount of time spent in warm waters and published Q10 values for ectotherms, we estimate a 7.2 ± 3.7% (range 1.3–17.8%) higher metabolic rate when sharks frequent the provisioning site. The observed behavioural, habitat use, and potential fitness shifts should be considered when developing guidelines for sustainable tourism, particularly in light of new provisioning sites developing elsewhere.

scholarly journals Seasonal Occurrence, Horizontal Movements, and Habitat Use Patterns of Whale Sharks (Rhincodon typus) in the Gulf of Mexico

2021 ◽  
Vol 7 ◽  
Author(s):  
Eric R. Hoffmayer ◽  
Jennifer A. McKinney ◽  
James S. Franks ◽  
Jill M. Hendon ◽  
William B. Driggers ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Habitat Use ◽  
Continental Shelf ◽  
Site Fidelity ◽  
Seasonal Occurrence ◽  
Whale Shark ◽  
Shelf Edge ◽  
Rhincodon Typus ◽  
Aggregation Site ◽  
Whale Sharks

In the northern Gulf of Mexico (GOM), whale sharks (Rhincodon typus) form large aggregations at continental shelf-edge banks during summer; however, knowledge of movements once they leave aggregation sites is limited. Here we report on the seasonal occurrence of whale sharks in the northern GOM based on over 800 whale shark sightings from 1989 to 2016, as well as the movements of 42 whale sharks tagged with satellite-linked and popup satellite archival transmitting tags from 2008 to 2015. Sightings data were most numerous during summer and fall often with aggregations of individuals reported along the continental shelf break. Most sharks (66%) were tagged during this time at Ewing Bank, a known aggregation site off the coast of Louisiana. Whale shark track duration ranged from three to 366 days and all tagged individuals, which ranged from 4.5 to 12.0 m in total length, remained within the GOM. Sightings data revealed that whale sharks occurred primarily in continental shelf and shelf-edge waters (81%) whereas tag data revealed the sharks primarily inhabited continental slope and open ocean waters (91%) of the GOM. Much of their time spent in open ocean waters was associated with the edge of the Loop Current and associated mesoscale eddies. During cooler months, there was a net movement southward, corresponding with the time of reduced sighting reports. Several sharks migrated to the southwest GOM during fall and winter, suggesting this region could be important overwintering habitat and possibly represents another seasonal aggregation site. The three long-term tracked whale sharks exhibited interannual site fidelity, returning one year later to the vicinity where they were originally tagged. The increased habitat use of north central GOM waters by whale sharks as summer foraging grounds and potential interannual site fidelity to Ewing Bank demonstrate the importance of this region for this species.

scholarly journals Seasonal habitat use of whale sharks in the northern Gulf of Mexico, USA 2003 - 2013

2013 ◽  
Author(s):  
Jennifer A McKinney ◽  
Eric R Hoffmayer ◽  
Jim S Franks ◽  
Jill M Hendon ◽  
William B Driggers
Keyword(s):  
Home Range ◽  
Gulf Of Mexico ◽  
Habitat Use ◽  
Whale Shark ◽  
Shelf Edge ◽  
Northern Gulf Of Mexico ◽  
Use Patterns ◽  
Core Habitat ◽  
Whale Sharks ◽  
Satellite Tagging

Background: Reports of whale sharks (Rhincodon typus) in the northern Gulf of Mexico (GOM) date back to the 1930s. In 2003, the Northern Gulf of Mexico Whale Shark Research Program was established and began making directed efforts to document the regional occurrence, seasonal distribution and habitat preferences of whale sharks. Methods: Whale shark sightings data (WSS: 1989 – present; n=644) and tagging geoposition data (TD: 2009-2012; n=450) were used in seasonal kernel density (KD) analyses to delineate home range (95%) and core habitat (50%) use areas in the northern GOM. Kernel density estimation of distribution is a statistically robust manner of handling data sources with differing sampling designs (anecdotal vs. directed). Habitat use patterns from the two datasets were used to identify critical use areas. Results: In the study area, whale shark home range was 276,000 km2 (WSS) to 369,000 km2 (TD) in size, with 52,000 km2 (WSS) to 62,000 km2 (TD) being core habitat. Whale shark habitat use varied seasonally, with the largest home range occurring during summer (WSS: 213,000 km2) and fall (TD: 221,000 km2). Tag data revealed more winter habitat (75,000 km2) than the sightings dataset (41,000 km2), which was shifted further offshore to slope waters. Significant use patterns occurred along the continental shelf-edge, encompassing shelf-edge banks south of Louisiana, and near the mouth of the Mississippi River. Conclusions: The combination of sightings data and satellite tagging data represents an effective methodology for assessing seasonality of occurrence, distribution, and habitat use of whale sharks. Shelf-edge bank habitats were most commonly used by whale sharks in the region. Satellite tagging data provided additional evidence of connectivity between multiple jurisdictions, which lends support for international management of the species.

scholarly journals Movements and habitat use of satellite-tagged whale sharks off western Madagascar

2018 ◽  
Author(s):  
Stella Diamant ◽  
Christoph A Rohner ◽  
Jeremy J Kiszka ◽  
Arthur Guillemain d’Echon ◽  
Tanguy Guillemain d’Echon ◽  
...  
Keyword(s):  
Habitat Use ◽  
Marine Protected Areas ◽  
Small Proportion ◽  
Kernel Density ◽  
Local Economy ◽  
Northwest Coast ◽  
Whale Shark ◽  
Rhincodon Typus ◽  
Whale Sharks ◽  
Main Activity

Whale sharks Rhincodon typus, the world’s largest fish, are routinely sighted off the northwest coast of Madagascar, particularly off the island of Nosy Be. Dedicated whale shark tourism has been developing in the area since 2011. During our first dedicated survey, from September-December 2016, we photo-identified 85 individual whale sharks, ranging from 3.5–8 m in total length (all juveniles). None had been previously identified from other known whale shark aggregations. We tagged eight sharks with tethered SPOT5 tags in October 2016, with tracking durations of 9–199 days. Kernel density plots showed that the main activity hotspot for tagged sharks was around the Nosy Be area. Three individuals were resighted back at Nosy Be in late 2017, after having lost their tags. A secondary hotspot was identified off Pointe d’Analalava, 180 km southeast of Nosy Be. Five sharks swam off the shelf into the northeastern Mozambique Channel, between Madagascar and Mayotte, and one of these continued to near the Comoros islands. Two sharks swam to southern Madagascar, with minimum track distances of 3414 km and 4275 km. The species is presently unprotected in Madagascar, although a small proportion of the high-use area we identified in this study is encompassed within two marine protected areas adjacent to Nosy Be. Whale sharks are globally endangered, and valuable to the local economy, so there is a clear rationale to identify and mitigate impacts on the sharks within the two hotspots identified here.

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