Tonic immobility is frequently used in both wildlife research and aquarium husbandry to sedate shark species during restraint and limit injury to both the animal and personnel (Henningsen 1994 Holland et al. Tonic immobility can be induced by several stimuli, but external pressure and physical restraint are the most common (Bayard 1957 Jones 1986). Tonic immobility causes muscle hypertonicity in terrestrial vertebrates but relaxed muscle tone and a ‘limp’ posture develops in fish species (Thompson et al. It is characterized by a reversible catatonic motionless posture, immobility, and an unresponsiveness to noxious or injurious stimulation. Tonic immobility is an innate, reversible, coma-like stasis displayed by a large number of wildlife taxa (Gallup 1974 Hennig et al. When capture and restraint is undertaken on wildlife, tonic immobility is often used as a method of calming or sedating the animal. As such, there is a need for the exploration of other non-lethal methods of capture of shark species, which cause less impact to the stress and welfare of captured animals (Barnett et al. 2001 Skomal 2007 Mandelman and Skomal 2008). 2012), which can lead to potentially lethal physiological consequences (Hoffmayer and Parsons 2001 Manire et al. However, although both techniques are potentially less stressful than some other capture methods, they may still result in captured animals struggling dramatically and thrashing violently (Brooks et al. Longline and drumline capture are the most frequent methods used. In order to implant tags to collect biological and movement data on shark populations, capture of target species is usually required. The relatively recent development of methodologies, such as acoustic and satellite telemetry and time depth recorders, have increased our knowledge of migration, distribution and population dynamics in shark populations (Heithaus et al. As such, management of shark populations has emerged as an important conversation priority (Godin and Worm 2010).
Over the past half century there has been a dramatic increase in worldwide catches of shark species (Baum et al. Tonic immobility induction and other methods of non-lethal capture deserve continued investigation. Decreased duration of anthropogenic intervention, and minimal physical struggle associated with this capture and restraint method is expected to reduce physiological markers of distress. Divers were then able to collect tissue samples for genetic analysis, and in some cases, maintain the animals in a state of tonic immobility during transport up to the research vessel for additional data collection.
Zebra shark length manual#
Zebra sharks were caught by free diving, and on SCUBA, inducing a state of tonic immobility by quickly applying tight-fisted manual pressure to the caudal fin, instead of the dorso-ventral inversion method. Here, we present a novel, non-lethal capture method of zebra sharks, Stegostoma fasciatum, using tonic immobility, in the field. Tonic immobility is an innate, reversible, coma-like stasis displayed by a large number of taxa, including sharks, and has been used for brief restraint, but is rarely used during capture itself. Items that fall may not be able to be retrieved.When conducting biological investigations on shark species, capture and brief restraint procedures may be required in order to collect ecological, behavioral and physiological data. Guests are encouraged to secure all items before entering Shark Bridge. Newport Aquarium is not responsible for lost or dropped items. Children younger than 5 years old must be accompanied by a parent, guardian, or chaperone. Closed-toe shoes are recommended and shoes must be worn at all times. For the safety of all guests running, jumping, rough play, climbing, food and drinks, hard or soft casts or braces of any kind are strictly prohibited on Shark Bridge. No guest may be carried. Shark Bridge is an able-bodied experience. All guests must use the entrance due to the one-way direction of travel. All guests must walk themselves. Walkers will experience slight side-to-side motion and some uneven footing. Shark Bridge is an interactive family walk through experience. Since opening last year, it has been estimated that guests have crossed Shark Bridge more than ONE MILLION times! Do YOU dare to cross? Shark Bridge is an interactive family walk through experience.ĭon’t fear! If Shark Bridge isn’t for you, you are welcome to walk along the edge of the tank and you can still view all of the amazing animals swimming inside.Ĭrossing Shark Bridge is included with Newport Aquarium admission.
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