Abstract
The great hammerhead shark Sphyrna mokarran is an endangered species that is exposed to several sources of anthropogenic mortality, including beach nets. Although not a major contributor to S. mokarran mortality, beach nets are utilized in several locations to minimize the potential harmful interaction between sharks and beachgoers. To address this mortality, permanent magnets have been employed to determine if these materials can deter sharks away from netted areas. The present study examined the effects of barium-ferrite (BaFe12O19) permanent magnets on S. mokarran behavior under several environmental and biological conditions. In the bait experiment, feeding frequency significantly decreased and avoidance frequency significantly increased with the magnet treatment, with exposure quantity yielding an increase in feeding frequency, although this effect was not statistically significant. For the barrier experiment, entrance frequency significantly decreased and avoidance and pass-around frequencies significantly increased with the magnet treatment, with heterospecific density also being a significant pre - dictor of entrance frequency. The findings demonstrate how permanent magnets can modify S. mokarran behavior and how this behavior is modified based on situational context. Since several other sphyrnid species are caught in beach nets more frequently than S. mokarran (e.g. scalloped hammerheads S. lewini), the present results may serve as a model for these other sphyrnid species and illustrate the potential conservation implications of future magnetic deterrent barrier technologies.
| Original language | English |
|---|---|
| Pages (from-to) | 243-256 |
| Number of pages | 14 |
| Journal | Endangered Species Research |
| Volume | 26 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 1 2015 |
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Keywords
- Beach nets
- Elasmobranch mortality
- Great hammerhead shark
- Permanent magnets
- Sphyrna mokarran
ASJC Scopus subject areas
- Nature and Landscape Conservation
- Ecology
Cite this
Effects of barium-ferrite permanent magnets on great hammerhead shark Sphyrna mokarran behavior and implications for future conservation technologies. / O'Connell, Craig P.; Hyun, Saang Yoon; Gruber, Samuel H.; He, Pingguo.
In: Endangered Species Research, Vol. 26, No. 3, 01.01.2015, p. 243-256.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of barium-ferrite permanent magnets on great hammerhead shark Sphyrna mokarran behavior and implications for future conservation technologies
AU - O'Connell, Craig P.
AU - Hyun, Saang Yoon
AU - Gruber, Samuel H.
AU - He, Pingguo
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The great hammerhead shark Sphyrna mokarran is an endangered species that is exposed to several sources of anthropogenic mortality, including beach nets. Although not a major contributor to S. mokarran mortality, beach nets are utilized in several locations to minimize the potential harmful interaction between sharks and beachgoers. To address this mortality, permanent magnets have been employed to determine if these materials can deter sharks away from netted areas. The present study examined the effects of barium-ferrite (BaFe12O19) permanent magnets on S. mokarran behavior under several environmental and biological conditions. In the bait experiment, feeding frequency significantly decreased and avoidance frequency significantly increased with the magnet treatment, with exposure quantity yielding an increase in feeding frequency, although this effect was not statistically significant. For the barrier experiment, entrance frequency significantly decreased and avoidance and pass-around frequencies significantly increased with the magnet treatment, with heterospecific density also being a significant pre - dictor of entrance frequency. The findings demonstrate how permanent magnets can modify S. mokarran behavior and how this behavior is modified based on situational context. Since several other sphyrnid species are caught in beach nets more frequently than S. mokarran (e.g. scalloped hammerheads S. lewini), the present results may serve as a model for these other sphyrnid species and illustrate the potential conservation implications of future magnetic deterrent barrier technologies.
AB - The great hammerhead shark Sphyrna mokarran is an endangered species that is exposed to several sources of anthropogenic mortality, including beach nets. Although not a major contributor to S. mokarran mortality, beach nets are utilized in several locations to minimize the potential harmful interaction between sharks and beachgoers. To address this mortality, permanent magnets have been employed to determine if these materials can deter sharks away from netted areas. The present study examined the effects of barium-ferrite (BaFe12O19) permanent magnets on S. mokarran behavior under several environmental and biological conditions. In the bait experiment, feeding frequency significantly decreased and avoidance frequency significantly increased with the magnet treatment, with exposure quantity yielding an increase in feeding frequency, although this effect was not statistically significant. For the barrier experiment, entrance frequency significantly decreased and avoidance and pass-around frequencies significantly increased with the magnet treatment, with heterospecific density also being a significant pre - dictor of entrance frequency. The findings demonstrate how permanent magnets can modify S. mokarran behavior and how this behavior is modified based on situational context. Since several other sphyrnid species are caught in beach nets more frequently than S. mokarran (e.g. scalloped hammerheads S. lewini), the present results may serve as a model for these other sphyrnid species and illustrate the potential conservation implications of future magnetic deterrent barrier technologies.
KW - Beach nets
KW - Elasmobranch mortality
KW - Great hammerhead shark
KW - Permanent magnets
KW - Sphyrna mokarran
UR - http://www.scopus.com/inward/record.url?scp=84921657490&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84921657490&partnerID=8YFLogxK
U2 - 10.3354/esr00629
DO - 10.3354/esr00629
M3 - Article
AN - SCOPUS:84921657490
VL - 26
SP - 243
EP - 256
JO - Endangered Species Research
JF - Endangered Species Research
SN - 1863-5407
IS - 3
ER -