[MARMAM] New paper: Long-term success of dolphin rescues

Katie McHugh kmchugh at mote.org
Tue Feb 16 08:05:33 PST 2021

My co-authors and I would like to share our recent paper evaluating the 
long-term success and potential conservation value of dolphin rescues, 
published as part of a Frontiers in Marine Science research topic on 
Small Cetacean Conservation:

McHugh, K. A., A. A. Barleycorn, J. B. Allen, K. Bassos-Hull, G. 
Lovewell, D. Boyd, A. Panike, C. Cush, D. Fauquier, B. Mase, R. C. Lacy, 
M. R. Greenfield, D. I. Rubenstein, A. Weaver, A. Stone, L. Oliver, K. 
Morse and R. S. Wells. 2021. Staying Alive: Long-term success of 
bottlenose dolphin interventions in southwest Florida. Frontiers in 
Marine Science 7: 624729.


Small cetaceans face persistent threats from fisheries interactions, 
making effective mitigation a priority for conservation. In southwest 
Florida, interactions come primarily from small-scale recreational hook 
and line and trap/pot fisheries, with regional stranding network 
partners working with federal agency managers to assess and intervene as 
possible in cases of live animal entanglement. Evaluating success of 
intervention cases is difficult due to financial and logistical 
constraints which may preclude detailed follow-up monitoring. Survival 
over the initial 6 weeks post-release has been used as a marker of 
short-term success for small-cetacean rescue and/or rehabilitation 
cases. Early intervention prior to stranding, especially via remote 
disentanglement or rescue and immediate re-release onsite, can save 
entangled free-ranging dolphins facing life-threatening anthropogenic 
injuries. However, given the costs associated with interventions, it is 
important to understand the benefits of these endeavors not only to save 
individuals, but also to establish if and how saved individuals 
contribute to social functioning, survival and reproduction within 
small, resident populations facing multiple concurrent threats. Here we 
provide evidence from 27 well-documented common bottlenose dolphin 
(/Tursiops truncatus/) intervention cases during 1985–2019 where 
follow-up monitoring over multiple years sheds light on the longer-term 
success of these efforts and potential benefits to local populations. 
Nearly all rescued individuals (92%) survived longer than 6 weeks 
post-release (mean minimum survival period = 5 years, range 0–35 years), 
with 13 still observed frequently within their prior resident 
communities, in good physical health, and engaging in normal behavior. 
Survivorship rates did not decline substantially between 1 and 5 years 
post-rescue, meaning survival beyond 1 year may be a useful benchmark of 
long-term success. Rescued females that reached reproductive maturity 
(/n/ = 4) have produced 12 post-intervention offspring to date. Social 
network analysis and demographic modeling applied to cases from the 
long-term resident community in Sarasota Bay confirmed that animals 
maintain social connections post-intervention and that interventions 
result in higher population growth rates. While not every intervention 
succeeds, this study demonstrates the conservation value of 
pre-stranding interventions which allow individuals that otherwise would 
be lost to remain viable and productive members of local populations 
when prevention of anthropogenic injury is not possible.

The paper is open access and freely available at: 

Feel free to contact me at kmchugh at mote.org with any questions about the 
study or to request a PDF copy.

Katie McHugh

Katherine McHugh
Staff Scientist
Chicago Zoological Society's
Sarasota Dolphin Research Program
c/o Mote Marine Laboratory
1600 Ken Thompson Pkwy
Sarasota, FL 34236

(941) 388-4441 x450 office
(650) 400-2776 cell

kmchugh at mote.org

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