Limit, cease or prohibit feeding of marine and freshwater mammals by tourists

Overall effectiveness category Likely to be beneficial
Number of studies: 1
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How is the evidence assessed?

Effectiveness

60%
Certainty

40%
Harms

0%

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Background information and definitions

The feeding of wild marine and freshwater mammals at tourist destinations can have negative impacts on mammal behaviour and population dynamics (Mann & Kemps 2003). This intervention involves limiting, ceasing or prohibiting the feeding of marine and freshwater mammals by tourists to reduce these effects. Enforcement may also be required to prevent illegal feeding (Powell et al. 2018).

Mann J. & Kemps C. (2003) The effects of provisioning on maternal care in wild bottlenose dolphins, Shark Bay, Australia. Pages 292–305 in: Marine mammals: fisheries, tourism and management issues. CSIRO Publishing, Collingwood.

Powell J.R., Machernis A.F., Engleby L.K., Farmer N.A. & Spradlin T.R. (2018) Sixteen years later: an updated evaluation of the impacts of chronic human interactions with bottlenose dolphins (Tursiops truncatus truncatus) at Panama City, Florida, USA. Journal of Cetacean Research and Management, 19, 79–93.

Study locations

Key messages

One study evaluated the effects of setting limits on feeding of marine mammals by tourists. The study was in Shark Bay (Australia).

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (1 STUDY)

Survival (1 study): One controlled, before-and-after study in Shark Bay found that after setting limits on feeding of bottlenose dolphins by tourists, the survival of calves born to females being fed increased and was similar to calves of non-fed mothers.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A controlled, before-and-after study in 1988–2011 at a marine reserve in Shark Bay, Western Australia (Foroughirad & Mann 2013) found that after setting limits on feeding of bottlenose dolphins Tursiops spp. by tourists, the survival of calves born to females being fed increased and was similar to calves of non-fed females, but calf behaviour differed to those of non-fed females. The survival rate of calves born to females being fed was higher after feeding limits were set (87%) than before (23%) and did not differ significantly to calves of non-fed females (62%). However, calves of females fed limited amounts spent less time in close contact with their mothers (average 33% of their time) and more time foraging (22%) than calves of non-fed females (with mother: 39%; foraging: 16%). In 1988–2011, dolphins were hand-fed fish by tourists in knee-deep water along 90 m of beach. In 1988–1993, dolphins were fed up to 120 kg of fish/month. In 1994–2011, feeding was limited to 2 kg of fish/day during a maximum of three sessions between 07:30 h and 13:00 h. Dolphins (seven fed females with 19–22 calves, 53 non-fed females with 82 calves) were observed during feeding sessions (total 308 h) and offshore (total 2,181 h) in 1988–2011 before and after feeding was limited (number of observations before and after not reported).
Study and other actions tested
Referenced paper
Foroughirad V. & Mann J. (2013) Long-term impacts of fish provisioning on the behavior and survival of wild bottlenose dolphins. Biological Conservation, 160, 242-249.

Please cite as:

Berthinussen, A., Smith, R.K. and Sutherland, W.J. (2021) Marine and Freshwater Mammal Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

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This Action forms part of the Action Synopsis:

Marine and Freshwater Mammal Conservation

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