This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A study published in the journal Oikos, titled "Forecasting the impact of food-provisioning and other stressors on a marine top-predator population," found that without protective management, the Indo-Pacific bottlenose dolphin population off Bunbury would fall from 350 to eight over 100 years. The first author of the international study, Dr.
Valeria Senigaglia, from QUT's School of Biology and Environmental Science, said it was well-established that wildlife tourism could affect animals' behavior and sometimes affect their reproduction and survival, but its impact at the population level was less understood. "While feeding wild dolphins is illegal in Australia, four locations have been granted permission from state regulators to provide limited food for tourism purposes," Senigaglia said. "Feeding dolphins has been correlated with high levels of begging behavior, e.g., approaching vessels for handouts, which leads to inappropriate food or injury, and the removal of bait from fishing gear that could lead to entanglement.
"While the practice of humans feeding wild dolphins has been shown to lower reproductive success and survival of their offspring, the impact of food provisioning can't be quantified in isolation. "This is because the dolphins face many other stressors from climate change, recreational watercraft, disease outbreaks and possible algal blooms, oil spills and habitat degradation." Senigaglia said the researchers used a decade-long systematic monitoring study of the Indo-Pacific bottlenose dolphin population in Bunbury and a population viability analysis model to simulate population dynamics over the next 100 years. "We compared scenarios containing fed and nonfed dolphins with additional scenarios including an outbreak of morbillivirus disease, human disturbances known to increase calf mortality, and a cumulative effects scenario containing morbillivirus outbreaks, additional human disturbance, and 'catastrophes' like harmful algal blooms and oil spills," she said.
"The fourth scenario we devised was based on management measures taken in Moray Firth, Scotland, which decreased calf mortality and doubled fertility of the local bottlenose dolphin population. "This scenario predicted an increase in population growth, assuming that similar results would arise in Bunbury by stopping feeding, establishing a wide protective area and further limiting industrial and recreational water activities. "While food provisioning is not the only reason for the projected decline under current conditions, and an outbreak of morbillivirus (a likely occurrence) would be much more detrimental, feeding wild dolphins accelerates the decline.
"Our results indicate that dolphin food provisioning increases the forecasted decline, doubling the probability of extinction over the next 100 years. Although differences in population trajectories with and without food provisioning were not immediately apparent within the first few years, they became evident after a decade. "Stopping this practice might increase dolphins' resilience and ability to withstand other, more severe, stressors." Valeria Senigaglia et al, Forecasting the impact of food‐provisioning and other stressors on a marine top‐predator population, Oikos (2026).
DOI: 10.1002/oik.12182 Provided by Queensland University of Technology BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries. Full profile → Master's in physics with research experience.
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