Illegal feeding increases risk of boat-strike and entanglement in Bottlenose Dolphins in Perth, Western Australia

Abstract

One reason for the legislative restrictions on feeding dolphins in many parts of the world is the putative increased risk of injury to dolphins conditioned to human interaction through food reinforcement. However, there are few empirical data to support this. Here, we present data for a population of Bottlenose Dolphins Tursiops sp. in Cockburn Sound, in the city of Perth, Western Australia, indicating higher incidence of boat strike injury and fishing line entanglement for dolphins conditioned to taking food from humans, compared to others in the population that were not conditioned. The data support prohibitions on feeding dolphins and rigorous enforcement of existing regulations.

Quantification of Interactions Between Common Bottlenose Dolphins (Tursiops truncatus) and a Commercial Shrimp Trawler near Savannah, Georgia

“…Gubbins (2002) hypothesized that provisioning was the most serious threat to the bottlenose dolphin population in Hilton Head Island, South Carolina, as it leads to behaviors and situations that make them vulnerable to injury or death. As bottlenose dolphins lose their wariness toward humans and are conditioned to approach boats, they become more likely to be struck by a boat or entangled in fishing gear (Donaldson et al, 2010). Several studies have noted injuries and deaths while observing bottlenose dolphins interacting with fisheries (Corkeron et al, 1990;Noke & Odell, 2002;Durden, 2005;Cunningham-Smith et al, 2006;Powell, 2009).…”

Perception of local inhabitants regarding the socioeconomic impact of tourism focused on provisioning wild dolphins in Novo Airao, Central Amazon, Brazil

“…The interactions through provisioning conducted in Novo Airão are likely to be harmful to botos and potentially dangerous to humans (Alves et al 2013). From an ethical perspective, the artificial feeding of wild dolphins causes avoidable and unnecessary harm (Donaldson et al 2010), especially in a region with high ecotouristic potential attractions (e.g., exhibits of traditional cuisine, songs, dances, religion, and economic history), while always respecting the limits and desires of the local actors.…”

“…Other problems include the alteration of natural behavior patterns and population; dependency and habituation; aggression; health/disease/ injury problems (Orams 2002); an increased risk of human-induced injury, such as boat strikes, entanglement (Donaldson et al 2010) and most likely ingestion of fishing gear; and deliberate harm. A large number of publications describing the risks associated with swimming with dolphins (for both humans and/or dolphins) also exist (e.g., Shane et al 1993, Santos 1997, Constantine 2001, Samuels and Bejder 2004.…”

The Negative Impacts of Whale-Watching

“…Another type of tourism involving marine mammals is "provisioning" or feeding wild cetaceans-which most famously occurs in Monkey Mia in Australia. There are many concerns about the impact of this activity on the target species [76][77][78][79][80] as well as the risk to humans [81,82]. However, for purposes of this paper, land-based and aerial whale watching and the impacts of wild cetacean feeding programs and swim-with-cetacean tourism are not discussed.…”