Marine wildlife tourism can be seen as a win-win industry, which promotes conservation by putting a monetary value on marine mammals other than from fishing and consumption, while enabling operators to make a living in places where there may be limited economic opportunities. But research highlights the need for such tourism to follow codes of practice to avoid harmful levels of disturbance caused by increasing numbers of tourism boats. We have reported studies on whale watching, sharks, and swimming with dolphins. Another charismatic marine species which is of value to tourism is manta rays, and now a study by Murdoch University in Australia has called for tighter control of the manta ray tourism industry at Ningaloo reef.
Both species of manta ray, Manta birostris and Manta alfredi, are classified as ‘vulnerable’ on the IUCN Red List of Threatened Species. Manta gill rakers (plates used to strain plankton) are made of cartilage and are used as a purported health tonic in China, making the animals a target for fishing. As an alternative use, manta ray-focused tourism operations exist in 25 different countries across the world; the direct annual revenue from these operations is estimated in a study in PLoS ONE at over US$73 million, and total economic impact at US$140 million. But increased popularity of marine tourism at some sites can lead to disturbance of the animals. Honours student Stephanie Venables and researchers from the Murdoch University Coral Bay Research Station developed a case study of manta ray tourism management at one of the most visited sites in Australia.
Five dedicated manta ray tour vessels now operate daily out of Coral Bay, which can collectively transport up to 139 passengers to interact with the animals each day. While there is a code of conduct which gives a maximum number of passengers on boats, limits on number of people interacting with individual manta rays, and distances to be kept from the animals, compliance is not mandatory, and commercial operators are not required to possess a specific manta ray interaction licence.
“This code of conduct was developed around ten years ago after operators expressed concerns regarding the nature of manta ray interactions; specifically the potential for disturbance at reef cleaning stations and animals engaged in courtship activities,” says lead author Stephanie Venables.
“Incidences of seemingly aggressive behaviour of manta rays towards swimmers, such as fin slapping or ramming, were also a cause for concern at the time.”
Murdoch University conducted a preliminary assessment of the impact of tourism on manta ray behaviour. Nearly 100 interactions were observed by researchers over a four month period. Short-term behavioural responses were identified during a third of tourism interactions. Manta rays exhibited responses such as changes in swimming speed and direction, ceasing feeding or leaving the area of a cleaning station. The researchers identified a number of factors that influenced how manta rays responded during interactions. These included the behavioural state and maturity of the manta ray, the amount of splashing and the way the swimmers approached the animals.
Ms Venables said: “Although none of these responses seem particularly catastrophic to the animals, these seemingly insignificant disturbances can build up over time and have long-term impacts.”
As a response to these concerns, the researchers have recommended that precautions are taken to proactively protect the animals. The precautionary principle supports the implementation of precautionary strategies to protect species and their environment from harm, even when the extent of the harm is yet to be confirmed. An increase in the level of industry management is recommended, including the implementation of a licensing system and adherence of all operators to a mandatory code of conduct during manta ray interactions.
Considering the well designed and precautionary-driven management program of the Ningaloo whale shark tourism industry operating within the same marine park, a management program with the same underlying principles and objectives is deemed to be an ideal framework to build a comprehensive management plan for the manta ray interaction industry. The authors suggest that the introduction of a well designed management program for the Coral Bay manta ray interaction industry could potentially provide a model that can be adapted and implemented in other manta ray tourism locations worldwide.
S. Venables, F. McGregor, L. Brain and M. van Keulen. Manta ray tourism management, precautionary strategies for a growing industry: a case study from the Ningaloo Marine Park, Western Australia, Pacific Conservation Biology (2016). DOI: 10.1071/PC16003
This is article was first published by CABI. Read the original article here: Regulation of manta ray tourism urged