Banned toxins passed from mother to young in European dolphins

Dolphins in the northern Adriatic contain high levels of PCBs – highly toxic chemicals banned in the 1970s and 1980s – and are passing the pollutant to their young, according to new research led by a marine scientist at the University of St Andrews.

An international team of researchers evaluated PCB and other organochlorine contaminants in bottlenose dolphins (Tursiops truncatus) living in the Gulf of Trieste (northern Adriatic Sea), the northernmost part of the Mediterranean Sea and one of the most human-impacted areas in the Mediterranean.

They found that, overall, 87.5% of dolphins had PCB concentrations above the toxicity threshold for the onset of physiological effects in marine mammals, while 65.6% had concentrations above the highest threshold published for marine mammals based on reproductive impairment in seals. Such high contaminant levels are of concern, particularly in combination with other threats to dolphins, including bycatch in fisheries, disturbance by boat traffic, and prey depletion.

The research, published in the journal Science of the Total Environment, involved Morigenos – Slovenian Marine Mammal Society (Slovenia), the Sea Mammal Research Unit at the University of St Andrews (UK), the Zoological Society of London’s Institute of Zoology (UK), the Centre for Environment, Fisheries and Aquaculture Science (CEFAS, UK) and the Institute of Marine Sciences of the Italian National Research Council (Italy).

Tilen Genov, lead author of the study and a PhD student at the University of St Andrews, said: “We have been studying these dolphins for over 16 years, so we know most of them well. Through long-term re-sighting histories of identified individuals, we were able to link PCB levels in individual dolphins to parameters such as sex, reproductive output and social group membership.

“The research showed that males have significantly higher pollutant concentrations than females. This is because females offload a substantial amount of their toxicological burden to their young through gestation and lactation.

“That is also why females that have not yet had calves had significantly higher concentrations than those that had previously produced at least one calf. Such results are expected based on our knowledge of mammal physiology, but it is not very common to demonstrate this phenomenon in wild whales and dolphins.”

Dr Paul Jepson, co-author of the study and specialist wildlife veterinarian at the Zoological Society of London’s Institute of Zoology, said: “This is another study showing high or very high levels of a very toxic and persistent pollutant – PCBs – in European dolphins. PCBs have the ability to cause diseases like cancer and can also suppress reproduction.”



How to avoid misunderstandings during interactive programs

In my extended years as a trainer I had the opportunity to train dolphins from scratch for shows and swimming programs many times. We trainers are very curious and we always enjoy to visit new facilities and see other animals and trainers working.

Over the years, during visits to facilities and observing others on-line, the one thing common to all of them, is the interaction between the trainers, customers and the animals. The experience for all should be pleasurable and if any person or animal is struggling during the experience, their enjoyment will suffer. I believe my experience and advice can help avoid any such struggle and help make the interaction really enjoyable for trainers, customers and animals alike. Hopefully my help will make it easier, especially for young trainers, to develop their skills, perform their tasks easier and create a positive environment for all.

Handling people in the water can be difficult in itself add to this, handling the animals’ behaviour at the same time and it can be very challenging. Furthermore, in seminatural environments, where sea currents are a factor, the weather can also add to the difficulty of that challenge.

Here is my advice to help with the challenge of handling both animals and customers in the water.

How to avoid confusion and accidents during swimming programs

Sometimes the dolphins, being animals, want to swim away and play with other dolphins, they are not totally under your control, swimming in-between the customers and generally not behaving in the best way. In that situation the trainer is struggling to ask the animal for a behaviuor or juggling with two animals and interacting with the people at the same time. The trick is, as a trainer you should be patient and actually take advantage of their playful nature and enjoy it together. If you are open minded, here are some techniques and tips you can use.

If your dolphins are chasing after each other, the best thing is to bring the people in the water, as close as possible to the platform or to an area where the water is shallow. Here the animal has less opportunity to manoeuvre, so stay there until the animals are ready to go on with the interaction.

If you are working with two dolphins and one of them is giving you trouble, ask the animal giving trouble, to go under your station as many times as possible, to create a break in their unwanted behaviour. When that animal least expects it, send them to do an interactive behaviour such as kiss or petting.

If the situation is too difficult, then ask another trainer, or use one of your assistants to help in the water, while you are correcting your animal’s behaviour. Having an assistant in the water during your program is actually more professional, you will get a much more positive outcome from the customers in the water. With staff in the water, people make better connections and interact more confidently, whilst also having much more fun. This will make the peoples experience, more exciting and unforgettable. If you have implemented, amongst the trainers, a set of signals to communicate in case of emergencies, then this will make it even easier. In addition, the trainer is more concentrated on the animal and has much more control.

Avoid problems when moving people around

Trainers are responsible for the program, they must keep their eyes wide open, observing closely at all times, whilst doing program. The area of interaction should be clear and enjoyable, for the animal, the people and the trainer. Trainers must keep their animals focused during an interactive program. Finally, it is important to remark and make clear, that the whole area in front of the platform is only for the animal to manoeuvre within, where they receive their reinforcement.

Avoid accidents by continuously scanning the environment during a program and by keeping the right distance.

Must Dolphinarium comply with international measurement rules, whether they are artificial or seminatural, trainers should be able to perform the programs in comfort. When starting a program, the people should be kept away from the front of platform, put them where you can see everyone’s movement, including the animals when they interact. After the introductions between the animals, the people and the trainer, place the people on the left side of the platform and one by one or two if you prefer send them forward to do the behaviour with the animal. When the behaviour has finished, send them to the right side of the platform. This means those who haven’t performed the behaviour are on the left of the platform and those who has done it are on the right.

For behaviours like petting or kissing, trainers should make sure they take the first people from the left and position the people in front of platform at least 4 metres away from the platform. When they have finished tell the people to go to wait on the right-hand side. For behaviours where the people should come closer to the dolphin, such as a kiss, trainers should keep the people at least one metre away from the animal and the best way of doing this is for the trainer to target or handle the animal very closely. Dolphins measure from six to twelve feet in length and their movements are very quick, so they need enough space to move around. They could hit somebody without even realising. Trainers must constantly monitor the distance between the animal and the people in the water, to avoid accidents, this is very important. Never forget, to keep a clear the space in front of the platform, this space is only for the animals.

Keep the animal engaged

Trainers should be able to know and understand the behaviour of the animal they are working with. Observe the animals body language, when they are about to misbehave, there is always a precursor, they usually give the trainer a look…like saying…watch what I am going to do next… The trainer’s job is to have the vision and to be able to predict their next unwanted behaviour, which is usually avoidable, if a trainer knows their animal and are focused. Their cheeky look to the trainer, will allow the trainer to anticipate their next move. When you see the first sign act on it. Change the scenario, in other words ask the dolphin for a behaviour that requires their concentration or move around with your animal or give the animal secondary reinforcement, anything that distracts them from what you preserved to be their next unwanted behaviour.

All situations have solutions

If your animal is not interested in a particular interaction, work with another animal, if available. If there are other programs around you can distribute your people amongst the other group, so they are distracted from the current situation.