Freediving with the Dolphins of Mikurajima (by Michelle)

Tokyo is a popular tourist destination, but most people are not aware that just a ferry ride away from the city, there exists a group of 11 charming little islands. In early June, a friend and I went to the island of Mikurajima, about 200 km from Tokyo, to freedive with their population of friendly Indo-Pacific Bottlenose dolphins. 

One of the relatively lesser inhabited (by people) islands, there are only about 320 people residing on the island. When we arrive on the island, we see a possible reason for this. The road up to the village is steep and winding, with little flat land in the surroundings to build on. A concrete wall has been built on the steep slopes in front of the port to protect it from landslides. But despite the steep gradients nature has managed to thrive and the rest of the island is covered in lush green forest, a stark contrast to the grey buildings and bright lights of Tokyo. 

The port at Mikurajima


Our hosts, Tama and Yu, pick us up at the port when we arrive off the overnight ferry, in the early morning. They are two of about 20 natures guides living on the island, hosting visitors at Tama's guest house and taking them on dolphin swims and hikes through the national park. The weather is gloomy and the sea a little rough, but we head out to find some dolphins anyway after a quick breakfast.

Together with 4 others who arrived the day before, we go out on a small boat which our captain skilfully drives through the swell. They tell us that their experience with the dolphins in the previous 2 swims was great and the dolphins were very interactive. It's what we want to hear!

The captain spots several fins break the water's surface a hundred meters away, but they are too close to shore and with the big swell, it isn't safe to bring the boat closer. We head further down the coastline to look for another group, passing Shirataki waterfall, which runs from 80 metres high up the slope into the sea, and manoeuvring between big, jutting out rocks as waves smash into them.

We meet another pod a few minutes later and jump into the water, but they don't seem interested in us and just swim by. The water is 24 degrees celsius and a little dark because of the overcast sky and waves. Perhaps the dolphins' moods are affected by the weather, like how it affects humans. We follow them down the coast for a while more then head back to land.

After a warm shower, we sip hot tea as Tama whips up delicious “omu rice” for us, which we try to savour and not wolf down to fill our stomachs; we are hungry from the morning's dive! The other guests are leaving, so we walk down to the port to see them off. By now, it has stopped raining and the sun is out, and the sea sparkles in the distance around the island. The weather has cleared up nicely, just in time for our hike into the forest.


Tama drives us up into the mountains where a layer of mist clings to the sides of the mountain. We pass the local school, where about 100 kids go from kindergarten to junior high, until they have to head to mainland for high school. On the winding road up to our destination, we stop at a small shrine. Tama explains that people stop her to pray for safe passage up and down the mountain (landslides do happen), and place leaves just in front of the shrine, one for each person, as an indication of how many people have gone up. There are 3 leaves there now, for another guide and 2 of his guests that passed us on the way up. We each pick a leaf from the surrounding vegetation and place it under a pebble, then perform the customary prayer by bowing twice, clapping our hands twice, saying a prayer and bowing once again.

The view as we drive up is breath taking. We pass a small waterfall, and Tama explains that all the water in the village comes from the mountain, clean enough to drink straight from the tap. She points to a small house-like structure further downhill, which she tells us is part of the hydroelectricity power plant. Dense, green forest extends skyward and towards the sea from the sides of the road. Having come from Singapore then Tokyo, it feels like a luxury to be surrounded by so much greenery; a sad realisation.


We stop at the entrance of the trail into the forest and Yu heads off to park the van while we follow Tama inside. 5 minutes into the walk, she stops by a big, slanted tree with low hanging branches. Around the base of the tree, there are many little caves dug into the ground. She tells us that these are the homes of the omizunagidori (Calonectris leucomelas, or streaked shearwater), a type of seabird that we saw while we were out at sea. The birds spend the entire day out at sea in a large flock, hunting fish, and return to their dens at night. The funny thing is that they are not very good at taking off and landing from the ground, so when they return, they simply crash-land into the vegetation, then waddle to their dens. The next morning, they find a big tree to climb and launch themselves from its branches to take to the air, sometimes requiring multiple attempts. We smile to ourselves while imagining the sight. Sadly, the omizunagidori population on Mikurajima is dwindling because of the stray cat population. Cats were introduced to the island to hunt rats, but found the ground-nesting, sleeping birds easier to catch. The birds also rear their chicks on the ground, making them easy pickings for the nocturnal hunters. This story has unfolded in many other places, where introduced cats, either stray or free roaming pets, prey on the local small mammals or birds, endangering their survival. Humans alter the ecosystem in more ways than they realise...


As we walked on, Tama told us how she came to live on the island. Originally from Saitama, she grew up wanting to be a nature guide, but followed societal norms and ended up working for the government. She was relatively satisfied with seeking nature in her spare time and on holidays, until she met a scuba diving instructor who seemed like he was thoroughly enjoying life, and she realised she wanted that too. At that point, 15 years ago, she decided to pursue her childhood dream of becoming a nature guide and moved to Mikurajima. Her decision paid off, and last year she managed to buy the house which she had been renting and operating her business from for the past few years (it is difficult for “outsiders” to buy property on the island). Over winter this year, she has plans to renovate the guest house to welcome more guests in the new year.

After about half an hour of walking and taking in the forest sights and sounds, we arrive at our destination. It is a large tree called “Oojii”, separated from the trail by a wooden fence. This tree is one of more than 500 “giant” trees, with a trunk circumference of 13.8m and said to be more than 100 years old. We looked up at its thick trunk and broad, spreading branches, wondering what life on the island was like a hundred years ago.

Back at the guesthouse, dinner was a delicious affair, with many of the ingredients sourced from the island itself. As we ate, the perfectly clear sky turned a brilliant pink at sunset. We hoped the good weather would last till the next morning for the dolphin swim.

At 7am the next day, we were up anxiously checking the weather. It was a little cloudy, but with hardly any wind. We ate a quick breakfast and made our way down to the boat in anticipation. As we left the marina, we counted 4 other boats that were heading out at the same time. Not far from the marine, the first boat dropped its guests in the water with the first pod sighted. Our captain drove us a little further down in order not to crowd the dolphins, but after a 5 minute of so wait it seemed like the dolphins were not heading our way, so we moved down the coast to find another pod.

A few hundred metres away, another pod broke the surface. We were in luck! Quickly, we put on fins on as our captain manoeuvred the boat to drop us right in front of the dolphins. On the captain's call, we slipped into the water, trying to minimise splash. We saw the dolphins approaching from the distance, then suddenly we were surrounded. Most of them just swam past, some glanced at us curiously, while a few swam around us in a playful circle. A few dolphins swam slowly towards me then changed direction abruptly, as if they were short sighted. There were quite a few baby dolphins swimming in a protective “sandwich” between their mothers and “aunts”, with white stripes prominent on the sides of their bodies. Some dolphins leapt out of the water as they went past, catching a breath while showing off their grace and athleticism. Most of the dolphins had tooth marks and scars on their bodies, some with round puncture wounds. Gradually the pod moved past, and we got back on the boat to move down the coast again. We did this several times during the session; drop in with a pod and swim with them till we could no longer keep up with them in the current, get back on the boat and either drop in on the same pod further down or with another pod. The boat captains were careful not to drop each group of people too close to each other in order not to overwhelm the dolphins and to give us the best experience. After 2 hours and multiple drop ins, we headed back to the marina, happy with the morning's proceedings. 


On reaching the guesthouse, we warmed up with a hot shower then watched the footage that Tama recorded, as she pointed out dolphin facts along the way. She explained that the toothmarks and puncture wounds on the dolphins were from fights amongst themselves, or bites from cookie cutter sharks. The white stripes on the young dolphins were from being curled up in their mothers wombs, and they disappear as they get older. One video showed a dolphin named “Smile”, so-called because the corner of her mouth is turned upwards more than in other dolphins, as if she were perpetually smiling. Tama mentioned that Smile is one of the more playful dolphins and dolphin would always approach people and swim around if she was there. Most of the dolphins in these pods are female, with the exception of the younger ones. Male dolphins leave the pod after a number of years with their mother, while female dolphins stay with the pod to raise their young or help other dolphins raise their young. The dolphin population of Mikurajima numbers about 120 individuals. Judging from the number of baby dolphins we saw, the dolphins seem to be doing well!

Soon after, it was time for us to leave Mikurajima. We wished Tama and Yu all the best, then boarded the ferry back to Tokyo and on to our next adventure, meeting and diving with the Ama divers of Shima City. Stay tuned for the next blog post to read all about it!