Swimming with Wild Dolphins in Kaikoura, New Zealand

Many of my most adventurous travel stories come from my time living in New Zealand.

In November 2018, I decided to live life to the fullest and say yes to all of the adventures that came my way in the country. This travel story is one of my favorite adventures: swimming with wild dolphins in Kaikoura.

I woke at 4 a.m. to a pitch-black hostel room, my eight roommates all still sound asleep at the early hour. I snuck out on tiptoes to change, crammed a cheese roll in my mouth, and dragged the suitcase holding a year of my life to the Kaikoura dolphin-watching tour office. With just a few hours of sleep in my system and more adrenaline(腺上肾素) than I had jumping out of a plane, I tugged on my insulated wetsuit in a blur.

The moment we dove off the water, I was shocked awake. No amount of coffee, tea, or sugar has ever given me such an intense wake-up. It turns out, the ocean is freezing at 5 a.m., before the sun has risen and in early-spring.

Don’t be scared off by the temperature, though, because 5 a.m. is when the dolphins are most playful!

For five seconds, I struggled to breathe through the cold. Then, the wetsuit flooded with water and I was warm.

A moment later, I was face to face with a wild dusky dolphin, one of the smallest species of dolphin in the world! Swimming with it, the dolphin twirled at the surface of the water while it spun in spirals beneath me.

I hummed strange Dory-esque whale noises to draw the attention of more members of the pod, including a tiny baby dolphin no bigger than my calf. He seemed most interested in the strange bug-eyed thing that kept getting tangled in her own flippers.

The sun rose, warming my back as I continued to flounder amongst the most elegant animals in the ocean. It was the most beautiful sight, watching as the dark blue of the ocean turned a sunny turquoise, brightening our swimming companions for the first few hours of dawn.

The practice of swimming with wild dolphins is banned in the North Island, where the species of Hector’s dolphins are in decline. But in Kaikoura, the practice is thriving and actually helping to restore the dolphin populations.

Baleen whales (须鲸) play a vital role in marine ecosystems. To communicate across vast distances and find each other, baleen whales depend mainly on the production of sounds that travels far in dark oceans. However, since whale songs were first discovered more than 50 years ago, it remained unknown how baleen whales produce their complex sounds — until now.

A new study led by voice scientist Coen Elemans reported that baleen whales evolved unique structures in their throat that enable their low-frequency sounds, but also limit their communication range.

To understand how muscle activity could change the calls, the researchers built a model of the entire whale throat. As a result, the researchers found baleen whales have a U-shaped tissue in their throat that allows them to breathe in huge amounts of air. They also have a unique fatty cushion (垫子)that isn’t found in other animals. When the whales push air from their lungs past the fatty cushion, it starts to produce very low-frequency underwater sounds. What’s more, the throat evolution of baleen whales lets them sing underwater without the risk of choking and drowning.

However, the researchers found while baleen whales are able to make a wide range of different sounds, they can’t produce sounds louder than noise from shipping lanes (航道), drilling activity and so on, which limits their communication range. Since baleen whales can’t sing loud enough to gloss over the noise from ships, they can’t hear each other properly, which means some can’t mate. Being unable to find a mate would in turn threaten their future population numbers.

“Regrettably, the frequency range and maximum communication depth of 100 meters we predict, overlaps completely with the dominant frequency range and depth of human-made noise caused by shipping traffic. Now we show despite baleen whales’ amazing physiology, they can’t escape the noise humans make in the oceans. We need strict regulations for such noise, because these whales are dependent on sound for communication,” Elemans said.

Among the many ecological disasters that terrify us today, one that only a handful of people have considered as sufficiently terrifying is the loss of the bats in our church tower. According to “The Darkness Manifesto” (Scribner), by the Swedish ecologist Johan Eklf, most churches in southwest Sweden had bat colonies back in the nineteen-eighties, and now most of them don’t.

Light pollution, his research suggests, has been a major reason: “District after district has installed modern floodlights to show the architecture it’s proud of, all the while the animals-who have for centuries found safety in the darkness of the church towers and who have for 70 million years made the night their home-are slowly but surely vanishing from these places.”

The difference between light and dark is, in a way, arbitrary: what counts as light and what as darkness depends on what wavelengths we can make out. But the nocturnal (夜间活动的) world gives rise to creatures, equipped with large-pupilled and infrared-sensitive eyes, that see what we cannot and that, under cover of darkness, act as we can only imagine.

We learn, for instance, of the ghost moths, a species in which the adult males appear in fields in twilight, floating weirdly as they signal to the females-only to mate once and then fall to the ground dead. Though Eklf tells us that these creatures are threatened by the confusing presence of artificial light and that moths play a crucial role as pollinators (“something of invaluable importance for keeping our ecosystem undamaged and thriving”), what one recalls is the sad fate of their couplings.

Nor are bugs and birds alone affected by the light; so are plants, and so are humans. Our eyes adapt badly to darkness, and our night vision-which is activated by the pigment protein rhodopsin (视紫红质)-takes a long while to turn on. By now, cities such as Singapore and Hong Kong are so brightly lit that their inhabitants scarcely call on night vision at all, and, as their rhodopsin becomes unnecessary, they may well create people in later generations who, in even middling darkness, are as blind as bats.