Rain, Soft Water, and Oceans
Rainfall veries from place to place, with some coastal areas on par with mainland Kagoshima, receiving around 2.5 meters of annual rainfall, while inland areas receive an average of 6-8 meters (Shiratani Unsuikyo) or even 10 meters (Yakusugiland). Here, it's not uncommon to top 200 or even 300 mm in a day. It's quite possible to have the average annual rainfall of London in under 24 hours, or the average annual rainfall of Seattle in two days.
Consequently, rivers rise quickly, and soil and nutrients are washed out to sea.
Spring water from the island's interior is some of the softest water in the world. The local bottling company, Jomon Sui, states a hardness of 10, with only 3mg of calcium per liter. (Soft water is often defined as having less than 60~100mg/L of calcium) Perhaps this is why the Yakusugi trees grow so slowly, or why the deer nibble on sign posts and eat their antlers when they fall off annually. Since the island is so small and the mountains so steep, we rarely have to worry about water quality and potability.
To keep the water this clean is the first item of the Yakushima Charter, established in 1993.
Although only short stretches of river are navigable, kayakking, show-climbing, and jumping into deep pools of river water are popular activities in the summer. Fishing is good around the mouths of rivers, or in the ocea.
Yakushima enjoys the warm waters brought by the Kurio Shio Current up from Taiwan and Okinawa. Despite having such steep mountains, Yakushima also has (disappearing) sandy beaches, as well as coral coasts supporting an array of both tropical and cold water fish -- almost as many species as one would find in Okinawa. At the Nagata-Inakahama Beach, designated a Rumsar Sight, loggerhead and green sea turtles make ten thousand landings a year during the nesting season.
Fishing has always been a large part of island life. Although overfishing--blamed mostly on large commercial boats encroaching on local waters--has become devastatingly apparent, the locals have adapted. Instead of Katsuo Tuna, smoked and cured macqueral from Yakushima is highly acclaimed. Maqueral fisherman used to mark fish reserved for their own families by breaking the necks, and this is now a popular way to enjoy fresh sashimi, too. Anbo is Japan's number one flying fish port. They say there used to be so many flying fish enjoying nourishment from coastal forests, that the delta would turn white during spawning season.
It is no wonder, then, that Ebisu, the patron god of fishing, is highly celebrated, with small shrines looking out to sea over all the harbors. Tourists and locals enjoy several swimming beaches, snorkeling, diving, kayakking, and fishing.
Tips for Enjoying the Water:
- Drink it!
- Tap water is safe and delicious in Yakushima, as in most of Japan, although, by law, it must contain trace amounts of chlorine. Water from small streams and springs in the mountains is the purest water you can get. Cold and delicious, it is almost always safe, so you don't need to carry water filters and purifiers. Avoid stagnant water and water flowing below huts.
- Keep the water clean.
- Please do not do anything that would damage water quality: Do not urinate or deficate in the bushes near trails. Instead, use restrooms, latrines, and disposable toilet boths, and carry a disposable toilet pack when hiking. Carry back leftover soft drinks and table scraps, and don't wash your dishes or spit out toothpaste in the streams.
- Enjoy swimming, but stay safe.
- When swimming in the ocean, stick to designated swimming areas, and areas popular for snorkeling/diving. Watch out for riptide, undertow, and sharp and poisonous shells and critters. During summer holidays, lifeguards are on duty in the daytime. Don't play in the rivers during/after heavy rains, and watch out for areas with strong river currents.
- Check out the tide pools.
- Even if you aren't up for snorkeling or diving, you can still peak at sea life in the tide pools at Haruta Hama Beach and the Youth Village in Kurio.
- Respect sea life, especially sea turtles.
- They need their space and artificial lights can disorient them easily.
- Enjoy waterfalls!
- Especially when the rains are too heavy for other activities, the waterfalls will take your breath away. Oko Waterfall and Senpiro Waterfall are the most popular, but Torohki which empties directly into the ocean and Nunobiki which often goes unnnoticed except after a good rain are easily reached. Others, like Ju no Guchi require a hike from downstream, and may not be approachable during heavy rains.
- Rent rain gear!
- For around 1000 yen for a day to around 1500 yen for two days, you can rent a set of breathable waterproof jacket and pants. When hiking in Yakushima, your rain gear is your first line of defence against the elements.