Monthly Archives: September 2011

September 2011: Baby Turtles in Shimoda

I’m really disappointed at failing my attempt to dive once a month following the cancellation of my September dives.  I’d been looking forward to joining my dive group in the crystal clear waters of Hachijojima, 12 hours south of Tokyo by ferry, but when an approaching typhoon forced the group to call off the trip, I knew that the right decision had been made, and that it was not worth taking any risks in the path of an oncoming storm.  To ease my disappointment, I joined some friends on the island of Kozushima, about 8 hours south of Tokyo, where we camped, snorkeled and swam under excellent weather.  However, we ended up heading to the mainland on our second day after discovering that the typhoon was heading our way, and spent a night camping in a popular area called Shimoda full of good beaches.  While hanging out on the beach that night, we saw some baby turtles heading out to sea.

Knowing how rare it is to witness this by chance, we were really moved with what we saw, and as I can’t write about diving this month, I decided to go online and find out more about these turtles instead.

To break open their shells, the hatchlings use a caruncle or temporary egg tooth, an extension of the upper jaw that falls off soon after birth.  They then take about three to seven days to head up to the surface.  Once there, they make a complete circle around their nest before instinct drives them towards the water.  They start crawling to the sea towards the brightest horizon and can apparently set an internal magnetic compass which is used for navigation away from the beach.  As they reach the water, they dive into the waves and are carried out into deeper waters.  They settle themselves in areas with floating seaweed where they can be camouflaged and find food.  The currents then carry them for years unless they are eaten by predators. They spend their first few years growing and eating in nearshore areas.  Once they reach adulthood, they then head to a new feeding ground.  The males never leave the water once they enter, but the female makes the long trip back to her natal beach to lay her eggs.  It was nice knowing that the turtles we saw will eventually return to Shimoda!

Some other interesting facts:  The sex of baby turtles depends on temperature.  If eggs are incubated at less than 28 degrees, all the hatchlings turn out to be male.  If they are incubated at 35 degrees or warmer, they are all female.  Any temperature between 28 degrees and 35 degrees produces both males and females.  They are also said to detect the angle and intensity of the Earth’s magnetic field and determine latitude and longitude once out at sea.

Seeing them has more than made up for this month’s lack of dives!

August 2011: Marine Life in Canada

With a coastline of 240,000km, Canada is one country teeming with all things marine – research facilities, diverse underwater creatures (lobsters, crabs, starfish, sea urchins, scallops, cod) and delicious seafood.  I was able to check these out for myself during a mid-August visit to Nova Scotia (Halifax), and of course ate plenty of fresh scallops and salmon along the way.

In all honesty, the idea of diving or studying in colder waters like the Atlantic has never really appealed to me, but a visit to the Bedford Institute of Oceanography near Halifax was well worth it and gave me a good insight into a different marine environment to my dive destinations in Japan.  The institute is a huge government ocean research facility, which studies fish stocks, shellfish, marine plants, coastal planning, ocean management and reducing risks from possible hazards.  Over 600 researchers, engineers, technicians and support staff are based there.

I participated in a guided tour, which began with a series of wall panels outlining the institute’s research and the marine life around Halifax.  I was struck by their Titanic exhibit which included a model of what the wreck is like now.  It wasn’t just about the accident though, the wreck is a habitat for a variety of fish and shellfish, and offers researchers much information.  An expedition to the wreck was held in 1991, and we got to see some images from this too.  Afterwards we entered the laboratories where I was able to see the students’ fish specimens and their notes on topics like population and behavioural monitoring.  Our tour ended with a visit to the Sea Pavilion, where a range of “touchable” animals are kept.  Starfish, sea cucumbers, lobsters and sea urchins were among the many creatures that we could quite literally pick up.

I also got to delve into the world of whales during my visit, thanks to a whale-watching tour along the Bay of Fundy.  Our boat departed from Brier Island, a feeding ground for dozens of marine species.  Blue fin tuna, seals, gannets and petrels all gather there, but what we were really after were humpback whales.

My marine biology course papers give some fun facts on these animals:

l       120 degree vision on either side of the head enables them to see to the sides and rear.

l       They can roll their eyes backwards to see in air as well as water.

l       They dive for up to 40mins (sperm whales hold their breath for well over 2 hrs and dive to around 2,000m).

l       They consume 1 to 1.5 tons of food a day.

Whale watching tours are very hit- and-miss, but ours proved successful in more ways than one.  The boat ride through the early morning fog brought us to our first designated spot.  The weather was clear and the sea was eerily calm.  Within a few minutes our group was leaning over the boat, waiting silently for any hint of movement.  Knowing the best areas to see whales requires lots of experience and knowledge, and our captain and guides had plenty.  The captain especially really seemed to know the waters, as he headed off in the correct direction whenever we heard or felt anything.  We watched in wonder as some beautiful whales, including a mother and her calf, came really close to the boat, circling gracefully and calmly around us and diving in and out of the surface.  Because they can’t always be seen, it was really special to be right next to them that day.  After a good 3 to 4 hours out at sea, it was time to head back to reality.

Canada certainly doesn’t give off a warm tropical vibe and isn’t the world’s top dive destination, but at the end of the day somebody’s got to don that dry suit and brave those colder waters, to study what’s happening down below, monitor the whales, or find out more about shipwrecks.  My visit to Canada really got me thinking about that.