Did you know?
Will a shark drown if it stops moving?
That depends on the shark! Generally, sharks have to swim for two reasons: first, sharks lack the swim bladder that most fish use to adjust their buoyancy. Swimming creates lift that prevents sharks from sinking, using much the same principle that a wing uses to lift an airplane.
Secondly sharks, like other marine animals, get their oxygen from the water. Bony fishes use muscles to pump water through their gills, where oxygen is extracted. Sharks, however, use a ramjet ventilation system that requires them to swim to force water to the gills.
However, sharks like nurse sharks or Wobbegongs have mechanisms to move water through their gills, and thus do not need to swim constantly to breathe. This method is called buccal pumping, whereby cheek muscles pull water into the mouth and over the gills. Dorsoventrally flattened sharks, but also rays that spend most of their time on the bottom of the ocean floor, also breathe this way.
How long can turtles stay underwater without breathing?
When they are active, sea turtles must swim to the ocean surface to breathe every few minutes. When they are resting, they can remain underwater for as long as 2 hours without breathing.
Why do underwater photos look so blue?
The ocean looks blue because water – even when very clear – absorbs and filters out the red side of the colour spectrum. So naturally our pictures will all look blue, unless you get close. So the basic tips for underwater photography are to go as close to the object as possible to get nice colours, and to shoot up or across, in order to make your subject to stand out from the background as good as possible.
Are our sharks dangerous?
No, our sharks are reef sharks and not interested in attacking humans. They have plenty of fish in the ocean to feed on. In the Maldives, no unprovoked shark attacks have been recorded in history. Remember that out of about 8-12 people who die of shark attacks worldwide every year, humans kill around 200 million sharks in the same time.
Is it true that the sea level is rising?
Yes. Over the past 100 years, the sea level has risen with an average of 10 – 25cm and scientists expect this rate to increase. Sea levels will continue rising even if the climate stabilises, because the ocean reacts slowly to changes. 10,000 years ago the ocean level was about 110m lower than it is now.
Why isn’t it allowed to take dead shells back home?
Empty shells, produced by snails and then discarded offer shelter for hermit crabs and therefore they must not be removed from our beaches. Hermit crabs have to protect their soft abdomen with a shell and have to find the right size of shell every time they outgrow their old “house”