Archive | January 2012

Explained: Ocean Acidification

This week school groups started up again at the Vancouver Aquarium and for the Cnidarian station I took the kids over to the coral exhibit. I told them about how sensitive corals are to their environment, and changes, including ocean acidification are causing them to die off in coral bleaching events.

Ocean acidification was a key topic throughout my undergrad degree. We were told the chemical reaction that occurs between CO2 and the ocean that creates acid.  Quickly I forgot the formula and “acidification” became the stock answer I gave whenever a prof asked what effects humans have on the oceans.

Now that I am teaching kids who haven’t taken Organic Chem, I struggle to find a way to explain it to the grade 11 and 12 students in a way that makes sense.

Today I stumbled upon this analogy via a twitter post from @theoceanproject

Imagine you are filling buckets to build a sand castle on the shore. Then someone begins to remove the sand from your buckets faster than you can add to your castle. Then you realize that the waves are beginning to lap at your castle. You are trying to build your castle, but someone is taking away your building material, while another force erodes your creation capacity.

This article also reminded me that Carbonic Acid is what forms when high CO2 concentrations and ocean water meet.

This week when I’m talking to school groups I’m going to challenge myself to stay focused on Acidification and its impact on the groups of animals we look at: Molluscs, Echinoderms, Arthropods, and Cnidarians.

Swam with a Shark (and lots of turtles)

On my recent trip to Maui, Hawaii I decided to do a boat dive to Molokini. Molokini is a sunken crater a few miles off the south coast of Maui.

Image courtesy of aloha-hawaii.com

There are numerous ways to dive the site, dives inside the crater are popular for their reef sharks, manta rays and abundant fish with a max depth of 40 ft. I was more interested in the backwall dive, where the crater exterior plunges down to depths of 350ft.  This diving requires good buoyancy but is worth it for advanced divers. I was amazed by the clarity of the water, which made visibility nearly 200ft. I remember looking down from the surface while waiting to be picked up by the boat as the remaining group continued the dive. I had left them at about  80ft and I could see them as clearly as if they were 10 ft below, even more I could see the wall fading into the blue 50ft below them. Overall amazing topography on this dive. I was happy to see at least one large pelagic (my first shark!), unfortunately no whales or dolphins though those types of underwater sightings are more rare.

For the second dive that day we went to a site called 5 graves/ 5 caves. This site is named after the ancient Hawaiian burial grounds located onshore and for the caves and tubes formed by gas bubbles in lava flows that are now hardened rock. I managed to get some good footage of this site with my camera.

See my facebook album of the dives here.

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