Sunday, August 12, 2007

Night paddle

On Saturday evening 20 of us gathered at the public wharf in Avondale for a night paddle under the leadership of Alex. Aside from all the usual gear,kayakers packed or wore a headlamp or waterproof flashlight and used glow stick on the stern. We only used the headlamps when boaters came close. As a result everyone's night vision quickly heightened. The big draw at this time of year was the phenomenom commonly seen in ocean waters at night called bioluminescence. We weren't disappointed. How Alex got all these sea creatures to cooperate we never found out. But at various times along the coast when we dipped our paddles deep we stirred up quite a brilliant display. Occasionally what appeared to be solid fistfuls were caught up in the wake of the paddle stroke from the kayak ahead.

Apparently bioluminescence is the result of a chemical reaction between a protein (luciferin) and an enzyme (luciferase) in the presence of oxygen. Most lightsources radiate heat, but not in sea creatures. One reference describes this phenomenom as 'cold fire'.The production occurs in photogenic cells called photophores.

As we paddled around we discussed what creatures had this ability - it turns out there are a number of sea animals capable of this feat ranging from one celled animals like planktons, dinoflgellates to jellyfish, squid and bacteria < 1 mm in length.

There may be a number of reasons for this occurrence, including environmental.Some species utilize bioluminescence to facilitate finding potential mates.It seems many creatures increase the frequency and intensity of bioluminescent displays during their mating period.

We spent a good bit of time investigating one of the whaling shipwrecks in Conception Hr, one protrudes well beyond the surface the other can be seen below the surface of the water with a strong waterproof flashlight.

On the return trip back we took a break and made a great landing in a small cove and beach - no small feat with only glow sticks and a couple of headlamps.

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