Thursday, January 12, 2012

10 January 2012: Hokitka: beach and glow-worms!

The seaside town of Hokitika is largely a tourist destination, rather than industrial area like Greymouth, and had ample opportunity to visit its beaches and take-in some biology, which included viewing glow-worms!

The glow-worms that inhabit a dell (a valley) near Hokitika are the larvae of the Fungus Fly, an insect that feeds on, you guessed it, fungus.  The dell was a small cove located about 30m from the highway, at the end of a short path.  The walls of the cove were nearly vertical, lined with ferns and other low-stature plants capable of clinging to the vertical surface of the cove.  The sounds of a light trickle of water contributed to the feeling of damp conditions within the dell. 

The Fungus Fly larvae occupy burrows, where they dangle their tails that glow a light-blue color.  The bioluminescence serves as a lure for prey that ultimately become ensnared in a string of silk excreted from the tail of the glow-worm.  It was not clear from the description on the road-side sign how the light was created, but Dr. Moran explained to our students how other organisms are able to ‘create’ light through biochemical processes (thanks Dr. Moran!).  The glow-worms do not begin emitting light until dusk, so our group decided to spend the waning hours of light walking the nearby beach.

The Hokitika beaches are largely flat and bounded on the shore side by small dunes lined with dune grass and few flax plants.  We walked the beach in search of one of the prized stones of New Zealand, jade (known as ‘pounamu’ to the Maori), skipped stones in the Tasman Sea, or walked quietly to reflect upon our trip and our families back home.  Black-backed gulls cruised the shoreline looking for tasty morsels, but they were the only birdlife using the beach: no penguins were found, despite the signs from the DoC that they may be found on the beach.  We watched the sunset through the cloud cover and then made our way back to the glow-worm dell to wait for the worms to do their thing!

As dusk approached, we watched in amazement as the glow-worms began to turn-on, an appearance that was magical, yet familiar: it looked like the stars coming out at night!  Our students patiently waited for the full show, which became more apparent as it grew darker.  Pictures of the glow-worms were difficult to obtain, but our students made their best efforts to capture this spectacular scene!

Dr. Moran contemplating life's great mysteries on a rock jetty on the beach in Hokitika.

Our group at sunset on the beach at Hokitika.

The glow-worm dell in Hokitika...check out those headlamps!

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