Tuesday, 5 August 2008

Down to the sea again

The tide was on its way in at Shelly Beach, near Portland, when I got there so I didn't spend much time beachcombing. But I braved the incoming Southern Ocean and the squalls to have a brief rummage through the piles of stranded shells. Who could resist? Not me, that's for sure.

During the 1930s, the shells were harvested and crushed to provide grit for poultry. Collector Ahmed loaded his calcareous loot onto camels for the journey to Portland. His diligent work soon reduced the bank of shells.

The material comes from two sources. Dunes contain shells that were washed ashore when the sea level was higher than it is now. They form distinct layers in the sand. These shells are returned to the beach when the dunes are eroded in rough weather. Most of that material is fragmented. Ready-made grit.

Lower down on the beach are recently dead shells that have been cast up from sea floor. There are plenty of bivalves but the most abundant species is the gastropod Bankivia fasciata. In Australian Seashore, William Dakin wrote of this species 'Once recognized, this shell will not be easily forgotten'. The patterns are varied and distinctive. Bankivia is known as a kelp shell but is actually a sand dweller. Although not often seen alive, it must be around in great numbers given its presence on the strandline.

Next time, I'd like to visit on a low tide with a hand lens so I can search for micromolluscs and a bivalvologist to identify those funny two-shelled things. Now that's my idea of good day on the beach.


mick said...

"Now that's my idea of good day on the beach." Mine too! I enjoyed your description of the shells and all the photos.

sarala said...

Beautiful shells. The only ones we see here in Lake Michigan are the zebra mussels and they are an invasive. Not very good to look at either.
I miss the ocean.

Mosura said...

Bankivia fasciata was among my favourites as a kid for the variety of patterns.

budak said...

nice sky and shore pics!

Gaye from the Hunter said...

I'm looking for an informed opinion on shell collecting (dead ones from the beach). Is it considered harmless to the environment?

Thank you.


Anonymous said...

Hiya Snail ... that view has me as close to "homesick" as I can manage ... very fond memories of being there with T, long ago now.
I'm so glad you called in.

Snail said...

A morning at the beach was just what the doctor ordered! I must find out more about Ahmed and his camels. Must 've been an interesting sight in Portland in the '30s.

Gaye, it can be destructive for a couple of reasons --- removing habitat for hermit crabs and other intertidal species that use shells as a home; and taking calcareous material from that location. I have problems trying to imagine the degree of damage because I picture the occasional beachcomber picking up a shell here and there. Of course, that's not always the case. The more popular beaches are under huge pressure --- and even some of the less frequented ones can suffer from commercial scale collecting for craft work. Because of the potential for damage, many states prohibit removal of dead shells from protected areas and they discourage beachcombing in non-protected areas.

Maybe a good analogy would be dead wood taken from forests? (Or maybe not. I haven't thought that one through.)

But it is a tough one --- a beach-collected shell can be a souvenir of a great holiday, an object ot wonder and/or an educational opportunity.

Gaye from the Hunter said...

I had not considered the comparison to collecting dead wood, but this could be quite a reasonable comparison.

Thank you for your input - food for thought.



Camels? I didn't know they ever used camels in Australia.

Snail said...

Camels (dromedaries) were used a lot in the 19th century as draught animals in the drier regions (ie most of the continent). As a consequence, we now have probably close to a million feral camels. There's even a thriving export business.

Wikipedia has an entertaining entry on Australian feral camels