The littoral zone

As I visit the beach each day and become aware of the daily changes, it occurred to me several days ago that it might be interesting to take some photos and say a bit about the ever changing littoral zone. But, though I took some photos and tried to find something to show and say, nothing of interest seemed to materialize.

I had pretty much given up on the idea until yesterday when, after the rain, I went to a slightly different part of the beach than I usually go (though I have been by this area many times this year on my way to old town) and found something new that made me think I might do the littoral zone thing after all. The above sunset photo does not show the new thing I am referring to but note the flat beach in this area.

I am sure everyone knows what the "littoral zone" is, but best not to assume - one dictionary definition is "relating to, or denoting the zone of the seashore between high-water and low-water marks". That's close enough.

As the littoral zone is constantly subjected to moving water, things like distribution of sand on a beach is always being revised. Fairly vigorous wave action and rain in the last few days have modified "our beach" substantially.

This is roughly the same area as the photo above and I hope you can appreciate the change from a totally flat to quite eroded beach.

Make sure to click on the photos to access a larger image.

It's interesting that this word, littoral, looks and sounds quite close to "litter", and in some ways what occurs in the littoral zone is a bit like littering, isn't it? The tide and waves wash in and depart leaving all manner of things behind, including our waste - note the plastic bottle here among the other debris.

Some of the leavings are food for the these gulls and, no doubt, for innumerable less visible residents.

In this low tide photo the littoral area is so smooth and clean except for  a few scattered shells and rocks. I particularly like this image.

And all this is fairly boring, which is why I hesitated to do this blog in the first place. So, speaking of shells and rocks, let's get to the bit that prompted me to do this post - it's these things you can see in this photo strewn along the beach in large numbers. What are they? 

Shells. Millions of them! What an incredible sight - all kinds of shells, all colours, sizes and shapes, piled on top of others and strewn for long sections along the beach. And when the waves roll in and out the shells make sounds like castanets as they are thrown against each other and shifted to a new location. 

In some of these photos you can see the shells under the receding water as well as on the sand; an indication of the extent of this accumulation of shells

Some of you who know the ocean much better than I may have seen this before, but it is a new and fascinating experience for me.

Why, suddenly, have all of these shells been deposited here now? They weren't here 3 days ago. We have experienced winds and significant wave action at other times like we had during the last few days but I don't recall seeing anything like this before.

I asked a Portuguese friend about it. She said that one possible explanation is the beach modification last spring that included bringing sand in from off shore. (see earlier blog) This no doubt stirred up the bottom freeing up a lot of material and the machines likely brought in, along with the sand, a lot of other ocean bed material. What the machines didn't bring in the water now seems to as all these shells get washed in and, presumably, out by the tide and wave action. Why they are there now and weren't earlier this year isn't so clear.

 

And, at this point in time they are shells but they were once part of the ocean life. Who knows when they became just shells.

What does seems clear is that when you change the ocean's littoral zone and modify the ocean floor in this way, you never know how the ocean will respond. Now there is more beach for people to walk on but they have to deal with the shells, beautiful for the likes of me to photograph, but not great to walk on, especially in bare feet. Can't beat the natural forces, at least not for long.