Purple Olive Snails at Radar Hill Beach

Radar Hill Beach
The sandy expanse of Radar Hill Beach is good habitat for Purple Olive Snails (Olivella biplicata).

With the good low tides this week my objective on my days off was to explore some beaches that I hadn’t visited before. One such destination was Radar Hill Beach in Pacific Rim National Park Reserve. This remote beach is accessible by a non maintained rough trail from the Radar Hill Parking area and because it is challenging to get to the intertidal life was excellent and I saw very few people while I was there.

One of the things that I noticed as I walked to where the waves were crashing onto the beach was a curious collection of markings in the sand close to the dynamic edge of ocean and sand. Shaped like some sort of strange language they formed thick lines and spirals, curves and question marks.

Purple Olive Snail Tracks
Markings on the surface of the sand are one of the ways to find Purple Olive Snail (Olivella biplicata).

With a little patience and some observation and the maker of these markings soon emerged from the sand. The Purple Olive Snail (Olivella biplicata) is often found at the lower tide levels of sandy beaches on the west coast of Vancouver Island, British Columbia and as it plows through the sand just below the surface looking for animal and plant matter to eat it leaves behind a trail. Males interested in mating find females by following these tracks.

Purple Olive Snail (Olivella biplicata)
A Purple Olive Snail (Olivella biplicata) burrows into the sand on Radar Hill Beach.

The Purple Olive is a beautiful snail with some interesting adaptations to the turbulent world of a wave swept sandy beach. I watched as the incoming surf picked up these snails and rolled them forward along the long axis of their oval olive-shaped shell. As soon as the water receded the snails would position themselves and dig down into the sand in preparation for the next wave. The foot of the snail is shaped somewhat like a plow and seems to facilitate both digging downward and moving through the sand. Purple Olive Snails also have a long siphon that rises up in front of the shell. Often the top of the shell and this siphon is the only thing that is visible in the sand.

I thoroughly enjoyed watching the activities of these wonderful snails, so much so that I ended up getting my hiking boots soaked! Still, I figured that the price of wet feet was more than offset by the opportunity to view these fascinating Purple Olive Snails.