Sunset on the Fan Shell?

Here lies the remains of the last Fan shell on Deeban Spit.

Possibly.

Over the last two years the number of Fan shells poking out of the sea grass on Deeban Spit at low tide has plummeted. Where once there was a field of a thousand gaping shells, there are now almost none, and those that do remain are empty.

I miss them.

Empty shells on oyster beds

Fan shells are known locally by the more dramatic, but incorrect name of Razor clams. Yet another animal menace just waiting to extract human blood. They are popular in recipes of an Asian flavour, put “razor clam” in your search engine and cooking pops up first, but you will notice that true Razor clams look like old-school cut-throat razors, while our Fan shells look like fans, or perhaps the ear of a donkey. They are all edible regardless of name.

The big shells out on Deeban Spit  are  Pinna bicolour, bivalve molluscs in the genus Pinna, latin for ear. Pinna bicolour is a widely distributed species named for the bright iridescence of the inner shell. It is restricted to the sandy seagrass beds where the larvae are able to settle and feed. Research done in the warm waters of Malasia and the cooler waters of South Australia shows that they grow quickly and reach 20cm in length in the first year. By the second year they reach 26 cm and they are full size in the third year at 35 cm. Lucky Fan shells may go on to live well over a decade, the old ones gather epibiota, just like the hull of a boat.  Eventually they get tired, weighed down and stop moving. Where the seagrass beds remain there is a good chance the Fan Shells will return.

live fan shell survivor
empty fields empty fields

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Tom Kristensen

Maianbarbarianism

12 thoughts on “Sunset on the Fan Shell?”

  2. Penny I believe that people with buckets carry the fan shells off to cook them up. They cannot possibly disappear of their own accord and no other animal would remove so many. It is possible that birds might take a few and drop them from a height onto the rocks to eat them. I have seen a couple smashed this way. I think only ravens would have the smarts to do this. I’m just guessing…

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  3. Sea temp? I think not. When the fan shells die their shells remain upright in the sand until they crumble away and I am not seeing any shells at all – which means they have been physically removed. People gathering shells to eat would pull out all shells dead or alive and cast away the ones they can’t use. Its the only explanation I have for the disappearance of hundreds, perhaps thousands of shells.

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    1. Thanks. I recollect that a group was lobbying the relevant Council about this issue…
      do you know whether there have been any moves towards enabling the area to recover?

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  4. There is no overall management plan for the Deeban Spit, but there needs to be. Council, National Parks, Fisheries and Maritime would all need to co-operate – a pretty tall order. The pressure of recreational fishing is pretty intense and gathering shells, although illegal is seen as normal cultural practice.

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      1. The Sutherland Shire Council have responsibility for managing Port Hacking.
        Good staff, less good councillors, spending decisions are driven by council resolution.

      2. Thanks Tom. I’ll start writing letters next week. Should I refer to fan shells _and_ razor clams, or only razor clams?

  5. Good question Penny, only biologists seem to refer to them as fan shells, but I think the name razor clam implies that they are a menace, so I call them fan shells. People who want to collect the shells access the sand flats of Deeban Spit at low tide by boat or by foot through the Royal National Park. I have seen collectors with buckets, and I have seen where they have been, they will pick their way along cleaning the rocks of all types of shells, except oysters – go figure?

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    1. I saw people collecting shells in this area years ago, and was alarmed. Perhaps that’s what prompted my current interest (apart from stumbling across your blog, if that’s what this is). Strangely, there is a giant fan shell lying in the grass of the house I’ve recently moved into.
      Will start ringing relevant people soon, and write letters..

      Reply

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