Oysters

We did some research on oysters after looking at oyster shells at dinner yesterday. How do you ‘farm’ oysters? We knew we saw ‘oyster beds’ in the tidal zones but what, exactly, gets put there? We’d heard that they re-used the shells – but how? Do oysters move into already-made shells? If so, how do they ‘close the door’ after themselves? Is that what accounts for their untidy shells?

It turns out that that last notion is completely wrong. They do grow their own shells around themselves. The old shells are sometime crushed to provide new habitat for new oysters. Or something like that. Frankly, it is hard to know for sure, because...

… Oyster research is full of wonderful sounding new words like ‘veliger larvae,’ ‘bivalve mollusks,’ ‘spat’ (or ‘spatfall,’) ‘cultch’ (the crushed shells) and ‘shell-boring mudworm’ (which is bad news for oysters.) Who wouldn’t be fascinated by a topic with such a creative vocabulary?

Oysters start as larvae and wander around looking for a place to settle for 2-3 weeks – a place that has a hard surface. Since, by then, they are referred to as ‘spat’, the place that oyster farmers provide to encourage them to settle where they can be harvested later is called ‘spat collecting sticks.’ (These are the ‘oyster beds’ we see.) They start out life as male and then ‘may’ change to female. I couldn’t find any reference to their motivation to do so or not – but, I mean, why wouldn’t they? What’s not to like about being a female oyster?

Anyway, then we get into a bunch of stuff about when the gonads are ripe but I sort of skipped over that part. Should only be of interest to another oyster.

Oysters feed through their gills and since they naturally live in tidal zones, some of the time food simply isn’t available to them – like when the tide goes out. But when people ‘farm’ oysters, they put them lower in the water so they can always feed – so they get bigger, faster. (I thought that was much more interesting than gonads.)

Also, pollution greatly affects their quality of life! Poor things.

When out of the water, oysters close their valves hermetically and in cool conditions can survive for up to 2 weeks in prime condition.

Oysters take about 3-4 years to reach marketable size (or 2-3 years, depending on which article you read, and what size you like your oysters, of course) during which time they grow their shells. And quite frankly, they are pretty messy and haphazard about it. (Which just furthers reckless speculation about re-using old ones.)

So there you have it. Oysters 101.



P.S. For everyone's edification, from the comments on this posting, here is the "view from Lauren's window:" (Thank you, Ryan!)