Healthy vs. Damaged Oyster Reefs

Dead margin in an unhealthy oyster reef

I was able to see, in person, damaged and restored oyster reef habitat this past weekend while touring areas of Mosquito Lagoon (the northernmost part of the Indian River Lagoon system).  See my previous note on oyster restoration.

You can see in these photos that there is a wide white shelf of exposed shells in the foreground.  What isnt as noticeable are the healthy scattered shells of a normal reef that are in the background.  Curiously, boat wakes are strongest at the side of this reef that shows damage in the form of a “dead margin” – as these exposed white shelfs are known.  The backside of the reef gets very little exposure to wake generated waves and has stayed healthy. 

Healthy reef with scattered submersed shell arrangements

As noted before, the precise mechanism of how boat wakes dismantle a reef isnt yet known.  Restoration of the reefs has already taken place and it was really interesting to see some of the deployed oyster mats already working their magic. 

Larval oysters and spat (what they call the baby shellfish) had already colonized spaces on many of the mats.  Mats that were in the water just a few months were practically covered.  Truly amazing to see what a little ingenuity and some zipties can do in the name of conservation. 

Healthy cluster of oyster shells

Wondering what sorts of critters call an oyster reef home?  Here’s a quick list of creatures that were hiding out in the shells:

  • Alpheus sp. pistol shrimp
  • Oyster toadfish
  • Frillfin goby
  • Striped blennies
  • Spider crabs
  • Juvenile blue crab
  • Mangrove crabs

I look forward to the day that sneaky, genius, elegant solutions like this can be found for the other troubles we have in the IRL system with seagrass bed restoration and mangrove restoration.  Maybe something as simple as agar-plugs will be the answer!

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