Nat Taylor — Blog, AI, Product Management & Tinkering

Oyster Gardening at Haversham

Published on Aug 19, 2013.

This spring my family volunteered our dock to become an oyster gardening site, as part of a Roger Williams University program aiming to rehabilitate the Rhode Island oyster population.  I just had the pleasure of spending a week there, and spent some time observing and learning about oysters.  With luck, our “efforts” will grow between 3,000 and 5,000 oysters that can be relocated to 1 of 10 dedicated sanctuary sites across the state.  The statewide effort should add over a million oysters to natural population this year alone.  Learn more at the RWU Oyster Gardening page, or see more of our photos and video at the oyster gallery.

I’m by no means an expert, but here is what I’ve learned.

Why do this? A bit of history.

About 20 years ago, oysters were abundant throughout coastal Rhode Island, playing a crucial role in the ecosystem.  However around that time, a combination of disease and over fishing all but wiped out the oyster population.  Besides the obvious implications for commercial fisherman (who resorted mostly to oyster farming,) the decline reduced habitat for other animals and reduced water filtering.

Benefits

Oysters provide a variety of services to the ecosystem including:

• Improved Water Quality
  A fully grown oyster filters up to 50 gallons of water per day, removing particulate as it seeks food and fuel to grow.  In addition to the particulate it removes directly, oysters also remove nitrogen and other nutrients (that can case deoxification) as they convert phytoplankton into tissue.  What’s more, they can further reduce nitrogen levels via chemical reactions that take place underneath the oyster bed.
• Habitat for Other Animals
  Other animals come to rely on the protection from predators, created by the nooks and crannies between layers of oysters on the bed.
• Marine Economy
  Abudant oysters mean more opportunites to enjoy they recreationally and commercially.

The OGRE Program

The OGRE program is genius, as they’ve basically found a successful formula and then crowd sourced the grunt work.  It works something like this, though the OGRE page has a better explanation.

1. Disease resistant oysters are grown in an RWU nursery
2. The larval oysters are allowed to set on previously harvested clam shells
3. The seeded clam shells are packed into mesh bags, then laid into a floating cage
4. The floating cages are distributed to the 100+ volunteer sites
5. After a few months, when the oysters are about 1″ across, the cages are collected
6. The seeded oysters are released into any of the 10 statewide sanctuaries

This method has been preliminarily shown to work, as it is:

• Scalable – the labor is distributed
• Provides safety – the young oysters are raised in the nursery, safe from predators
• Provides ample food – the young oysters live in the nutrient rich, top 12″ of the water column

Turning the Oysters

We took some time to examine the growing oysters while we flipped them.