Marylanders Grow Oysters

Join The Team Of Oyster Growers On The Severn River

In 2008, Maryland created the Marylanders Grow Oysters (MGO) program to enlist everyday citizens in the push to repopulate our rivers and the Chesapeake Bay with the Eastern Oyster — nature’s powerhouse water treatment system.

The MGO program will help harness the cleaning power of the oyster – each mature oyster can filter up to 50 gallons of water a day — to rebuild our Severn River fishery and oyster reefs and ensure that our river and creeks are always safe to swim in.

You can help by joining the MGO program! For more information:

To appreciate the lifecycle of our new oysters, click here to review a nice explanation by the  University of Maryland Center for Environmental Sciences.

The Center operates the Horn Point Hatchery in Cambridge, Md., which supplies all over our spat for the Severn River oyster re-population effort.

The Severn River was once a thriving fishery.

We were home to dozens of healthy oyster reefs from the mouth of the Severn all the way into Round Bay and nearly on the doorstep of Severna Park.

This was documented in the 1911 Yates Oyster Survey. The pale green areas on the chart below were once active oyster reefs.1911 Yates Oyster Reef Survey

Unfortunately, the fishery is today off limits to harvesting.

The state started closing our oyster reefs in 1912 due to sewage problems in the Severna Park area.

Since then, the combination of human activity, development, pollution and diseases degraded water quality to the point where there were no more live oysters.

To remedy this situation, the Maryland legislature adopted the MGO program in 2008 to reintroduce oysters into the Chesapeake Bay watershed.

SRA was an early adopter of this program. We started participating in 2009, and today we have more than 400 voluntary oyster growers helping restore the oyster in the Severn.

Why Bring Back Oysters?

Oysters can help restore water quality in the Severn River because they are nature’s way of cleaning a waterway!

That’s why the Severn River Association joined with the Department of Natural Resources (DNR) and the Oyster Recovery Partnership (ORP) to create an army of volunteer oyster growers on the Severn River.

Our goal is to repopulate the Severn River with millions, perhaps billions, of oysters, and then let the oysters go to work. Here’s how it works:

In September, SRA distributes millions of cages full of oyster spat-on-shell to our volunteer growers to raise of their piers in the river.

Over the winter, they care for the oyster spat attached to an oyster shell so the oysters can form their own shells and turn into baby oysters.

Then in June, we host an oyster roundup.

Our oyster growers bring their year-old oysters to plant them on an historic oyster reef known as Traces Hollow. This reef is marked by four orange flags in the river, just downstream from the Rt. 50 Bridge. These buoys to form a square to indicate where growers plant their oysters. See picture at left.

One day, we’ll have enough oysters to filter the entire river in a month, then a week and maybe one day, every three days — like oysters used to do.

How To Become An Oyster Grower?

Our partners produce the oyster spat-on-shell at the Horn Point Hatchery in Cambridge, Md., which is run by University of Maryland Center for Environmental Science.

ORP provides the oyster spat-on-shell, cages and arranges delivery from the Cambridge hatchery to the Severn River.

Then SRA helps distribute the oyster spat-on-shell and cages to our team of volunteers who hang their cages from their piers during the winter hatching season (September-May). All that is required to be a grower is able to:

  1. Hang your oyster cages off a private or community pier deep enough to so that the spat are under water even during the super low tides following winter storms,
  2. Visit your oysters once a month during the growing season (September-May) and tend to the cages controlling their depth by season and shaking them up a bit to knock off the debris to ensure a free flow of current can bring food to your spat, and
  3. Deliver your baby oysters to the Traces Hollow MGO reef for planting in June.
It’s easy. This quick video explains all there is to it: click here.

This is what the MGO oyster planting event looks like in June:


Then during the summer, it’s time to clean your cages and prepare for arrival of new spat-on-shell in September. Check out this video for a simple cleaning technique, click here.
To volunteer, please email:


Severn River Association, Oyster Recovery Partnership, Maryland Department of Natural Resources, University of Maryland’s Horn Point Hatchery, University of Maryland Center for Environmental Science, and more than 400 volunteer oyster growers.


Program Goal

To raise millions, perhaps billions, of year-old oysters and plant them in the river every year  so the oysters can perform their natural and historic function — to filter the river and help create a resilient reef habitat that sustains oysters, fish and other wildlife.

Currently, through the efforts of SRA’s volunteer oyster growers, the Severn River is home to over 2,000 MGO oyster cages. We’d like to see that number break 3,000 and then hit 5,000!

Program Outcome

  • Improve conditions in the river to enhance fishing, swimming, crabbing, and recreational activities.
  • Raise public awareness about the land-based activities that adversely effect oyster habitat.
  • Educate the public about ways to improve the river ecosystem.
  • Improve and increase marine life habitat surrounding oyster reefs.
  • Create a sustainable oyster fishery.

With your support, we can restore one of nature’s hardest working species and let them do what they do best – filter the water so that the Severn and its inhabitants can thrive now and into the future!

To volunteer, please email: