2023 Oyster Dive Report

Published: November 14, 2023


Photo Captions: Cody and Sarah Dive at Wade 2 – Measuring an oyster – Natural reproduction!

SRA has been conducting annual scientific oyster diving operations to monitor the health of five restoration reefs in the Severn River between the Rt. 50 and US Naval Academy Bridges, since 2019. For 2023, survival rates for one-year-old oysters ranged from 75% to 86% in samples collected during scientific oyster dive operations last month.  

On a bright, calm, and sort-of warm morning in early October, divers Cody Lassiter,  Sarah Winchester, and John Anderson sampled oysters on the restoration reefs known as Wade 2, outside of Weems Creek, and a section of Peach Orchard, in front of the Manresa assisted living facility. 

Scuba diving in the Severn is a bit different from Key West. Visibility here is basically zero, even in October. This is because there is still plenty of algae activity that turns the river into a greenish fog. Finding oysters is all done by touch. 

Once on the bottom, divers deploy a meter-square quadrat over the oysters. Then they collect everything they can feel inside the quadrat (rocks, shells, oysters), place everything in large sample bags, and bring the haul to the surface where it is collected on SRA’s research vessel, Sea Girl

Photo Captions: John getting ready to dive – Sarah with the quadrat – Emi and Ben counting oysters

The team then moved over to the Peach Orchard reef in front of Manresa where our newest team member, John Anderson, learned the art of collecting oysters. This area was planted in 2021 and we found healthy oysters that were 4 inches long and looking ready to reproduce! There are also a mix of oysters that appeared to be much older, and evidence that some oysters are naturally reproducing in the river. 

After the divers collect the oysters and sort them into buckets according to reef location, the team brings oysters to shore to measure and calculate live/dead percentages. Volunteer Emi McGeady, and SRA staffers, Ben Fertig and Tom Guay, helped count and measure the oysters. All oysters are then returned to their home reefs in the river. 

The dive reports reveal that the Severn River is an excellent location for oyster restoration. 

Large-scale oyster planting is accomplished in partnership with the Oyster Recovery Partnership, the Department of Natural Resources and private donors, to ramp up oyster restoration operations in the Severn River. 

SRA has a goal to plant at least 25 million baby oysters a year with the larger goal of one day hosting 1.2-billion mature oysters in the river so they can clean and filter the river every week. 

For more information, contact:
SRA Program Officer, Tom Guay