When it comes to protecting our waterways, science and smart solutions go hand in hand. That’s exactly what played out along Pleasure House Creek in Virginia Beach—right in front of the iconic Brock Environmental Center—when MSA was called in to help resolve an environmental controversy surrounding artificial oyster reefs.
The Backstory
To help rehabilitate Virginia tidal water bodies, the Chesapeake Bay Foundation (CBF) received a permit from the Virginia Marine Resources Commission (VMRC) to build artificial oyster reefs as part of restoration work in the Lynnhaven Watershed, including in front of the Brock Environmental Center.
Initially, the reefs were built by placing oyster shells in designated areas. However, in some areas, much of the shells sank into soft tidal mud, resulting in considerable loss of the valuable donated shells. To address this, CBF received a permit amendment that allowed them to use crushed concrete as a base material, having a similar chemical composition to oyster shells, and then place oyster shells on top. An independent non-profit organization constructed the reefs.
The Concern
Later, some citizens raised concerns after noticing unauthorized or deleterious materials, such as steel, asphalt, and glass, mixed in with some of the crushed concrete. The regulatory concern focused primarily on asphalt, which can leach harmful polycyclic aromatic hydrocarbons (PAHs) into the water. Rather than recovering the unauthorized materials, the VMRC ordered the entire removal of some reefs, even though removal could impact surface water and harm the developing aquatic habitat by disturbing the sediment and resident marine life.
Some of the artificial reefs were removed. However, the last reefs under scrutiny were those in front of the Brock Center, which were considered a showcase reef.
At that point, MSA was brought in to assess the situation. MSA:
- Surveyed the reefs
- Conducted site investigations at low tide.
- Used an underwater scope to search for deleterious materials.
- Found minimal unauthorized materials.
- Recovered some asphalt samples and had them tested for PAHs.
- Collected young oysters growing on asphalt pieces and native oysters and tested for PAHs.
- Conducted a controlled study using river water and recovered asphalt placed in an isolated tank submerged in the creek, and then testing the water after 1 week, 1 month, and 3 months.
- Tested surface water above the reefs and from creeks near heavily developed, paved areas.
The results showed:
- Only trace levels of PAHs remained in the collected asphalt samples.
- No measurable PAHs were released into the water during the controlled study.
- No measurable PAHs in oyster tissue from artificial reef or native oysters.
- Those results demonstrated that most of the harmful material had already leached out, posing no remaining environmental threat.
- The only detected PAH in the Lynnhaven watershed surface water was found in creek water near heavily paved, developed areas; none were detected around the artificial reefs in question.
- Healthy marine life, including minnows, baby crabs, periwinkles, oyster spat, and juvenile oysters, was found inhabiting the reefs, indicating that a vibrant habitat had formed.
MSA compiled these findings into a report for CBF, who submitted it to the VMRC, showing:
- Minimal unauthorized material was present.
- No environmental harm was currently occurring.
- Removing the reefs would likely cause more harm than good.
The VMRC agreed, and the reefs were saved.
They remain in place today in front of the Brock Center, continuing to support the local ecosystem.
Tags: environmental, watershed