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Does Oyster Aquaculture Help or Hurt the Environment? – Part II

 

Background: The information from Part 1 (“Help”) of this two part article is substantiated by a study that The Nature Conservancy (TNC) conducted in partnership with the Virginia Institute of Marine Sciences (VIMS) and local growers.



Information for Part II (“Hurt”) of this 2-part article is drawn from regulation, popular press and personal observations.


 

Introduction:


Oyster aquaculture is an environmentally sustainable practice. Although, as concerns about the health of our oceans escalate, one must ask whether oyster farming, and how one chooses to practice it, is without any environmental risk. In this article, LOC explores four areas of concern and how regulations and voluntary best practices mitigate the risks.


 

1. Habit Alteration:


Part 1 of this article, we explained how oyster aquaculture operations can help generate productive marine environments by creating surface area upon which marine life can “take root”. This is particularly true for the shell the industry generates.


Oysters contribute to SAV habitat by filtering sun-blocking sediment and nutrients from the water. When native oyster populations crashed, so did SAV. This is one of the reasons oysters are considered a keystone species.

Because oyster aquaculture often involves the installation of structures such as cages, racks, or bags, irresponsible installation of these structures could disrupt existing habitats, primarily seagrass beds and submerged aquatic vegetation (SAV), which serve as crucial habitats for various marine organisms.


For this reason, the Virginia Marine Resource Commission (VMRC) monitors and prohibits aquaculture gear to be placed on SAV. In short, if regulations are followed, there is no risk of critical habitat alteration.  


 

2. Energy and Resource Consumption:


Oyster Seed Holdings, Inc. well maintained grow-out rooms require temperature and water circulation systems to keep oysters viable.

During the early stages of oyster life when the first steps of the supply chain begin with hatcheries and upwelling operations, oyster aquaculture relies on energy and resources (marine water) to grow oysters from microscopic to 5mm in size, at which time they can be placed out on farms without mechanical assistance.


These operations require a significant amounts of energy. The construction and maintenance of aquaculture facilities, transportation of seed and equipment, as well as the energy needed for water circulation and temperature control, contribute to the carbon footprint of the industry.


However, in Part 1 of this article, we reported how oysters sequester atmospheric carbon in the creation of their shells. Thus, oyster aquaculture might be able to claim a negative or net zero impact when it comes to carbon emissions. As of this printing, no carbon accounting research could be found to see how the industry's release of carbon compares to its carbon capture. By promoting oyster aquaculture, oyster consumers not only capture carbon in the aquaculture product itself, but also in the promotion of additional wild oyster habitats. Lessening atmospheric particulates like carbon is a common strategy towards stabilizing air quality and temperature.


 

3. Material Shedding:


LOC’s oyster gear and handling equipment (such as 5-gallon buckets) is constructed of UV resistant, heavy duty and food-grade plastics. As you know, oysters are sharp and as they pass through bag, basket or bucket, they score the plastic surface. With continued use, it is likely that with score upon score, a small shard of plastic eventually becomes separated and enters the environment.


LOC is mindful in limiting its use of plastic. Metal gear is one alternative, but the wire is treated with coatings to prevent rust and with time, these coatings degrade and peel off also.


Most research on micro-plastics is focused on single-use consumer plastics and how they break down and enter the environment following disposal. Oyster aquaculture’s commercial re-use of plastic equipment and the resulting material shedding is likely a very low overall contributor to the micro-plastic problem when compared to single-use consumer plastics such as shopping bags and water bottles.

 

4. Politics:


Introduced in the 2024 General Assembly Legislative session, Senate Bill 275 (SB275) Prohibits the Marine Resources Commission from issuing any permit for any floating oyster cage in a water column, rack-and-bag, or other similar apparatus for oyster aquaculture in the Lynnhaven River or its tributaries.

What do politics have to do with the environment, you ask? In this case, a lot! This risk also hits close to home. As many developed coastal communities embrace the “grown local” movement, and appreciate the value of locally sourced seafood, oyster aquaculture is not so appreciated and is considered by many waterfront homeowners to be misplaced. The “not in my backyard anti-oyster movement” has influenced proposed legislation to change Virginia law and ban oyster operations in the Lynnhaven watershed.



As reported in Part 1 of this 2 part article, there are many positive outcomes and environmental benefits to oyster aquaculture that far outweigh the risks introduced in this segment. Many of these positive outcomes benefit recreational use such as swimming and fishing, rather than limit it as oyster opponents suggest.


Unfortunately, if only the politics of a select few influence lawmakers and a ban becomes law, this would be a situation in which those who oppose oyster aquaculture also oppose the benefits the industry provides - for all of us. In an ironic twist, if oyster aquaculture cannot be practiced, the benefits are not realized and the environment will be worse off because of it.

 

Conclusion:


When practiced responsibly oyster aquaculture is a win-win for the environment and for people. Oyster farming supports sustainable seafood production and provides economic stimulus for Virginia. As previously highlighted by LOC, the direct and indirect economic impact of Virginia’s oyster aquaculture industry is significant. Embracing oyster aquaculture is not just a path to environmental restoration but is a key move towards securing a more resilient future.

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