What is Shellfish Aquaculture Operation?

A shellfish aquaculture operation refers to any site focused on the farming or harvesting of marine invertebrates. Depending on the farmed species, sites can look and operate quite differently.

Marine invertebrates encompass a wide range of aquatic species, but mainly focuses on the following:

Oysters: Oysters are frequently moved to a floating upwelling system (called a flupsy). Ocean water is circulated through the flupsy and juvenile animals, kept in trays, are able to grow to a larger size. When they are large enough, the young oysters are moved to be reared in a grow out system. The most common growout techniques are raft, adjustable longline and fixed systems.
Clams: Clams are spread on subtidal tenures where they burrow and mature to marketable size over a period of two to four years.
Mussels: Mussels are relocated to deepwater tenures where they are suspended in mesh socks to mature to marketable size over a period of 18 to 36 months.
Scallops: Scallops are transferred to deepwater tenures where they are suspended in a mesh bag or tray (suspension culture) or are seeded on the ocean floor (bottom culture). Maturation to marketable size takes six to 36 months in suspension culture and an additional 24 to 36 months for bottom culture.

How are shellfish farmed?

Shellfish of all types begin as larvae. These larvae will typically begin in hatchery tanks, where they will mature into either ‘seed’ or ‘juvenile animals’ depending on the species. Once past the larvae stage, shellfish should be relocated to an aquaculture site where they will grow until market size.

How much is Shellfish Aquaculture worth?

As the seventh largest seafood exporter in the world (source), Canada’s presence on the world’s aquaculture stage is notable. According to the DFO, Canada exports $1.0 billion in seafood each year, with 18% of that volume being shellfish. As Canada’s largest coastal province, British Columbia (BC) is home to some of the richest shellfish aquaculture sites in the country. Producing up to $25 million of shellfish annually, BC’s shellfish industry plays an important role in the province’s economy, accounting for an estimated 8% of their GDP.

Grow out Systems for Oyster Farms

Raft Systems

A raft system is a culture method in which a floating raft is constructed from interconnected beams and floats. Polyethylene or polypropylene ropes are then hung from the raft with oyster shells spaced evenly apart. Oyster larvae are attracted to these empty shells, making them optimal for farming new oysters. Weights are suspended at the bottom of the ropes to maintain vertical stature during growth. The stock will grow for 4-6 months and require regular inspections for condition and prevalence of predators like crabs, starfish, barnacles, etc.

Adjustable Longline Systems

Adjustable longline systems, as the name suggests, consists of long ropes suspended across anchored posts. Oyster grow out bags are then suspended from the lines to sit about one foot under the water level to mature until harvest. The system is designed so that line tension can constantly be adjusted to achieve different depths for storm events or preventing befouling. Due to the fully enclosed bags, oyster larvae are protected from natural elements and predators, providing a more secure system.

Fixed Systems

Similarly to adjustable longline systems, fixed systems suspend oyster bags along hanging horizontal ropes. However, in a fixed system, farm operators have no control over the height of the bags since the structure is completely fixed. Establishing a fixed system can be done in either an intertidal or subtidal zone. Subtidal zones would keep the oysters completely submerged for a rapid growing process, while subtidal would allow the oysters to surface during low tide for befouling control and harder shells.

Shellfish Farming’s Prevalence in British Columbia

Why is Shellfish Farming environmentally sustainable?

As a whole, shellfish aquaculture is a sustainable form of food production. Rather than eating commercial fishmeal, shellfish primarily feed on phytoplankton. Additionally, marine biotoxins, chemical contaminants, and pathogenic microorganisms can also be consumed by shellfish, effectively removing them from ocean water. This improvement in water quality helps prevent harmful algal blooms and promotes healthy vegetation growth.

New Regulations Happening to the BC Shellfish Aquaculture?

Although shellfish aquaculture has the capacity to produce truly sustainable animal protein for the global food supply, abandoned or discarded fishing gear (aka ghost fishing gear) is becoming a growing concern in the environmental space. According to the UN Food and Agriculture Organization, ghost fishing gear represents approximately 10% of marine debris by volume, and negatively affects up to 30% of harvestable fish populations (source).

In BC’s coastal communities where shellfish aquaculture is common, debris like plastic shellfish trays, buoys, netting, rope, and styrofoam floats are being left in the ocean. These synthetic materials, if left, breakdown into microplastics and become completely irretrievable. To combat this, the DFO instituted a new set of regulations set to come into place in 2023, and the BC Shellfish Growers Association (BCSGA) has voluntarily launched an immediate shellfish environmental program to assist in meeting the new rules.

Some of the actionable regulations to be set in place include: Mandatory inspections and cleanings of the seafloor beneath the farm at least once a year - starts April 1, 2022 Styrofoam floats must be encased in a hard casing - starts April 1, 2023 Correctly identify, mark and tag gear and equipment with right information according to guidelines - starts April 1, 2023

How Does this Affect BC Shellfish Farms?

The new regulations set in place will place an additional pressure on farm owners for debris maintenance. Currently, the BCSGA estimates it spends 50 per cent of its time dealing with debris issues. New regulations will put increased stress on farms monetarily via the cost of hard casings and commercial divers for inspections and gear retrieval. Additionally, the time required to keep up with gear tagging and working with dive teams for debris management can be extensive.

These pressures are felt especially hard by smaller operations, and can act as an operational barrier for small scale sites. Beyond the upfront and recurring costs, site owners are also at risk of facing fines for non-compliances. Fines can range from hundreds to thousands of dollars, and can result in a loss of license for repeat or severe violations. Without a dedicated inspection system, non-compliances can go undetected by farm owners, however traditional methods come at a cost.

How Shellfish Farmers Can Use Commercial Divers for Necessary Seafloor Surveys

Under the DFO’s regulations, one of the methods of seafloor surveys is via commercial divers. As laid out in the new policy, seafloor surveys must include:

Survey of the seafloor:

a. must cover the entire area within the licensed facility boundaries;

b. should be completed using commercially certified divers or a Remotely Operated Vehicle; and

c. must consider methodology of underwater visibility and be adjusted accordingly.
The license holder must complete a detailed report outlining all items identified and retrieved during the seafloor survey. The report shall be produced or submitted upon request by a Fishery Officer or Fishery Guardian.
Survey report including:

a. DFO Facility Reference number;

b. BC Land File number, if applicable;

c. name and contact information of the individual or company that conducted the survey and cleanup;

d. description of the survey methodology;

e. date of survey clean up;

f. start and end times of survey and clean up (if survey and clean up occur over the course of several days, the start and end times must be recorded each day);

g. photographs showing all items retrieved from the seabed. Each item needs to be identified in a Summary Table (see example); and

h. the following Summary Table populated accordingly.
All debris items within the licensed facility must be identified and retrieved.

If relying on commercial divers for the process, they must conduct the entire inspection following survey methodology while diligently photographing and retrieving debris. The first major concern with certified divers is the cost. Depending on the size of the site and severity of discarded gear, inspection and cleanup can take hours or days, and cost thousands of dollars to complete each time. This time can also be a concern for productivity as operations can be limited while divers are underwater. Additionally, since contracted divers are not familiar with the site and may work in multiple industries, they may require initial training on DFO compliant investigations. Without this, divers may be unable to properly assess the debris and result in consequences to the farm owner.

Finally, safety is a major concern whenever a diver enters the water. Although advancements in equipment technology and procedures can assist in diver safety, incidents still occur. As a whole, commercial diving experiences a disproportionate number of accidents according to the Maritime Injury Center.

How Shellfish Operators ROVs Can Conduct Mandatory Seafloor Inspections

As an alternative to divers, the DFO allows for underwater remote operated vehicles (ROVs) to be utilized for inspections and retrievals. These vehicles are equipped with HD waterproof camera systems as well as a variety of intuitive tools for physical tasks like debris retrieval. While there is an upfront cost, long product lifespans and minimal maintenance allows for long-term cost effectiveness.

Beyond cost, utilizing an ROV in lieu of divers empowers BC oyster farmers to build a dedicated inspection routine due to the ease of deployment. Taking a minute or less to launch and capable of running for 8+ hours, farm staff can quickly conduct routine inspections and cleanings while the pilot remains safely topside. This drastically reduces the opportunity for drifting off site pollution in comparison to inspections only being conducted annually.

Improving Seafloor Inspections and Clean-ups with Deep Trekker ROVs

Deep Trekker offers three ROV models capable of a wide variety of underwater inspection tasks. Ranging in price (low to high) to fit different budget sizes, the DTG3, PIVOT, and REVOLUTION are powerful tools for seafloor surveys. Their battery operation allows for convenient portability, while their 220 - 270 degree rotatable cameras provide superior visibility at virtually any angle. All three models can snap 1080p or 4K photos and videos for thorough inspection reports.

Coming standard on the PIVOT and REVOLUTION (and as an add-on for the DTG3), grabber arms can effectively be used as a retrieval method for smaller debris like netting or styrofoam floats. Additionally, for larger or tangled nets, ropes, or wires, a cutter attachment can be used to divide debris into smaller pieces. As an example, Ghost Diving, the largest organization dedicated to removing ghost fishing gear, has been using Deep Trekker’s DTG3 for years as an effective tool for identifying and removing plastic/debris from our oceans.

While human intervention may be necessary for large-scale retrievals, Deep Trekker ROVs can improve the safety of divers entering the water. Either as a pre-dive check or as a monitoring system alongside a diver, ROVs can provide critical information to commercial divers for ensuring a safe mission.

As always, our team of experts is available to answer any questions you may have. If you’re looking to streamline aquaculture inspections, rely on the ROVs trusted by Fisheries and Oceans Canada. Reach out to get your customized quote today.