Harvesting Shellfish From Cages And Bags

Harvesting Shellfish from Cages and Bags

Harvesting Shellfish from Cages and Bags

Harvesting shellfish from cages and bags is a common practice in shellfish farming, especially for species like oysters, mussels, and clams. These methods are typically used in aquaculture systems where shellfish are grown in suspended cages, mesh bags, or nets, rather than being directly planted on the seafloor. These systems offer advantages such as reduced exposure to predators, easier maintenance, and better water circulation, which can lead to faster and more uniform growth. 

1. Choosing the Right Harvest Time

The first step in harvesting shellfish from cages and bags is determining when they are ready for harvest. The timing varies depending on the species, growth rates, and market conditions. Typically, shellfish grown in cages and bags are harvested when they reach their desired size, are in good health, and have reached market readiness.

a. Oysters

Oysters grown in cages and bags generally take 1 to 3 years to reach harvestable size, depending on environmental conditions such as water temperature and food availability. Oysters are typically harvested when they are 3 to 5 inches in length.

Signs oysters are ready for harvest:

• Shells should be tightly closed.

• The oyster should feel heavy and full.

• The shell color should be bright and clean, without significant barnacle growth or damage.

b. Mussels

Mussels grown in cages or bags typically take 12 to 18 months to grow to market size. Mussels are usually harvested when they are 2 to 3 inches in length.

Signs mussels are ready for harvest:

• Shells should be tightly closed.

• The mussels should feel firm and full inside their shells.

• There should be no signs of disease or excessive byssal thread growth.

c. Clams

Clams grown in cages or bags can also be harvested once they reach the desired size. Soft-shell clams, for example, can take anywhere from 2 to 4 years to reach market size.

Signs clams are ready for harvest:

• The shell should be smooth, clean, and tightly closed.

• The clam should feel plump and full.

• The clam should not show signs of disease or damage.

2. Preparing for Harvest

Before beginning the harvest, it's important to ensure that all necessary tools and equipment are ready. Proper preparation minimizes damage to the shellfish and ensures a smooth harvest.

a. Tools and Equipment

• Harvesting Tongs or Hooks: Used for gently pulling up cages or bags from the water.

• Buckets or Containers: For holding the shellfish after they are removed from the cages or bags.

• Gloves: To protect hands from sharp shells or barnacles.

• Boat or Floating Platform: If farming in deeper water, a boat or floating platform will be needed to reach the cages or bags.

b. Checking Equipment

Before starting, inspect the cages or bags to ensure that they are in good condition. Check for any signs of wear or damage, especially if they have been in use for a long time. Strong tides, storms, or marine organisms like barnacles can damage the bags or cages, potentially leading to shellfish loss.

3. Harvesting Shellfish from Cages and Bags

a. Oysters

• Step 1: Bring up the cages: Use tongs or hooks to lift the oyster cages carefully out of the water, making sure not to damage the oysters inside.

• Step 2: Remove the oysters: Once the cages are at the surface, gently shake or pull the oysters out of the cages. Be careful not to damage the shells, as cracked shells can reduce the quality and marketability of the oysters.

• Step 3: Clean the oysters: After removal, oysters may need to be cleaned of any excess algae, mud, or barnacles. This can be done using a brush or by soaking them in seawater for a short period.

• Step 4: Sort and pack: Sort the oysters by size and quality. Market-ready oysters should be tightly closed, clean, and of uniform size. Once sorted, pack the oysters in mesh bags or boxes, ensuring they are well-ventilated and kept cool.

b. Mussels

• Step 1: Lift the bags or ropes: Use hooks or tongs to lift the mussel bags or suspended ropes from the water. These are often attached to floats or rafts.

• Step 2: Detach the mussels: Once lifted, gently cut the mussels from the ropes or remove them from the bags. For mussels grown on ropes, this process involves cutting the mussels from the ropes with a knife or shears.

• Step 3: Clean the mussels: Clean any debris or algae from the mussels, as excessive growth can reduce quality and marketability. Scrub the shells gently or use a pressure washer to clean them.

• Step 4: Sort and pack: Sort mussels by size, removing any that are too small or damaged. Mussels are usually sold in mesh bags or plastic containers, and they should be kept cool and well-ventilated until they are sold.

c. Clams

• Step 1: Lift the bags: If clams are grown in bags, use hooks or tongs to pull them out of the water. Clam bags are often suspended in the water column, so the process is similar to mussel harvesting.

• Step 2: Empty the bags: Once the bags are out of the water, empty the clams into containers. If the clams are individually bagged, you may need to cut or untie the bags to remove them.

• Step 3: Clean the clams: After harvesting, rinse the clams to remove sand, mud, and debris. Cleaning ensures the shellfish are appealing to consumers and helps to avoid contamination.

• Step 4: Sort and pack: Sort clams by size and quality. Store the clams in cool, moist environments, such as refrigeration or chilled seawater, until they are sold.

4. Post-Harvest Handling

After harvesting, shellfish need to be handled carefully to preserve their quality. Proper post-harvest handling is essential for maintaining freshness, ensuring product quality, and extending shelf life.

a. Cleaning and Sorting

• Clean shellfish thoroughly to remove any debris, mud, or barnacles. A gentle scrub or rinse with seawater can help with this.

• Sort shellfish by size and quality. Damaged or undersized shellfish should be discarded or returned to the farm for further growth.

b. Storage and Packaging

• Oysters and Mussels: Store shellfish in cool, moist conditions, either in mesh bags or containers that allow for proper ventilation. Shellfish should not be submerged in water, as they need air to breathe.

• Clams: Like oysters, clams should be stored in cool, moist conditions, with proper ventilation to maintain freshness.

• Packaging: For transportation, pack shellfish in sturdy containers that protect them from damage and allow for air circulation. Proper labeling, including harvest date and farm information, is also important for marketing purposes.

5. Marketing and Selling Shellfish

Once the shellfish are harvested, cleaned, sorted, and packed, they are ready to be marketed and sold. You can sell directly to consumers at local markets, through wholesalers, or supply local restaurants and seafood markets.

• Oysters: Often sold live in the shell, oysters can be marketed fresh or shucked for specific products like oyster meat.

• Mussels: Mussels are typically sold live in the shell and can be marketed directly to restaurants, markets, or consumers.

• Clams: Clams can be sold fresh in the shell or shucked for use in cooking.

6. Tips for Successful Harvesting from Cages and Bags

• Check regularly for any damage to bags or cages, as this could result in loss of shellfish or decreased growth.

• Harvest at the right time to ensure your shellfish are of marketable size and quality.

• Handle with care to minimize damage to the shells, as cracked or damaged shellfish may not meet market standards.

• Clean thoroughly to maintain high-quality products, especially if you are selling to high-end markets or restaurants.

Harvesting shellfish from cages and bags is an efficient and effective method for shellfish farming. Whether you are growing oysters, mussels, or clams, proper harvesting techniques are essential to ensure the highest quality products. Using the right equipment, harvesting at the right time, and following best post-harvest practices, you can maximize the profitability of your shellfish farm and provide consumers with fresh, high-quality seafood.