Harvesting Techniques

Hand Harvesting

• Hand harvesting is the most traditional technique, often used in small scale operations.
• Fish are caught using nets or by hand, typically in smaller containers or ponds.
• It requires little equipment and can result in lower stress levels for the fish.

Netting

• Netting involves the usage of nets to gather a large number of fish at once.
• Seine netting is a common type; a net with weights on the bottom and floats on the top is used to enclose fish.
• Cast nets can also be employed where a circular net with small weights around the edge is thrown out and then slowly pulled back in, capturing fish in the process.

Pump Harvesting

• A pump harvesting system uses a large pump to suck the fish out of the water.
• It is important to adjust the pump pressure to avoid harming the fish.
• This method allows for faster harvesting, but the size and shape of fish that can be harvested may be restricted by the pump dimensions.

Electrofishing

• Electrofishing is another option, especially useful for capturing specific species or individuals.
• This method stuns the fish temporarily by sending an electric current in water, so they can be easily collected.
• It requires careful regulation to prevent long-term harm to fish and is generally used for research or population management rather than commercial harvesting.

Harvesting Timing

• The timing of harvesting can have a significant impact on fish quality and yield.
• Fish are often harvested during cooler parts of the day to reduce stress and improve meat quality.
• Periods of fasting can also be used prior to harvest to clear the fish's digestive systems, improving the product's quality.

Fish Welfare During Harvest

• Fish welfare is a key part of any harvesting technique.
• Using techniques to reduce stress, such as lower temperature, food deprivation, or certain chemicals, can improve fish welfare.
• Every harvesting technique should minimise physical damage to fish. Methods that cause high mortality or injury rates should be avoided.

Post-Harvest Care

• Once harvested, fish should be quickly and efficiently chilled.
• Improper cooling can lead to quality loss and spoilage.
• Washing fish can remove dirt and bacteria, it should be done carefully to prevent any damage to the fish.
• It is also important to properly store and transport fish after harvest to maintain its quality.

Each harvesting technique has its advantages and disadvantages. Factors such as scale of farming, type of species, and regulatory guidelines should be considered while applying these techniques. Combining different techniques can sometimes help overcome limitations and optimise results.