How to Farm Clams? A Detailed Guide to Farming Methods and Key Technical Points
Clams are a seafood product we often see in daily life. Their meat is delicious, smooth yet not greasy, many people like to eat them, and market demand is relatively large. How are clams farmed?
How to farm clams
1. There are several strict requirements for a clam farm: convenient transportation, no pollution sources, and smooth tidal flow. The substrate of the farm must be stable; tidal flats in the middle and low tide zones with a sand content of 70%-90%, as well as ponds with suitable substrate and water quality conditions, are both good choices.
2. Tidal flats (or pond bottoms) that have been used for farming for many consecutive years need to be turned over and improved. After the turned-up mud and sand are washed multiple times by tides and exposed to the sun, level the flat surface and remove harmful organisms and debris. For beds prone to erosion by floods and coverage by mud and sand, use miscanthus to build embankments for flood control, with a width of 30-40 cm and a height of 20-30 cm above the bed surface, to stabilize the bed surface and prevent seed loss.
3. Choose natural beach tidal flats as the farming site. The sand thickness of the tidal flat should exceed 0.3 m, the sand should be fine, soft and clean, and the tidal flat should be relatively flat, with obvious coverage or exposure during the rise and fall of seawater, and a seawater layer thickness of 0.8±0.4 m at high tide. Within the farming tidal flat area, use enclosures to separate it from the surrounding area, with an enclosure height of 20-30 cm; set up blocking nets outside the enclosures. Pre-disinfect the farming tidal flat: at low tide, soak it with a 5-10 ppm chlorine dioxide seawater solution for 24 hours, then wash it clean with incoming tide seawater.
4. For farming clams in ponds and tidal flats within reclamation areas, repair embankments and sluice gates well. One month before sowing seedlings, drain the pond water first, expose the pond bottom to continuous sunlight for 15-20 days, then splash bleaching powder over the whole pond for disinfection. After disinfection, fill with filtered seawater and soak for 2-3 days, drain the pond water, and repeat soaking and draining 2-3 times. After pond clearing, fill with water to a depth of 30-50 cm. Every 2-3 days, apply 0.5-1 g of urea and 0.1-0.5 g of superphosphate per cubic meter as base feed to make the water color light brown, which benefits clam growth.
5. When farming clams, pay attention to the farming temperature. Generally speaking, seawater temperatures of 15-30°C are very suitable for clam growth. When the water temperature drops below 10°C, clams stop growing. If farmers raise clams in shrimp ponds, they should control the water surface height at 30-50 cm.
6. Seedlings can be sown according to different specifications: small seedlings generally in April-May, medium seedlings from December to February-March of the following year, and large seedlings before spawning. There are two sowing methods, dry sowing and wet sowing. In dry sowing, after the tide recedes and the bed surface is exposed, evenly broadcast the clam seedlings to prevent them from clustering. Wet sowing is done before the tide recedes from the bed surface, evenly broadcasting in areas with slow tidal currents. Wet sowing takes longer and has a higher survival rate, but it is only suitable for medium and large seedlings.
7. During the grow-out period, inspections should be carried out frequently to promptly remove seriously harmful organisms, and attention should be paid to water quality. For clam farming with stored water in reclamation areas, observe changes in water color. On sunny days, apply 0.5-1 g of urea per cubic meter every 2-3 days to keep the water color light brown. If the water becomes clear and feed is insufficient, 1 g of soybean milk per cubic meter can be fed as a substitute feed.
8. Clam seedling rearing takes place in summer, when high temperatures can easily cause death and spoilage. In the seedling rearing process, sterilization can be carried out by sedimentation, ultraviolet light, or other methods, or by splashing bleaching powder for disinfection. To inhibit excessive reproduction of clam seedlings, 1-2 g of oxytetracycline per cubic meter can also be added to the pond.
After clams have been cultivated for 1-2 years, they can be harvested when the shell length reaches 3 cm.