Fishing, Storage, Transportation, Fishing Seasons and Waters of Ship-Frozen Pacific Mackerel

Fishing steps

1. Fishing Methods

The common fishing methods include light purse seine fishing and trawl fishing:

Light purse seine fishing leverages the phototaxis of Pacific mackerel. Fish schools are lured by lights first, then captured using a purse seine.

Trawl fishing involves dragging fishing nets through the water to catch mackerel schools.

2. Fishing Precautions

When catching large quantities of Pacific mackerel, on-board gutting is usually not performed—this is because the fish are small in size and large in number. The intestines of Pacific mackerel often contain a large amount of food; if not handled promptly and kept at a low temperature, digestive juices may quickly damage the fish’s abdominal walls, causing the fish meat to soften. Generally, if the temperature is not lowered within 6 hours after capture, the fish’s abdomen may rupture.

Storage and Transportation Process

1.       On-Board Fresh Preservation

The commonly used method is chilled seawater preservation:

Place the catch into insulated holds.

Add ice and salt (ice is used to lower the temperature, while salt lowers the freezing point).

Once the holds are full, inject seawater and start the refrigeration system to maintain the mackerel temperature between 0°C and -1°C.

This method enables rapid cooling and timely handling of large quantities of mackerel fish. However, it has drawbacks: the fish may absorb water and salt, resulting in slightly salty meat, and the shaking of the ship may cause damage to the fish bodies.

2. Transportation

A low-temperature environment must be maintained during transportation. Refrigerated transport ships or refrigerated containers are generally used, with the temperature usually kept below -18°C. This inhibits bacterial growth and enzyme activity, thereby extending the shelf life of Pacific mackerel.

Fishing Seasons

In the Sea of Japan, the fishing season for Pacific mackerel(scomber japonicus) generally runs from August to April of the following year.

Fishing Waters

Pacific mackerel are widely distributed in the western Pacific Ocean, and fishing operations are conducted in the coastal waters of countries such as China, Japan, and South Korea. Specific fishing waters include the East China Sea and the Sea of Japan. In addition, Pacific mackerel are also fished in the Indian Ocean—for example, Chinese ocean-going fishing vessels catch ship-frozen Pacific mackerel in Indian Ocean fishing grounds.