[Seawater decomposition] Why do flounders keep being caught? Management of fisheries resources to protect our tables

[※ Editor's note = The Ministry of Oceans and Fisheries, which moved to Busan, celebrates its 30th anniversary this year. Marine and fisheries administration spans a variety of fields, from sea safety to marine research, but its role and importance are not easily revealed. Yonhap News publishes a special article once a week that ‘disassembles’ the work of the Ministry of Oceans and Fisheries and its affiliated organizations one by one.]

(Busan = Yonhap News) Reporter Park Seong-je = Flatfish, one of the fish commonly found in raw fish restaurants.

The official name of flounder, loved for its chewy texture and light taste, is flounder.

However, among the flounder caught in the sea, there are fish that were raised by humans when they were young and then released into the sea.

This is the result of artificially produced young flounder, or fry, being released into the sea to increase fisheries resources.

So, the more young flounder released, the better?

That's not necessarily true.

Artificially produced halibut may have low genetic diversity.

Releasing large quantities of flounder with similar genetic characteristics can also affect the genetic diversity of flounder in the sea.

This is the opportunity for the Korea Fisheries Corporation to implement the ‘Released Seed Certification System’ starting in 2016.

The Corporation secures wild flounder every year and supplies fertilized eggs with genetic diversity to private companies, and certifies the young flounder produced through this for release.

Currently, all flatfish released into Korean seas are fry born from fertilized eggs supplied by the corporation.

It's not just about releasing a lot of fish, it's about managing them to maintain healthy fisheries resources.

The Korea Fisheries Resources Corporation is increasing and managing the marine resources of the sea so that the marine products on our tables can be produced in abundance in the future.

Releasing young fish into the sea does not automatically increase fisheries resources.

It is also important to manage the fish to avoid catching too many grown fish.

Marine products that often appear on our tables, such as mackerel and squid, are bound to become scarce if we catch them recklessly.

The system operated to prevent this is the ‘Total Allowable Catch (TAC)’.

Considering the status of fishery resources, the amount that can be caught per year is determined and fishing is limited to that range.

How can we check how much fishing boats actually caught?

When a mackerel fishing boat enters the port after finishing its fishing operation and unloads the caught mackerel, a fishery resources inspector on site checks the catch.

The confirmed catch is deducted from the TAC assigned to the fishing vessel.

When the National Institute of Fisheries Science evaluates the resource status of each fish species and the Ministry of Oceans and Fisheries confirms the annual TAC, the Corporation verifies the catch amount on site.

To this end, the corporation deploys about 130 fishery resource investigators to 135 designated sales locations across the country to manage the catch and TAC exhaustion rate of each fishing vessel.

Unlike checking the catch at a port, fishery resources can be inspected directly on a fishing boat in the distant sea.

A representative example is ‘international observers’ who board deep-sea fishing vessels.

International observers are professional personnel who independently observe and record the fishing process of deep-sea fishing vessels in accordance with the rules established by the International Fisheries Management Organization.

We investigate everything from when, where, and how the fish were caught to what species of fish and how much were caught.

The body length and weight of the caught fish are measured, and whether they are released back into the sea is also recorded.

During the fishing process, we also check whether sharks, sea turtles, seabirds, marine mammals, etc. are unintentionally caught together.

The data collected in this way is submitted to the International Fisheries Management Organization and used to assess the stock status of major fish species and ensure that international fishing rules are followed.

There are also problems that are difficult to solve simply by increasing the number of fish and managing the amount caught. It's climate change.

Pollock, which was once common on our tables, has become rare, and the marine ecosystem is changing rapidly, with squid, which was mainly caught on the east coast, now being found on the west coast.

Over the past 57 years, the surface water temperature of the sea around Korea has risen 1.58 degrees. This is more than twice the global average increase.

In preparation for climate change, the Corporation plans to spend 19.8 billion won to build a 'Climate Response Fishery Life Resources Center' on Jeju Island and develop seed production and management technologies for new varieties that adapt to high temperatures, such as tilefish and barley.

We also plan to pay attention to the carbon absorbed by seaweed in the sea, measure how much carbon seaweed absorbs, and establish a system to record and verify the results.

An official from the Corporation said, "We will do our best to protect the marine products on our tables, from increasing the number of fish in the sea to preparing for the future marine environment."