Why do starfish gather?

This is not the first time this has happened. A large number of starfish gathered in 2007 and last year. The fishermen at that time were all aware of this situation and worked with the local government to control the massive breeding. Starfish have been hunted and killed, but the results are not satisfactory. The situation of starfish gathering and harming the ecological chain of the surrounding sea areas has not been resolved.

Starfish are called "undersea locusts". Once they attack, clams, oysters and other seafood will be damaged. The starfish that have exploded in Qingdao waters in recent years are mainly starfish of the class Spiny Sea Spiny, which are common cold-water species along the Yellow Sea coast in my country. The optimum growth temperature is 15-20°C, and the upper limit of the optimum temperature is 25°C. It grows from October to January of the following year. Reproduction occurs every month. Starfish are greedy predatory organisms that have a great impact on the composition of the benthic animal community in the distribution area. They are an ecological harmful organism and an important harmful organism in the marine aquaculture industry.

For example, on March 15, 2021, according to the Qingdao Municipal Ocean Development Bureau, the starfish outbreak that year was mainly concentrated in the oyster and clam bottom-sown sea area in Jiaozhou Bay. According to rough statistics, the starfish density reached an average of 50/square meter. meters, the affected area is about 100,000 acres, and the economic loss is expected to be about 100 million yuan. After the starfish outbreak, local fishermen used artificial fishing and other methods to kill about 450,000 kilograms of starfish. However, the situation this year is not better than last year. The reason is mainly affected by the following three reasons:

First, changes in the marine ecological environment

The nutrition of sea water quality Changes in various hydrological factors such as salt, pH value, and water temperature provide suitable natural conditions for the growth and reproduction of starfish. Starfish have strong reproductive power and a very low survival rate. However, studies have shown that if slight changes occur in the marine ecosystem, resulting in an increase in the survival rate of starfish larvae, then with almost no natural enemies, starfish will easily increase in large numbers and starfish will move from the deep sea. to shallow seas, causing starfish to rapidly spread and explode in shellfish breeding areas.

2. The feeding habits of starfish

Starfish have the habit of gathering in food-rich areas and mainly prey on bivalves, sea urchins, oysters and sea anemones. As a shellfish breeding area, Jiaozhou Bay's bottom-sown oysters and clams provide sufficient food for starfish and provide an environmental foundation for the mass reproduction of starfish. Some scientific researchers have conducted surveys in shellfish breeding areas. There are often many starfish in the breeding areas, but there are very few outside the breeding areas. Starfish outbreaks in Qingdao in 2007 and this year almost all occurred in breeding areas.

3. The number of natural enemies has decreased

Due to climate and other factors, the number of fish that prey on starfish eggs and larvae in coastal waters has dropped sharply, providing the possibility for an increase in starfish biomass. .

Among these three reasons, changes in the marine ecological environment are the main cause. In the past, the temperature and sea water in nature were not suitable for the growth of starfish, but in the past two years, changes have quietly occurred that have made starfish The survival rate increased geometrically. But natural changes do not happen once a year, and change takes a long time. Faced with the thorny problem of starfish flooding, all we can do is to increase our efforts to catch starfish and minimize the harm.

Of course, some people have fantastic ideas and wonder if we can destroy them with our stomachs if we increase our intake of starfish. This idea is very beautiful, but in reality it is not easy to realize. First, the growth and reproduction of starfish are too fast. Without control, human natural consumption alone will never be able to keep up with its reproduction speed. In addition, starfish are troublesome to use in food processing, and their meat quality is not acceptable to the public. Again, the idea is beautiful, but the reality is very skinny.

We can also see from this how important it is to protect our oceans and natural environment. This is the cornerstone of peaceful coexistence between humans and other creatures. When each other’s territory is invaded, the two parties The beginning of conflict for survival, and there is no beauty at all.