China along the offshore frequent starfish outbreaks, undersea locust plague suffering shellfish farmers, but also to sound the ecological alarm.
“On average, one person fishes 8 or 900 pounds (of starfish) a day, and there are many places to gather piles of ah!” Qingdao fishermen busy unloading, “this year than in previous years came more.” A fishing boat full of dock, but the fishermen look sad, starfish like locusts sweeping shellfish culture area, salvage to hand weak every day.
In the past few years, China’s “submarine locust plague” has been spread frequently, like an explosive fuse planted along the offshore, from the Yellow Sea, East China Sea all the way to the South China Sea, different kinds of starfish outbreak invasion. The echinoderms, which are both familiar and unfamiliar to humans, have assembled as an army of “assassins”, carrying a silent flare that man-made disasters are far greater than natural ones.
Super Assassin Raids Jiaozhou Bay
The latest uninvited guest to invade Qingdao’s waters is a multi-spined sea pannier. (Photo by Kunxuan Li)
The starfish that recently appeared in large numbers in Jiaozhou Bay in Shandong Province is Asterias amurensis, said Dr. Kun-Chuan Lee, assistant researcher at the National Museum of Natural Science in Taiwan, adding that this starfish is native to the Yellow and Bohai Seas and Japanese waters around China, Korea, Japan and Russia, and was later brought around the world with the ballast water of ships, and is listed as one of the top 100 invasive alien species in the world. prefer cold seawater from 5 to 20°C, while the salinity that they can tolerate varies greatly, so they can appear in the sea near estuaries and survive in marine environments from the intertidal zone to water depths of 220 meters, and the sandy bottom and reef area seabed can be adapted.
“Multi-spined sea coasters of different ages will gather in groups and like to prey on bivalve shellfish, like oysters, clams, sea fans and other economic species.” Kun-Xuan Li has been studying the ecology of sea stars for many years and has also visited Qingdao, “The sea pansies have a significant impact on the ecology and economy of the invasion site, even causing the decline of some endangered species.”
The average density of starfish in Qingdao’s aquaculture area is as many as 50 per square meter, with more than 450,000 pounds salvaged by mid-March. Li Kunxuan pointed out that the diameter of the multi-spined sea pannier is about 20 to 30 centimeters, and with this year’s density, it is almost equal to two layers of starfish per square meter of seafloor, which can be said to be a major outbreak of conditions.
Qingdao farmers are like a big enemy, because where the starfish arrive, scallops and clams are almost swept away, and the economic loss this year is estimated at RMB 100 million.
“The multi-spined sea disc car has strong carpal feet that can pull a slit in the bivalve shell hard, then the stomach turns out and sticks inside the shell slit, then secretes digestive juices and ingests the shell meat.” Winston Lee illustrates the unique feeding style of sea stars, “They are very greedy, eating half of them and throwing them away to find the next one again, so they are very harmful to farmers.”
An imbalanced marine ecology
Shandong’s coast is not the only starfish outbreak, seaweed and jellyfish infestations are also headaches
Scientists see the “epidemic” of starfish flooding as one of the indicators of the deterioration of the marine environment and climate change. Huang Dengfu, professor emeritus of the Marine Biotoxicology Research Office of Ocean University in Taiwan, believes that the starfish outbreak is related to the pollution of Shandong waters, plus the size of the snails may be fished out, the natural enemies of the starfish followed by the disappearance of the marine ecological environment is out of balance.
The Institute of Oceanography of the Chinese Academy of Sciences has been monitoring and researching in Qingdao waters for several years, and Kun-Xuan Li said that one of the answers is that the marine ecology has changed significantly, with various chemicals and fertilizers flowing into the local waters from the land, making the water eutrophic, and the water temperature has also changed under the influence of land-based activities. causing an increase in the survival rate of starfish larvae and a large outbreak in a short period of time.
“As a shellfish farming area, Jiaozhou Bay provides sufficient food for starfish with its bottom-sown oysters, clams and scallops, providing an environmental basis for their mass reproduction.” Kunxuan Li further analyzed, “In addition, under the influence of climate and overfishing, the number of fish and invertebrates that prey on starfish eggs and larvae offshore has declined sharply, which also provides the possibility for the growth of starfish biomass.”
Kun-Xuan Li pointed out that the whole sea near the Yellow and Bohai Seas and the Sea of Japan has seen an increasing population, disturbances from human activities and pollutants discharged into the sea have damaged the marine ecological chain, causing some species to disappear and others to find room to survive and explode, not only starfish, but also jellyfish almost every year, and the whole sea is getting worse and worse. Huang Dengfu said, China’s coast from time to time there are large outbreaks of algal blooms, Qingdao waters are the hardest hit, which means that the sea appears obvious eutrophication, resulting in abnormal algal blooms.
The footprints of the multi-spined sea coasters have also crept into the waters of Taiwan’s home island, “The live ones collected around 1995 were from the eastern lead of Matsu, however, in 2011 they were surprisingly found in crab cages on the north coast, and there have been quite a few of them, and they were even put on sale at the stalls of Fuki Fishing Port on the north coast.” Winston Lee said, “This may have something to do with global warming and rising seawater temperatures, so the habitat is expanding from the temperate zone to Taiwan’s waters.”
Devil starfish chew up coral
The crown-of-thorns starfish is known as a coral killer and a serious threat to the biodiversity of coral reef areas.
Not only the multi-spiny sea plate car, in recent years the waters of southern China also appear large-scale “coral killer” spiny crown starfish (or long spiny starfish, Acanthaster planci), Hainan Yalong Bay coral reserves have been spiny crown starfish sweep, gnawing after a large coral white bones, from the Great and Little East China Sea to the South China Sea of the Xisha In 2010, the four islands of Penghu, Taiwan also had a large number of suspected outbreaks.
“Most of the spiny crown starfish inhabits tropical and subtropical waters, the main food is coral, once a large number of growth, the local coral may die or become extinct, and coral reef areas provide living space for a variety of marine organisms, the starfish after large-scale destruction, causing serious threats to biodiversity.” Huang Dengfu points out the potential crisis, “this starfish has at least 3 types of toxins, just touch it will be painful or neurological symptoms, so also known as the devil starfish.”
The density criteria for starfish biohazards vary according to species and condition. For example, in the case of Australia’s crown-of-thorns starfish, each one can eat about 5 to 13 square meters of live coral per year, less than one per hectare under natural conditions, and if there are more than 30 per hectare, it is considered a major outbreak.
The number of spiny starfish skyrocketed, experts generally attributed to the eutrophication of the water, the French snail, the Sumi fish and other natural enemies are also an important reason for the reduction. Huang Dengfu said that the Penghu waters may appear spiny crown starfish with nutrient salts become rich, some speculate that the Yangtze River dam has changed the concentration of nutrient salts, starfish larvae drift to Penghu waters, the number of communities grow rapidly.
Agricultural fertilizers irrigate starfish
China’s fertilizer use accounts for about 30% of the global total, fertilizer also indirectly for the ocean “fertilization”, contributing to the proliferation of starfish.
Australia’s Great Barrier Reef has repeatedly seen a proliferation of crown-of-thorns starfish, swallowing coral reefs, scientists point the finger at human activities, including the decline in water quality and a large amount of agricultural fertilizers into the sea. “Starfish larvae are zooplankton and feed on planktonic algae in the water, these agricultural fertilizers are equivalent to fertilizing the sea to make the planktonic algae grow better and increase the food and survival rate of starfish larvae.” Winston Lee explained, “International studies have shown that every doubling of the density of large planktonic algae allows 10 times more growth and survival of starfish larvae, so causing a vicious cycle of a major starfish outbreak.”
There is a long-standing problem of fertilizer pollution along the coast of Shandong, and in recent years the saline wasteland in the Bohai Sea area has been developed in a big way as a granary, with coastal agricultural activities providing environmental conditions suitable for the survival of starfish. According to Kun-Xuan Li, after the development of saline wastelands, land-based fertilizers wash into the sea, increasing nutrients for algae and providing a juvenile food source for starfish, also contributing to the starfish population.
In the face of the difficult starfish epidemic, most countries around the world take human resources to remove them. In addition, the Great Barrier Reef in Australia also uses bile salt injections for starfish to kill them directly in the sea; multi-spined sea plates are also caught ashore by diving, which is the This is the most effective way to suppress them, and they can be sold to recover some costs.
On the contrary, the authorities in Qingdao, in order to quickly solve the starfish disaster, in addition to manual fishing, the simultaneous opening of the use of ground cage net trapping or trawling, the time limit until the end of April, and later depending on the effect of starfish cleanup to study and determine. Winston Lee said the hidden problems, “This is not only the marine life caught up, together with the destruction of the sea floor topography and habitat, this is not a good way.”
Starfish plague feeds on itself
Stallholders can be found in Beijing and Qingdao, China, selling starfish skewers.
Qingdao local people are also encouraged to eat starfish, buyers are “star-crossed” flock to the sea, in the end the sea plate car can eat? Huang Dengfu said, multi-spined sea car contains saponification (saponin) this ingredient, this herb was included in Li Shizhen’s “Compendium of Materia Medica”, the Chinese community also used as an ingredient, some people will eat too much diarrhea or headache, which may be the saponin in play, however, there are many types of starfish, toxic may appear vomiting or coma and other symptoms, the current use and consumption of starfish generally no food hygiene units to keep watch. And information is also quite lacking, consumers should be extra careful.
“Most of the local dishes are steamed and eaten from the gonads inside the starfish, similar to sea urchins. Winston Lee said of his experience in Qingdao, “I tried it myself and it was very fishy and hard to eat.”
However, starfish are a plague, and humans can’t stop catching and eating them, so they will eventually eat the consequences. The only way to maintain a stable balance in nature is to reduce human intervention and avoid the discharge of chemicals and pollutants into the sea, which is also the way to cure marine biological disasters.
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