Change of Fish Distribution
Change of Korea Fish Distribution
Change of Korea Fish Distribution
Increasing appearance of jellyfish
On the other hand, recently sea nettle recognized as a leading marine biological disturbances is treated in connection with climate change issues. jellyfish inhabit 250 species in the world and koras had found 31 species. In particular, 'ipgit Nomura jellyfish' is a great deal problem in our country. The maximum size 1.5m, 200kg and has a weak toxicity.
In the South China Sea and the South China Sea seems to be caused entering our country. The operation problem is generated mainly in the summer by this. The reason of repeatedly appeared of a large mass of jellyfish estimated to be combination of the competitors decreasing and habitat increasing due to rising water temperature.
It is determined that the emergence tropical organisms and habitats expansion is due to increased minimum temperature of the water of determining inhabit range(limit). While a filefish, walleyed pollack (cold water fish) has disappeared. Walleyed pollack, fish caught in the East Sea one of the most well, was the lowest annual catches about 1t in 2010. The annual caught of walleyed pollack was 96,000t in 1980.
Emergence of subtropical species
It was confirmed that subtropical species commonly found such as whale sharks, tremoctopus violaceus gracialis, blue Marlin, Black marlin, Excuse rockfish. The impact of global warming occurs increasing ocean current power. So the southern subtropical in the south come up to Korea coast.
Three kinds of coastal fisheries was occupied catches rate of 52.1% for the entire country in 2000s. Three kinds of coastal fisheries is mackerel and anchovies, squid. The catch rate of these three species was only 22.3% in the 1970s, 20.8% in the 1980, climbed to 40.5% in the 1990s, surpassed the half in the 2000s. In particular, these species including 10 kinds of fish(pike, bass, yellowtail, mackerel, mullet, mackerel, sardines, etc) catches rate of turbulent surface layer were accounted for nearly 60 percent.
The catch rate of about 10 species in the turbulent was increased from 28.0% in the 1970s to 59.2% since 2000.
Change of fish distribution
Global warming has caused 3 unsual pharmacists about change of fishery resource with regard to the ocean changes around korea. First, turbulence fishing speices going north, and then capture period of this species are increasing, Lastly,a catch during the winter season is a greatly increased. Especially, there is deeper change of fishery environment that fishery in littoral sea is decreased an output of cold-water fishes like pollack, sailfin sandfish due to change temperature and increased of warm-water fishes like squid, anchovy and tuna.
Rising temperature in Korea
Rising temperatures of Korean sea water is three times faster than the global average. After studying Jeongseon about Ocean observations 207 places of the coastal waters, The nation’s Fisheries Research and Development Institute issued. The temperature of the surface layer around Korea were up by 1.29 degree from 1968 to 2010 for 43 years.
Considering only increase 0.4 degree of the temperature of global surface layer during that same time period, the temperature of littoral sea exceed three times faster than the global average.
Climate change like rising water temperature, there are ecological change about a catch, fishes distribution in Korea. In the case of Korea, water temperatures rised 1.35 degree on Feb, 0.7 degree on Aug. since the summer season, the winter session showed high rate of rise. For search a rate of rise , that is increased steeply in recent time.
Inshore turbulent species such as anchovy, mackere, squid was northward distribution in the winter, also increases catch due to high density distribution.In the case of squid, fishery was moved northward between 1998 and 2000 compared to the mid-1970s. As a result, catches in winter has increased 2.5~6 times compared to the previous 1980s since 1995. Recently chromis notata that famous for main template area is Cheju has caught a lot of the South Sea.Also recent trend fishery is Northward up to the east sea. Percentage of annual catches for the winter fishing had less than 5% before 1975 but increased to 13% level since 1990s.
Only obsereved in Jeju subtropical species such as Saw crab, gaetga residence, tiger shrimp, and tropical creatures have emerged the south coast. It was confirmed that the subtropical coral reef that found the first south coast in 2007 has spread across the south coast.