![]() ![]() increase the quantity of phytoplankton and lead to abnormal primary production. ![]() Jellyfish blooms also influenced the marine organism community, which might reduce the biomass of some fish and zooplankton, increase the amount of bacterioplankton, indirectly. The pH decreased by 1.3, while the mean dissolved oxygen demand reached 32.8 micromol x kg(-1) x h(-1). Venus’s girdle ( Cestum veneris ), a belt shaped comb jelly, can be 40 inches (1 meter) long. Larger individuals have been seen, but they are not typical. Jellyfish decomposition could cause seawater acidification and lowered level of dissolved oxygen and finally made the ambient water become acidic and hypoxic. The largest jellies are the Lion’s Mane Jellyfish ( Cyanea capillata ), which can be almost 6 feet wide (1.8 m) with tentacles over 49 feet (15 m) long. As jellyfish decomposing, the effluxes of total N and total P were 4000 micromol N x kg(-1) x d(-1) and 120 micromol P x kg(-1) x d(-1), respectively, while the efflux of DOC reached 30 micromol C x g(-1) x d(-1). Live jellyfish released dissolved organic carbon (DOC) at a rate of 1.0 micromol C x g(-1) x d(-1). Jellyfish excreted NH4+ and P04(3-) at a rate of 59.1-91.5 micromol N x kg(-1) x h(-1) and 1.1-1.8 micromol P x kg(-1) x h(-1), which could meet about 8%-10% and 21.6% of the phytoplankton primary production requirement of N and P, respectively. Jellyfish could significantly influence the form distribution and biogeochemical cycling of biogenic elements. Eutrophication, climate change, overfishing, alien invasions and habitat modification were all possible important contributory factors of jellyfish blooms. Jellyfish blooms may benefit from warmer temperature that could increase the food availability of jellyfish and promote jellyfish reproduction, especially for warm temperate jellyfish species. The temperature variations of seawater might be the major inducing factor which could result in jellyfish blooms. Jellyfish abundance increased rapidly when it encountered suitable conditions. The results showed that jellyfish blooms had a close contact with its physiological structure and life history, which had favorable characteristics including simple body struc- ture, rapid growth, thriving reproduction and short generation interval to tolerate harsh environment better. In this study, we summarized the possible inducements of jellyfish blooms, and the influences of jellyfish blooms on biogenic elements, dissolved oxygen, seawater acidity and biological community were discussed emphatically. Jellyfish blooms have damaged the normal composition and function of marine ecosystem and ecological environments, which have been one of the new marine ecological disasters. ![]()
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