What Is the 'Giant Jelly' in Rivers Making Fishermen Cry Over Dwindling Catches?

Unidentified aquatic organisms have been found in swarms in the upper reaches of the Bukhan River in Gangwon Province.

What exactly are they?

Recently, around Lake Paro in Hwcheon-gun, Gangwon Province, large colonies of Pectinatella magnifica (sessile moss animals) have been spotted spread out in lump-like forms in shallow waters.

They were found in large quantities, particularly in sections where water flow is blocked and prone to stagnation.

Pectinatella magnifica is an invasive species consisting of tiny individuals around 1 millimeter in size clustered together in a gelatinous substance, forming large rugby ball-like shapes.

Local fishermen are voicing grievances, stating that their numbers increase during severe droughts or hot weather, and that fish catches decrease accordingly.

However, based on a 2014 research study, the Ministry of Environment has previously stated that Pectinatella magnifica itself has no ecotoxicity or harmfulness.

Environmental groups argue that the frequent appearance of Pectinatella magnifica indicates an abundance of green algae or aquatic microorganisms, which serve as their food source, and could be a sign of worsening water quality.

(Photo: Yonhap News)
※ Please note: This article was translated by AI and may contain errors.