Following the report of
Crambionella orsini
bloom
in the project of stock assessment of benthic resources in the Oman Sea and the announcement of its density and distribution in the deep layers of the ocean and in the various regions, it has been repo
rted by fishermen during traditional fishing in Chabahar County that
Crambionella orsini
were massively entrapped in tuna gillnets in the offshore waters of the Oman Sea in the latitude of 14 to 24 degrees north and longitude 63 to 66 degrees east. Trapping
Crambionella orsini
in tuna gillnets has caused the nets to compact in the water, which eventually results in reduced fishing efficiency of tuna gillnets at each stage of the catch and ultimately at each voyage. Upon examination of the available documents, it was found that the invasive jellyfish was
Crambionella orsini
which previous reports also indicated. Given the reports of
Crambionella orsini
bloom in the waters of other countries around the Persian Gulf and the Oman Sea as well as observations by local fishermen engaged in tuna fishing in the offshore waters of the Sistan and Baluchestan Province, it can be concluded that the bloom of this species of jellyfish species is not specific to the Iranian waters of the Oman Sea, but that
Crambionella orsini
bloom is widespread in the Western Indian Ocean. This species is native to the Western Indian Ocean region and adjacent basins. Therefore, it can be assumed that due to the influence of ocean currents, Crambionella orsinibloom in the Western Indian Ocean region has extended to the waters of the Oman Sea and it has remained stable after reaching the Oman Sea due to the favorable ecological conditions in the region.The presence of specific environmental conditions such as ocean currents brings the jellyfish together and this causes the jellyfish to form huge colonies which can lead to jellyfish bloom in the territorial waters and causing damage to fishing activities in the area. Therefore, monitoring of their distribution and factors affecting the bloom of this species is the first step in predicting and managing the effects of jellyfish bloom.