en Ecology Ecology پژوهشي Orginal research papers <span style="font-size:11pt"><span style="line-height:120%"><span sans-serif="" style="font-family:Calibri,"><i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">Noctiluca</span></span></span></span></i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"> is a dinoflagellate genus that causes algal bloom and is distributed in the tropical coastal waters of the Pacific and the Indian Oceans. </span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">The blooming of the species on the southeastern coast of Iran (the north part of the Oman Sea) is usually green and happens in the cold seasons. </span></span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">A dense harmful bloom of <i>Noctiluca</i> <i>scintillans</i> was reported in February and March 2020 along the coastal waters of Chabahar Bay (Iran) on a significant scale. </span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">Sampling was carried out from three stations located in the bloom areas. This study aimed to evaluate the distribution of the bloom in Chabahar Bay using field data and remote sensing, as well as examining <i>N. scintillans</i> cells and identifying the species that were present in the bloom area. The results of microscopic counting revealed a high density of <i>N. scintillans</i>. The bloom duration was about 22 days; with a density of 2</span></span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">.37</span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"> &times; 10⁵ cells L^-1. Apart from <i>N. scintillans</i>, 20 species of phytoplankton including 10 species of dinoflagellates, 9 species of diatoms, and 1 other phytoplankton species were identified. The bloom caused the mortality of marine organisms including jellyfish, crabs, and green sea turtles. Although <i>N. scintillans</i> is classified as a non-toxic species, it can lead to the mortality of marine organisms such as fish and invertebrates by causing severe hypoxia and ammonia release.</span></span></span></span></span></span></span> Bioluminescent dinoflagellate, HABs, Chlorophyll a, Gulf of Oman, Red tides 261 277 http://jifro.ir/browse.php?a_code=A-10-4593-1&slc_lang=en&sid=1 M.A. Asefi M.ali.asefi@gmail.com 100319475328460047740 100319475328460047740 No Department of Marine Biology, Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran G. Attaran-Fariman gilan.attaran@gmail.com 100319475328460047741 100319475328460047741 Yes Department of Marine Biology, Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran