The “blue tears” in Matsu County might be a result of environmental stresses affecting the reproductive cycle of the organisms that cause the phenomenon, a study in Frontiers in Marine Science authored by a research team at National Taiwan Ocean University said.
The blue luminescence in the sea near Matsu from April to August — known locally as “blue tears” — is a tourist attraction and has been listed by CNN as one of the top 15 natural scenic wonders of the world.
The blue tears result when sexual reproduction among Noctiluca scintillans, a bioluminescent red-tide algae, rapidly increases, National Taiwan Ocean University professor Chiang Kuo-ping (蔣國平) said on Friday.
Photo courtesy of Lienchiang County Government
The study sought to determine factors that prompt an uptick in sexual reproduction of the organisms, which usually reproduce asexually, and the ecological role in that change, Chiang said.
“Reproduction in N scintillans involves both sexual and asexual processes. The vegetative cell, or trophont cell, mostly undergoes binary fission, but randomly undergoes gametogenesis, which produces gametes that afterward fuse in pairs form zygotes,” the authors wrote, adding that gametogenesis — which enables sexual reproduction — might be triggered by environmental stresses, “including temperature, light exposure time, prey concentration, N scintillans concentration, cultivation time, cultivation volume and simulated wave motion.”
The reproduction cycle occurs annually, usually between March and July, with the arrival of sediment from the Min River (閩江) — which enters the Taiwan Strait near Fuzhou in China’s Fujian Province — resulting in red tides in the morning and the “blue tears” at night, Chiang said, adding that the phenomenon usually occurs for one or two days.
The critical value for N scintillans to reproduce sexually was found to be 35,400 prey cells for each N scintillans, indicating that the fewer prey cells there are after a certain amount of population growth, the more likely it is that N scintillans would reproduce sexually, he said.
The team found that after an exponential phase of population growth, the encounter rate with prey decreases, prompting an increase in the sexual reproduction rate from the usual 1 percent to as much as 10 percent of the population, Chiang said.
This results in the “blue tears” bloom and also lays the foundation for the next bloom period, he said.
The study, Sexual reproduction in dinoflagellates — the case of Noctiluca scintillans and its ecological implications, was authored by doctoral student Jeffery Lee (李良能), and coauthored by Chiang and assistant professor Tsai Sheng-fang (蔡昇芳).
It was published in the journal’s Nov. 17 edition.
Considering that most countries issue more than five denominations of banknotes, the central bank has decided to redesign all five denominations, the bank said as it prepares for the first major overhaul of the banknotes in more than 24 years. Central bank Governor Yang Chin-lung (楊金龍) is expected to report to the Legislative Yuan today on the bank’s operations and the redesign’s progress. The bank in a report sent to the legislature ahead of today’s meeting said it had commissioned a survey on the public’s preferences. Survey results showed that NT$100 and NT$1,000 banknotes are the most commonly used, while NT$200 and NT$2,000
The Centers for Disease Control (CDC) yesterday reported the first case of a new COVID-19 subvariant — BA.3.2 — in a 10-year-old Singaporean girl who had a fever upon arrival in Taiwan and tested positive for the disease. The girl left Taiwan on March 20 and the case did not have a direct impact on the local community, it said. The WHO added the BA.3.2 strain to its list of Variants Under Monitoring in December last year, but this was the first imported case of the COVID-19 variant in Taiwan, CDC Deputy Director-General Lin Ming-cheng (林明誠) said. The girl arrived in Taiwan on
South Korea is planning to revise its controversial electronic arrival card, a step Taiwanese officials said prompted them to hold off on planned retaliatory measures, a South Korean media report said yesterday. A Yonhap News Agency report said that the South Korean Ministry of Foreign Affairs is planning to remove the “previous departure place” and “next destination” fields from its e-arrival card system. The plan, reached after interagency consultations, is under review and aims to simplify entry procedures and align the electronic form with the paper version, a South Korean ministry official said. The fields — which appeared only on the electronic form
The Ministry of Foreign Affairs (MOFA) is suspending retaliation measures against South Korea that were set to take effect tomorrow, after Seoul said it is updating its e-arrival system, MOFA said today. The measures were to be a new round of retaliation after Taiwan on March 1 changed South Korea's designation on government-issued alien resident certificates held by South Korean nationals to "South Korea” from the "Republic of Korea," the country’s official name. The move came after months of protests to Seoul over its listing of Taiwan as "China (Taiwan)" in dropdown menus on its new online immigration entry system. MOFA last week
RSS