Koh Lan: Azure sea turns green from wastewater-induced phytoplankton bloom
In the popular tourist island of Koh Lan off the coast of Pattaya Beach, a startling twist of events made headlines when the placid blue seawater abruptly turned into an unattractive shade of green, as reported by the Department of Marine and Coastal Resources (DMCR).
Koh Lan, characterised by its renowned turquoise shoreline, is found 7 kilometres off the coast of Pattaya Beach and was checked for possible issues when alarming photographs of its transformed green sea surfaced online. This inspection, driven by a post on the We Love Pattaya Facebook page, was conducted at Ta Waen Beach on the island.
DMCR deputy director Apichai Aekwanakul guessed that the significant transferal of wastewater into Koh Lan’s seabed, which has been perpetuated over time, is one of the primary catalysts for the discolouration of the sea. Observable on Saturday, swimming in the sea was cautioned against due to reduced visibility. The water’s green hue, according to Apichai, is the consequence of a blooming of a particular kind of phytoplankton known as Noctiluca scintillans, which, while not deadly, usually surfaces annually across the eastern seaboard.
The progression of the bloom escalates exponentially during the rainy season, as nitrogen and phosphorous stemming from wastewater become washed into the sea. These nutrients invigorate the growth of the phytoplankton, eventually causing the emergence of its characteristic green hue alongside an unwelcome odour. The DMCR, along with associated agencies, is set to conduct further investigations into the health repercussions of this event, the potential requirement for warnings and the undertaking of additional research.
A faculty member from Kasetsart University’s Faculty of Fisheries, Thon Thamrongnawasawat, stated that this phytoplankton bloom, in conjunction with the extraordinary spawning behaviour of leatherback turtles in Phuket during the off-season, should be observed closely by environmental enthusiasts. Thon explained on his Facebook page that these occurrences are indicative of changes in the marine ecosystem caused by natural patterns and human activities.
Thon noted that the appearance of the phytoplankton bloom during a period when the impact of El Nino is set to intensify is unusual and should prompt investigations. Despite diminished rainfall usually resulting in a decreased likelihood of phytoplankton blooms, this year seems to be an exception to the rule, especially in the upper parts of Thailand’s Gulf within the Eastern Economic Corridor (EEC).
The United Nations recently associated these growing irregularities with global boiling, and Thon speculated that these anomalies, specifically the plankton bloom, might pose a threat to the tourism industry, especially in peak seasons, reported Bangkok Post.
