Some areas near the shore at Bostanlı beach in Izmir's Karşıyaka district, western Türkiye, have turned green due to an increase in nitrogen and phosphorus levels in the water, leading to the growth of seaweed. Professor Dr. Ergün Taşkın, head of the Hydrobiology Department at Manisa Celal Bayar University’s Faculty of Engineering and Natural Sciences and a marine biologist, stated, "As we enter the gulf, a seasonal increase in algae can be observed. Although there may be a slight decrease in winter, a significant rise will occur again in spring."

Certain points near the shore at Bostanlı Beach have been covered by seaweed caused by increased nitrogen and phosphorus levels in the water. Algae, which emerge due to seasonal changes and pollution, have spread in the polluted Izmir Gulf. Professor Dr. Taşkın noted that nutrient elements brought to the Inner Gulf by waste and discharge waters and from streams have contributed to the increase in water weeds, explaining that algae along the Inner Gulf coasts can appear several times throughout the year.

Dr. Taşkın emphasized that algae help balance the marine ecosystem, stating, "At one point, algae were collected from the coast; due to their collection, there was an increase in phytoplankton in the inner gulf, which caused fish deaths by clogging their gills. Although we do not want such macroalgae in the gulf, they are beneficial for regulating the nutrient elements and pollution that come to this area."

He added that algae do not harm humans, but "They create visual pollution. Excessive algae growth harms the ecosystem; when they die at the end of summer, their decomposition consumes oxygen and produces carbon dioxide. This leads to an oxygen-depleted environment and creates a muddy structure at the bottom, which can result in odor."

"The most important thing that can be done here is to completely stop terrestrial inputs, discharges and wastewater and then use dredging methods to collect the sediments at the bottom for disposal. If nutrient elements and polluted water inputs are prevented, opportunistic algae will gradually be removed from the environment."

Dr. Taşkın pointed out that some algae are opportunistic and tolerant species, continuing, "As we enter the gulf, a seasonal increase in algae can be observed. While there may be a slight decrease in winter, a significant rise will occur again in spring. This is because algae reproduce with spores. Even if you collect them from the shore, their spores remain in the water, and when conditions are suitable, they can quickly grow and cover the area again."

This comes after a troubling situation in Izmir Bay, where pollution-related odors and fish deaths adversely affect local businesses in Kordon, a popular tourist destination on the Aegean coast of western Türkiye. The environmental crisis began on Aug. 20, with dead fish washing ashore at Turan Beach in Bayraklı and has since expanded to various shores of the bay.

Changes in the sea's color and the presence of dead fish have been reported in the Kordon area, which stretches approximately 4 kilometers (2.48 miles) between Konak and the Port of Alsancak, contributing to the worsening odors.