Fish deaths and unpleasant odors observed along the coastline of the Bayraklı district in Izmir Bay on the Aegean coast of Türkiye have spread to the Karşıyaka shore.

Following the discovery of dead fish and foul odors on Aug. 20 at the Turan area of Bayraklı district, cleaning operations have been underway by the Izmir Metropolitan Municipality. The Provincial Directorate of Agriculture and Forestry and the Provincial Directorate of Environment, Urbanization and Climate Change are also conducting laboratory analyses of water and dead fish samples.

The fish deaths have now spread to the Bostanlı shore in Karşıyaka district, with numerous dead fish seen floating on the sea surface and washing ashore. The color of the seawater in the bay has turned green and brown.

Professor Esin Süzer, a faculty member of the Marine Sciences Department at Dokuz Eylül University Institute of Marine Sciences and Technology, stated that they have been studying Izmir Bay since 1999. Although there is a treatment system in the bay, the high population density has led to domestic and industrial pollution.

Süzer noted, "This has resulted in high levels of nitrogen and phosphorus nutrients in the bay, causing microalgae blooms. When these algae proliferate excessively, the oxygen levels in the water drop to critically low levels, leading to fish deaths. The low oxygen saturation due to high temperatures and slow currents, particularly in the inner bay, exacerbates this issue. These deaths are a consequence of pollution-induced oxygen deficiency and gill blockages."

Professor Ergün Taşkın, head of the Hydrobiology Department at Manisa Celal Bayar University's Faculty of Engineering and Natural Sciences, noted that their research indicates Izmir Bay is among the lowest in Türkiye for water quality.

Taşkın confirmed that the main cause of the fish deaths is oxygen deficiency due to pollution, with hot weather also playing a role.

Nursel Ölmez, the mukhtar of the Turan neighborhood, highlighted that the area is experiencing intense odors due to the fish deaths and expressed the need for prompt removal of the dead fish.