Catastrophic Impact of Red Tides of Cochlodinium polykrikoides on the Razor Clam Solen dactylus in Coastal Waters of the Northern Persian Gulf

A Cochlodinium polykrikoides red tide occurred in northern coastal waters of the Persian Gulf which killed million tons of fish and benthic animals. This study reports high mortality rate of Solen dactylus (razor clam) populations on the Golshahr coast of Bandar Abbas to show that management and monitoring plans are necessary to prevent future mass mortalities. Specimens of S. dactylus were collected during the red tide for three months in November 2008, February and April 2009. In April 2009, no clams were found in this area because all clams had died before the investigation. Abundance of razor clams showed no significant relationship with sea-surface physical and chemical factors such as sea-surface temperature, salinity, dissolved oxygen and pH (p≥0.05). Total weight of razor clams was not significantly different between November 2008 and February 2008 (p≥0.05), however, the gonad weight of razor clams in February 2009 was significantly lower than that in February 2008 (p≤0.05).