Fish Kill Incidents and Harmful Algal Blooms in Omani Waters

Abstract

Red tide, one of the harmful algal blooms (HABs) is a natural ecological phenomenon and often this event is accompanied by severe impacts on coastal resources, local economies, and public health. The occurrence of red tides has become more frequent in Omani waters in recent years. Some of them caused fish kill, damaged fishery resources and mariculture, threatened the marine environment and the osmosis membranes of desalination plants. However, a number of them have been harmless. The most common dinoflagellate Noctiluca scintillans is associated with the red tide events in Omani waters. Toxic species like Karenia selliformis, Prorocentrum arabianum, and Trichodesmium erythraeum have also been reported recently. Although red tides in Oman have been considered a consequence of upwelling in the summer season (May to September), recent phytoplankton outbreaks in Oman are not restricted to summer. Frequent algal blooms have been reported during winter (December to March). HABs may have contributed to hypoxia and/or other negative ecological impacts.

Overview of Decadal Ecosystem Changes in the Western Arabian Sea and the Occurrence of Algal Blooms

“…This is similar to Korean waters where large annual blooms of Cochlodinium occurred from 1995 to 2007 and since 2008 there has been a sharp decrease in blooms of this species for unknown reasons (Lee et al 2013). Occasionally the large nitrogen-fixing cyanobacterium Trichodesmium erythraeum, the dinoflagellates, Karenia selliformis and Prorcentrum arabianum and some diatoms also contribute to the blooms (Al-Gheilani et al 2012).…”

“…5) and this change occurred about the same time as the decrease in red Noctiluca. More HABs have been observed to occur along the northern area adjacent to the Gulf of Oman possibly because more research has been conducted in this area (Thangaraja et al 2007;Al-Azri et al 2012;Al-Gheilani et al 2012). Another plausible explanation is that bloom development is initiated in the Arabian Gulf and then cells are exported into the Gulf of Oman where further growth occurs.…”

Seasonal and Interannual Changes of Indian Oil Sardine, Sardinella longiceps, Landings in the Governorate of Muscat (the Sea of Oman)

“…Data on sardine landings were complemented by the monthly frequency of fi sh kill incidents and algal blooms along the Omani coast, available from the archives of the Marine Science and Fisheries Research Center (Muscat, Oman) and Al-Gheilani et al (2012).…”

Effect of Losing Nitrogen Fertilizers on Living Organism and Ecosystem, and Prevention Approaches of their Harmful Effect

“…It is calculated that 383 million fish have lost their lives due to hypoxia along the Texas coast during the fifty years [34]. Over $2.2 billion losses have been estimated by eutrophication-related practices every year [35] and 3000 tuna fish were killed by hypoxia in Kharan Bandar in Oman water in 2004 [36]. The United States Environmental Protection Agency [37] reported that eutrophication damages tourism and recreation, commercial fishing, property values, and human health.…”