An overview of historical harmful algae blooms outbreaks in the Arabian Seas

Reverse osmosis desalination system and algal blooms Part I: harmful algal blooms (HABs) species and toxicity

The catastrophic 2008–2009 red tide in the Arabian gulf region, with observations on the identification and phylogeny of the fish-killing dinoflagellate Cochlodinium polykrikoides

Chapter 9 - Satellites-Based Monitoring of Harmful Algal Blooms for Sustainable Desalination

A novel harmful algal bloom classification from the Persian Gulf to the Arabian Sea using satellite reflectance data and a hybrid ocean color index.

Keeping Tabs on HABs: new tools for detecting, monitoring, and preventing harmful algal blooms.

In the ocean, microscopic plankton algae constitute a crucial food supply for filter- feeding bivalves, shellfish (oyster, mussels, scallop and clams), as well as larvae of commercially important crustaceans and finfish. In most areas, the proliferation of plankton algae (so called "algal blooms"; consisting of millions of cells per liter) is beneficial for aquaculture, recreational and commercial fisheries. However, sometimes algal blooms may have a negative impact. Mass occurrences of harmful microalgae, harmful algal blooms (HABs), are a globally growing concern. Most HAB species cause harm due to their production of toxins. HAB species may kill marine wildlife directly, or the algal toxins may accumulate in the food web, causing illness and mortality of fish, seabirds, marine mammals and humans consuming the toxic seafood products. There is scientific consensus that the HAB problem is increasing globally, with increasing numbers of toxic blooms and associated economical loss. The most significant reasons for the increased occurrence of HABs are increased eutrophication of marine coastal areas and spreading of harmful species to new areas. During the last three decades, the Arabian Gulf area has experienced massive marine mortalities, resulting in serious economic losses (Kuwait, Saudi Arabia, Iran, U A E, Oman, Bahrain and Qatar). A documented example is an eight-month-bloom during 2008-2009 of the dinoflagellate Cochlodinium polykrikoides, killing thousands of tons of fish, hampering traditional fisheries, impacting tourism, forcing closure of desalination plants, and damaging coral reefs. The frequency and severity of HAB events are increasing in the Arabian Gulf, and the distribution of harmful species within the region appears to be expanding. In this situation, exchange of information and cooperative research has become obvious to scientists working in the Gulf region. To date, only a small number of studies have been conducted on diversity, distribution and toxicity of HABs in the Arabian Gulf, including Qatari waters. A project on harmful algae is needed here, focusing on biodiversity and ecology based on state of the art techniques, and involving capacity building of local Qatari staff.

Abstract. Recent years have shown an increase in harmful algal blooms in the Northwest Arabian Sea and Gulf of Oman, raising the question of whether climate change will accelerate this trend. This has led us to examine whether the Earth System Models used to simulate phytoplankton productivity accurately capture bloom dynamics in this region – both in terms of the annual cycle and interannual variability. Satellite data (SeaWIFS ocean color) show two climatological blooms in this region, a wintertime bloom peaking in February and a summertime bloom peaking in September. On a regional scale, interannual variability of the wintertime bloom is dominated by cyclonic eddies which vary in location from one year to another. Two coarse (1°) models with the relatively complex biogeochemistry (TOPAZ) capture the annual cycle but neither eddies nor the interannual variability. An eddy-resolving model (GFDL CM2.6) with a simpler biogeochemistry (miniBLING) displays larger interannual variability, but overestimates the wintertime bloom and captures eddy-bloom coupling in the south but not in the north. The models fail to capture both the magnitude of the wintertime bloom and its modulation by eddies in part because of their failure to capture the observed sharp thermocline and/or nutricline in this region. When CM2.6 is able to capture such features in the Southern part of the basin, eddies modulate diffusive nutrient supply to the surface (a mechanism not previously emphasized in the literature). For the model to simulate the observed wintertime blooms within cyclones, it will be necessary to represent this relatively unusual nutrient structure as well as the cyclonic eddies. This is a challenge in the Northern Arabian Sea as it requires capturing the details of the outflow from the Persian Gulf – something that is poorly done in global models.

Characteristics and renewal of zooplankton communities under extreme environmental stresses in the oligotrophic hypersaline Arabian Gulf

An investigation of cyanobacteria, cyanotoxins and environmental variables in selected drinking water treatment plants in New Jersey

Hydrographic data and oxygen isotopic analyses performed on surface waters and planktonic foraminiferal tests, collected during early summer from two succeeding years (1984, 1985) throughout the Red Sea, reveal two different hydrographic regimes. In 1984 the summer “normal” situation prevailed where surface waters from the Red Sea flowed out into the Gulf of Aden, while in 1985 a reversed inflow current occurred. The higher temperatures and salinities observed in 1985 indicate high evaporation rates and increased aridity in the northern Red Sea and caused this inflow of Indian Ocean Surface Water which origins from the active upwelling region in the Arabian Sea. Lower salinities and lower oxygen isotopes were observed up to 18°N. The occurrence of Globorotalia menardii during 1985 with its surprisingly constant isotope values up to the Gulf of Suez indicates northward flowing surface currents for the entire Red Sea. Isotope values from Neogloboquadrina dutertrei (1985) indicate subsurface shell formation to about 50 m water depth. Oxygen isotope analysis on Globigerinoides ruber and Globigerinoides trilobus from the 1984 and 1985 tracks suggests that both species calcify in isotopic equilibrium with the surrounding water in the Gulf of Aden and in the northern Red Sea, while an offset from equilibrium values of up to −0.4‰ is found in the Red Sea. Occurrences of G. menardii in Red Sea sediments may be useful as a tool for detecting unusual hydrographic situations preserved in the sediment record, when subsurface water was brought to the surface by upwelling in the Arabian Sea and flowed into the Red Sea. As this process is triggered by high evaporation rates in the northern Red Sea region, the appearance of this species in Red Sea sediments may also indicate periods with extreme arid conditions.

The incidence of harmful algal blooms (HABs) in the Arabian Gulf, especially, in 2008 and 2009 has heightened concern regarding monitoring programs. Giovanni is a tool for cheap and rapid assessment of HAB incidences. In order to identify changes in phytoplankton species composition, specifically incidences of HABs, we employed web-based Giovanni coupled with satellite imagery and reported data from literature. In this study, we pinpointed and linked the time of algal bloom occurrence and the region affected in the Arabian Gulf. The data presented graphically and visually using Giovanni emphasized the incidence of HABs in the Arabian Gulf as reported in literature. Giovanni generated high-quality data which is vital to rapid assessment. The deployment of Giovanni as a complementary tool to support comprehensive and robust HAB monitoring in the Arabian Gulf region is indeed recommended.

More than 1,000 manmade satellites currently orbit our planet.1 Some are near the edge of the Earth’s atmosphere just a few hundred kilometers up. Others are tens of thousands of kilometers above us.2 They aid in communication, navigation, defense, and science. A small number3,4 play a critical and quickly expanding role: monitoring the Earth’s surface and atmosphere to track environmental conditions that are intimately tied to human health. A number of new Earth-observing missions are planned for the next decade, including Sentinel-5 aboard the European Space Agency’s MetOp Second Generation satellites (pictured).48 In the meantime researchers are finding new uses for the satellite ... Researchers and government agencies worldwide already use satellite data to monitor air pollutants, infectious disease epidemics, harmful algal blooms (HABs), climate change, and more. But as current research indicates, that’s only the beginning of what we can do with the technology, broadly referred to as “remote sensing.” In the coming years, new satellites will offer higher-resolution imagery in conjunction with more robust and precise algorithms to process the data they deliver. As a result, researchers expect to dramatically expand their ability to view and understand Earth’s land, water, and air, from its remotest ocean waters to its largest cities. The National Aeronautics and Space Administration (NASA) launched its first satellite in 1958,5 and TIROS-1, the country’s first meteorological satellite, came 2 years later.6 Within a few decades members of the epidemiological and public health communities began actively looking at satellite data, says John Haynes, program manager of the NASA Applied Sciences Health and Air Quality Applications Program. In recent years interest in remote-sensing data has soared, with newer avenues being developed and fine-tuned, including air-quality measurements and vector-borne disease projections. “There’s really been a paradigm shift in the use of remote sensing for public health issues,” Haynes says. “Every year there seems to be more and more interest.” Indeed, by March 2015 NASA will have launched 6 Earth-observing missions in 12 months,7 more than in any year in at least a decade.8 New launches include a “global precipitation observatory” that will make frequent global measurements of rain and snowfall, plus one satellite designed to measure soil moisture and another that will measure how carbon moves through the Earth’s atmosphere, land, and oceans. In addition, the International Space Station will receive three new instruments, one that will observe how winds behave around the world, one that will measure clouds and aerosols (particles suspended in the atmosphere)—two variables that remain difficult to predict in climate-change models—and one that will take global, long-term measurements of key components of the Earth’s atmosphere, including aerosols and ozone.9 The momentum will carry through at least the next 8 or so years, with NASA and other space agencies in Europe and Asia planning to launch new satellites that will provide even higher-resolution snapshots of the Earth. Along with technological and scientific advances, a third development is leading to new and improved applications of satellite data: NASA and the National Oceanic and Atmospheric Administration (NOAA) have made their satellite data available free of charge, Haynes says, while the European Space Agency (ESA) has reduced prices and promised to provide free access to data from its next generation of instruments. “More people use the data, and you get more out of it than when you try to restrict it,” says Raphael Kudela, an oceanographer at the University of California, Santa Cruz, who uses satellite imagery to study HABs. This free sharing of data has been instrumental in his field, allowing researchers at institutions around the world to study HABs from above and to improve systems to track and predict them.

Harmful algal blooms (HABs) and the high biomass associated with them have afflicted marine desalination plants along coastal regions around the world. Few studies of HABs have been conducted in the Red Sea, where desalination plants along the Saudi Arabian Red Sea coast provide drinking water for millions of people. This study was conducted along the Saudi Arabian Red Sea coast from 2014 to 2015 to assess the potential for using Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing of chlorophyll a (Chl a) or fluorescence line height (FLH) to identify risks for biofouling at these desalination plants. Ship-based surveys of phytoplankton were conducted along the Saudi Arabian coastline offshore of desalination plants at Jeddah, Al Shoaibah and Al Qunfudhuh to assess the density of phytoplankton populations and identify any potential HAB species. Ship-based surveys showed low to moderate concentrations of phytoplankton, averaging from 1800–10,000 cells L−1 at Jeddah, 2000–11,000 cells L−1 at Al Shoaibah and 1000–20,500 cells L−1 at Al Qunfudhuh. Sixteen different species of potentially toxigenic HABs were identified through these surveys. There was a good relationship between ship-based total phytoplankton counts and monthly averaged coastal MODIS Chl a (R2 = 0.49, root mean square error (RMSE) = 0.27 mg m−3) or FLH (R2 = 0.47, RMSE = 0.04 mW m−2 µm−1 sr−1) values. Monthly average near shore Chl a concentrations obtained using MODIS satellite imagery were much higher in the Red Sea coastal areas at Al Qunfudhuh (maximum of about 1.3 mg m−3) than at Jeddah or Al Shoaibah (maximum of about 0.4 and 0.5 mg m−3, respectively). Chlorophyll a concentrations were generally highest from the months of December to March, producing higher risks of biofouling desalination plants than in other months. Concentrations decreased significantly, on average, from April to September. Long-term (2005–2016) monthly averaged MODIS Chl a values were used to delineate four statistically distinct zones of differing HAB biomass across the entire Red Sea. Sinusoidal functions representing monthly variability were fit to satellite Chl a values in each zone (RMSE values from 0.691 to 0.07 mg m−3, from Zone 1 to 4). December to January mean values and annual amplitudes for Chl a in these four sinusoidal functions decreased from Zones 1–4. In general, the greatest risk of HABs to desalination occurs during winter months in Zone 1 (Southern Red Sea), while HAB risks to desalination plants in winter months are low to moderate in Zone 2 (South Central Red Sea), and negligible in Zones 3 (North Central) and 4 (Northern).

Harmful Algal Blooms (HABs) have significant ecological and economic effects on the marine environment and use. In recent years, researchers have been increasingly developing and testing methods to treat and control HABs. General categories or strategies proposed as HAB control technologies include mechanical, biological, chemical, genetic, and environmental controls. The authors of this paper suggest using floating desalination plants to treat or control red tides. HAB producing dinoflagellates have been shown to be sensitive to physical and chemical changes in the environment, such as changes in temperature and salinity. The typical response of dinoflagellates is to form cysts that then settle out of the water column. The discharges from a floating desalination and water pumping plant can rapidly change the temperature and salinity in the water column. These changes could be expected to induce encystment in the dinoflagellate species that form cyst and could cause mortality in those species unable to form temporary cysts. Preventing population growth, inducing encystment, or causing mortality would effectively end a HAB. Discharges from a desalination plant are temporary in nature and include hypersaline water, freshwater (hyposaline water), and heated warmer. By discharging the heated hyposaline water at a low depth in the water column, due to its lower density than seawater, the discharge would move upward towards the surface. Since the hypersaline water would be denser than seawater, by discharging it at the surface, the hypersaline water would sink. In environments where a stratified water column exists, pumping water could disrupt the stratification without the need for additional desalination. The discharges from a floating desalination plant would stress the red tide with surfacing warmer fresh water and sinking hypersaline water. The stresses caused by these disturbances can disrupt a HAB. These temperature and salinity changes that could be created by a floating desalination plant would be achieved without the discharge of chemicals or other materials that could have other detrimental environmental impacts. A good aspect of this treatment is that, with continued mixing after discharge, the water would return to ambient temperature and salinity relatively quickly with minimal effect on the marine environment. Since the dinoflagellates have been shown to react quickly to environmental changes, the temperature and salinity of the discharges could be controlled to reduce adverse impacts on other marine organisms. B

A 3D high-resolution general ocean circulation model was implemented and validated to study the characteristics and seasonal variability of the internal tides in the Arabian Sea (AS). Three major source locations of internal tides were identified: Socotra Island, the northeastern shelf area of AS, and the Maldives. Around Socotra Island, internal tides propagate both southward and northward, before quickly dissipating. The internal tides generated in the northeastern AS split into two branches: Branch-I propagates perpendicular to the shelf, whereas Branch-II propagates more southernly. The internal tides originated in the Maldives propagate almost latitudinally both eastwards and westwards. Generally, the internal tides in the AS are more pronounced in January as shown by the forcing function, energy flux, and conversion rate. The hourly average conversion rate for the entire domain, including the AS, the Red Sea, and the Arabian Gulf – was 34.28 GW in January and 20.51 GW in July, suggesting a slightly larger barotropic-to-baroclinic conversion rate in January, probably due to the strong stratification around 100 meters in winter.