Harmful Algae Blooms (HABs) and significance of dinoflagellate cysts

The harmful algae blooms in many co astal areas are worldwide dispersion. In the recent decade, phytoplankton bloom has also incr eased significantly in the southern coast of the Iran. Fundamental of red tide research is id entification of HABs former species and assessin g of their complex life history. Almost 70% of HABs and toxin producer’s species are dinoflagellate that some generate resting cyst during their life cycle with a completely different morphology (Fig. 1). Cysts are resting cells formed during the process of sexual reproduction and also adverse conditions that can survive and stay dormant, waiting for better environmental cond itions to germinate. Therefore, cysts are considered as Seed Bank for population flora in the s ediment, which can initiate planktonic blooms w ith excystment. Alternation between planktonic life stage in the water column and resting stage in the sediment is one of the fundament al issues determining the occurrence, timing and expansion of HABs Many studies have been conducted on phytoplankton planktonic stage in the southern co ast of the Iran. Although 95% of the red species belong to the dinoflagellates that form the cysts, there is a little study of the cyst stages. More th an 100 phytoplankton cysts species have been identified in the coast of the Oman Sea and the Pe rsian Gulf. Researches showed the presence of s ome cyst species from sediments that previousl y had not been reported from water column their plankton stage. Cysts evaluations provide earl y warnings of the presence of potentially HABs former species in a given area. In order to iden tify and introduce key areas, from species abunda nce point of view, with the potential of bloom fo rmation, study of cysts is vital in each ecosystem,

The harmful algae blooms in many co astal areas are worldwide dispersion. In the recent decade, phytoplankton bloom has also incr eased significantly in the southern coast of the Iran. Fundamental of red tide research is id entification of HABs former species and assessin g of their complex life history. Almost 70% of HABs and toxin producer’s species are dinoflagellate that some generate resting cyst during their life cycle with a completely different morphology (Fig. 1). Cysts are resting cells formed during the process of sexual reproduction and also adverse conditions that can survive and stay dormant, waiting for better environmental cond itions to germinate. Therefore, cysts are considered as Seed Bank for population flora in the s ediment, which can initiate planktonic blooms w ith excystment. Alternation between planktonic life stage in the water column and resting stage in the sediment is one of the fundament al issues determining the occurrence, timing and expansion of HABs Many studies have been conducted on phytoplankton planktonic stage in the southern co ast of the Iran. Although 95% of the red species belong to the dinoflagellates that form the cysts, there is a little study of the cyst stages. More th an 100 phytoplankton cysts species have been identified in the coast of the Oman Sea and the Pe rsian Gulf. Researches showed the presence of s ome cyst species from sediments that previousl y had not been reported from water column their plankton stage. Cysts evaluations provide earl y warnings of the presence of potentially HABs former species in a given area. In order to iden tify and introduce key areas, from species abunda nce point of view, with the potential of bloom fo rmation, study of cysts is vital in each ecosystem,