Ecologicial Assessment of Ca-aminoclay to control HABs, Cochlodinium polykrikoides and Chattonella marina in natural conditions using 100 L microcosms

Abstract

Harmful algal blooms (HABs) have increasingly impacted natural ecosystem damaged coastal environments as well as human health, caused significant economic losses to fisheries. We approach harnesses the algicidal effects of artificial clay, Ca-aminoclay, which are comprised of a high density of primary amine groups covalently bonded by metal cation backbones and assess to suppress HABs (Cochlodinium polykrikoides and Chattonella marina) as well as ecological risk using 100 L microcosms. Positively charged colloidals of Ca-aminoclay induce cell lysis in HABs within several minutes’ exposure but have negligible impact on non-harmful phytoplankton. However, Ca-aminoclay to control HABs has adverse impacts such as increase in levels of dissolved inorganic nitrogen, dissolved inorganic phosphorus, dissolved silica, and dissolved inorganic carbon and change in anoxic condition. In addition, most planktonic communities responded drastically to the presence of Ca-aminoclay: total bacterial abundances increased for the first two-three days and then decreased rapidly for the remainder of the experiment. The abundance of heterotrophic flagellates and ciliates increased rapidly in association with the increase in bacterial cells. Therefore, caution should be taken when considering the direct application of Ca-aminoclay in natural environments, even though it has the advantage of rapidly removing HABs. Also, prior to field applicCa-aminoclay, which are comprised of a high density of primary amine groups covalently bonded by metal cation backbones and assess to suppress HABs (Cochlodinium polykrikoides and Chattonella marina) as well as ecological risk using 100 L microcosms. Positively charged colloidals of Ca-aminoclay induce cell lysis in HABs within several minutes’ exposure but have negligible impact on non-harmful phytoplankton. However, Ca-aminoclay to control HABs has adverse impacts such as increase in levels of dissolved inorganic nitrogen, dissolved inorganic phosphorus, dissolved silica, and dissolved inorganic carbon and change in anoxic condition. In addition, most planktonic communities responded drastically to the presence of Ca-aminoclay: total bacterial abundances increased for the first two-three days and then decreased rapidly for the remainder of the experiment. The abundance of heterotrophic flagellates and ciliates increased rapidly in association with the increase in bacterial cells. Therefore, caution should be taken when considering the direct application of Ca-aminoclay in natural environments, even though it has the advantage of rapidly removing HABs. Also, prior to field applic