Viability of Calcareous Seed Populations in the hypoxic zone

Abstract

Anthropogenic eutrophication is considered as one of the largest pollution problems globally, and usually induces hypoxia and anoxia which is responsible for about half the known dead zones. The conditions of water column in hypoxic and anoxic zones are normally coupled with pH decreases, indicating that bottom sea waters are acidified and that benthic organisms with calcium carbonate (CaCO3) skeleton and shells can be suffered from the acidic environments. In the hypoxic zones (Gamak and Jinhae Bays in Korean coastal waters), we have found the morphological variations of calcareous seed populations. This study investigates why morphological variations of calcareous cysts are observed from natural sediments and how the calcareous cysts respond to environmental conditions in a hypoxic zone, and we discuss the viability as seed populations of calcareous cysts in marine ecosystem.