Reduced inorganic sulfur in sediments of the mariculture region of Sanggou Bay, China

Abstract

Reduced inorganic sulfur (RIS) and organic matter (OM) in a mariculture region (Sanggou Bay, China; SGB) and at a reference station without mariculture were determined to assess the influence of mariculture on sulfide accumulation and the benthic environment. To this end, sediment acid-volatile sulfide (AVS), pyrite sulfur (pyrite-S), elemental sulfur (ES), OM, porosity, reactive iron, and pore water sulfate were measured. The results indicate that the concentration of RIS was negatively correlated with dissolved oxygen concentration. Principal component analysis showed that sulfide distribution was influenced by sediment porosity, OM, and reactive iron concentration. In addition, sulfide distribution was influenced by water current and water depth. More sulfide content accumulated at an oyster monoculture site than at a scallop/ kelp polyculture site and a kelp monoculture site. We found no significant difference in ES concentration among the 3 mariculture types. While no significant influence on benthic OM accumulation was observed, except slightly enhanced reactivity of the OM (making it easily decom-posable), mariculture activities in SGB significantly promoted sulfide accumulation compared to the reference station. However, there was no potential threat of toxic sulfide to the benthic bio-mass in SGB.

Carbon Sequestration in the Form of Recalcitrant Dissolved Organic Carbon in a Seaweed (Kelp) Farming Environment

“…The bay is connected by only a small seasonal river (the Gu River) and the river’s runoff is minimal during the dry season (i.e., January to May), therefore, the bay was weakly affected by freshwater input during our sampling period (i.e., end of May). Very high-density kelps are cultured at the mouth of the bay with a monoculture mode, while in the inner bay, a polyculture mode (mainly including shellfish, sea cucumber, fish and relatively low-density kelp) is employed . Since shellfish are usually harvested during March, there was less disturbance from shellfish during our sampling period.…”

“…Very high-density kelps are cultured at the mouth of the bay with a monoculture mode, while in the inner bay, a polyculture mode (mainly including shellfish, sea cucumber, fish and relatively low-density kelp) is employed. 32 Since shellfish are usually harvested during March, 31 there was less disturbance from shellfish during our sampling period.…”

The impacts of suspended mariculture on coastal zones in China and the scope for Integrated Multi-Trophic Aquaculture

“…Common inorganic substances include nitrogen, phosphorous, and sulfur compounds such as ammonia, nitrate, phosphate, sulfate, and pyrite-S (Cai et al 2016;Duan et al 2016;Kang, Liu, and Ning 2016). Organic waste includes fish feed and feces, urea, dead and decaying culture organisms, and methane (Leung, Chu, and Wu 1999;Hou et al 2016).…”

“…Settling biodeposits, synthetic compounds, or metals are commonly recorded from sediment in aquaculture zones (Wang et al 2013;Wang et al 2014a;Ren and Zhang 2016). The natural chemical reactions for processing waste from fish farms can give rise to hypoxic or anoxic sediment and water bodies (Zhang, Huang, and Huang 2013;Kang, Liu, and Ning 2016). Chemical impacts from suspended aquaculture are generally caused by the continuous or pulse release of waste substances associated with normal husbandry activities (Yang et al 2006;Xu et al 2011).…”

Identification of sulfur-oxidizing bacteria from fishponds and their performance to remove hydrogen sulfide under aquarium conditions

“…H 2 S causes problems such as sh mortality (Poulton et al 2002;Lahav et al 2004), a decrease in sh growth (Pillay 2008), and high oxygen consumption (Kang et al 2016). Hydrogen sul de can inhibit Cytochrome-c oxidase activity, the electron transport system, and aerobic respiration, which increases blood lactate and tissue hypoxia (Affonso et al 2004).…”