Combined effects of ocean acidification and hypoxia on the early development of the thick shell mussel Mytilus coruscus

Xinghuo Wang,Hui Kong,Yuewen Deng,Menghong Hu,Youji Wang,Jinlong Yang,Yueyong Shang

doi:10.1186/s10152-020-0535-9

Abstract

Ocean acidification has become serious, and seawater hypoxia has become evident in acidified waters. The combination of such stressors may have interactive effects on the fitness of marine organisms. In order to investigate the interactive effects of seawater acidification and hypoxia on the early development of marine bivalves, the eggs and sperm of the thick shell mussel Mytilus coruscus were exposed to combined treatments of pH (8.1, 7.7, 7.3) and dissolved oxygen (2, 6 mg/L) for 96 h culture observation to investigate the interactive effects of seawater acidification and hypoxia on the early development of marine bivalves. Results showed that acidification and hypoxia had significant negative effects on various parameters of the early development of the thick shell mussel. However, hypoxia had no effect on fertilization rate. Significant interactions between acidification and hypoxia were observed during the experiment. Short-term exposure negatively influenced the early development of the thick shell mussel but did not affect its survival. The effects of long-term exposure to these two environmental stresses need further study.

Highlights

Ocean Acidification (OA), i.e., a decrease in seawater pH associated with a change in carbonate equilibrium system, is a consequence of the large amount of anthropogenic C O2 absorbed by the ocean [1,2,3]
The effects of acidification or hypoxia on marine organisms have been studied, most works are based on single factor effects; only a few focused on the combined stress of acidification and hypoxia on marine organisms [34, 45]
The results showed that ocean acidification and hypoxia negatively affected the early development of the thick shell mussel

Summary

Introduction

Ocean Acidification (OA), i.e., a decrease in seawater pH (increased acidity) associated with a change in carbonate equilibrium system, is a consequence of the large amount of anthropogenic C O2 absorbed by the ocean [1,2,3]. Seawater acidification does not occur alone in the natural environment. Other stressors, such as hypoxia, affect the marine environment [18,19,20,21,22]. Hypoxia are areas with hypoxic conditions that the dissolved oxygen (DO) concentration in the water is < 2.0 mg/L [23]. OA is likely to occur in areas where the seawater is deficient in oxygen [24, 25]. Low DO in water negatively influences marine organisms and even threatens the survival of marine life [26,27,28]. Clark and Gobler [29] found that low DO inhibits the development and significantly reduces the survival rate of bay scallop Argopecten irradians larvae (2.33 mg/L)

Methods

Results

Discussion

Conclusion