Located in an extensive spread of estuaries alongside the Atlantic coast, blue crabs are of ecological importance and one of the most precious and valued fisheries in the United States. Blue crab spawn in estuaries at a time of year when problems with water quality, such as low pH (acidification) and low dissolved oxygen (hypoxia) are the most persistent and the most serious concerns. A group from the laboratory of Christopher Gobler, a professor at the Stony Brook School of Ocean Sciences and Atmosphere (SoMAS), investigated the effects of these individual and combined stress factors on the early stages of blue crab life. Their research, recently published in PLoS One, proves that mortality in larval crabs is higher when exposed to low oxygen and pH conditions at the usual levels in degraded estuaries.
Although hypoxia is a common condition in coastal areas, recent studies around the world have shown that many estuaries that are nitrogen-enriched and contain poor oxygen at the same time have low pH and acidification. Although the impact of hypoxia on marine life has been well understood through various studies, however, this is the earliest study to evaluate the impacts of these two factors on larval crabs. The research comes at the right time when climate change has also reduced the pH values and oxygen in the oceans.
Co-author Stephen Tomasetti, a Ph.D. student at Stony Brook University’s SoMAS Marine Science program, explained that even at reasonable levels of oxygen that exceeded the usual regulatory goals, larval survival was reduced. “This is worrying given the fact that climate change is likely to worsen conditions.” By focusing on restoration and sound management, guest environments can see improvements in water quality, “he said.
“Global climate change is acidifying and depleting our oceans and these processes are becoming uncontrollable,” Gobler said.