No effect of high pCO2 on juvenile blue crab, Callinectes sapidus, growth and consumption despite positive responses to concurrent warming

Abstract

Future climate scenarios predict increases in both ocean temperature and dissolved carbon dioxide (pCO2) over the next century. Calcifying invertebrates, which depend on specific conditions of temperature and carbonate chemistry for many processes, may be especially affected by these changes. In our study, juvenile blue crab, Callinectes sapidus, were exposed to one of four temperature/pCO2 treatments (ambient/low, ambient/high, high/low, and high/high) for two complete molts. Our study is the first to examine the effect of multiple climate stressors on blue crab and therefore basic responses, including the growth per molt (GPM), inter-molt period (IMP), and food consumption, were quantified. GPM was not affected by either increased temperature or pCO2. Although increased pCO2 did not significantly influence the duration of crab IMP, crabs in warm water had significantly shorter IMP (10.6 ± 3.1 days (± SD)) than crabs in ambient water (12.5 ± 2.8 days). Increased pCO2 did not significantly affect the amount of food crabs consumed, but crabs in warm water ate significantly more food than those in ambient water. These data suggest that the impact of warming outweighs the impact of acidification in juvenile blue crab. The effects of these changes on more complex physiological parameters such as metabolism and carapace chemistry remain to be examined. Additionally, quantifying the changes to the Chesapeake Bay food web that may occur due to the observed increase in crab growth and consumption is important to ensure sustainability of this resource in the face of future climatic changes.

Resilience of Oxygen Consumption Rates in the Juvenile Blue Crab Callinectes sapidus to Future Predicted Increases in Environmental Temperature and pCo2 in the Mesohaline Chesapeake Bay

“…This study supplements the growing body of knowledge on the general impact of climate stressors on estuarine crustaceans. It complements other recent work that has quantified the effects of increased temperature and pCO 2 on the growth and food consumption (Glandon & Miller 2017) and shell properties (Glandon et al 2018) of juvenile blue crabs.…”

“…Here, oxygen consumption rates of juvenile blue crabs from the mesohaline Chesapeake Bay were quantified in response to two key climate stressors (increased temperature and pCO 2 ). Treatment levels of temperature and pCO 2 were chosen to reflect current and future predicted climate conditions for the mesohaline Chesapeake Bay by the year 2100 (see Glandon & Miller 2017). The juvenile life stage was examined because of its role in regulating overall crab population dynamics (Miller 2001) and because juveniles are the earliest life stage to live entirely in the estuary (prior development occurs in marine waters).…”

Acidification in the U.S. Southeast: Causes, Potential Consequences and the Role of the Southeast Ocean and Coastal Acidification Network

“…Another commercially-important inhabitant is the Atlantic blue crab, Callinectes sapidus. When the ambient pCO 2 was raised from 800 to 8,000 µatm, juvenile blue crabs showed no sensitivity to the duration of the intermolt period or to food consumption rate (Glandon and Miller, 2017). Additional studies using the same pCO 2 changes showed small but significant changes in the high-magnesium calcite weight in the carapace of juvenile blue crabs and an increase in magnesium content (Glandon et al, 2018).…”

Oceanography and Marine Biology

“…These investigations have usually found that temperature has a larger impact on the biology of the studied species than acidification (e.g. Wood et al 2010, Noisette et al 2014, Collard et al 2016, Zhang et al 2016, Glandon & Miller 2017, Karelitz et al 2017.…”