Effect of ocean acidification on growth and otolith condition of juvenile scup, Stenotomus chrysops

Abstract

Increasing amounts of atmospheric carbon dioxide (CO2) from human industrial activities are causing changes in global ocean carbonate chemistry, resulting in a reduction in pH, a process termed “ocean acidification.” It is important to determine which species are sensitive to elevated levels of CO2 because of potential impacts to ecosystems, marine resources, biodiversity, food webs, populations, and effects on economies. Previous studies with marine fish have documented that exposure to elevated levels of CO2 caused increased growth and larger otoliths in some species. This study was conducted to determine whether the elevated partial pressure of CO2 (pCO2) would have an effect on growth, otolith (ear bone) condition, survival, or the skeleton of juvenile scup, Stenotomus chrysops, a species that supports both important commercial and recreational fisheries. Elevated levels of pCO2 (1200–2600 μatm) had no statistically significant effect on growth, survival, or otolith condition after 8 weeks of rearing. Field data show that in Long Island Sound, where scup spawn, in situ levels of pCO2 are already at levels ranging from 689 to 1828 μatm due to primary productivity, microbial activity, and anthropogenic inputs. These results demonstrate that ocean acidification is not likely to cause adverse effects on the growth and survivability of every species of marine fish. X‐ray analysis of the fish revealed a slightly higher incidence of hyperossification in the vertebrae of a few scup from the highest treatments compared to fish from the control treatments. Our results show that juvenile scup are tolerant to increases in seawater pCO2, possibly due to conditions this species encounters in their naturally variable environment and their well‐developed pH control mechanisms.

Elevated Temperature Does Not Substantially Modify the Interactive Effects Between Elevated CO2 and Diel CO2 Cycles on the Survival, Growth and Behavior of a Coral Reef Fish

“…Previous experiments testing the effects of stable elevated CO 2 on fish early life stages have produced highly variable and species-specific results, with negligible, negative and positive effects on survival and growth all reported (Heuer and Grosell, 2014). The sensitivity of marine fish to OA conditions has often been linked to the environmental CO 2 levels they experience in natural habitats, with tolerant species generally occurring in areas that have daily and seasonal CO 2 cycles, and thus may already be physiologically adapted to elevated CO 2 (e.g., Munday et al, 2011;Bignami et al, 2013;Frommel et al, 2013;Perry et al, 2015). A recent meta-analysis lends some support to this theory by showing that mortality increased in pelagic species under elevated CO 2 , whereas mortality often decreased in benthic species, which experience higher and more variable CO 2 compared with pelagic species (Cattano et al, 2018).…”

Divergent responses of Atlantic cod to ocean acidification and food limitation

“…Such a pronounced interspecies variability is possibly due to different experimental setups, different analysed life stages (often limited to very early life stages, e.g., embryos, nonfeeding larvae), and short-term versus long-term effects of the applied treatments. For example, no effect on growth rate was observed for walleye pollack (Theragra chalcogramma; Hurst, Fernandez, & Mathis, 2013), juvenile scup (Stenotomus chrysops; Perry et al, 2015) and the larvae of yellowtail kingfish (Seriola lalandi; Watson et al, 2018). For other species, a decrease in growth rate under elevated CO 2 was observed, for example in the inland silverside (Menidia beryllina; Baumann, Talmage, & Gobler, 2012), for yellowfin tuna (Thunnus albacares; Bromhead et al, 2015), and Atlantic herring (Clupea harengus; Frommel et al, 2014).…”

Sand smelt ability to cope and recover from ocean's elevated CO2 levels

“…Although ocean acidification impacts are often species specific, reduced growth sizes associated with the exposure to high levels of pCO 2 have been reported and related mainly with decreased energy levels available for tissue synthesis and other important functions, given that physiological adaptation mechanisms rely on expensive metabolic costs (Baumann et al, 2012;Hamilton et al, 2017). Other studies, on the contrary, have provided evidence of increased growth or a lack of effect under increased environmental pCO 2 (Munday et al, 2009b(Munday et al, , 2011Hurst et al, 2012;Perry et al, 2015), which has been associated with more efficient capacity of acid- Fig. 2.…”