Learn how plants respond to higher atmospheric CO2 concentrations

How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Pikeperch Fish Response to Super High CO2 Levels

Paper Reviewed
Steinberg, K., Zimmermann, J., Stiller, K.T., Meyer, S. and Schulz, C. 2017. The effect of carbon dioxide on growth and energy metabolism in pikeperch (Sander lucioperca). Aquaculture 481: 162-168.

Pikeperch (Sander lucioperca) is a fish commonly used for human consumption. It is widely distributed across Europe and Asia, inhabiting large rivers and eutrophic lakes. However, they also tolerate brackish water and are found in coastal lakes and estuaries.

In a study published in the journal Aquaculture, Steinberg et al. (2017) set out to investigate the impact of very high carbon dioxide concentrations on the growth and energy metabolism of pikeperch. The CO2 levels selected in their study (~2800, 9300 and 19,000 µatm, with equivalent pH values of 7.19, 6.68 and 6.38, respectively) corresponded to values often observed in intensive aquaculture production systems, which can reach CO2 concentrations that are 20 to 100 times higher than normal air. Adult pikeperch were kept in these three CO2 regimes for a period of 58 days, during and after which multiple measurements were made on factors related to growth performance, body composition and metabolism. So how did the fish respond to such super high levels of pCO2? Was it a recipe for disaster?

Despite such high pCO2 levels, there was only one fish mortality in all three treatments, which occurred in the lowest pH regime. Feed intake initially increased after the first four weeks of the experiment but faded after eight weeks, indicating, in the authors' words, "a habituation to the hypercapnia conditions." Final body weight, on the other hand, was 6% lower in fish in the highest CO2 treatment (19,000 µatm) compared to those in the lowest CO2 treatment (2800 µatm). Nevertheless, fish in the highest CO2 treatment still experienced an average 67% increase in body weight by the end of the study; and this occurred despite a decrease in metabolic oxygen consumption rates.

Steinberg et al. also report that protein biosynthesis, an energetically costly process, was unchanged in all three pCO2 treatments, suggesting that pikeperch maintained a favorable energy metabolism. Furthermore, they note that fish in each treatment group exhibited stable body composition, adding that "the fish were neither fatty nor malnourished." Consequently, in light of all of these and still other findings, the five scientists conclude that "pikeperch can tolerate carbon dioxide concentrations of up to 19,000 µatm." And that is one incredible feat!

Posted 12 February 2018