Effect of Simulated Co2 Leakage on Blood Indexes of Crucian Carps in Water

Abstract

Aquatic animals are important components of aquatic ecosystems such as lakes, swamps and reservoirs. Their normal growth and development are important signs of the healthy development of aquatic ecosystems. The blood components of fish are not only the result of their reaction to the aquatic environment, but also the premise of their intrinsic physiological changes. CCS (Carbon Dioxide Capture and Storage) is an important measure to combat climate change. Due to the defects of its projects, however, it may result in the release of sequestered CO2 into aquatic ecosystems, and affecting ecosystems represented by fish. By breeding aquarium and blood gas analysis method, the impact on the blood gas of crucian carp at different CO2 flow rates were studied in this paper. The main conclusions were obtained as follows: (1) In the injection of CO2 conditions, the dioxide oxygen partial pressure (PCO2) and the oxygen partial pressure (PO2) in venous blood of experimental groups were overall higher than the control group. With the increase of CO2 flow rates and time, the value and its fluctuation of PCO2 and PO2 in venous blood of crucian carp increased, in which the increase of PCO2 is due to the diffusion of CO2 through the gill, and the increase in PO2 is due to the decrease in the absorption of oxygen by tissue induced by anaesthesia of CO2. (2) Under the condition of introducing CO2, the pH in venous blood of crucian carp was mostly higher than that of CK group, and gradually decreased with the increase of CO2 flow rate and time. The behaviour of squid was characterized by active first and then calm, and the increase in the activity of crucian carp led to the increase in ammonia emissions and pH. Thereafter, the pH decreased as the flow rate of introducing CO2 increased. However, due to the body fluid regulation mechanism of crucian carp, the pH blood were always stable within the normal range. (3) The change of Na+ concentration was basically consistent with the change of pH. The changes of K+, Ca2+ concentration were opposite with the pH, but the crucian carp still kept the electrolyte concentration within the normal range through the humoral regulation mechanism. The regulation of Na+ mainly depends on the permeability of cell membrane. The regulation of K+ and Ca2+ mainly relies on H+ ion channel to realize H-Ca and H-K exchange. When a large amount of CO2 was introduced for a long time, the surge phenomenon of K+ indicated that the body fluid regulation of the squid may be disordered. (4) The difference between the actual bicarbonate ion content (AB) and the standard bicarbonate ion content (SB) were always greater than the control group, i.e. CO2 in water can caused respiratory acidosis or metabolic alkalosis of the crucian carp. (5) The lactic acid content of crucian carp in the experimental groups were lower than that of the control group (4 mmol/L). In particular, when the CO2 influx were greater than 40 ml/min, the lactic acid content in the venous blood of the crucian carp reduced sharply, and fluctuated at a concentration of 1 mmol/L.