الفهرس 
ClamsOnly 14 pages are availabe for public view
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Abstract
One of the most important topics the world is most concerned about is global climate change, as it is already affecting aquatic Environments. “Climate change’s an equally evil twin” is what is called on ocean acidification. A phenomenon known as ocean acidification is caused by a number of changes in seawater chemistry; the major cause is the increasing rate at which the ocean is absorbing anthropogenic CO2. The dissolution of CO2 in oceans causes increasing in acidity (decrease in pH) and a reduction in the obtainable carbonate ions (CO32-) concentration.
In the current experiment, Juvenile clams (avg. Shell Length, SL= 23.22 ± 0.84 mm) were incubated in CO2 enriched seawater at four different CO2 concentrations, 420 ppm (ambient control), 550 ppm, 750 ppm, and 1050 ppm representing projected atmospheric CO2 concentration scenarios for the year 2100 by IPCC. Clams were fed daily with Isochrysis galbana. The studied biological parameters as; shell length, total weight, and condition index were measured by comparing the beginning of the experiment and the end after 36 days.
While the physiological responses as; metabolic rate, ammonia excretion, and clearance rate were measured at time intervals within the experiment. Furthermore, calcification response was detected by SEM, XRD, and comparing the periostracum layer to the control group.
Also, biochemical enzymes as; antioxidant enzymatic activities [catalase (CAT)] and lipid peroxidation [malondialdehyde (MDA)] were measured before and after the experiment. Standard length decreased as pCO2 concentration increased, with a maximum average decrease of (-0.12) recorded at 750 ppm as compared to the control group.