| THE INFLUENCE OF ENVIRONMENTAL HYPERCAPNIA ON COBIA,
RACHYCENTRON CANADUM
|
| EBANKS, D., University of Miami, Miami, Florida, USA 33145 |
| Since the pre-industrial period atmospheric CO2 levels have increased from 280 ppm to 379 ppm, which has caused a decrease in oceanic pH of 0.1 as of 2005 with continued projected decreases of 0.14 to 0.35 over the course of the 21st century according to the 2007 report by the Intergovernmental Panel on Climate Change (IPCC). Studies on the effects of these abiotic environmental changes on marine teleosts are warranted due to anticipated near-future changes; however this is an understudied area. Therefore, the goal of my research is to assess the impact that projected changes in CO2 and pH, may have on the recruitment of cobia, Rachycentron canadum, a widely distributed marine teleost with documented juvenile growth rates of 2.46% body mass day -1 in sub-optimal conditions and up to 6 kg in 1 yr. These high growth rates will likely contribute to high sensitivity in detection of treatment response. Cobia eggs were incubated in water with a [CO2] of 380-454 (control), 560-625 (2065 projection), or 800-870 ppm (2100 projection). Newly hatched cobia eggs (~ 2 h old) were sub-sampled, fixed with 10% formalin, and photographed. Photographed hatchlings were measured for head length, notochord length, and total length. Preliminary data indicated a significant difference for the three parameters measured, except head length, which was not significantly different between control and the 2065 projection. All three parameters displayed a similar trend of being less than control values at the 2065 projected concentration but higher than control values at the 2100 projection. |
| back |
|
|
 |
