Temporal and fine-scale variation in the biogeochemistry of Jervis Bay
Temporal and fine-scale variation in the biogeochemistry of Jervis Bay
Temporal and fine-scale variation in the biogeochemistry of Jervis Bay
- No tags were found...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
CERF Mar<strong>in</strong>e Biodiversity Hub <strong>Jervis</strong> <strong>Bay</strong> Survey Report, February 2009Figure 12: Comparison <strong>of</strong> benthic irradiance (Kd) based measurements taken <strong>in</strong> August2008 (top panel) <strong>and</strong> February 2009 (bottom panel). The 20 m depth contour comprises<strong>the</strong> hashed l<strong>in</strong>e through <strong>the</strong> diagram.The dissolved oxygen data (concentrations <strong>and</strong> percent saturation) are provided <strong>in</strong> <strong>the</strong>format <strong>of</strong> contour plots <strong>in</strong> Figure 13 toge<strong>the</strong>r with similar plots from August 2008. Theranges <strong>of</strong> dissolved oxygen concentrations were lower <strong>in</strong> February 2009 (6.4 - 8.4 mg L -1 )than <strong>in</strong> August 2008 (8.1- 9.1 mg L -1 ). These differences are due <strong>in</strong> part to <strong>the</strong> effect <strong>of</strong>higher water temperatures <strong>in</strong> February (16.3 ± 1.4 o C compared to 14.2 ± 0.2 o C) <strong>in</strong>lower<strong>in</strong>g <strong>the</strong> solubility <strong>of</strong> dissolved oxygen <strong>in</strong> seawater. However, <strong>the</strong> percent saturationvalues <strong>of</strong> dissolved oxygen were also lower <strong>in</strong> February (95.5 ± 7%) than <strong>in</strong> August (106± 2.7%) (Figure 13) <strong>in</strong>dicat<strong>in</strong>g that benthic respiration rates were probably also higherdue to <strong>the</strong> enhanced organic matter production expected <strong>in</strong> <strong>the</strong> summer months. Thesaturation values <strong>of</strong> dissolved oxygen are a measurement that is <strong>in</strong>dependent <strong>of</strong> watertemperature <strong>and</strong> sal<strong>in</strong>ity. The vial <strong>in</strong>cubation experiments, which measure CO 2production over a set time <strong>in</strong>terval, should be able to resolve this supposition.16