A microfluidic test card contains a seawater sample inside a square diagnostic chamber, as shown in the diagram:
The square chamber is 15 mm15\text{ mm}15 mm wide on each side, and the depth of the seawater sample within the chamber is 0.04 mm0.04\text{ mm}0.04 mm.
Calculate the volume of seawater in this square chamber in mm3\text{mm}^3mm3.
A marine biologist counts 1.89×1051.89 \times 10^51.89×105 microalgae cells in the water sample within the square chamber. Calculate the concentration of microalgae cells per mm3\text{mm}^3mm3 for this sample.
The healthy ecological baseline range for this species of microalgae is 4.0×103 to 1.8×104 cells per mm34.0 \times 10^3\text{ to }1.8 \times 10^4\text{ cells per mm}^34.0×103 to 1.8×104 cells per mm3. Does this water sample provide evidence of ecological stress due to an overpopulation of microalgae? Justify your answer.