Based on the description of the graph, the curved line begins flat at the bottom of quadrant 2 and passes through the y-axis. This suggests that the population of the invasive species at the starting point (when they began recording data, at year 0) is indicated by the value on the y-axis where it intersects with the line.
If the line appears to intersect the y-axis around a certain value, you would look at that value to determine the initial population size. Since I don't have the actual image to reference, I can't provide the exact number. However, if you provide the population value from the graph at the y-axis, I can help you round it to the nearest tens.
Please refer to the graph and provide the value indicated at the y-axis for the population when recording started.