Measuring density of burrowing crayfish chimneys at Apex Park using transects
1. Write up your experimental report using Title, Aim, Materials, Method, Results, Discussion (questions below) and Conclusion.
2. Show your results in a table or diagram.
3. Calculate an average of our transect data, using the density of crayfish burrows per metre for each of the five groups (10 transects, so divide by 10, ignoring any ‘outliers’.)
4. Are the freshwater crayfish burrows evenly distributed throughout the park? Why or why not? What factors (biotic and abiotic) do you think will affect the distribution of crayfish in Apex Park?
5. Work out the area of Apex Park, using Google Maps or Google Earth, and estimate a percentage of this area that is suitable crayfish habitat.
6. Using your estimate of the suitable habitat area and an average number of burrows per metre square, calculate the total number of burrows at Apex Park. (10,000 square metres in a hectare – the whole of Apex Park is about 3 hectares) What assumptions are you making here?
7. Can you assume that the number of burrows is equal to the number of crayfish? Why or why not?
8. Discuss the different habitats in Apex Park – one transect had 13 burrows in a 12 metre squared area. What factors do you think contributed to the high burrow density at this location?
9. For your conclusion, discuss what factors may affect the reliability of your results. Can your data be used as a reliable estimate of burrowing crayfish numbers in the Hawkesdale district?
