A marine biologist investigated the benthic community surrounding a deep-sea hydrothermal vent. Table 1 shows the number of individuals of each invertebrate species recorded within a designated sampling quadrat.
Table 1
| Species | Number of individuals (nnn) |
|---|---|
| Riftia pachyptila | 15 |
| Rimicaris exoculata | 24 |
| Bathymodiolus thermophilus | 11 |
| Alvinella pompejana | 9 |
| Bythograea thermydron | 6 |
| Thermarces cerberus | 5 |
Calculate the index of diversity (ddd) for this hydrothermal vent community using the formula:
d=N(N−1)∑n(n−1) d = \frac{N(N-1)}{\sum n(n-1)} d=∑n(n−1)N(N−1)Show your working and give your answer to 2 decimal places.