An ecology student investigated the trophic structure of a marine kelp forest community. The table below displays the data collected from a surveyed zone.
| Organism | Number of organisms | Mean dry biomass of each organism in kg | Dry biomass of population in kg |
|---|---|---|---|
| Giant kelp | 25 | 84.00 | 2100.0 |
| Purple sea urchins | 1450 | 0.08 | ? |
| Sea otters | 15 | 28.00 | 420.0 |
| Great white shark | 1 | 850.00 | 850.0 |
Calculate the dry biomass of the population of purple sea urchins in this surveyed zone.
