Aquarium diving officer - FT.com Jamie Oliver in the shark tank at The London Aquarium Jamie Oliver, Sea Life London Aquarium I'm responsible for the day-to-day running of many of the exhibits at the London Aquarium. This means ensuring they are healthy and the water quality is good and the filtration systems are maintained. We replenish saltwater tanks by making about 60,000 litres of seawater a week on site using artificial sea salt. I also clean tanks, including the ones that contain sharks. With the big tanks, which hold 1m litres of water and are 5.5m deep, you need to put on a wetsuit and Scuba gear and get in. I clean the glass and ensure the floor is covered with sand. In the reef tank, we hand-feed the fish: getting close lets you judge how healthy and happy they are. The other big tank has seven species of shark, some of them 10ft long. There's no real risk of being savaged, as we enter the tank in pairs and they don't see us as a threat or as food. But you do need special training to work in the shark tank - there are rules and you need to be more aware of the animals. You wouldn't make a sudden movement, for instance, as you could put a shark in a position where it takes a defensive bite out if you. We now offer snorkelling in the tank in a net enclosure, which gives people a chance to get up close to sharks. We hope it inspires them to take away a conservation message, which is important as sharks in the wild are under threat of extinction.