New, factory sealed.  Pristine.

Filming took place over a 25-month period, an unusually tight timescale for a natural history production of this scale. In some cases, the events were not guaranteed to occur every year, so working to such a rapid schedule meant that the film crews ran the risk of having nothing to film. Producer Karen Bass described the series as "a minor miracle, given the constraints of luck and timing - we were totally dependent on events happening when they were supposed to." One of the most challenging sequences to film was the climax of "The Great Tide" episode, featuring aerial and underwater footage of dolphins, sharks and gannets attacking a sardine shoal. In 2007, the sardine run didn't take place, and after weeks of fruitless searching, the crew had to give up. The following year, there was a second and final opportunity. Just in case they were unsuccessful again, the producers devised an alternative sixth episode which would have explored the science behind seasonal changes, looking at how the "Great Events" are triggered and how environmental change may be affecting them. As luck would have it, the sardine run returned for the first time in three years and the team captured the shots they needed.