Dr. Brendan O'Connor:

I would guess up to 20 years. It is a very slow process for nitrogen to be released from the sediment. It will take a long time. Something else that would be important is that, during the recovery phase, animals come down, sit into the sediment and eat it. This is another way it can be bioprocessed. Once we get this system going, it speeds up. Without intervention of any sort - intervention is also problem because of the area's status as an SAC and SPA - it will take this length of time.