I couldn't deal with all my villagers worried about food on my last village(and I was attached to them), so I decided to pause the village for a few days, checking in every morning to unpause, have the chief make food, and then pause again. I did this until I had enough food to last them the amount of time to make the points they needed. With 5 researchers, they were doing 3500 points per hour approx. on fast speed, so with 16, that would be about 10,000 per hour, so you could get the sharks gone in about 3 hours or so... just get enough food to keep them happily working that long. Maybe over a thousand? If you have the patience...