1）Fishing boats have decreased the number of herring in the sea. Explain why that could affect the number of offspring puffins can raise.
2） Which animals have a bigger food supply now there are fewer herrings?
3） Global warming is expected to reduce the biomass of phytoplankton in the oceans. What effect will that have on the rest of the food web?

1) When the number of herrings decrease, the food available for the puffins decrease and therefore they will not be able to feed their offspring. This will cause the number of offspring to decrease.

2) Any other animal(s) which hunts and eats the same prey as a herring will now have a bigger food supply.

3) When the biomass of phytoplankton decrease, the next animal in the food web will not have any food and their numbers will decrease, decreasing the number of the animals next in the web, as they too lose their food. This will continue for the rest of the food web and the number of animals will decrease.