Describe how population size of lobsters affects the extent of kelp forests on the North Atlantic ...

Lobsters off the coast of Nova Scotia are the dominant predators of sea urchins in kelp forests. When the population size of lobsters declines as a result of overfishing, the population size of sea urchins explodes with devastating effects on kelp forests. The unchecked urchins graze down the young kelp plants before they grow to any meaningful size and the urchins will also eat away at the holdfasts of kelp plants. This will weaken these algae in the face of winter storms and leads to a reduction in the size of kelp forests.