Question

In the early 2000s, there were thick kelp forests in the Pacific Ocean. Kelp is a photosynthetic brown algae that can grow very tall and thick, and is used as food by herbivores such as sea urchins and as a habitat by many species. In 2013-2015, a toxic algal bloom, unusually warm waters, and the outbreak of a new disease killed many starfish and created unfavorable conditions for kelp. As a result, kelp forests are 93% smaller now than they were in 2006. Sea urchins eat kelp, and sea otters eat sea urchins. Sea otters are preyed upon by killer whales (orcas). If killer whales move away from this coastal area because of the reduced kelp forests, what do you expect will occur soon after the whales leave?

Answer 1

The departure of killer whales may lead to an increase in the sea otter population, which in turn could decrease sea urchin numbers and potentially allow some recovery of the kelp forests, assuming environmental conditions are also favorable.

Step-by-step explanation:

When killer whales leave an area due to reduced kelp forests, we can expect changes in the local marine ecosystem. With the top predator gone, this could lead to an increase in the number of sea otters, as they would have fewer natural enemies. However, this increase in sea otters may then lead to a decrease in sea urchin populations, as sea otters are known predators of sea urchins. Since sea urchins feed on kelp, a decline in their numbers could potentially allow for some recovery of kelp forests, provided that other environmental conditions also become favorable for kelp regrowth.

However, this scenario depends on a delicate balance of factors, as the recovery is not solely dependent on predator-prey relationships but also on environmental conditions such as water temperature and nutrient availability, which affect kelp growth. If other conditions remain unfavorable, even a reduced sea urchin population might not enable the kelp forests to recover significantly.

Answer 2

Based on the information given the killer whale was the top predator, but if there is anything that needs the killer whale to survive it must move away too. Also any animal that is not dependent upon the brown algae for food but was hunted by the killer whale will have a population increase.