Sea Otter Heroes: The Predators That Saved an Ecosystem

Gr 4–7—With their big eyes; soft, furry faces; and playful behavior, sea otters are a favorite marine mammal among kids and teens. Protective measures have stabilized sea otter numbers after the mammals once came close to extinction. Only recently, through the work of marine biologist Brent Hughes, has their role in maintaining ecosystems come to light. The Elkhorn Slough, an inlet of Monterey Bay in Northern California, is a nutrient-polluted estuary fed by the fertilizers and pesticides used in nearby farming. This work chronicles the mystery of why this ecosystem is far healthier than scientists would expect. Using the tools of scientific research, Hughes has discovered that sea otters, the top predators in the food chain, help keep the sea grass algae-free through their feeding habits, which in turn allows the growth of a fish population and preserves a natural barrier to storms. The step-by-step process of ascertaining that the sea otter was responsible for the thriving ecosystem provides a strong example of the value and excitement of primary research. Clear, full-color photographs show how Hughes confirmed his theory. However, this title resembles a picture book, which may deter older readers.