Food web

Puget Sound hosts more than 100 species of seabirds, 200 species of fish, 15 marine mammal species, hundreds of plant species, and thousands of invertebrate species. These species do not exist in isolation, but rather interact with each other in a variety of ways: they eat and are eaten by each other; they serve as vectors of disease or toxins; they are parasitic; and they compete with each other for food, habitat, and other resources.

--Source: Sound Science 2007 

Overview

The health of an ecosystem is tied closely to the health of its food webs. This article provides an overview of the concept, origin, and characteristics of a food web and how predator and prey relationships are shaped in the Salish Sea.  

Bear eats salmon. Photo: Robert Voors (CC BY-NC-ND 2.0) https://www.flickr.com/photos/robert_voors/1303192433

Related Articles

A 2021 paper in the journal PLoS ONE provides a clearer picture of what endangered southern resident orcas eat throughout the year. Chinook salmon make up the bulk of the whales' diet, but the paper suggests that other salmon species and non-salmonid fishes can also play important roles depending on the season.

A river spawning species of forage fish known as the longfin smelt is rare and getting rarer in the Salish Sea. Biologists are looking into the mysterious decline of the ‘hooligans’ of the Nooksack.

Tiny bone samples show that seals alter their diets as conditions change. The findings could help scientists understand whether seals are contributing to local salmon declines.

They rival tropical forests in their richness and diversity, but Puget Sound's kelp beds have declined steeply in recent decades. Scientists are just starting to understand the extent of these losses. What they are finding is bringing kelp to the forefront of Puget Sound's environmental concerns.

In July, the recent trends of warm, dry conditions lessened; however, river flows remain low. Extensive macroalgae drifted through South and Central Sound and washed up on beaches. Macroalgae growth is fueled by excessive nutrients and sunshine. When it washes onto the beach, it is called beach wrack, and it can be a health risk to beachgoers because of bacteria it can harbor. From our aerial photography, we saw that Southern Hood Canal looks tropical because of a bloom of coccolithophores coloring the water turquoise. Schools of fish congregate in South Sound and southern Hood Canal. Jellyfish are abundant in Quartermaster Harbor.

Each winter and spring, researchers survey the sometimes spectacular spawning events of Puget Sound's Pacific herring. They have found wide swings in the fish's population and an overall decline in herring numbers since the 1970s, but little is known about the cause or what this might mean for the health of the food web. We spent a day with a biologist spotting herring eggs and considering the future of one of our region's most ecologically and culturally important fish species.