Species and food webs

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 (Armstrong et al. 1976; Thom et al. 1976; Canning and Shipman 1995). Visit our species page for a full list. The array of species found in Puget Sound reflects its high productivity, the wide diversity of habitats present, and its unique geographic location at the interface of “northern” and “southern” ranges for many 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.

There is no single food web in the Puget Sound ecosystem. Instead there are many marine food webs that reside in the soft-bottomed nearshore, in rocky-bottomed areas, in habitats dominated by eelgrass or kelp, and in pelagic areas as well. Similarly, there are terrestrial and freshwater aquatic food webs that occur in alpine habitats, mid-elevation and lowland forests, and rivers, lakes, and streams. The food webs in each of these areas are not discrete and independent, but rather are highly interconnected by organic matter sources, physical proximity, exchange of water, and organisms that change habitats during the course of their life cycles.

Food webs also change both in time and space due to variation in stratification, prey availability, organic-matter source availability and quality, and other local and regional conditions. In addition, some species occupy multiple places or play multiple roles in the food web depending on their life stage, size, habitats they occupy, and time of year.

Sources:

Sound Science: Synthesizing ecological and socioeconomic information about the Puget Sound ecosystem. Published 2007. Used by permission.

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 June 19, 2013 paper in the journal PLoS ONE hypothesizes that regional declines in Western Grebe populations may be related to decreasing numbers of forage fish. Using citizen science data from 36 years of bird counts, researchers were able to look at population trends up and down the entire West Coast, finding that abundance of grebes decreased in the Salish Sea but increased in southern California. North American population declined by 52% overall.

A new paper by Puget Sound area scientists from the SeaDoc Society and their collaborators represents the most complete summary to date of killer whale (Orcinus orca) strandings in the North Pacific. The authors analyzed stranding records dating back to 1925, obtained from scientists worldwide, finding that very few whales are stranded (an average of ten a year over the last twenty years). However, most of those strandings result in death. Only 12% of stranded whales survive.

Necropsy of stranded whales can provide important information about life history, health, genetics, and causes of death, but few of the stranded carcasses

Audio recordings of the Mazama Pocket Gopher.

Sediment health in Central Puget Sound has shown a recent steep decline, according to a report by the Washington Department of Ecology. The report compares monitoring data over a ten-year period between 1998/1999 and 2008/2009.

Researchers monitored populations of benthic invertebrates, sediment-dwelling organisms that depend on an environment free of pollutants, as part of the Puget Sound Ecosystem Monitoring Project (PSEMP). The report shows that adversely affected invertebrates were found across 28% of the region, compared with 7% ten years prior.

Sediment samples were also tested for 133 different potentially toxic chemicals. Samples revealed an overall increase in low-level toxicity

Seabird populations are declining worldwide. This paper looks at the impact of gillnets on bird populations.

This 2004 report looks at the status of Washington's four killer whale populations.