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

Harbor porpoise (Phocoena phocoena) are one of the most frequently sighted cetaceans in the Salish Sea. Anecdotal information, possibly supported with stranding encounter rate data, suggests that harbor porpoise may have increased in Puget Sound, or have shifted their distribution back to Puget Sound relative to earlier decades.

Harbor porpoises were once common in Puget Sound, but had all but disappeared from local waters by the 1970s. Regular and numerous anecdotal sightings in recent years show that populations of these cetaceans are now increasing and may be approaching their former status. The attached document from NOAA Fisheries describes harbor porpoise numbers and their geographic range in Puget Sound as of 2011. 

HARBOR PORPOISE (Phocoena phocoena vomerina): Washington Inland Waters Stock (NOAA Fisheries 2011)

Species and their habitats are a foundation of the ecosystem framework, but there is currently no generally agreed upon habitat classification system for Puget Sound. The closest thing for its marine and nearshore environments may be Dr. Megan Dethier’s 1990 resource A Marine and Estuarine Habitat Classification System for Washington State. Much of the work for that document was done in the general vicinity of Puget Sound, and it has been an influential resource for major habitat mapping efforts in the region, such as Shorezone.

A paper in the February 2014 journal Diseases of Aquatic Organisms examines the effect of leaf age on wasting disease in eelgrass across sites in the San Juan Archipelago. Co-author: Encyclopedia of Puget Sound topic editor Joe Gaydos. 

The Salish Sea Hydrophone Network and Orca Network are two citizen science projects dedicated to furthering our understanding of abundance, distribution, behavior, and habitat use by the endangered population of Southern Resident Killer Whales, also called orcas. The Hydrophone Network lets the public listen for orcas through their computers and phones, while the Orca Network gathers and disseminates sightings of orcas as they move between Puget Sound, the Fraser River, and the Pacific Ocean.

A January 2014 USGS report discusses approaches for measuring the effect of bivalves on nutrient availability in different regions of Puget Sound.