Six things that people should know about ecosystem modeling and virtual experiments

The Salish Sea Model is a computer model used to predict spatial and temporal patterns related to water circulation in the Salish Sea. It was developed at the United States Department of Energy's Pacific Northwest National Laboratory with funding from the Environmental Protection Agency. It is housed at the University of Washington Center for Urban Waters which is affiliated with the Encyclopedia of Puget Sound.  

This article is the latest in a series about computer models and their uses within the Puget Sound ecosystem. Today, we look at the Salish Sea Model, one of several models in the region helping to predict water circulation, water quality and food-web relationships.

One of the first working models of Puget Sound was a scaled-down concrete reproduction, with actual water running through channels, around islands and into bays, inlets, and harbors. Motors, pumps and timing gears are part of an elaborate mechanism that replicates tides and river flows in the still-functioning model.

The skeletal beginnings of nearly all models is a conceptual understanding of the basic workings of the system being studied: Who are the important actors, and what are their roles within the system?

Many types of computer models are helping researchers study the health of Puget Sound. Bayesian network models are used to examine the probabilities that certain actions will take place within the ecosystem.

The Ecopath model, designed to describe the flow of energy through a food web, as evolved since it was first developed in the early 1980s in Hawaii. This article is part of a series focused on different models and their uses within the Puget Sound ecosystem.

The three-dimensional Atlantis model can represent physical, chemical and biological processes and can incorporate direct human involvement, such as fisheries management, habitat improvements and economic outcomes. It has been used to study the food web to determine whether salmon in Puget Sound are more threatened by predators or by the lack of a stable food supply and to evaluate specific recovery actions to help the endangered Southern Resident killer whales.

Biologist and science writer Eric Wagner recently returned from a trip to observe pigeon guillemots on Protection Island. He wonders: How much do we really know about the health of seemingly abundant bird populations?

The marine heat wave that struck the Pacific Ocean in late 2013 also caused large changes in temperature in the Salish Sea, but scientists are still puzzling over the impacts of those changes on Puget Sound's food web. The so-called "blob" of warmer than average water was thought to have increased the production of plankton, which potentially benefits creatures like herring and salmon that feed on the tiny organisms. A new paper in the journal Frontiers in Marine Science calls that interpretation into question, pointing to a computer model that links the cause to higher-than-normal river flows in the region.   

Scientists are using computer models to address complex issues in the Salish Sea like the rise of harmful algal blooms and the movement of toxic PCBs. LiveOcean, Atlantis and the Salish Sea Model are three systems that are changing the game for ecologists and other researchers.

A 2019 paper in the Journal of Geophysical Research: Oceans outlines how the Salish Sea Model describes the impacts of climate change, sea level rise and nutrient loads on the region's nearshore environment.

LiveOcean is a computer model simulating ocean water properties in Puget Sound and the Pacific Northwest. It is produced by the University of Washington Ocean Modeling Group and makes three-day forecasts of currents, temperature, salinity and many biogeochemical fields including harmful algal blooms.

The Puget Sound Coastal Storm Modeling System analyzes the potential impacts of sea level rise on nearshore areas of the Puget Sound region. 

The Puget Sound Ecosystem Monitoring Program (PSEMP) is an independent program established by state and federal statute to monitor environmental conditions in Puget Sound. 

The Puget Sound Model was designed and built by the University of Washington School of Oceanography in the early 1950s to simulate the tides and currents of Puget Sound. A series of videos produced by the Encyclopedia of Puget Sound describes its construction and operation.

The Puget Sound Model was designed and built in the early 1950s at the University of Washington School of Oceanography as a research and teaching tool for understanding Puget Sound circulation patterns.