Tuesday, May 6, 2014

Beware the Shifting Baseline

Jonathan Stone
Executive Director

VIEW FROM THE BRIDGE

How do we know when we’ve achieved our goal of restoring Narragansett Bay to health? One challenge in answering this question is the problem of the shifting baseline. 

The concept of the shifting baseline arose in the study of fisheries. Scientist Daniel Pauly in his paper, “Anecdotes and theShifting Baseline Syndrome of Fisheries,” observed that fisheries scientists sometimes fail to identify the magnitude of decline in the abundance of a particular species by adopting as their reference point the state of that fishery at the start of their careers. In this way, large declines in ecosystems or species over long periods of time are masked. 

We often compare the Bay today to what we experienced in our lifetime, perhaps when we first learned to swim or sail or fish. Because we weren’t around 100 years ago, we don’t necessarily appreciate the extraordinary changes the Narragansett Bay ecosystem has undergone. 

We have lost 90% of the eelgrass beds in Narragansett Bay over the last century. Without eelgrass there are fewer fish and scallops. Populations of fish species with significant commercial value have collapsed to less than 10% of levels seen 100 years ago. Our salt marshes—nurseries to crabs, shellfish, and forage fish—have been degraded or completely lost to filling, coastal development, erosion, and rising seas. Our dynamic beaches have migrated hundreds of feet inland, despite repeated attempts to arrest their movement. 
Eelgrass
In our role as advocate for and voice of Narragansett Bay, we are all too familiar with the complacency that comes with this “shifting baseline” syndrome. In the Spring issue of Tides magazine, Tom Kutcher, our Narragansett Baykeeper, writes about the importance of restoring a healthy population of menhaden, known locally as pogies. While fisheries managers have made progress in arresting the collapse of the menhaden fishery, baseline population of menhaden in the Bay today is a small fraction of what it was just a generation ago. 

This is unacceptable. Complacency is our own worst enemy. Our goal is a Bay safe for swimming and shellfishing year-round; teeming with shellfish, crustaceans, fish, and birds; its shores and waters accessible to the public. When we accept the condition of Narragansett Bay as it is, we lose sight of what it could and should be.

- Jonathan


This post was published in the Spring 2014 issue of Tides, Save The Bay's biannual magazine.