A school of herring.Washington Sea Grant
Fisheries managers typically strive to strike a delicate balance between two, often competing, types of needs: the needs for fishermen's profits and the needs for the planet. But in 1994, entrepreneur John Elkington posited that true sustainability requires consideration of a third "P" - the needs of the people. In making this argument, he coined the term "the triple bottom line."
In a new study, an interdisciplinary group of researchers used Pacific herring in Haida Gwaii, British Columbia, as a case study for modeling the implicit tradeoffs within the triple bottom line that result from various fisheries management decisions. They found that considering spatial dynamics is a key component of this modeling process - for example, considering the geographic areas of the fish populations, the areas that are important to the various communities of people, and the areas that are impacted by management decisions.
Published Sept. 30 in the journal Fish and Fisheries, the study is one of the outcomes of the Ocean Modeling Forum, a collaboration between the University of Washington and The Nature Conservancy that aims to use models to provide insights on how to best address complex ocean issues.
Pacific herring provided a relevant and timely prototype for modeling the economic, ecological and socio-cultural tradeoffs within a fishery. Herring is in high commercial demand, is a vital part of the food web, and has been central to the social, cultural and economic life of Indigenous communities in the Pacific Northwest for millennia. Herring fisheries have also borne out steep management consequences: the collective North American herring fishery collapsed in 1993, and has required careful management to recover.
"There are so many people who rely on fishing as part of their way of life," said Daniel Okamoto, assistant professor of biological science at Florida State University who led the modeling component of the study. "Everyone wants their piece of the pie. But we need a better way of making decisions regarding fisheries."
While most herring fisheries remain closed or severely limited, some British Columbia stocks have rebuilt to a level at which managers are considering reopening the fishery. However, several critical factors that would determine the success of reopening these fisheries are still missing, the researchers said, including a social-ecological framework to address issues of equity in decision making by integrating traditional knowledge and ecosystem services into management. This study demonstrates a new and concrete way to fill this void.
These social and cultural considerations are notoriously difficult to quantify in such a way that they can be measured against the economic and ecological ones.
"We started from qualitative ethnographic information, including local and traditional knowledge, to identify indicators linked to various benefits and values of herring," explained co-author Melissa Poe, a social scientist at Washington Sea Grant based at the University of Washington. "We then surveyed different user groups to generate quantitative scores for select indicators to determine outcomes for various fishing sectors, abundances of herring and places of harvest."
The social benefits of the herring fishery included in the study were the ability for the commercial fishing fleet to practice harvest, the ability for Indigenous Haida to practice harvest, and community and social relationships within the Indigenous Haida community.
The researchers incorporated these social-ecological indicators along with economic and ecological metrics into a model to analyze their relative tradeoffs under different management scenarios. These management scenarios included four target harvest rates of the total herring population, ranging from 10% to 37.5%; three upper-limit harvest thresholds, ranging from 25% to 70%; and two spatial closures, in which a traditional roe, or egg, harvest area is closed to commercial fishing.
"As expected, many management options result in sharp tradeoffs in the triple bottom line," said co-author Tessa Francis, managing director of the Ocean Modeling Forum and lead ecosystem ecologist with the Puget Sound Institute at UW Tacoma. "For example, higher commercial catches reduce ecological and social benefits - this could have been predicted. What's interesting is where we found more balance among the multiple benefits."
Spatial closures often resulted in win-win-wins: they allow for commercial harvest at open locations while also protecting cultural benefits and reducing the risk of collapse in protected areas. That said, the location of these closures must be carefully considered, accounting for both ecological productivity and the implications to different user groups. For example, while commercial fishermen are relatively mobile, Indigenous harvesters are often constrained to fishing in traditional areas. This shows the need for fishery management models that allow for evaluation at a spatial scale that is culturally relevant.
No one management strategy within the study's model optimized the benefits to all of the people, planet and profit factors. However, having a framework to understand the relative tradeoffs to each of these factors is the first step toward responsibly balancing them, the researchers said. The model developed in this case study could be used not only to evaluate management strategies for Pacific herring fisheries as managers consider reopening them, but also for other fisheries that face similar dilemmas across the globe.
"This work has the potential to be game changing," said co-author Phil Levin, UW professor of practice and lead scientist at the Nature Conservancy. "For years researchers have talked about the triple bottom line but lacked the ability to really assess it. By directly linking quantitative fisheries models for social and cultural outcomes, we now have the ability to truly evaluate the full impacts of alternative management strategies."
