Nutrient Trading: Our Concerns

By Bill Dennison | January 24, 2012 |

(Posted by Bill Dennison)

Nutrient trading is the buying and selling of nutrient reduction credits that have a monetary value for the reduction of either nitrogen or phosphorus loading to the waterways. The concept of nutrient trading is to unleash free market forces for nutrient reduction strategies, similar to the approach used with carbon trading to address global warming.

Nutrient trading is a relatively new concept in ecosystem restoration that has been initiated for the Chesapeake Bay. Using the new Google analysis tool (‘ngrams’), nutrient trading only appears in the literature around 1990, but has increased rapidly, with a doubling of citations roughly every three years. There is excitement about nutrient trading as a new approach, and this excitement is evident in the various policy statements explaining nutrient trading. Along with this excitement, there is considerable skepticism also evident, and the issue is often emotive.

The Senior Bay Scientists and Policymakers group has reviewed the status of nutrient trading as applied to Chesapeake Bay restoration. We found that there are a variety of different definitions for nutrient trading being used by the U.S. Environmental Protection Agency and state agencies, and that there is a lack of data and case studies to support or refute assertions about nutrient trading. The fact that nutrient trading is complicated, emotive and data poor makes this approach one that deserves close scrutiny and scientific rigor. Within the Senior Bay Scientists and Policymakers group, our nutrient trading report is a carefully crafted consensus between fairly intense and polarized viewpoints and it took quite a bit of effort to strike this balance.

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Chesapeake Bay Literacy Meets Chesapeake Bay Action

By Bill Dennison | April 5, 2011 |

(Posted by Bill Dennison.) The seven essential things that one needs to know to become literate about Chesapeake Bay have been described in a previous post on the Integration and Application Network blog as the following: Chesapeake Bay is a large, shallow and productive estuary formed by a drowned river valley. The extensive Chesapeake watershed…

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Comparing Two Icons: Chesapeake Bay and the Great Barrier Reef

By Bill Dennison | February 21, 2011

Posted by Bill Dennison.

The Integration and Application Network has been working with various groups in Queensland, Australia to produce an environmental report card for the Great Barrier Reef, modeled in some ways after the Chesapeake Bay report card. Comparisons between the two large ecosystems can be made and these comparisons can provide insight into both Chesapeake Bay and the Great Barrier Reef.Great Barrier Reef

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Chesapeake Nutrient Trajectories: A New Data Analysis Reveals the Real Story

By Bill Dennison | February 6, 2011

Posted by Bill Dennison.

Bob Hirsch and co-workers at the U.S. Geological Survey have developed a new method of analyzing long-term trends in nutrients that enter Chesapeake Bay from the rivers or tributaries that flow into the Bay. This method accounts for seasonal changes and year-to-year variation in flow, so that one can see the “forest for the trees.” The difficulty in analyzing flow and nutrients that enter Chesapeake Bay is the high degree of variability (or noise) in the data, making it difficult to discern trends, particularly long-term trends. Bob was able to use daily water flow data over a 31-year period, stretching from 1978 until 2008 from nine sites around Chesapeake Bay. Bob took these 100,000+ daily streamflow measurements and combined them with 13,000+ nutrient measurements to come up with daily nutrient loading estimates at each site. Then he was able to calculate a “flow-normalized daily flux,” which takes out the variations in flow due to weather. In this way, the long-term trends could be distinguished from the short-term variations.

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