A Fresh Set of Tools: New Information for Managing Fisheries During Changes in River Discharge Active
The Bonnet Carré spillway (BCS) is a flood-control structure along the Lower Mississippi River designed to prevent flooding in the city of New Orleans by diverting excess water into the nearby Lake Pontchartrain estuary. Alarmingly, the BCS was opened as many times over the past decade (2011–2020) as it had been over the six prior decades combined (1951–2010), with devastating effects on the estuary’s valuable fisheries. Because the BCS was rarely used in the past, there is little science-based guidance for state agencies to consult when trying to manage these events.
In light of the unprecedented increase in BCS operation, this project will conduct research to understand (1) how opening the BCS affects Lake Pontchartrain estuary fisheries and (2) if the recent increase in use of the BCS is predicted to continue into the future. While focused on the Lake Pontchartrain estuary, this project will also investigate how nutrient increases provided by the BCS-introduced freshwater may lead to robust, yet delayed, fisheries recovery in later years. This hypothesized sequence of events, whereby excess freshwater initially destabilizes fisheries, but later leads to strong recoveries because of high nutrient delivery and phytoplankton growth, can be transferred to other locations in future studies.
This project will provide Louisiana Department of Wildlife and Fisheries (LDWF) resource managers and Louisiana Sea Grant marine extension agents with science-based guidance to anticipate (1) how often the BCS is likely to be operated in the future, (2) how severely different fisheries will be disrupted and (3) for how long. This actionable knowledge can guide decisions related to which species to target with limited sampling resources and when/if to close fisheries during BCS episodes.
- Source: USGS Sciencebase (id: 649db2aad34ef77fcb03fd84)
The Bonnet Carré spillway (BCS) is a flood-control structure along the Lower Mississippi River designed to prevent flooding in the city of New Orleans by diverting excess water into the nearby Lake Pontchartrain estuary. Alarmingly, the BCS was opened as many times over the past decade (2011–2020) as it had been over the six prior decades combined (1951–2010), with devastating effects on the estuary’s valuable fisheries. Because the BCS was rarely used in the past, there is little science-based guidance for state agencies to consult when trying to manage these events.
In light of the unprecedented increase in BCS operation, this project will conduct research to understand (1) how opening the BCS affects Lake Pontchartrain estuary fisheries and (2) if the recent increase in use of the BCS is predicted to continue into the future. While focused on the Lake Pontchartrain estuary, this project will also investigate how nutrient increases provided by the BCS-introduced freshwater may lead to robust, yet delayed, fisheries recovery in later years. This hypothesized sequence of events, whereby excess freshwater initially destabilizes fisheries, but later leads to strong recoveries because of high nutrient delivery and phytoplankton growth, can be transferred to other locations in future studies.
This project will provide Louisiana Department of Wildlife and Fisheries (LDWF) resource managers and Louisiana Sea Grant marine extension agents with science-based guidance to anticipate (1) how often the BCS is likely to be operated in the future, (2) how severely different fisheries will be disrupted and (3) for how long. This actionable knowledge can guide decisions related to which species to target with limited sampling resources and when/if to close fisheries during BCS episodes.
- Source: USGS Sciencebase (id: 649db2aad34ef77fcb03fd84)