Strategic Habitat Conservation for Gulf Sturgeon

Science Center Objects

WARC researchers partnered with Gulf Sturgeon decision makers and biologists to develop a Bayesian network model that uses habitat characteristics to predict the quantity of juvenile winter foraging habitat under alternative river discharge and timing of juvenile arrival scenarios.

juvenile Gulf sturgeon

Juvenile Gulf Sturgeon (Acipenser oxyrhynchus desotoi) (USGS)

The Science Issue and Relevance: The Gulf Sturgeon, listed as threatened under the U.S. Endangered Species Act, inhabits estuaries and coastal waters in the Northern Gulf of Mexico for part of the year, and then heads into rivers from Louisiana to Florida where they spawn. Historical spawning habitats in rivers are impeded by dams, which limits the recovery of some populations. Recovery might be further limited by factors (e.g., increased salinity) that reduce juvenile winter foraging habitat in critical estuarine habitats (Fig 1). A general lack of information for juvenile Gulf Sturgeon makes it difficult to identify which factors influence the quantity of winter foraging habitat. This hinders efforts to protect these habitats and assess risks from emerging threats. Consequently, identifying and reducing these gaps could aid in the development of quantitative, spatial decision support tools to guide strategic habitat conservation for Gulf Sturgeon.

Methodology for Addressing the Issue: We partnered with Gulf Sturgeon decision makers and biologists to develop a Bayesian network model that uses habitat characteristics to predict the quantity of juvenile winter foraging habitat under alternative river discharge and timing of juvenile arrival scenarios. We used the model to identify information gaps that limit the ability to assess the quantity of critical estuarine habitat. The greatest gaps involved water condition data (i.e., salinity, temperature, oxygen): Water condition data were available for only one of the six critical estuarine habitats (Apalachicola Bay, FL) and the model’s predictions were most sensitive to water condition. A detailed description of the study is in Dale et al. (2021) and the products are on ScienceBase Cronin et al. (2021b).

Future Steps: This work guides future research by identifying where geospatial data are most limited and by quantifying uncertainty in knowledge of the processes that determine habitat availability for juvenile Gulf Sturgeon. If these gaps are overcome, the methodology provided through these efforts can be used to estimate the total available habitat area for alternative scenarios of river discharge and month of arrival.

Gulf Sturgeon model study area

Fig 1. Juvenile Gulf Sturgeon Bayesian network model study area (Fig. 1 in Dale et al. 2021).