DRERIP Ecosystem Conceptual Model: Sacramento splittail

Model has not yet fully completed the peer review and collegial review process and final modifications may be required of the developers. Model may not be cited or circulated until that process is complete. It may be used in identifying and evaluating restoration actions with assistance from content experts. Model is appropriate for use by experienced evaluation team with input from content experts as necessary.

The purpose of this conceptual model is to aid management decisions for the continued persistence and recovery of Sacramento splittail. This model, along with the suite of models developed through ERP as well as other information and tools, is intended to be used for evaluating proposed restoration actions for the Delta and throughout the species geographic range. It is a qualitative life-cycle conceptual model that attempts to bring together many sources of information to build a comprehensive document that represents the current state of knowledge for the species. It is not a quantitative model however. It will not provide quantitative limits on species take or population number outcomes. It will only provide an indication of anticipated population response (i.e. increase or decrease with a magnitude of x or y) based on the most current scientific knowledge. With this knowledge, proposed restoration actions can be grouped and a positive population response can be developed through an adaptive management framework. The model must be read and understood in its entirety and does not provide users/readers quick solutions or answers. The entire life-cycle of the animal must be understood by decision makers if they intend to make sound choices in the future. The conceptual model diagram and associated tables can be used to focus the reader on potential species and population limiting factors given the current scientific understanding under current conditions. The model has a specific emphasis on the Delta; however the entire species range must be considered when population level responses are of concern. For this reason the geographic scope of this document is beyond the legal boundaries of the “Delta”. This is not intended to be the final version of this conceptual model. As new information becomes available through research and in the scientific literature, this model will be updated as time allows providing managers with the most current information available. This conceptual model relies heavily on the extensive work done by Peter Moyle and others in their 2004 white paper Biology and Population Dynamics of Sacramento Splittail (Pogonichthys macrolepidotus) in the San Francisco Estuary: A Review which was published in the San Francisco Estuary and Watershed Science online journal. Content in the model is taken from that review unless otherwise indicated. These sections will be introduced with a citation to Moyle et al. 2004. This model also takes into account new research on Sacramento splittail which has occurred subsequent to the white paper.