Dynamic Solutions

Ecological Modeling

The responses of the species inhabiting estuaries and freshwater systems to changes in salinity, water quality, flow, nutrients and sediments due to ecosystem restoration efforts is the bottom line indicators for planning evaluations and tracking the relative effectiveness of proposed plans. Ecosystem restoration projects will differentially affect the aquatic ecosystems and their inhabitants based on the spatial and temporal scale of the projects, the complexity and redundancy within the existing ecosystems, and the variation in the species life history strategies, dependence on habitat, and population dynamics.

From the Comprehensive Aquatic Systems Model (CASM), to Individual Based Models (IBMs) to Wetland Value Assessments (WVAs), Dynamic Solutions, LLC is highly experienced with the use and application of a variety of ecological models that range in complexity, scale and suitability for describing and understanding the ecological processes in the system and simulating the responses to changes in the ecosystem such as the installation freshwater diversions or other restoration measures.

Dynamic Solutions, LLC has extensive experience in developing and applying food web and ecosystem models such as CASM to aquatic systems. Aquatic food web models are useful for understanding and evaluating the interactions among species and the energy flow within the ecosystem, and for simulating the ecosystem responses to changing environmental conditions. Dynamic Solutions worked closely with CPRA and NMFS on the project modification teams for the Caernarvon and Davis Pond Diversions to provide a detailed description and review of available ecosystem modeling approaches (i.e., Ecopath with Ecosim, ATLANTIS and CASM) that could be used for describing population responses to the diversion operational alternatives. A Dynamic Solutions team member also worked with the developer of the Ecopath with Ecosim software (C. Walters) to use her IBM that simulated fine-scale predator-prey interactions on an hourly time step to project the aggregate feeding responses used in the EwE software to describe predator-prey relationships that occur on kilometer spatial scales using a monthly time step. Dynamic Solutions is adapting a version of the CASM to simulate the food web dynamics of key fishery species in the Barataria Basin ecosystem, and coupling the food web model to the Myrtle Grove hydrodynamic model outputs (salinity, elevation) to evaluate the habitat-population responses occurring over the 50-year project life for the proposed diversion. Extensive literature review, data summarization and analysis, and redesign and testing of the ecological model are underway for the Myrtle Grove application.

The team has experience with Wetland Value Assessments (WVA) that use a series of simple cause and effect functions to describe hydraulic-habitat relationships and then habitat-population relationships (HSIs). WVAs are effective for describing large-scale and even coast-wide habitat-population responses to multiple coastal restoration measures. Members of team Dynamic Solutions worked with the Coastal Protection Restoration Authority (CPRA) on the modification projects for Caernarvon and Davis Pond Diversions to review and interpret the WVA analyses performed by USFWS that described the habitat changes in the basins due to the diversion operational alternatives. Dynamic Solutions provided scientific reviews and guidance to members of the project modification teams on using the available Habitat Suitability Index (HSI) models for evaluating species-specific responses to the diversion operational alternatives to be incorporated into the environmental assessments and impact statements prepared by the ACOE. To additionally support the ecological modeling efforts of the project modification teams, Dynamic Solutions provided several literature reviews, technical comments, and data analyses for determining the ecological cause and effect relationships due to diversion operation changing salinity, hydrology and sediments in the receiving basins.

Team member Dynamic Solutions also has experience in the development and application of numerical ecological modeling methods that are used to describe and simulate the dynamics of aquatic populations and communities, food webs and ecosystems. The team member has extensive experience in the development and application of age- and stage-structured population models that are often used to evaluate the entire life cycle of a population and when differences in growth or mortality among the ages or developmental stages of a species are important to consider. These structured population models are commonly used in fisheries stock assessments and for risk analysis of populations. Dynamic Solutions has developed numerous structured population models to simulate the long-term dynamics and stress responses of recreational fishery species in large lakes, and more than 20 North American bird species.

Dynamic Solutions also has extensive experience in the development of individual-based models (IBMs) for aquatic populations and communities. IBMs are useful to represent and evaluate individual variation in traits and behavior/movement, individual-level exposure to stress or contaminants, and fine-scale differences in habitat or varying environmental conditions over time. A member of Dynamic Solutions developed a spatially-explicit IBM of a tidal marsh community comprised of six abundant eco-indicator species in coastal Louisiana, and evaluated population responses to fine-scale changes in habitat and exposure to hypoxia over time. Members of Dynamic Solutions have also performed IBM studies that scale individual-level effects measured in the laboratory to observable population responses detected within the field, evaluate movement algorithms to describe animal distributions in the field, and determine the level at which individual variation can obscure aggregate population responses detected within the field data.

Please read about some of our Ecological Modeling studies below:

Delta Ecological Modeling – CASM

Myrtle Grove Ecological Modeling – CASM

 

Read more about CASM

Ecological Modeling Consulting Services: Ecological modeling can be an effective tool for decision makers who need to evaluate multiple management alternatives in complex Ecological systems.
Dynamic Solutions was instrumental in developing the Coastal Protection and Restoration Authority’s 2017 Coastal Master Plan: Strategy for Selecting Fish Modeling Approaches.

 

Read the PDF here.