Chapter 1 Introduction

This chapter will provide an overview of the HREP mussel modeling process described in this technical report.

1.1 Need for the Study

Mussels are receiving increased attention in UMRR HREPs not only for the purpose of avoiding mussel habitat impacts from the construction of habitat features, but for designing restoration features that benefit mussels.

  • Mussels are important UMR biotic communities!
  • Few methods exist for evaluating mussel habitat suitability for UMRR HREPs
  • Spatially explicit models are helpful to evaluate spatial variation of habitat suitability across projects
  • Evaluate impact of project features on existing mussel communities
  • Evaluate likelihood that project features will create suitable habitat for mussels

1.2 Species Distribution Modeling

Species Distribution Modeling (SDM) has become a common method for mapping suitable habitats for many species or taxa groups (Elith, Leathwick, and Hastie 2008, Elith and Leathwick (2009)). The spatially explicit nature of these models makes them extremely well suited for HREP design as they predict habitat suitability across the study area. The Maxent software for modeling species niches and distributions (Phillips et al. 2017) has been used for modeling a wide range of species, taxa group, guilds, and communities (Merow, Smith, and Silander Jr 2013).

1.3 Previous UMR Mussel Modeling

  • UMESC Pool 10 (Steuer, Newton, and Zigler 2008)
  • UMESC Pool 8 (Zigler et al. 2008)
  • UMESC Pool 8 mussel model (Newton et al. 2011)
  • UMESC Pool 18 mussel model (Zigler et al. 2012)

Presence Data (dependent variables)

  • Take advantage of existing UMR mussel data

Predictor Variables (independent variables)

  • Many HREPs invest in 2D hydraulic models. Let’s use them!
  • Mapping substrate is expensive
  • Hydraulic only mussel models explain ~%60 of variation
  • Is that good enough to make better informed HREP planning decisions?

1.4 Workflow

HREP Mussel Modeling Workflow.

Figure 1.1: HREP Mussel Modeling Workflow.

1.5 Mussel Database

The USACE Mussel Database

HREP pre-project survey

  • 2018 Steamboat survey
  • 2014 Cordova survey
  • 2010 Cordova survey

1.6 Calculate MCAT Metrics

1.7 Calculate Background

1.8 Prepare Hydraulic Predictors

1.9 Prepare Wind-Wave Predictors

1.10 Run Maxent

1.11 Evaluate Model

1.12 Repeat for Each Alternative

References

Elith, Jane, John R Leathwick, and Trevor Hastie. 2008. “A Working Guide to Boosted Regression Trees.” Journal of Animal Ecology 77 (4). Wiley Online Library: 802–13. doi:10.1111/j.1365-2656.2008.01390.x.

Elith, Jane, and John R Leathwick. 2009. “Species Distribution Models: Ecological Explanation and Prediction Across Space and Time.” Annual Review of Ecology, Evolution, and Systematics 40. Annual Reviews: 677–97. doi:10.1146/annurev.ecolsys.110308.120159.

Phillips, Steven J, Robert P Anderson, Miroslav Dudík, Robert E Schapire, and Mary E Blair. 2017. “Opening the Black Box: An Open-Source Release of Maxent.” Ecography 40 (7). Wiley Online Library: 887–93. doi:10.1111/ecog.03049.

Merow, Cory, Matthew J Smith, and John A Silander Jr. 2013. “A Practical Guide to Maxent for Modeling Species’ Distributions: What It Does, and Why Inputs and Settings Matter.” Ecography 36 (10). Wiley Online Library: 1058–69. https://doi.org/10.1111/j.1600-0587.2013.07872.x.

Steuer, Jeffrey J, Teresa J Newton, and Steven J Zigler. 2008. “Use of Complex Hydraulic Variables to Predict the Distribution and Density of Unionids in a Side Channel of the Upper Mississippi River.” Hydrobiologia 610 (1). Springer: 67–82. https://doi.org/10.1007/s10750-008-9423-z.

Zigler, Steven J, Teresa J Newton, Jeffrey J Steuer, Michelle R Bartsch, and Jennifer S Sauer. 2008. “Importance of Physical and Hydraulic Characteristics to Unionid Mussels: A Retrospective Analysis in a Reach of Large River.” Hydrobiologia 598 (1). Springer: 343–60. https://doi.org/10.1007/s10750-007-9167-1.

Newton, Teresa J, Steven J Zigler, James T Rogala, Brian R Gray, and Mike Davis. 2011. “Population Assessment and Potential Functional Roles of Native Mussels in the Upper Mississippi River.” Aquatic Conservation: Marine and Freshwater Ecosystems 21 (2). Wiley Online Library: 122–31. https://doi.org/10.1002/aqc.1170.

Zigler, Steven J, Teresa J Newton, Mike Davis, and James T Rogala. 2012. “Patterns in Species Richness and Assemblage Structure of Native Mussels in the Upper Mississippi River.” Aquatic Conservation: Marine and Freshwater Ecosystems 22 (5). Wiley Online Library: 577–87. https://doi.org/10.1002/aqc.2255.