Chapter 4. Factors Influencing Viability

In this chapter, we evaluate the past, current, and future factors that are affecting what the Panama City crayfish needs for long term viability. Freshwater aquatic systems face a multitude of natural and anthropogenic threats and stressors (Neves et al. 1997). The Florida Fish and Wildlife Commission have identified multiple factors that have impacts on PCC populations and habitats, most of which are related to human activities (FWC 2017). Due to land uses within its natural habitats, the PCC is presently found primarily in man-altered habitats. These include roadside ditches, rights-of-way, clearings in silvicultural land, and residential property. Potential threats to PCC include habitat loss and degradation, habitat fragmentation, and subpopulation isolation due to residential development. We also consider other possible factors including direct mortality related to construction activities, inappropriate application of pesticides and other toxic substances, chemical spills, off- road vehicle use, illegal harvest, and direct competition with indigenous and/or nonindigenous species.

Generally, these factors (Figure 4.1) can be categorized as either environmental stressors (orange boxes; e.g., residential and commercial development) or systematic changes (purple ovals; e.g., climate change). Current and potential future effects, along with current distribution and abundance help inform viability and, therefore, vulnerability to extinction.

Factors affecting PCC viability
Figure 4.1. Influence diagram illustrating how stressors influence habitat, breeding, feeding, and sheltering needs of the species, and ultimately influence Panama City crayfish population viability.

Dynamic recovery addition: Relative importance of threats

NOTE: The chart below uses made-up percentages. For illustration only.