Shoreline Hardening Affects Nekton Biomass, Size Structure, and Taxonomic Diversity in Nearshore Waters, with Responses Mediated by Functional Species Groups

  • Matthew S. Kornis
  • Donna M. Bilkovic
  • Lori A. Davias
  • Steve Giordano
  • Denise L. Breitburg
Article

Abstract

Coastal shoreline hardening is intensifying due to human population growth and sea level rise. Prior studies have emphasized shoreline-hardening effects on faunal abundance and diversity; few have examined effects on faunal biomass and size structure or described effects specific to different functional groups. We evaluated the biomass and size structure of mobile fish and crustacean assemblages within two nearshore zones (waters extending 3 and 16 m from shore) adjacent to natural (native wetland; beach) and hardened (bulkhead; riprap) shorelines. Within 3 m from shore, the total fish/crustacean biomass was greatest at hardened shorelines, driven by greater water depth that facilitated access to planktivore (e.g., bay anchovy) and benthivore-piscivore (e.g., white perch) species. Small-bodied littoral-demersal species (e.g., Fundulus spp.) had greatest biomass at wetlands. By contrast, total biomass was comparable among shoreline types within 16 m from shore, suggesting the effect of shoreline hardening on fish biomass is largely within extreme nearshore areas immediately at the land/water interface. Shoreline type utilization was mediated by body size across all functional groups: small individuals (≤60 mm) were most abundant at wetlands and beaches, while large individuals (>100 mm) were most abundant at hardened shorelines. Taxonomic diversity analysis indicated natural shoreline types had more diverse assemblages, especially within 3 m from shore, although relationships with shoreline type were weak and sensitive to the inclusion/exclusion of crustaceans. Our study illustrates how shoreline hardening effects on fish/crustacean assemblages are mediated by functional group, body size, and distance from shore, with important applications for management.

Keywords

Shoreline modification Shoreline armoring Habitat degradation Fish Crustaceans Chesapeake Bay 

Supplementary material

12237_2017_214_MOESM1_ESM.docx (32 kb)
ESM 1(DOCX 31 kb)
12237_2017_214_MOESM2_ESM.mpg (82.1 mb)
ESM 2(MPG 84024 kb)

Copyright information

© 2017 2017

Authors and Affiliations

  • Matthew S. Kornis
    • 1
    • 2
  • Donna M. Bilkovic
    • 3
  • Lori A. Davias
    • 1
  • Steve Giordano
    • 4
  • Denise L. Breitburg
    • 1
  1. 1.Smithsonian Environmental Research CenterEdgewaterUSA
  2. 2.Green Bay Fish and Wildlife Conservation OfficeUS Fish and Wildlife ServiceNew FrankenUSA
  3. 3.Virginia Institute of Marine ScienceCollege of William & MaryGloucester PointUSA
  4. 4.Department of CommerceNOAA National Marine Fisheries ServiceSt. PetersburgUSA

Personalised recommendations