Landscape pattern influences nekton diversity and abundance in seagrass meadows

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 507:139-152 (2014) - DOI: https://doi.org/10.3354/meps10818 Landscape pattern influences nekton diversity and abundance in seagrass meadows Geoffrey M. Hensgen1,*, G. Joan Holt2, Scott A. Holt2, Jason A. Williams3, Gregory W. Stunz3 1Colorado River Alliance, 3625 Lake Austin Boulevard, Austin, TX 78703, USA 2Marine Science Institute, University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX 78373, USA 3Harte Research Institute for Gulf of Mexico Studies, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA *Corresponding author: ghensgen@gmail.com ABSTRACT: We studied how spatial qualities and configuration of seagrass patches influence the diversity and abundance of resident nekton. Shallow landscapes of equal area (4225 m2) in 2 bays were mapped and sampled in the summer and fall to identify different qualities of landscape structure and the abundance and diversity of nekton. Two suites of characteristics were found to describe the natural landscape structure: (1) habitat area, connectivity, patch proximity and patch density; and (2) patch shape complexity and edge length. These were used to quantitatively distinguish between 3 naturally occurring seagrass landscape patterns: (1) small, isolated patches; (2) reticulated edge patches; and (3) continuous cover. Species evenness (Pielou’s J’) was significantly lower in small, isolated patches and reticulated edge patches compared to continuous cover. This pattern was temporally consistent despite significant seasonal differences in total nekton density and seasonal shifts in the distribution of individual species among landscape patterns. Nekton species density (no. of species per 61.2 m2 of seagrass) and species richness (no. of species per 1683 ind. sampled) did not differ significantly among landscape patterns; however, a landscape structure threshold may exist for species evenness between 45 and 85% cover. High densities of shrimp in small, isolated patches and reticulated edge patches during summer drove species evenness levels lower and overall nekton density levels higher than in continuous cover. Large expanses of continuous seagrass harbor more stable nekton communities across time. They may provide enough space for different species to feed and reproduce without depleting food resources to the point that nekton populations become unstable. KEY WORDS: Biodiversity · Seagrass · Landscape structure · Habitat fragmentation Full text in pdf format Supplementary material PreviousNextCite this article as: Hensgen GM, Holt GJ, Holt SA, Williams JA, Stunz GW (2014) Landscape pattern influences nekton diversity and abundance in seagrass meadows. Mar Ecol Prog Ser 507:139-152. https://doi.org/10.3354/meps10818 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 507. Online publication date: July 17, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.