Document Type

Article

Publication Date

3-2015

Publication Title

Copeia

Keywords

Community-Structure; Population Dynamics, Temporary Wetlands, Florida Everglades, Gambusia-Affinis, Dispersal, Disturbance, Model, Restoration, Ecosystem

ISSN

0045-8511

Volume

103

Issue/No.

1

First Page

157

Last Page

169

Abstract

Spatial ecology and movement strategies of aquatic organisms may limit their response to human-caused drying of wetland habitats. We characterized the movement strategies of the most abundant species of fish in the wetlands of the Everglades (USA) to better understand how they cope with annual fluctuations in aquatic habitat size. Over a six-year period, we used a sampling method designed to measure the density, activity levels, and movement direction of small fishes. We estimated changes in displacement speed and directional bias to identify patterns of movement that different fishes use to disperse over the gradient of disturbance in this environment. Movement of fishes ranged from highly active and directed to passive and random, and varied with hydrological condition (water rising, stable, or dropping). Six of the eight species studied displayed "directed" movement (possibly displaying taxis along environmental gradients) that varied in both speed and directional bias in response to hydrological cues. The remaining two species did not adjust the direction that they moved in response to hydrological cues, but their activity levels increased. Moving with directional bias may improve a fish's chance of early arrival in a newly available habitat or of escaping the risk of desiccation in drying wetlands. Fishes that change activity levels may improve their likelihood of reaching favorable environments by increasing diffusion rates and greater sampling of the environment. Interspecific variation in movement strategies is predicted to play a large role in community structure and may be a primary driver of the dynamics of the Everglades fish metacommunity.

Comments

©2015 by the American Society of Ichthyologists and Herpetologists

Additional Comments

NSF grant #: DEB-9910514

DOI

10.1643/CE-14-040

Peer Reviewed

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