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Surface water connectivity drives richness and composition of Arctic lake fish assemblages

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Full Publication: https://doi.org/10.1111/fwb.12769

Product Type: Journal Article
Year: 2016

Authors: Laske, S. M., T. B. Haynes, A. E. Rosenberger, J. C. Koch, M. S. Wipfli, M. Whitman, and C. E. Zimmerman

Suggested Citation:
Laske, S. M., T. B. Haynes, A. E. Rosenberger, J. C. Koch, M. S. Wipfli, M. Whitman, and C. E. Zimmerman. 2016. Surface water connectivity drives richness and composition of Arctic lake fish assemblages. Freshwater Biology. doi:10.1111/fwb.12769

Abstract

Summary

  1. Surface water connectivity can influence the richness and composition of fish assemblages, particularly in harsh environments where colonisation factors and access to seasonal refugia are required for species persistence.
  2. Studies regarding influence of connectivity on Arctic fish distributions are limited and are rarely applied to whole assemblage patterns. To increase our understanding of how surface water connectivity and related hydrologic variables influence assemblage patterns, we investigated species richness and composition of Arctic lake fishes over a large region, 8500 km2, of the central Arctic Coastal Plain, Alaska.
  3. We collected fish presence/non-detection data from 102 lakes and used a hierarchical multispecies occupancy framework to derive species richness and inform species composition patterns. Our mean estimate of regional richness was 12.3 (SD 0.5) species. Presence of a permanent channel connection was an overriding factor affecting species richness (mean 3.6, 95% CI 3.1–4.9), presumably driving lake colonisation potential. In lakes without a permanent channel connection, data suggest richness (mean 2.0, 95% CI 1.7–3.3) increased with the availability of in-lake winter refugia and with the potential of ephemeral connections during spring floods.
  4. Fish species functional traits and environmental faunal filters contributed to patterns of richness and assemblage composition. Composition corresponded with richness in a coherent manner, where each successive level of richness contained several discrete assemblages that showed similar responses to the environment. Lakes with permanent channel connections contained both widespread and restricted species, while the species-poor lakes that lacked a connection contained mainly widespread species.
  5. This work provides useful baseline information on the processes that drive the relations between patch connectivity and fish species richness and assemblage composition. The environmental processes that organise fish assemblages in Arctic lakes are likely to change in a warming climate.

Keywords: surface water connectivity, Arctic fish, fish assemblages, freshwater lakes, Arctic Coastal Plain

Annotation

In the Alaskan Arctic, surface water connectivity plays a vital role in structuring lake fish communities. New climate patterns are predicted to alter the existing hydrologic regime by lengthening the ice free season, degrading permafrost, and increasing evapotranspiration. Landscape change such as petroleum development could alter surface water dynamics including connectivity. Alterations to surface water hydrology and dynamics could lead to profound changes in lake fish assemblages. Given that fish are an important ecosystem component, an understanding of natural patterns and processes will help interpret whether and how petroleum development and climate change may affect energy flow, terrestrial-aquatic linkages, and fishes in Arctic ecosystems.