Document Type

Article

Publication Date

2014

Abstract

To assess possible impacts on Lake Pontchartrain fishes from the 2005 hurricanes, we 45 compared trawl, beach seine, and gillnet collections taken before (2000-2003, 2005) and after 46 (2006-2009) to determine if significant assemblage changes occurred. We also compared basic 47 environmental variables to test for hurricane-related changes. Significant post-hurricane changes 48 in fish assemblages occurred in trawl (ANOSIM, R < 0.090, p < 0.05) and beach seine 49 (ANOSIM, R < 0.120, p < 0.05) collections across all seasons. Gillnet assemblages exhibited 50 changes in only one season (ANOSIM, R = 0.045, p < 0.05). These consistently low global R 51 values (all R < 0.120) across all gears suggest only minor compositional changes in species. 52 When peak abundance periods were compared for individual species, Gulf menhaden 53 (Brevoortia patronus) declined in trawl collections after the hurricanes (Friedman’s test, χ2 = 54 6.00, p = 0.014) but increased in gillnet collections (Friedman’s test, χ2=5.00, p = 0.025). 55 Hardhead catfish (Ariopsis felis) increased in trawl collections, but Gulf pipefish (Syngnathus 56 scovelli), naked gobies (Gobiosoma bosc), and rough silverside (Membras martinica) all 57 declined in beach seine samples and Atlantic croakers (M. undulatus), Spanish mackerel 58 (Scomberomorus maculatus), and sand seatrout (Cynoscion arenarius) all declined in gillnet 59 samples. In general, salinity increased and water clarity and dissolved oxygen decreased after 60 the hurricanes. While the overall composition of Lake Pontchartrain fish assemblages remains 61 stable, the significant decline of some species and changes in certain environmental variables are 62 cause for concern. Future monitoring should determine if all elements of this estuary will 63 recover from these impacts.

Journal Name

Estuaries and Coasts

Comments

The final publication is available at Springer via http://dx.doi.org/10.1007/s12237-013-9675-3

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