Benthic community structure and composition in sediment from the northern Gulf of Mexico shoreline, Texas to Florida

Demopoulos, Amanda W.J.; Strom, Douglas G.

Abstract:

From April 20 through July 15, 2010, approximately 4.93 million barrels of crude oil spilled into the Gulf of Mexico from the British Petroleum Macondo-1 well, representing the largest spill in U.S. waters. Baseline benthic community conditions were assessed from shoreline sediment samples collected from 56 stations within the swash zone (for example, sample depth ranged from 0 to 1.5 feet) along the northern Gulf of Mexico coastline. These sites were selected because they had a high probability of being impacted by the oil. Cores collected at 24 stations contained no sediment infauna. Benthic community metrics varied greatly among the remaining stations. Mississippi stations had the highest mean abundances (38.9 ± 23.9 individuals per 32 square centimeters (cm²); range: 0 to 186), while Texas had the lowest abundances, 4.9 ± 3 individuals per 32 cm² (range: 0 to 25). Dominant phyla included Annelida, Arthropoda, and Mollusca, but proportional contributions of each group varied by State. Diversity indices Margalef‘s richness (d) and Shannon-Wiener diversity (H‘) were highest at Louisiana and Mississippi stations (0.4 and 0.4, for both, respectively) and lowest at Texas (values for both indices were 0.1 ± 0.1). Evenness (J‘) was low for all the States, ranging from 0.2 to 0.3, indicating a high degree of patchiness at these sites. Across stations within a State, average similarity ranged from 11.1 percent (Mississippi) to 41.1 percent (Louisiana). Low within-state similarity may be a consequence of differing habitat and physical environment conditions. Results provide necessary baseline information that will facilitate future comparisons with post-spill community metrics.

Genre:

USGS Numbered Series

ProdID:

70039558

Citation Author:

Demopoulos, Amanda W.J.; Strom, Douglas G.

Citation Contributing Office:

Southeast Ecological Science Center

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Citation Language:

English

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Citation LatN:

0303000

Citation LatS:

0240000

Citation LonE:

-0810000

Citation LonW:

-0953000

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Citation Phsyical Description:

iii, 15 p.

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Citation Publisher:

U.S. Geological Survey

Citation Series:

Open-File Report

Citation Series Code:

OFR

Citation Series Number:

2012-1153

Citation Search Results Text:

Benthic community structure and composition in sediment from the northern Gulf of Mexico shoreline, Texas to Florida; 2012; OFR; 2012-1153; Demopoulos, Amanda W.J.; Strom, Douglas G.

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Citation Year:

2012

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citation/reference

Text:

Benthic community structure and composition in sediment from the northern Gulf of Mexico shoreline, Texas to Florida; 2012; OFR; 2012-1153; Demopoulos, Amanda W.J.; Strom, Douglas G.