Diversity and composition of macrobenthic community associated with sandy shoals of the Louisiana continental shelf

被引:35
作者
Dubois, Stanislas [1 ,2 ,3 ]
Gelpi, Carey G., Jr. [3 ]
Condrey, Richard E. [3 ]
Grippo, Mark A. [2 ]
Fleeger, John W. [2 ]
机构
[1] IFREMER, DYNECO Ecol Benth, F-29280 Plouzane, France
[2] Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA
[3] Louisiana State Univ, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 USA
关键词
Biodiversity hotspot; Continental shelf; Gulf of Mexico; Hypoxia refuge; Louisiana; Sand bank; Shallow habitat; BENTHIC COMMUNITY; COASTAL WATERS; SOUTHERN BIGHT; WINTER STORMS; INNER SHELF; HYPOXIA; OXYGEN; SEA; BIODIVERSITY; SEDIMENTS;
D O I
10.1007/s10531-009-9678-3
中图分类号
X176 [生物多样性保护];
学科分类号
090705 ;
摘要
Along the Louisiana, USA continental shelf, sandy shoals are shallow, possibly oxygen-rich "islands" surrounded by deeper muddy deposits prone to hypoxia. Shoals also contain significant quantities of fine sand that may be mined in the future for coastal restoration. The ecological role of shoals remains poorly understood and we hypothesized that shoals provide critical habitat for benthic invertebrates. Using Ship Shoal as a model system, we assessed the diversity and structure of macrobenthic assemblages and how community structure varies with season and environmental parameters. High biomass (averaging 26.7 g m(-2)) and high diversity (161 species) of macrobenthos was found in 2006. Polychaetes (45%-72 species) and crustaceans comprised most of the species (28%-46 species); spionids and amphipods dominated the polychaete and crustacean groups respectively, both in terms of number of species and abundances. Sharp decreases in diversity, abundance and biomass occurred from spring to autumn. Species diversity and total abundance significantly increased with decreasing sediment grain size and increasing bottom water dissolved oxygen. Across seasons, mole crabs Albunea paretii and amphioxus Branchiostoma floridae typified the community and contributed most of the biomass. The polychaetes Nephtys simoni, Neanthes micromma, Dispio uncinata, Mediomastus californiensis and Magelona sp. A, the amphipod Acanthohautorius sp. A and the burrowing shrimp Ogyrides alphaerostris also contributed to variation in community composition. Cluster analyses quantified seasonal variation, mainly based on sharp decreases in abundance, as well as spatial differences in species composition oriented along both east-west and north-south gradients. Variation in benthic assemblages was correlated with water depth and sediment characteristics (mean grain size and percentage of gravel-sized shell debris). We conclude that Ship Shoal is an unrecognized biodiversity hotspot and a hypoxia refuge compared to the immediate surrounding area where the benthic community is affected by seasonal hypoxia events and we discuss how sand-mining may influence this community.
引用
收藏
页码:3759 / 3784
页数:26
相关论文
共 75 条
[1]   Storm layer deposition on the Mississippi-Atchafalaya subaqueous delta generated by Hurricane Lili in 2002 [J].
Allison, MA ;
Sheremet, A ;
Goñi, MA ;
Stone, GW .
CONTINENTAL SHELF RESEARCH, 2005, 25 (18) :2213-2232
[2]  
[Anonymous], 1996, MULTIPLE COMP THEORY, DOI DOI 10.1201/B15074
[3]  
BAUSTIAN MM, 2009, J EXP MAR B IN PRESS
[4]  
BAUSTIAN MM, 2005, THESIS LOUISIANA STA
[5]   Behavioral responses of free-ranging blue crabs to episodic hypoxia. II. Feeding [J].
Bell, GW ;
Eggleston, DB ;
Wolcott, TG .
MARINE ECOLOGY PROGRESS SERIES, 2003, 259 :227-235
[6]  
Berthot A., 2004, 12th International Biennial Conference on Physics of Estuaries and Coastal Seas, P526
[7]   GRADISTAT: A grain size distribution and statistics package for the analysis of unconsolidated sediments [J].
Blott, SJ ;
Pye, K .
EARTH SURFACE PROCESSES AND LANDFORMS, 2001, 26 (11) :1237-1248
[8]   DEEP-SEA BENTHIC SAMPLING WITH THE GOMEX BOX CORER [J].
BOLAND, GS ;
ROWE, GT .
LIMNOLOGY AND OCEANOGRAPHY, 1991, 36 (05) :1015-1020
[9]   The benthic community of the eastern US continental shelf: A literature synopsis of benthic faunal resources [J].
Brooks, R. Allen ;
Purdy, Carla N. ;
Bell, Susan S. ;
Sulak, Kenneth J. .
CONTINENTAL SHELF RESEARCH, 2006, 26 (06) :804-818
[10]  
Cheung M.M., 2006, Benthic polychaete assemblages on Sabine and Heald sand banks, northern Gulf of Mexico: a pre-disturbance study on a sand extraction site, USGS Outer Continental Shelf Ecosystem Studies Program Report