Relation of fish and shellfish distributions to habitat and water quality in the Mobile Bay estuary, USA

Abstract

The Mobile Bay estuary in the northern Gulf of Mexico provides a rich habitat for many fish and shellfish, including those identified as economically and ecologically important. The National Estuary Program in Mobile Bay has focused on restoration of degraded estuarine habitat on which these species depend. To support this effort, we used statistical techniques of ordination, cluster analysis, and discriminant analysis to relate distributions of individual fish and shellfish species and species assemblages to two dozen water quality and habitat variables in a geo-referenced database. Species appeared to respond to dominant gradients of low to high salinity and upland to offshore habitat area; many of the 15 communities identified via cluster analysis showed aggregated spatial distributions that could be related to habitat characteristics. Species in the Mobile River Delta were distinct from those in other areas of the estuary. This analysis supports habitat management in the Mobile Bay estuary; however, due to mobility of organisms among sampling locations and the dynamic environmental conditions in estuaries, we conclude that the analyses presented here are most appropriate for an evaluation of the estuary as a whole.

Field Investigation on River Hydrochemical Characteristics and Larval and Juvenile Fish in the Source Region of the Yangtze River

“…Water quality parameters are important factors affecting the distribution of fish in river water [30]. Salinity is one of the key water quality factors affecting the distribution of fish in the Gulf [31]. Nutrients such as total phosphorus are positively correlated with fish distribution (> 10cm) in lakes [32].…”

Evaluation of the potential impacts of the proposed Mobile Harbor navigation channel expansion on the aquatic resources of Mobile Bay, Alabama

“…High biodiversity reflects the ecological importance of this drainage network, including inflows from the Black-Warrior, Tombigbee, and Alabama Rivers. Habitat complexity in the Bay, including seagrass beds, dunes and interdune wetland swales, saltwater marshes, freshwater wetlands, and bottomland hardwood forests, directly maintains this high biodiversity (Rashleigh et al 2009).…”

Development and validation of fish-based, multimetric indices for assessing the ecological health of Western Australian estuaries

“…In addition to standardising catch data to overcome gear-related biases, we have also accounted for the natural spatio-temporal variability of fish assemblages by defining appropriate reference conditions for each zone in each season (Karr, 1999;Kennard et al, 2006a;Coates et al, 2007). Although several authors have reported that fish-based multimetric indices for assessing the biotic integrity of riverine systems were unaffected by intra-annual variability in fish community composition (Karr et al, 1986;Pyron et al, 2008;Qadir and Malik, 2009), the effects on estuarine biota of highly seasonal freshwater flows and strong physico-chemical gradients potentially impact the reliability of indicators developed 411 for these ecosystems (Lobry et al, 2006;Chainho et al, 2007;Pérez-Ruzafa et al, 2007;412 Bilkovic and Roggero, 2008;Mazor et al, 2009;Rashleigh et al, 2009) and must be taken 413 into account when setting reference conditions. 414 415…”

“…Loneragan et al, 1989;Loneragan and Potter 1990;b Sarre, unpublished data; cKanandjembo et al, 2001; d Hoeksema and Potter, 2006; e Hoeksema, unpublished data; f Valesini et al, 2009; g Hallett, 2010. …”