Quantifying the Spatial Extent and Distribution of Estuarine Habitat with Changing Salinity: Do Positive, Neutral, and Negative Estuaries Respond Differently to Salinity Variation?
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Salinity is known to be a driving factor in defining habitat suitability for estuarine-dependent species. With increased demands placed on freshwater resources and extreme drought conditions becoming prevalent for many coastal regions, it is important to understand how these changes may impact the extent and distribution of suitable habitat for species that rely on the passage of freshwater to the coastal region. Here, habitat suitability models were constructed for three estuarine species (Farfantepenaeus aztecus, Micropogonias undulatus, and Cynoscion nebulosus) across three estuary classes (based on freshwater balance: positive, neutral, and negative estuaries) and for three simulated salinity regimes (low, moderate, and high salinities). The impact of changing salinity regimes on habitat suitability varied most notably at the species level but also varied significantly across the three estuary types examined. Of the three species examined, F. aztecus showed relatively little salinity-related variation in habitat extent or distribution. Variation in M. undulatus and C. nebulosus salinity impact was especially clear in relatively neutral and positive estuaries where distribution of habitat within the estuary under the varying salinity regimes followed intra-estuarine salinity gradients to match salinity preference for each species and typically resulted in a gradual shrinking of highly suitable habitat area into the far upper estuary as salinities increased. While salinity was not found to be the only or even the most impactful of variables regarding habitat suitability, model outputs show that at the estuary scale, salinity can have substantial influence on the spatial extent and distribution of suitable habitat and this influence is not constant across estuary types. Modeling exercises such as this are the first step in communicating such impacts and focusing the vigilance of resource managers towards vulnerable species and habitat regions.
KeywordsHabitat suitability Freshwater inflow Climate change Estuary Predictive modeling
I would like to thank the many TPWD-Coastal Fisheries Division staff members who came before me and had the foresight to implement and maintain one of the most comprehensive and longest running fisheries-independent monitoring programs in the world. Without such long-term monitoring, analyses such as this would never be possible. I would like to thank M. Fisher, G. Sutton, and several anonymous reviewers who provided useful discussion and feedback that greatly improved the quality of this manuscript. Finally, I would like to thank my graduate committee at Texas A&M University-Corpus Christi: G. Stunz, J. Tolan, J. Pollack, and P. Montagna.
- Anderson, J., Z. Olsen, T. Wagner, G. Sutton, C. Gelpi, and D. Topping. 2017. Environmental drivers of the spatial and temporal distribution of spawning female blue crabs, Callinectes sapidus, in the western Gulf of Mexico. North American Journal of Fisheries Management 37 (4): 920–934.CrossRefGoogle Scholar
- Beck, M.W., K.L. Heck Jr., K.W. Able, D.L. Childers, D.B. Eggleston, B.M. Gillanders, B. Halpern, C.G. Hays, K. Hoshino, T.J. Minello, R.J. Orth, P.F. Sheridan, and M.P. Weinstein. 2001. The identification, conservation, and management of estuarine and marine nurseries of fish and invertebrates. BioScience 51 (8): 633–641.CrossRefGoogle Scholar
- Bushon, A. 2006. Recruitment, spatial distribution, and fine-scale movement patterns of estuarine dependent species through tidal inlets in Texas. Master’s Thesis. Texas A&M University- Corpus Christi.Google Scholar
- Elton, C. 1927. Animal Ecology. London: Sedgwick and Jackson.Google Scholar
- Finkbeiner, M., J.D. Simons, C. Robinson, J. Wood, A. Summers, and C. Lopez. 2009. Atlas of shallow-water benthic habitats of Coastal Texas: Espiritu Santo Bay to Lower Laguna Madre, 2004 and 2007. Charleston: NOAA Coastal Services Center.Google Scholar
- Holt, G.J., and S.A. Holt. 2002. Effects of variable salinity on reproductive and early life stages of spotted seatrout. In Biology of the Spotted Seatrout, eds. S.A. Bortone. CRC Press.Google Scholar
- Longley, W.L., ed. 1994. Freshwater inflow to Texas bays and estuaries: Ecological relationships and methods for determination of needs. Austin: Texas Water Development Board and Texas Parks and Wildlife Department 386 p.Google Scholar
- Martinez-Andrade, F. 2015. Marine resource monitoring operations manual. Austin: Texas Parks and Wildlife Department.Google Scholar
- Martinez-Andrade, F., P. Campbell, and B. Fuls. 2005. Trends in relative abundance and size of selected finfishes and shellfishes along the Texas coast: November 1975–December 2003. Austin: Texas Parks and Wildlife Department- Coastal Fisheries Division Management Data Series No. 232.Google Scholar
- Montagna, P.A., and R.D. Kalke. 1995. Ecology of infaunal Mollusca in South Texas estuaries. American Malacological Bulletin 11: 163–175.Google Scholar
- Olsen, Z. 2014. Potential impact of extreme salinity and surface temperature events on population dynamics of black drum, Pogonias cromis, in the Upper Laguna Madre, Texas. Gulf of Mexico Science 2014: 60–68.Google Scholar
- Parker, J.C. 1971. The biology of the Spot, Leiostomus xanthurus Lacepede, and Atlantic Croaker, Micropogon undulatus (Linnaeus) in two Gulf of Mexico nursery areas. PhD Thesis, Texas A&M University.Google Scholar
- Petrik, R., P.S. Levin, G.W. Stunz, and J. Malone. 1999. Recruitment of Atlantic croaker, Micropogonias undulatus: Do postsettlement processes disrupt or reinforce initial patterns of settlement? Fishery Bulletin 97: 954–961.Google Scholar
- Ridgeway, G. 2013. gbm: Generalized Boosted Regression Models. R package version 2.1. http://CRAN.R-project.org/package=gbm.
- Rooker, J.R., S.A. Holt, G.J. Holt, and L.A. Fuiman. 1999. Spatial and temporal variability in growth, mortality, and recruitment potential of postsettlement red drum, Sciaenops ocellatus, in a subtropical estuary. Fishery Bulletin 97: 581–590.Google Scholar
- Tolan, J.M. 2013. Estuarine Fisheries Community-Level Response to Freshwater Inflows. In Water Resources Planning, Development, and Management. ed. Ralph Wurbs. IntechOpen. https://doi.org/10.5772/52313.
- Tunnell, J.W., Jr., and F.W. Judd, eds. 2002. The Laguna Madre of Texas and the Tamaulipas. College Station: Texas A&M University Press.Google Scholar