FIGURE 21.1 Conceptual diagram showing the major steps in the construction of an ecological model. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.2 The Mississippi River discharges (Q, a) and corresponding areas of summertime bottom hypoxia (b) in the northern part of Gulf of Mexico during 1985, 1988, and 1993. The solid line represents the mean monthly discharge for a given year, and the dashed line is the mean monthly discharge for the 1985–1993 period. The shaded areas represent the distributions of bottom waters with dissolved oxygen concentration below 2mg O2/l. Note that during 1988, hypoxia was observed only at one location off the Louisiana coast. The reference station C6 is indicated in the upper panel of (b) Source: Reprinted from Justić et al., 2003, with permission from Elsevier. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.3 Observed and predicted monthly averages of (a) surface (0–10m) and (b) bottom (10–20m) oxygen concentrations at station C6 for the period June 1985–November 1993. Source: Reprinted from Justić et al., 2002, with permission from Elsevier. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.4 Simulated changes in the average (a) surface (0–10m) and (b) bottom (10–20m) oxygen concentrations at station C6 for the period January 1955 to May 2000. Shaded area in the lower chart denotes hypoxic conditions (<2mg O2/l) in bottom waters. Source: Reprinted from Justić et al., 2002, with permission from Elsevier. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.5 The four spatial maps of vegetated and water cells in the 100 × 100 grids used for simulating individual brown shrimp growth, mortality, and movement. The two maps on the top row had similar total amount of vegetated cells (50%). The left-side map had this arranged in large clumps and thus low edge, while the right-side map has smaller clumps and thus higher edge. The bottom row had few vegetated cells (about 30% of the map) and also arranged such that the left-side map had low edge and the right-side map had high edge. The four maps can be thought of as showing a progression of degradation as one goes clockwise starting at the top left map. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.6 Location of the Caernarvon basin where the watershed model was applied to simulate long-term plant community changes under different fresh water input scenarios. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.7 Habitat map for 1988 (a) estimated by the US Fish & Wildlife and (b) predicted by the watershed model. ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~

FIGURE 21.8 Predicted habitat maps for the no discharge, scheduled releases, and pulsed releases scenarios for year 50 of model simulations. Also shown are the difference maps that compare cell by cell the predicted habitat map under no discharge in year 50 to the map under the scheduled scenario in year 50 and the no discharge to the pulsed scenario. The colors on the difference maps indicate the type of habitat changes that were predicted: open water to brackish marsh (blue), salt marsh to brackish marsh (yellow), and brackish to salt marsh (light green). ESTUARINE ECOLOGY, Second Edition. John W. Day JR, Byron C. Crump, W. Michael Kemp, and Alejandro Yánez-Arancibia. Copyright © 2013 by Wiley-Blackwell. All rights reserved ~