## 4 Results  
### Electromagnetism  
1.1 Spatio-Temporal EM Apparent Conductivity Changes during the 2016 Dry Season in the Seven Palm System  
In the Seven Palm system at monthly intervals during the 2016 dry season, the apparent conductivity measurements increased from February to April (Figure 4). The 1 KHz apparent conductivity ranged from 800 mS/m at the northern end of Seven Palm Lake to 1400 mS/m at southern end in February 2016, whereas in April 2016, it ranged from 930 to 2150 mS/m. Similarly, the apparent conductivity along 4 KHz ranged from 900 to 1500 mS/m in February 2016 to a range of 1000 to 2800 mS/m in April 2016 (Figure 4). This showed that the apparent conductivities increased from north to south at all frequencies. In addition, for example, in northwest Seven Palm Lake, the 1 KHz apparent conductivities increase from around 800 mS/m in February to around 1070 mS/m in March to over 1100 mS/m in April. In Middle Lake, the apparent conductivities increased from around 1500 mS/m in February to 1700 mS/m in March to over 1800 mS/m in April. In Monroe Lake, it increased from around 2300 mS/m in March to over 2500 in April. This trend is consistent for 4 KHz data as well. The apparent conductivity of the 16 KHz data varies from 1100 to 2000 mS/m in February 2016 and from 1200 to 2400 mS/m in March 2016 and from 1400 to 3200 mS/m in April 2016 from north to south along the profile line. This is consistent with the increase in conductivity and salinity seen in the surface probe measurements. In general, during the 2016 dry season, the median apparent conductivity measurements increased from February to April at all frequencies as shown in the boxplot (Figure 5). In the boxplot, the interquartile range (IQR) of the March 2016 data is highly dispersed compared to the other EM data set, because the survey line covered a larger portion of Monroe Lake (Figure 5), which is highly influenced by Florida Bay (Figure 1). 1.2 Spatio-Temporal EM Apparent Conductivity Changes between 2016 and 2017 in the Coastal Lakes of ENP  
The EM data show a considerable decrease in apparent conductivity between February 2016 and January 2017 in both the Seven Palm and West Lake systems. In the Seven Palm system, the apparent conductivity showed a general decrease of 150 mS/m in the Seven Palm system and 300 mS/m in the Middle Lake (Figure 6A,B). In the Seven Palm system, the 1 KHz apparent conductivity ranged from 800 mS/m at the northern end of Seven Palm \begin{table}
\begin{tabular}{c c c c} \hline \(i\) & \(a_{i}\) & \(b_{i}\) & \(c_{i}\) \\ \hline
0 & 0.008 & 0.0005 & 6.766097 \(\times\) 10\({}^{-1}\) \\ \hline
1 & \(-\)0.1692 & \(-\)0.0056 & 2.00564 \(\times\) 10\({}^{-2}\) \\ \hline
2 & 25.3851 & \(-\)0.0066 & 1.104259 \(\times\) 10\({}^{-4}\) \\ \hline
3 & 14.0941 & \(-\)0.0375 & \(-\)6.9698 \(\times\) 10\({}^{-7}\) \\ \hline
4 & \(-\)7.0261 & 0.0636 & 1.0031 \(\times\) 10\({}^{-9}\) \\ \hline
5 & 2.7081 & \(-\)0.0144 & \\ \hline \end{tabular}
\end{table} 
Table 3: The coefficients used to calculate salinity. Lake to 1400 mS/m at the southern end in February 2016 (Figure 6A), whereas in January 2017, it ranged from 740 to 1200 mS/m (Figure 6B). Similarly, the apparent conductivity along 4 KHz ranged from 870 to 4000 mS/m in 2016 (Figure 6C) to a range of 800 to 2400 mS/m in 2017 (Figure 6D). Figure 4: Map of apparent conductivities at 1, 4, and 16 KHz in 2016 in the Seven Palm system, Middle Lake and Monroe Lake. The star shows the location of the monitoring well. The EM results show the same trend in the West Lake system. The apparent conductivity of the 1 KHz data decreases from a range of 1200 to 1700 mS/m in 2016 to 950 to 1850 mS/m in 2017 (Figure 6A,B). In addition, the result along 4 KHz dropped from 1600 mS/m in 2016 to 1500 mS/m in 2017 (Figure 6C,D). Similarly, the result along 16 KHz dropped from 1800 mS/m in 2016 to 1600 mS/ in 2017 (Figure 6E,F).