## 4 Discussion
### TC Impacts on Terrestrial Vegetation and Chl-a Concentration in Coastal Waters
Under normal conditions, average Chl-\(a\) offshore of the Campeche Sound have been reported to be in the range from 0.6 to 2.5 mg/m\({}^{3}\) in areas adjacent to the coastline [118]. The highest Chl-\(a\) estimated for Stan in the northeastern (7-8 mg/m\({}^{3}\); Figure 10A) and east (>8 mg/m\({}^{3}\)) regions of the YP might be related to the weaker wind speeds (<74 km/h; Figure 5) but longer residence time over the YP in comparison to the other TCs. We hypothesize that such an increase in Chl-\(a\), up to 4x the average annual value, is caused by the interaction between hydrostatic pressure and storm-induced precipitation, promoting water column mixing offshore, submarine discharge, and excess surface water run-off within hours after TC impact. This increase in Chl-\(a\) has been characterized as \"anomalies\" without a direct attribution to TCs (e.g., [87]). Because the YP is basically a large karst aquifer (~165,000 km\({}^{2}\)) with complex groundwater hydraulic conductivity [37], submarine discharge is a key lateral water flux that hydrologically connects the YP with adjacent coastal waters, particularly during the wet season [38; 119]. It is estimated that submarine groundwater discharge in the YP ranges from 36-95 m\({}^{3}\) m\({}^{-1}\) d\({}^{-1}\) and contains about 75% of terrestrial groundwater [120]. The transport of nutrients via this submarine discharge has been measured at some locations along the YP Caribbean coast [62; 121], although further work is needed to evaluate loading rates in the northern and western coasts [39; 66; 122]. Increasing human activities (e.g., agriculture, industry/urban development, tourism) in the YP during the last 20 years has exacerbated groundwater eutrophication and is presently a problem affecting water quality and human health as indicated by the presence of toxic algae blooms [40], microalgae extension [123], pharmaceutical products [123], and high nitrate concentrations from fertilizers [41; 124; 125; 123; 121]. Thus, the increasing eutrophication of the YP's aquifers and corresponding submarine water discharge currently compares to other large river-dominated watersheds in the GOM. In these coastal zones, peak discharge drives both high Chl-\(a\) and water column productivity (e.g., Apalachicola River, [126; 127]; Mississippi River, [128]; Galveston Bay, [129; 130]; Grijalva-Usumacinta River; [131; 132]), similar to the pulsing discharge induced after storm passage. When building a landscape-level water balances for the YP, surface water run-off is generally ignored [113]. Yet, run-off caused by TCs becomes a significant pulsing of freshwater and nutrients inputs into the coastal zone as indicated by the variable discharge from the Champion River. This export was indirectly gauged by analyzing changes in Chl-\(a\) along the transect depicted in Figure 10, which extends off the coast along the periphery of the YP encompassing the coastline of Campeche, Yucatan, and partially, northern Quintana Roo. Chl-\(a\) along this transect shows a sharp increase after Stan (5 mg/m\({}^{3}\); Figure 11) and Dean (\(\sim\)3 mg/m\({}^{3}\); Figure 11) in the southeastern region of Campeche, where surface run-off is more common due changes in elevation and the presence of large watersheds (e.g., Grijalva-Usumacinta; [132]) and associated estuarine end members. For instance, Terminos lagoon (Figure 1B), the largest coastal Lagoon in Mexico (2500 km\({}^{2}\); [133]) and part of the Grijalva-Usumacinta deltaic system [134], exports inorganic nutrients and organic matter to the adjacent Campeche Sound during peak river discharge and strong tidal exchange [135]. This export is noticeable in large plumes of freshwater extending into the Sound with moderate Chl-_a_ (\(<\)4 mg/m\({}^{3}\)) after Emily, Stan, Wilma, and Dean passage (Figures 1 and 10A).