## 4 Discussion
### TC Impacts on Terrestrial Vegetation and Chl-a Concentration in Coastal Waters
In contrast, the absence of high Chl-_a_ peaks (\(>\)0.5 mg/m\({}^{3}\)) along the transect beyond the state of Campeche in the case of Dean (Figure 11) underscores the complex interaction between the storm trajectory, rainfall patterns before and after landing, and the YP geohydrology. This interaction among those factors is illustrated by the increase in Chl-_a_\(>\)0.5 mg/m\({}^{3}\) on the northeastern tip of the YP (i.e., Cabo Catoche; Figure 10B) following the passage of both Wilma (\(\sim\)10 mg/m\({}^{3}\)) and Dean (\(\sim\)4 mg/m\({}^{3}\)). Indeed, this coastal region is identified as both a major groundwater recharge area [37] and a seasonal upwelling region where phytoplankton blooms (mean Chl-_a_ 1.45 mg/m\({}^{3}\); [79; 80; 81]) are fueled by Ekman-layer transport and slope water intrusion from the Yucatan channel. How this increase in Chl-_a_ caused by pulsing TCs will impact secondary production (e.g., fisheries) in the long term along the YP coastal regions is unknown [136]. In addition to an increase in Chl-_a_ induced by both submarine discharge and upwelling in the Yucatan continental shelf [79; 81], surface run-off can also modify phytoplankton community structure and diversity [129]. Previous studies in phytoplankton community variations along the northern YP coastline show that subterranean water discharge interacting with coastal waters' water quality and salinity play a key role in relative differences in dominance, for example, of thick-valve pennate diatoms and dinoflagellates among sites [122]. This difference in phytoplankton groups and taxonomy significantly influences upper trophic levels in the pelagic food webs (i.e., trophic cascade; [43; 137]). For instance, despite the overall oligotrophic conditions of the YP coastal waters, especially in the Caribbean region, biodiversity [138] and secondary production is high, characterized by extensive coral reefs [139; 140; 141; 142] and charismatic filter-feeding, e.g., whale sharks and rays [47; 143], and sea turtles [144]. Further, key ecosystems services, such as artisanal and industrial fisheries, represent a critical economic source providing a combined value (i.e., Campeche, Yucatan, Quintana Roo) ranging from US $130-180 million in the period from 2006-2014 [145; 146]; these fisheries include shrimp [147], red grouper [45; 148], sea cucumber [46], octopus [149; 150], and lobster [151; 152]. If TC frequency and strength increases in the next decades as forecasted by climate models and recent global warming trends [102; 25], then major changes in the food web structure/dynamics and associated ecosystem services should be expected. Further systematic work is needed to directly measure nutrient loading rates controlled by groundwater discharge in the long term along the YP coastline, especially before and after storm passage (e.g., [9; 21]). Overall, there is still a lack of data and information needed to determine if extreme climatic events, such as wetter than normal years caused by TC or droughs, determine whether a specific coastal region will act as a recharge or discharge zone [113; 121], thus influencing coastal trophodynamics in the long term [43].