Submerged Groundwater Discharges as Source of Fecal Material in Protected Karstic Coastal Areas

Abstract

Coastal zones are vital for their ecosystem services and socioeconomic value. Accordingly, several zones have been protected to limit anthropogenic development and to avoid environmental degradation. Nevertheless, some of these protected areas keep deteriorating probably related with anthropogenic contributions not considered in legislation. Specifically, submerged groundwater discharges (springs) could be releasing anthropogenic materials carried from remote inland areas to the coast. Here we evaluate the role and temporal variation of submerged groundwater discharges as sources of anthropogenic materials using the 5 -stanol C 27 markers in the natural protected area of Dzilam de Bravo, Yucatán, Mexico. Results demonstrate that (1) submerged groundwater discharge flux velocity and direction vary between hydrological season, exhibiting higher flow rates in Nortes season contrary to dry season and (2) the presence of coprostanol and epicoprostanol (anthropogenic fecal matter markers) in sediments surrounding the submerged groundwater discharges provides proof of allochthonous anthropogenic fecal material in a protected area, probably from remote inland sites. Thus, it is vitally important that inland anthropogenic materials transported in groundwater and released in the coastal environment by submerged groundwater discharges be considered in protection plans, like protection perimeters, for coastal zones.

Seagrass contribution to blue carbon in a shallow karstic coastal area of the Gulf of Mexico

“…In karst systems, it is common to observe P limitations ( Álvarez Góngora & Herrera-Silveira, 2006 ); the connectivity between mangroves and seagrasses in this area, provides favorable conditions for the development of quality SAV. However, this leads to significant vulnerability if groundwater discharges begin to show signs of pollution, as they have in the northern and eastern regions of the Yucatan Peninsula ( Herrera-Silveira & Morales-Ojeda, 2009 ; Arcega-Cabrera, Barroso & Oceguera-Vargas, 2014 ; Kantun-Manzano et al, 2018 ). However, due to the connectivity between mangroves and seagrasses, the light and concentration of nutrients in this area favor conditions for the healthy development of SAV.…”

“…On the coast of Quintana Roo, currents average 25 cm sec −1 , and patches of scattered seagrasses covering between 10 and 50% of the available area ( Badan Jr et al, 2005 ; Arellano-Méndez, Morales-Ojeda & Herrera-Silveira, 2014 ). On the northern Yucatan coast, currents range between 10 and 20 cm sec −1 , with seagrass patches covering between 40 and 80% of the available area ( Appendini et al, 2012 ; Kantun-Manzano et al, 2018 ). Finally, on the coast of Campeche, where the Los Petenes protected area is located, currents are very low at <10 cm sec −1 ( López & Sierra, 1998 ), favoring the extension and coverage of seagrasses.…”

“…The concentration of chlorophyll-a (Chl-a) was also determined using the method of Parsons, Maita & Lalli (1984). From these environmental variables, the trophic index ''TRIX'' was calculated (Vollenweider et al, 1998;Melaku, Solidoro & Umgiesser, 2003;Jorgensen et al, 2005).…”

Sandy Beach Macrofauna of Yucatán State (Mexico) and Oil Industry Development in the Gulf of Mexico: First Approach for Detecting Environmental Impacts

“…The effects of these sedimentary dynamics on the diversity and community structure of the macrofauna have not been evaluated in this region, but it has been demonstrated in other latitudes (Walker et al, 2008;Schlacher et al, 2012;Munari, 2013). In addition, there are other sources of pollution related to the karstic characteristics of the Yucatan Peninsula, that allow pollutants generated by activities carried out inland to permeate, flow and enter to the coast by submerged groundwater discharges; some evidence of that is the presence of human fecal material (coprostanol and epicoprostanol) in sediments surrounding the springs located in Dzilam de Bravo (Kantun-Manzano et al, 2018), as well as the results reported by Arcega-Cabrera et al (2015) concerning heavy metal pollution in Chelem Lagoon connected to inland anthropogenic activities along with local factors.…”

Identity Crisis: An Integrative Re-Evaluation of Typhlatya Shrimp within the Karst Aquifer of the Yucatán Peninsula, Mexico.

“…Typhlatya dzilamensis is not federally listed and yet was here found to be distinct from all other species, representing the only high salinity species with a habitat range restricted to coastal systems throughout the Peninsula. Thus, T. dzilamensis is an excellent candidate in need of evaluation, given its association with karst coastlines, which are particularly vulnerable to anthropogenic impacts and coastal development changes 68,72,73 . Lastly, the identification of two unknown species, which were 'rare' among our newly sequenced samples and in previously published data, warrants further study to better understand their distributions and population genetic structure.…”