Spatiotemporal variability in Terminos Lagoon (Mexico) waters during the 2009–2010 drought reveals upcoming trophic status shift in response to climate change

Abstract

The 2009-2010 El Niño was accompanied by a severe drought strongly impacting Mexico as well as Central America, the Caribbean, and the southern USA. The present work aims at assessing how such a major climatic event impacted the hydrological typology of transitional waters in Terminos Lagoon, one of the largest shallow tropical lagoons fringing the Gulf of Mexico. Spatiotemporal inter-comparison of hydrological conditions was conducted by pairing a reference multiparametric dataset (14 hydrological parameters versus 34 sampling stations) averaged over the October 2008 to July 2010 period with each sampling occurrence dataset and running Principal Component Analyses (PCA), setting the reference-survey dataset as active variables and each sampling occurrence dataset as non-active (supplementary) variables. It revealed that the exceptional deficit in freshwater supply to the lagoon during the 2009-2010 El Niño drastically reduced hydrological diversity and lowered the trophic status of the lagoon. Short-term shifts in environmental status are common in transitional waters and responsible for temporary shifts in community structure but climate change projections show a significant long-term decrease in the freshwater discharge at the regional scale that will impact Terminos Lagoon as well as other coastal lagoons of Mexico and Central America. When combined with sea level rise, such a decrease will result in a long-term shift in hydrological conditions with a subsequent increase in salinity and a decrease in the diversity of environmental conditions affecting trophic status, will have a long-term impact on the biota.

Evaluación del estado ecológico de laguna de Términos con base en la estructura de asociaciones de diatomeas bentónicas

“…In this study, the combination of PCA and KW analysis, allowed us to confirm our hypothesis, this is, that there are spatiotemporal differences between samplings, generated by the high hydrological variability in Términos lagoon Fichez et al, 2019). These differences are explained by the variation and interaction of different parameters in each sampling.…”

“…However, the most frequently referred classification for TL divides it into two main regions: (1) East zone, related to marine conditions, i.e., high salinity and low nutrient concentrations, and (2) West zone, where the Palizada river has notorious influence such as high nutrient and organic matter concentrations Fichez et al, 2019). This zonation though does not exhibit a time-space consistency, and indicate that these regions behave almost as independent water bodies if the epicontinental water discharges into the lagoon do not increase significantly because they generate the hydrological homogenization of the lagoon.…”

“…The great variability that characterizes these systems can be approached confidently using multivariate methods, inasmuch these allow an integrated view of the environmental variables involved , thus representing a rigorous approach for assessing space and time variations in these environments (Fichez et al, 2019). In addition, multivariate methods also allow identification of environmental variables interactions, allowing a better understanding of the fluctuations inside the system.…”

“…In view of the above, principal components analysis is one of the most employed multivariate methods for environmental characterization in aquatic systems (Pilkaityte and Razinkovas, 2006;Schenone et al, 2008;Abou Zakhem, 2016;Carayon et al, 2020), and it has been used for analyzing the hydrology of Términos lagoon previously, e.g., Fichez et al (2019) used it to recognize the lagoon variation that occurred along a two-year study which determined the repercussions of climate change in the system. Their approach allowed them to create a synthetic vision (model) of the variability of the lagoon, so that its possible to compare it against further additional samplings.…”

Benthic diaetm distribution in a tropical coastal lagoon in relation to substrate and its environmental factors

“…This may reflect the influence of environmental variables at each site as it has been observed elsewhere (Frankovich et al, 2006;Kelly et al, 2009), and whose variability is very high in coastal ecosystems (Day et al, 2013). Terminos lagoon exhibits high temporal and spatial variations (Fichez et al, 2019;Guerra-Santos & Kahl, 2018) and usually is divided in zones related to the influence of surrounding systems. However it has been observed that these zones are not constant and that the lagoon presents a series of environmental gradients which vary spatially and temporally (López-Mejía et al, 2022).…”