Proposal for Geoconservation of Two New Coastal Geosites for the Sabana-Camagüey Archipelago, Cuba: Los Caimanes and El Jato Lagoons

The designation of geological sites in Cuba is relatively new. During the early years of the 21st century some sites were proposed, but only in the province of Pinar del Rio have geosites been officially approved. Here we propose two further geosites, one at Cayo Sabinal (Camagüey Province) and the other at Cayo Coco (Ciego de Ávila Province). Recent studies show stromatolites at both sites, important in understanding microbialite formation and the role of microbes in geochemical signatures and mineral diversity. According to the approved Cuban scoring methodology, El Jato Lagoon obtained 79 points and Los Caimanes Lagoon 77 points. Both were regarded as Class B. Although located in tourist areas, they lack aesthetic values. However, both are on the coastal zone, where natural and anthropogenic impacts could affect their conservation

Mapping and Monitoring of the Invasive Species Dichrostachys cinerea (Marabú) in Central Cuba Using Landsat Imagery and Machine Learning (1994–2022)

[EN] Invasive plants are a serious problem in island ecosystems and are the main cause of the extinction of endemic species. Cuba is located within one of the hotspots of global biodiversity, which, coupled with high endemism and the impacts caused by various disturbances, makes it a region particularly sensitive to potential damage by invasive plants like Dichrostachys cinerea (L.) Wight & Arn. (marabú). However, there is a lack of timely information for monitoring this species, as well as about the land use and land cover (LULC) classes most significantly impacted by this invasion in the last few decades and their spatial distribution. The main objective of this study, carried out in Central Cuba, was to detect and monitor the spread of marabú over a 28-year period. The land covers for the years 1994 and 2022 were classified using Landsat 5 TM and 8 OLI images with three different classification algorithms: maximum likelihood (ML), support vector machine (SVM), and random forest (RF). The results obtained showed that RF outperformed the other classifiers, achieving AUC values of 0.92 for 1994 and 0.97 for 2022. It was confirmed that the area covered by marabú increased by 29,555 ha, from 61,977.59 ha in 1994 to 91,533.47 ha in 2022 (by around 48%), affecting key land covers like woodlands, mangroves, and rainfed croplands. These changes in the area covered by marabú were associated, principally, with changes in land uses and tenure and not with other factors, such as rainfall or relief in the province. The use of other free multispectral imagery, such as Sentinel 2 data, with higher temporal and spatial resolution, could further refine the model’s accuracy.S

Estados ecosistémicos coexistentes en una laguna costera tropical bajo eutrofización creciente en la cayería norte de Cuba

Through a nested suite of methods here we contrast the coexistence of different ecosystem states in a tropical coastal lagoon, the Laguna Larga, with increasing eutrophication stress between 2007 and 2009. Water temperature averaged 27.4°C in the lagoon and showed a slight positive trend during the study period. Salinity averaged 35.0±6.2, exhibiting high spatial and temporal variability, and also a slight positive trend in time. In contrast, dissolved oxygen showed a substantial decreasing trend (–0.83 ml L–1 y–1; –13.3% y–1) over the period, while nutrients increased dramatically, particularly total phosphorus (2.6 µM y–1), in both cases sustaining the progression of eutrophication in the lagoon during the three years we sampled. The Karydis nutrient load-based trophic index showed that the lagoon has a spatial pattern of increasing eutrophication from the sea and the outer sector (oligotrophic-mesotrophic) to the central (mesotrophic) and the inner sector (mesotrophic-eutrophic). Two ecosystem states were found within the lagoon. In the outer oligotrophic sector, the dominant primary producers were macroalgae, seagrasses and benthic diatoms, while mollusc assemblages were highly diverse. In the inner and central sectors (where trophic status increased toward the inner lagoon) a phytoplankton-dominated ecosystem was found where mollusc assemblages are less diverse. In spite of the progression of eutrophication in the lagoon, these two different ecosystems coexisted and remained unchanged during the study period. Apparently, the effect of water residence time, which increases dramatically toward the inner lagoon, dominated over that of nutrient loadings, which is relatively more homogeneously distributed along the lagoon. Therefore, we consider that actions that reduce the water residence time are likely the most effective management options for this and other similarly choked lagoons.Mediante la conjunción de una diversidad de métodos y observaciones, se contrasta la coexistencia de diferentes estados ecosistémicos en Laguna Larga, una laguna costera tropical sometida a una eutrofización creciente entre 2007 y 2009. La temperatura media en la laguna fue de 27.4°C y mostró una ligera tendencia positiva en este periodo. La salinidad mostró alta variabilidad espacial y temporal alrededor de una media de 35.0±6.2 y también tuvo una tendencia temporal positiva. En contraste, el oxígeno disuelto mostró una sustancial tendencia negativa (–0.83 ml L–1 y–1; –13.3% y–1) en el mismo periodo, al tiempo que los nutrientes se incrementaron drásticamente, en particular el fósforo total, a una tasa de 2.6 µM y–1, respaldando ambas tendencias el incremento de la eutrofización a lo largo de los tres años observados. El índice trófico de Karydis, basado en las cargas de nutrientes, mostró un patrón espacial de incremento de la eutrofización desde el mar hacia el sector exterior (oligotrófico-mesotrófico), el sector central (mesotrófico) y el sector interior (mesotrófico-eutrófico). Se identificaron dos estados ecosistémicos dentro de la laguna. En el oligotrófico sector exterior, los productores primarios dominantes fueron macroalgas, pastos marinos y diatomeas bénticas, en tanto que las asociaciones de moluscos fueron altamente diversas. En los sectores central e interior (incrementándose el estatus trófico hacia este último), se encontró un estado ecosistémico dominado por el fitoplancton y en el que las asociaciones de moluscos son menos diversas. A pesar del incremento de la eutrofización, estos dos ecosistemas distintos coexistieron y permanecieron sin cambios durante el periodo estudiado. En Laguna Larga, el efecto del tiempo de residencia del agua, que se incrementa dramáticamente hacia el interior de la laguna, domina aparentemente sobre el de la carga externa de nutrientes, que está distribuida de manera relativamente más homogénea a lo largo de la laguna. Por ello, consideramos que las acciones dirigidas a disminuir el tiempo de residencia del agua son probablemente las más efectivas en esta laguna y otras similarmente aisladas

Cálculo del área y volumen de agua de dos reservorios de Cuba Central usando métodos de sensores remotos. Una nueva perspectiva

[EN] The availability, quality and management of water constitute essential activities of national, regional and local governments and authorities. Historic annual rain (between 1961 and 2020) in Chambas River Basin (Central Cuba) was evaluated. Two remote sensing methods (Normalized Difference Water Index and RADAR images) were used to calculate the variation of water area and volumes of two reservoirs (Chambas II and Cañada Blanca) of Ciego de Ávila Province at end of wet and dry seasons from 2014-2021. The results showed that mean annual rain was 1330.9 ± 287.4 mm and it did not showed any significant tendency at evaluated period. For both reservoirs, mean water areas measured with two methods were 19 % and 8 % smaller than the mean water area reported by authorities for the same period. The static water storage capacity (water volume) of both reservoirs varied (as area) between seasons with the greatest volume in both reservoirs recorded in October of 2017 (30.5 million of m3 in Chambas II and 45.1 million of m3 in Cañada Blanca reservoir). Large deviations of water area and volumes occurred during the dry season (lower values) and the wet season of 2017 (influenced by rain associated to of Hurricane Irma) and wet season of 2020 (influenced by rain associated to tropical storm Laura). Calculated area volume models with significant statistical correlation are another useful tool that could be used to improve water management in terms of accuracy and to increase reliable results in cases where gauge measurements are scarce or not available.[ES] La disponibilidad, calidad y manejo del agua constituye actividades esenciales de los gobiernos y autoridades regionales y locales.  Fue evaluada La lluvia anual histórica (entre 1961 y 2020) de la Cuenca del Río Chambas. Para el cálculo de la variación de las áreas y volúmenes del agua en dos reservorios de la Provincia de Ciego de Ávila al término de las temporadas lluviosa y poco lluviosa entre 2014 y 2021 fueron usados dos métodos de sensores remotos (Índice Normalizado de Diferencia de Agua e imágenes del RADAR). Los resultados mostraron que la lluvia media anual fue 1330.9±287.4 mm y no mostró tendencia significativa en el período evaluado. Para ambos reservorios, las áreas promedio de agua medidas con los dos métodos fueron 19 % y 8 % menores que el área de agua reportadas por las autoridades para el mismo período. La capacidad estática de almacenamiento de agua (volumen de agua) de los dos reservorios varió (como el área) entre temporadas, con el mayor volumen determinado en ambos reservorios en octubre de 2017 (30.5 millones de m3 en Chambas II y 45.1 millones de m3 en Cañada Blanca). Grandes desviaciones de las áreas y volúmenes del agua ocurrieron durante la temporada poco lluviosa (menores valores) y la temporada lluviosa de 2017 (influenciada por las lluvias asociadas el huracán Irma) y la temporada lluviosa de 2020 (influenciada por la lluvia asociada a la tormenta Laura). Los modelos calculados para la relación área volumen con una significación estadística son otra herramienta útil que podría ser usada para mejorar el manejo del agua en términos de precisión y el incremento de resultados confiables en casos donde la medición de los niveles de agua son escasos o no están disponibles.Valero-Jorge, A.; González-De Zayas, R.; Alcántara-Martín, A.; Álvarez-Taboada, F.; Matos-Pupo, F.; Brown-Manrique, O. (2022). Water area and volume calculation of two reservoirs in Central Cuba using Remote Sensing Methods. A new perspective. Revista de Teledetección. (60):71-87. https://doi.org/10.4995/raet.2022.17770OJS71876

Water area and volume calculation of two reservoirs in Central Cuba using Remote Sensing Methods. A new perspective

[EN] The availability, quality and management of water constitute essential activities of national, regional and local governments and authorities. Historic annual rain (between 1961 and 2020) in Chambas River Basin (Central Cuba) was evaluated. Two remote sensing methods (Normalized Difference Water Index and RADAR images) were used to calculate the variation of water area and volumes of two reservoirs (Chambas II and Cañada Blanca) of Ciego de Ávila Province at end of wet and dry seasons from 2014-2021. The results showed that mean annual rain was 1330.9 ± 287.4 mm and it did not showed any significant tendency at evaluated period. For both reservoirs, mean water areas measured with two methods were 19 % and 8 % smaller than the mean water area reported by authorities for the same period. The static water storage capacity (water volume) of both reservoirs varied (as area) between seasons with the greatest volume in both reservoirs recorded in October of 2017 (30.5 million of m3 in Chambas II and 45.1 million of m3 in Cañada Blanca reservoir). Large deviations of water area and volumes occurred during the dry season (lower values) and the wet season of 2017 (influenced by rain associated to of Hurricane Irma) and wet season of 2020 (influenced by rain associated to tropical storm Laura). Calculated area – volume models with significant statistical correlation are another useful tool that could be used to improve water management in terms of accuracy and to increase reliable results in cases where gauge measurements are scarce or not available.S

Coastal flooding associated with hurricane Irma in Central Cuba (Ciego de Ávila Province)

Irma was a major hurricane that developed during the 2017 season. It was a category 5 on the Saffir–Simpson Hurricane wind scale. This hurricane caused severe damage in the Caribbean area and the Florida Keys. The social, economic, and environmental impacts, mainly related to coastal flooding, were also significant in Cuba. The maximum limits of coastal flooding caused by this hurricane were determined in this research. Field trips and the use of the GPS supported our work, which focused on both the northern and southern coasts of the Ciego de Ávila province. This work has been critical for improving coastal flooding scenarios related to a strong hurricane, as it has been the first experience according to hurricane data since 1851. Results showed that the Punta Alegre and Júcaro towns were the most affected coastal towns. The locals had never seen similar flooding in these places before. The differences between flood areas associated with Hurricane Irma and previous modeled hazard scenarios were evident (the flooded areas associated with Hurricane Irma were smaller than those modeled for categories 1, 3, and 5 hurricanes). The effects of this hurricane on the most vulnerable coastal settlements, including the impacts on the archeological site “Los Buchillones”, were also assessed.Agencia Estatal de Investigación | Ref. RYC2021-034044-

Aquatic plants in the freshwater artificial lagoons in Ciego de Avila, Cuba

Seven artificial freshwater lagoons (L1-L7) were studied in Ciego de Ávila, Cuba. They were characterized using different genetic, hydrologic, and morphologic criteria. All the environments were young and lagoons of anthropogenic origin; one is a temporary pond (L.1), and the others are permanent. A floristic list was made to identify the plants present in delineated parcels at the borders of the lagoons. The identified taxa were classified according to their origin and presence in Cuba, growth form, usefulness for humans, response to anthropic impacts, and conservation status. Forty-nine (49) species from 44 genera and 34 families were recorded. Most species (27 and 26, respectively) were identified at L.3 and L.6 (lagoons formed in old stone quarries used to construct the local airport). The least(seven) at L.1. Exotic and synanthropic plants prevailed, and invasive species were abundant, which indicates the transition through the early stages of ecological succession. 31 % of autochthonous plants and 2 % of endemic plants were recorded. 4 % is critically endangered. 39 % of these plants are medicinal, 29 % ornamental, 12 % are phytoremediators, and 4 % are frequently used in folklore-related practices. Plants that live in the freshwater environments of Ciego de Avila municipality have diverse characteristics, values, and uses that increase the environmental services of these ecosystems.Se estudiaron siete lagunas artificiales de agua dulce (L1 – L7) en el municipo de Ciego de Ávila (Cuba), los cuales se caracterizaron según criterios genéticos, hidrológicos y morfológicos. Todas son lagunas, de origen antrópico, relativamente recientes. Una de ellas es semipermanente (L.1) y las restantes son permanentes. A partir de la identificación de las plantas presentes en parcelas delineadas, desde los bordes de las lagunas, fue confeccionada una lista florística. Los taxones identificados fueron catalogados según su origen y presencia en Cuba, hábito de crecimiento, utilidad para el hombre, comportamiento ante el impacto antrópico y estado de conservación. Se registraron 49 especies pertenecientes a 44 géneros y 34 familias. En L.3 y L.6 (lagunas ubicadas en las Canteras del Aereopuerto) se identificó el mayor número de especies (27 y 26 respectivamente) y en L.1, el menor (7). Predominaron plantas exóticas y sinantrópicas y abundaron las invasoras, lo cual indica el tránsito por etapas tempranas de la sucesión ecológica. No obstante, se detectó un 31 % de plantas autóctonas y un 2 % de endemismo. Un 4 %se encuentran amenazadas de extinción, clasificadas en Peligro Crítico. El 39 % tiene uso medicinal, el 29 % ornamental, el 12 % son fitorremediadoras y el 4 % aparecen frecuentemente incorporadas a prácticas folclóricas. Las plantas asociadas a estas lagunas artificiales del municipio de Ciego de Ávila presentan condiciones, valores y usos diversos, lo que incrementa los servicios ambientales de estos ecosistemas

Impacto ambiental del vial de distribución principal de Cayo Cruz, Camagüey / Environmental impacts of main distribution road of Cayo Cruz, Camagüey

The article aims to expose the results of the environmental impact assessment carried out to the main distribution road project in the tourist pole Cayo Cruz, Camagüey. A total of 32 impacts between positive and negative were identified. The facilitation of tourism development is the most important of the positive impacts. The potential negative impacts of greater range are biological / ecological, such as those related to the possible effects on species of special interest for biological diversity and can be mitigated with the implementation of a group of measures that are suggested in this work.El artículo persigue exponer los resultados de la evaluación de impacto ambiental realizada al proyecto del vial principal de distribución en el polo turístico Cayo Cruz, Camagüey. Se identificaron un total de 32 impactos entre positivos y negativos. La facilitación del desarrollo turístico es el más importante de los impactos positivos. Los impactos negativos potenciales de mayor rango son los biológicos/ecológicos, como los relacionados con las posibles afectaciones a las especies de especial interés para la diversidad biológica y pueden ser mitigados con la implementación de un grupo de medidas que son sugeridas en el presente trabajo. / The article aims to expose the results of the environmental impact assessment carried out to the main distribution road project in the tourist pole Cayo Cruz, Camagüey. A total of 32 impacts between positive and negative were identified. The facilitation of tourism development is the most important of the positive impacts. The potential negative impacts of greater range are biological / ecological, such as those related to the possible effects on species of special interest for biological diversity and can be mitigated with the implementation of a group of measures that are suggested in this work

Nitrogen and Phosphorous Retention in Tropical Eutrophic Reservoirs with Water Level Fluctuations: A Case Study Using Mass Balances on a Long-Term Series

Nitrogen and phosphorous loading drives eutrophication of aquatic systems. Lakes and reservoirs are often effective N and P sinks, but the variability of their biogeochemical dynamics is still poorly documented, particularly in tropical systems. To contribute to the extending of information on tropical reservoirs and to increase the insight on the factors affecting N and P cycling in aquatic ecosystems, we here report on a long-term N and P mass balance (2003–2018) in Valle de Bravo, Mexico, which showed that this tropical eutrophic reservoir lake acts as a net sink of N (−41.7 g N m y) and P (−2.7 g P m y), mainly occurring through net sedimentation, equivalent to 181% and 68% of their respective loading (23.0 g N m y and 4.2 g P m y). The N mass balance also showed that the Valle de Bravo reservoir has a high net N atmospheric influx (31.6 g N m y), which was 1.3 times the external load and likely dominated by N fixation. P flux was driven mainly by external load, while in the case of N, net fixation also contributed. During a period of high water level fluctuations, the net N atmospheric flux decreased by 50% compared to high level years. Our results outlining water regulation can be used as a useful management tool of water bodies, by decreasing anoxic conditions and net atmospheric fluxes, either through decreasing nitrogen fixation and/or promoting denitrification and other microbial processes that alleviate the N load. These findings also sustain the usefulness of long-term mass balances to assess biogeochemical dynamics and its variability.This research was funded by UNAM, PAPIIT-IN207702 and CONACYT-SEMARNAT, C01-1125 projects to M.M-