Determinación de macroalgas en el Parque Nacional Arrecifes de Cozumel
The Mesoamerican Barrier Reef System (SAM) is the second largest in the world. Coral reefs, among the world's most productive and biologically diverse ecosystems, are characterized by their high rate of primary productivity, with benthic producers, microalgae, and macroalgae being the main cont...
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:f1881m523 |
| Acceso en línea: | https://doi.org/10.24275/uami.f1881m523 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Reef ecology -- Mexico info:eu-repo/classification/LEM/Ecología de arrecifes -- México info:eu-repo/classification/LEM/Algas marinas info:eu-repo/classification/LEM/Marine algae info:eu-repo/classification/cti/2 |
| Sumario: | The Mesoamerican Barrier Reef System (SAM) is the second largest in the world. Coral reefs, among the world's most productive and biologically diverse ecosystems, are characterized by their high rate of primary productivity, with benthic producers, microalgae, and macroalgae being the main contributors. Macroalgae, in addition, play a role in reef construction and cementation, influencing the balance of oxygen, carbon dioxide, and dissolved nutrients in the water. Environmental factors such as light, water temperature, sediment deposition, and depth, impact their distribution. In the Parque Nacional Arrecifes de Cozumel, the deterioration of reef ecosystems highlights the need for studies that assess the diversity of macroalgae and their relationship with the environment, serving as a reference point for assessments that contribute to the conservation of these ecosystems. Objectives. 1) Identify the species of macroalgae present in the Parque Nacional Arrecifes de Cozumel (PNAC); 2) Evaluate environmental variables (depth, temperature, salinity, dissolved oxygen, and pH) and sedimentary factors (sediment texture, organic carbon content, and sediment carbonates); 3) Establish the correlation between environmental and sedimentary variables with macroalgal species in the PNAC; 4) Determinate if there are bioindicator macroalgae for pollution in the PNAC and their possible correlation with water and sediment variables. Materials and Methods. Sampling was carried out in October and November 2018 in 14 reefs of the Parque Nacional Arrecifes de Cozumel, and environmental variables were assessed. Morpho-anatomical observations were performed using both, optical and stereoscopic microscopes. Taxonomic determination was made based on specialized literature. Specialized techniques were employed for the characterization and evaluation of sediments. Multivariate analyses were carried out to determine correlations. Results. Fifty-six taxa were identified: 38 Chlorophyta, 12 Rhodophyta, and six Ochrophyta. New records for the Parque Nacional Arrecifes de Cozumel were described, including Lobophora guadeloupensis as a new record for Mexico. Additionally, four species indicative of increased nutrient levels were identified. The mean sampling depth was 16.3m, with variation explained by reef bathymetry. The water temperature was 28.7°C, common in the area as the PNAC is situated in a region characteristically warm in Mexico. The average salinity was 34.66 UPS, accordenly with most reports for Caribbean reef zones. Mean dissolved oxygen concentrations were 6.2 mg/L, typical for a reef ecosystem under normoxic conditions, and the recorded pH averaged 8.2, indicative of alkaline conditions. Regarding sedimentary variables, the median sand fraction dominated; the percentage of organic carbon (0.55%) was estimated as characteristic for a reef zone; the average CaCO3 was considered high (95.5%) and biogenic in origin. Correlations: Some Chlorophyta were correlated with depth, and Rhodophyta were correlated with temperature. Bioindicator macroalgae for nutrient increase correlated with organic carbon content, while calcifying algae correlated with CaCO3. Conclusions. The algal richness in the studied locations within the Parque Nacional Arrecifes de Cozumel comprised 56 species, being Chlorophyta predominating. Furthermore, 18 new macroalgal records for the PNAC were obtained, including a first record for Mexico. This study represents a first aproximation to correlate environmental variables (depth, temperature, salinity, and pH) and sedimentary factors (texture, organic carbon content, and carbonates) with the presence of macroalgae in the PNAC. Applying Canonical Correspondence Analysis (CCA) to environmental variables and phycoflora determined that green algae positively correlated with depth; however, red algae correlated with temperature. Concerning sedimentary variables, bioindicator macroalgae positively correlated with organic carbon, while calcifying macroalgae correlated with carbonates. Four species, considered bioindicators of high nutrient content Chaetomorpha linum, Cladophora catenata, Ulva intestinalis, and Laurencia intricata were identified. Keywords: algae, Chlorophyta, correlation, bioindicators, diversity, Ochrophyta, Rhodophyta, sediment, environmental variables. |
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