Tropical landscape and seascape systems are intimately linked by complex ecological relationships... more Tropical landscape and seascape systems are intimately linked by complex ecological relationships that provide environmental services to human societies located in coastal areas and beyond. Paradoxically, nonsustainable activities from these human societies are threatening the functions and benefits of these systems. Anthropogenic processes that damage tropical seascapes are rapidly increasing as a result of coastal and tourism development, increasing human population, unsustainable economic growth, and extensive transformations of natural landscapes. In addition to this overwhelming trend, tropical coastal seascapes are threatened by global climate change. Thus, to address this problem, it is essential to understand the complex ecological relationships between the components of coastal seascape systems and their links to land ecosystems, including the positive and negative effects of humans. The physical and ecological relationships between tropical landscapes and seascapes often define the energy and matter fluxes through which human activities exert their influence on coastal ecosystems. We illustrate these relationships by presenting a case study and conceptual model of coastal and tourism development in the Yucatan Peninsula, Mexico. Scientific knowledge and proposals for better governance practices are available to guide management actions and to protect the connectivity of seascape systems. Nonetheless, political will, coupled with the implementation of local and regional integrated management schemes of coastal zones, is urgent. More examples are needed of inland and coastal human societies that successfully integrate scientific knowledge of the links among ecosystems and their decision-making processes in order to achieve sustainable development based on the services provided by their surrounding seascapes.
ABSTRACT Global climate change and local anthropogenic pressures are among the primary factors le... more ABSTRACT Global climate change and local anthropogenic pressures are among the primary factors leading to the decline of functional biodiversity and critical habitats in coral reefs. Coral bleaching, the potential decreases in dissolved oxygen concentration (deoxygenation) and pH (acidification) in the oceans can induce severe changes in coral reef ecosystem biodiversity and functionality. The main objective of this study was to apply four Ecopath with Ecosim models of a Caribbean coral reef system to individually and collectively model the effects of coral bleaching on the trophic web, deoxygenation on fish, and acidification on calcifying organisms. These three sources of stress were used as forcing functions on several trophic groups depending on the model. The forcing functions were scaled according to the species’ responses achieved in previously tested climate change marine models. For the bleaching model, a mediation function was also considered that represents the degree of coral reef protection on small and intermediate fish groups. The dynamic models were constructed from an extensive database of 171 reef fish species (abundance and biomass) and benthic communities from 13 coral reefs that were evenly distributed parallel to approximately 400 km of the Mexican Caribbean coast as well as fishery landings in this area. Simulations driven with these different forcing and mediation functions predicted different changes in the biomasses of fish and non-fish functional groups as well as the biomass of the functional groups of fished species. Coral bleaching and pH reduction caused a phase shift to a decrease in coral biomass and an increase in primary producer biomass. This shift produced a cascading decrease in the biomass of small and intermediate fish groups. Additionally, the fished functional group biomass increased with coral bleaching but decreased with the effects of decreased oxygen on fish and pH on calcifying organisms. The biomasses of certain macroinvertebrate functional groups were predicted to respond favourably to the combined effect of the sources of stress. However, when all the sources of stress were combined, we found a general decrease of biomass in fish, non-fish, and some commercially valuable fish and macroinvertebrate functional groups, suggesting that the combined effects of stress induced synergistic effects as a result of global climate change and overfishing, which can result in a potential loss of biodiversity and ecosystem services in coral reefs.
The explanatory value of four hypotheses for geographic variation in total species richness and s... more The explanatory value of four hypotheses for geographic variation in total species richness and species richness was evaluated per family in coral and fish communities in the North Sector of the Mesoamerican Barrier Reef System (NS-MBRS). The four hypotheses emphasize different reefscape attributes that are important for coral and fish: reef area (RA), live coral cover (LCC), habitat complexity (HC), and coral richness itself and for fish. For both coral and fish communities, we estimated the total number of species and number of species per family on 11 coral reefs along a 400-km section of NS-MBRS. Hard coral cover and HC were quantified using line and chain transects, respectively, and RA was estimated using Landsat TM images and a geographic information system. We used multiple regression and canonical redundancy analysis to study the fish-environment and coral-environment relationships. The three reefscape features (RA, LCC, and HC) in combination were much stronger explanatory...
... 3 Laboratorio de Ecosistemas Marinos y Acuicultura (LEMA), Departamento de Ecología, CUCBA, U... more ... 3 Laboratorio de Ecosistemas Marinos y Acuicultura (LEMA), Departamento de Ecología, CUCBA, Universidad de Guadalajara, Carretera Guadalajara–Nogales Km 15.5, AP ... en influir sobre la composición local de las especies y la diversidad en peces y corales: (a) el área del ...
The structural patterns and trophodynamics of the different fish species in the reef complex of P... more The structural patterns and trophodynamics of the different fish species in the reef complex of Palancar-Chunchakaab, located in the South of Cozumel Island, Mexican Caribbean, were studied. A total of 166 species were identified for the whole reef complex. The analysis of 19,636 recorded and 2291 fish collected allowed the populations to be characterized in terms of diversity, distribution, abundance, dominant species and habitat-fish interactions. Using these parameters, three well defined reef-fish communities were described in relation to three zones: (1) Thalassia zone (THZ), (2) Lagoon (LA) and (3) Shelf-Edge Reef (SER). These communities included 64 species (39% of the total number) that were restricted to a single zone,. The remaining 61% consisted of migratory species that interacted between the defined zones (interdependence of habitat): (1) THZ-LA, (2) THZ-LA-SER, and (3) LA-SER. Diversity was highest in the rainy season in SER (H′ n = 3.3). Analysis of distribution and frequency of 42 of the recorded species revealed that for 25%, life cycle and THZ-SER were closely related. The remaining 75% were more associated with SER or THZ and they used these habitats for feeding, breeding and/or protection. In THZ, > 70% of the total number of species were juveniles; in LA, 40% were preadults-adults; and in SER 80% were adults. The obvious interdependence between habitats suggested a distinct use of the resources by means of migration patterns. By decreasing the order of importance, the major diet types can be ranked as follows: (1) type I carnivores, mainly active by day, preying on small organisms such as crustaceans, polychaetes, mollusks, echinoderms; (2) type II carnivores, nocturnal species consuming larger crustaceans and fish; (3) strict piscivores species; (4) herbivores species; (5) planktivores species; (6) omnivores species; and (7) sessile invertebrate browsers. With the exception of SER, 14%–44% of the type II invertebrate feeders were restricted to the three defined habitats. Of the migratory species, the large invertebrate feeders were the dominant group (21%–41%). The present study suggests that the variation of species diversity patterns and trophic structure are associated with sequential habitat use according to the life cycle. This type of study allowed us to compare the diversity and trophic community of reef fish of the same system and to recognize the energetic interdependence that exists between the habitats.
As the impact of anthropogenic activity and climate change continue to accelerate rates of degrad... more As the impact of anthropogenic activity and climate change continue to accelerate rates of degradation on Caribbean coral reefs, conservation and restoration faces greater challenges. At this stage, it is of particular importance in coral reefs to recognize and to understand the structural spatial patterns of benthic assemblages. We developed a field-based framework of a Caribbean reefscape benthic structure by using hermatypic corals as an indicator group of global biodiversity and bio-construction patterns in 11 reefs of the northern sector of the Mesoamerican barrier reef system (nsMBRS). Four hundred and seventy four video-transects (50 m long by 0.4 m wide) were performed throughout a gradient of reef complexity from north to south (∼400 km) to identify coral species, families and ensembles of corals. Composition and abundance of species, families and ensemble showed differences among reefs. In the northern zone, the reefs had shallow, partial reef developments with low diversities, dominated by Acropora palmata, Siderastrea spp., Pseudodiploria strigosa, and Agaricia tenuifolia. In the central and southern zones, reefs presented extensive developments, high habitat heterogeneity, and the greatest diversity and dominance of Orbicella annularis and Orbicella faveolata. These two species determined the structure and diversity of corals in the central and southern zones of the nsMBRS and their bio-construction in these zones is unique in the Caribbean. Their abundance and distribution depended on the reef habitat area, topographic complexity and species richness. Orbicella species complex were crucial for maintaining the biodiversity and bio-construction of the central and southern zones while A. palmate in the northern zones of then sMBRS.
Tropical landscape and seascape systems are intimately linked by complex ecological relationships... more Tropical landscape and seascape systems are intimately linked by complex ecological relationships that provide environmental services to human societies located in coastal areas and beyond. Paradoxically, nonsustainable activities from these human societies are threatening the functions and benefits of these systems. Anthropogenic processes that damage tropical seascapes are rapidly increasing as a result of coastal and tourism development, increasing human population, unsustainable economic growth, and extensive transformations of natural landscapes. In addition to this overwhelming trend, tropical coastal seascapes are threatened by global climate change. Thus, to address this problem, it is essential to understand the complex ecological relationships between the components of coastal seascape systems and their links to land ecosystems, including the positive and negative effects of humans. The physical and ecological relationships between tropical landscapes and seascapes often define the energy and matter fluxes through which human activities exert their influence on coastal ecosystems. We illustrate these relationships by presenting a case study and conceptual model of coastal and tourism development in the Yucatan Peninsula, Mexico. Scientific knowledge and proposals for better governance practices are available to guide management actions and to protect the connectivity of seascape systems. Nonetheless, political will, coupled with the implementation of local and regional integrated management schemes of coastal zones, is urgent. More examples are needed of inland and coastal human societies that successfully integrate scientific knowledge of the links among ecosystems and their decision-making processes in order to achieve sustainable development based on the services provided by their surrounding seascapes.
ABSTRACT Global climate change and local anthropogenic pressures are among the primary factors le... more ABSTRACT Global climate change and local anthropogenic pressures are among the primary factors leading to the decline of functional biodiversity and critical habitats in coral reefs. Coral bleaching, the potential decreases in dissolved oxygen concentration (deoxygenation) and pH (acidification) in the oceans can induce severe changes in coral reef ecosystem biodiversity and functionality. The main objective of this study was to apply four Ecopath with Ecosim models of a Caribbean coral reef system to individually and collectively model the effects of coral bleaching on the trophic web, deoxygenation on fish, and acidification on calcifying organisms. These three sources of stress were used as forcing functions on several trophic groups depending on the model. The forcing functions were scaled according to the species’ responses achieved in previously tested climate change marine models. For the bleaching model, a mediation function was also considered that represents the degree of coral reef protection on small and intermediate fish groups. The dynamic models were constructed from an extensive database of 171 reef fish species (abundance and biomass) and benthic communities from 13 coral reefs that were evenly distributed parallel to approximately 400 km of the Mexican Caribbean coast as well as fishery landings in this area. Simulations driven with these different forcing and mediation functions predicted different changes in the biomasses of fish and non-fish functional groups as well as the biomass of the functional groups of fished species. Coral bleaching and pH reduction caused a phase shift to a decrease in coral biomass and an increase in primary producer biomass. This shift produced a cascading decrease in the biomass of small and intermediate fish groups. Additionally, the fished functional group biomass increased with coral bleaching but decreased with the effects of decreased oxygen on fish and pH on calcifying organisms. The biomasses of certain macroinvertebrate functional groups were predicted to respond favourably to the combined effect of the sources of stress. However, when all the sources of stress were combined, we found a general decrease of biomass in fish, non-fish, and some commercially valuable fish and macroinvertebrate functional groups, suggesting that the combined effects of stress induced synergistic effects as a result of global climate change and overfishing, which can result in a potential loss of biodiversity and ecosystem services in coral reefs.
The explanatory value of four hypotheses for geographic variation in total species richness and s... more The explanatory value of four hypotheses for geographic variation in total species richness and species richness was evaluated per family in coral and fish communities in the North Sector of the Mesoamerican Barrier Reef System (NS-MBRS). The four hypotheses emphasize different reefscape attributes that are important for coral and fish: reef area (RA), live coral cover (LCC), habitat complexity (HC), and coral richness itself and for fish. For both coral and fish communities, we estimated the total number of species and number of species per family on 11 coral reefs along a 400-km section of NS-MBRS. Hard coral cover and HC were quantified using line and chain transects, respectively, and RA was estimated using Landsat TM images and a geographic information system. We used multiple regression and canonical redundancy analysis to study the fish-environment and coral-environment relationships. The three reefscape features (RA, LCC, and HC) in combination were much stronger explanatory...
... 3 Laboratorio de Ecosistemas Marinos y Acuicultura (LEMA), Departamento de Ecología, CUCBA, U... more ... 3 Laboratorio de Ecosistemas Marinos y Acuicultura (LEMA), Departamento de Ecología, CUCBA, Universidad de Guadalajara, Carretera Guadalajara–Nogales Km 15.5, AP ... en influir sobre la composición local de las especies y la diversidad en peces y corales: (a) el área del ...
The structural patterns and trophodynamics of the different fish species in the reef complex of P... more The structural patterns and trophodynamics of the different fish species in the reef complex of Palancar-Chunchakaab, located in the South of Cozumel Island, Mexican Caribbean, were studied. A total of 166 species were identified for the whole reef complex. The analysis of 19,636 recorded and 2291 fish collected allowed the populations to be characterized in terms of diversity, distribution, abundance, dominant species and habitat-fish interactions. Using these parameters, three well defined reef-fish communities were described in relation to three zones: (1) Thalassia zone (THZ), (2) Lagoon (LA) and (3) Shelf-Edge Reef (SER). These communities included 64 species (39% of the total number) that were restricted to a single zone,. The remaining 61% consisted of migratory species that interacted between the defined zones (interdependence of habitat): (1) THZ-LA, (2) THZ-LA-SER, and (3) LA-SER. Diversity was highest in the rainy season in SER (H′ n = 3.3). Analysis of distribution and frequency of 42 of the recorded species revealed that for 25%, life cycle and THZ-SER were closely related. The remaining 75% were more associated with SER or THZ and they used these habitats for feeding, breeding and/or protection. In THZ, > 70% of the total number of species were juveniles; in LA, 40% were preadults-adults; and in SER 80% were adults. The obvious interdependence between habitats suggested a distinct use of the resources by means of migration patterns. By decreasing the order of importance, the major diet types can be ranked as follows: (1) type I carnivores, mainly active by day, preying on small organisms such as crustaceans, polychaetes, mollusks, echinoderms; (2) type II carnivores, nocturnal species consuming larger crustaceans and fish; (3) strict piscivores species; (4) herbivores species; (5) planktivores species; (6) omnivores species; and (7) sessile invertebrate browsers. With the exception of SER, 14%–44% of the type II invertebrate feeders were restricted to the three defined habitats. Of the migratory species, the large invertebrate feeders were the dominant group (21%–41%). The present study suggests that the variation of species diversity patterns and trophic structure are associated with sequential habitat use according to the life cycle. This type of study allowed us to compare the diversity and trophic community of reef fish of the same system and to recognize the energetic interdependence that exists between the habitats.
As the impact of anthropogenic activity and climate change continue to accelerate rates of degrad... more As the impact of anthropogenic activity and climate change continue to accelerate rates of degradation on Caribbean coral reefs, conservation and restoration faces greater challenges. At this stage, it is of particular importance in coral reefs to recognize and to understand the structural spatial patterns of benthic assemblages. We developed a field-based framework of a Caribbean reefscape benthic structure by using hermatypic corals as an indicator group of global biodiversity and bio-construction patterns in 11 reefs of the northern sector of the Mesoamerican barrier reef system (nsMBRS). Four hundred and seventy four video-transects (50 m long by 0.4 m wide) were performed throughout a gradient of reef complexity from north to south (∼400 km) to identify coral species, families and ensembles of corals. Composition and abundance of species, families and ensemble showed differences among reefs. In the northern zone, the reefs had shallow, partial reef developments with low diversities, dominated by Acropora palmata, Siderastrea spp., Pseudodiploria strigosa, and Agaricia tenuifolia. In the central and southern zones, reefs presented extensive developments, high habitat heterogeneity, and the greatest diversity and dominance of Orbicella annularis and Orbicella faveolata. These two species determined the structure and diversity of corals in the central and southern zones of the nsMBRS and their bio-construction in these zones is unique in the Caribbean. Their abundance and distribution depended on the reef habitat area, topographic complexity and species richness. Orbicella species complex were crucial for maintaining the biodiversity and bio-construction of the central and southern zones while A. palmate in the northern zones of then sMBRS.
Tropical landscape and seascape systems are intimately linked by complex ecological relationships... more Tropical landscape and seascape systems are intimately linked by complex ecological relationships that provide environmental services to human societies located in coastal areas and beyond. Paradoxically, nonsustainable activities from these human societies are threatening the functions and benefits of these systems. Anthropogenic processes that damage tropical seascapes are rapidly increasing as a result of coastal and tourism development, increasing human population, unsustainable economic growth, and extensive transformations of natural landscapes. In addition to this overwhelming trend, tropical coastal seascapes are threatened by global climate change. Thus, to address this problem, it is essential to understand the complex ecological relationships between the components of coastal seascape systems and their links to land ecosystems, including the positive and negative effects of humans. The physical and ecological relationships between tropical landscapes and seascapes often define the energy and matter fluxes through which human activities exert their influence on coastal ecosystems. We illustrate these relationships by presenting a case study and conceptual model of coastal and tourism development in the Yucatan Peninsula, Mexico. Scientific knowledge and proposals for better governance practices are available to guide management actions and to protect the connectivity of seascape systems. Nonetheless, political will, coupled with the implementation of local and regional integrated management schemes of coastal zones, is urgent. More examples are needed of inland and coastal human societies that successfully integrate scientific knowledge of the links among ecosystems and their decision-making processes in order to achieve sustainable development based on the services provided by their surrounding seascapes.
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