Island nations in the developing world are some of the communities most at-risk to the effects of climate change and are under increasing pressure from globalized seafood markets. Indigenous Fijians have a stark understanding of environmental change because of their economic and dietary reliance on marine resources, including shark fisheries and tourism. Sharks are important apex predators with deep cultural significance in Fiji and they are thus useful species to focus on when investigating historical ecology. However, they are difficult to study; sharks have cartilaginous skeletons, making full body fossils rare, and their behavior can make them difficult to survey with traditional methods. Sharks are also covered in dermal denticles which they shed throughout their lives and which compose some of the most extensive and oldest fossil types. All fish, including sharks, also shed their teeth, and together these microfossils are called ichthyoliths. Scientists in the Caribbean have developed innovative techniques to use ichthyoliths to illuminate the importance of parrotfish to coral reef ecology and trace historical and pre-anthropogenic shark populations. However, this microfossil approach has not yet reached Fiji. We developed a trait-based character coding scheme to describe denticle morphology based on both modern denticles and fossil denticles and discuss our work to expand current denticle reference collections. When combined with ecological factors, morphological analysis can identify temporal periods and spatial regions of importance in both modern and paleo-ocean ecosystem dynamics and aid historical ecologists in describing shark communities of the past. We are embarking on a research project to collect cores from Fiji to examine parrotfish and shark ecology through time. Here we summarize the methods we will use and how we have tailored them to our study region and invite input from the conservation paleobiology community on our study design.
{"title":"Using Fish Remains to Trace Dynamic Exchanges Between Ecology and Economy in Fiji","authors":"Leah D. Rubin, E. Sibert, J. Drew","doi":"10.58782/flmnh.quco5184","DOIUrl":"https://doi.org/10.58782/flmnh.quco5184","url":null,"abstract":"Island nations in the developing world are some of the communities most at-risk to the effects of climate change and are under increasing pressure from globalized seafood markets. Indigenous Fijians have a stark understanding of environmental change because of their economic and dietary reliance on marine resources, including shark fisheries and tourism. Sharks are important apex predators with deep cultural significance in Fiji and they are thus useful species to focus on when investigating historical ecology. However, they are difficult to study; sharks have cartilaginous skeletons, making full body fossils rare, and their behavior can make them difficult to survey with traditional methods. Sharks are also covered in dermal denticles which they shed throughout their lives and which compose some of the most extensive and oldest fossil types. All fish, including sharks, also shed their teeth, and together these microfossils are called ichthyoliths. Scientists in the Caribbean have developed innovative techniques to use ichthyoliths to illuminate the importance of parrotfish to coral reef ecology and trace historical and pre-anthropogenic shark populations. However, this microfossil approach has not yet reached Fiji. We developed a trait-based character coding scheme to describe denticle morphology based on both modern denticles and fossil denticles and discuss our work to expand current denticle reference collections. When combined with ecological factors, morphological analysis can identify temporal periods and spatial regions of importance in both modern and paleo-ocean ecosystem dynamics and aid historical ecologists in describing shark communities of the past. We are embarking on a research project to collect cores from Fiji to examine parrotfish and shark ecology through time. Here we summarize the methods we will use and how we have tailored them to our study region and invite input from the conservation paleobiology community on our study design.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133902422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephen R. Durham, G. Dietl, J. Handley, Q. Hua, Cheryl Clark, Jaleigh Q. Pier, D. Kaufman
A lack of location-specific, long-term data is a common obstacle to assessing trends in condition of coastal habitats over time. Without historical monitoring records or other documentation, filling such data gaps can be difficult, but sedimentary records such as death assemblages (DAs; the accumulated, identifiable remains of organisms that lived in or near the habitat in the past) are relatively untapped, location-specific archives of ecological information from the past. In 2018, the Florida Department of Environmental Protection and the Paleontological Research Institution began a collaboration to study the use of oyster reef (Crassostrea virginica) DAs to address monitoring information gaps for oyster size. To-date, our project has sampled DAs from over 30 intertidal oyster reefs around Florida, radiocarbon dated most of the samples, and measured over 26,000 oyster shells. In the process, we found that C. virginica DAs are recent and high-resolution archives, with most samples from 15-35cm burial depth dating to within the last 80 years. We also developed a model to combine the DA data with real-time monitoring data on live oyster sizes from the same reefs to estimate reef- and locality-level size trends from as early as the 1960s to the present. This information is adding temporal context for our overwhelmingly short (~5-10 years) and recent (many post-2010) time series of live C. virginica size data. This case study demonstrates the potential utility of DA data for supplementing real-time monitoring data during the assessment and management of coastal habitats.
{"title":"Oyster Death Assemblages as Archives of Historical Information for Studying Long-Term Trends in Oyster Body Size","authors":"Stephen R. Durham, G. Dietl, J. Handley, Q. Hua, Cheryl Clark, Jaleigh Q. Pier, D. Kaufman","doi":"10.58782/flmnh.otub3709","DOIUrl":"https://doi.org/10.58782/flmnh.otub3709","url":null,"abstract":"A lack of location-specific, long-term data is a common obstacle to assessing trends in condition of coastal habitats over time. Without historical monitoring records or other documentation, filling such data gaps can be difficult, but sedimentary records such as death assemblages (DAs; the accumulated, identifiable remains of organisms that lived in or near the habitat in the past) are relatively untapped, location-specific archives of ecological information from the past. In 2018, the Florida Department of Environmental Protection and the Paleontological Research Institution began a collaboration to study the use of oyster reef (Crassostrea virginica) DAs to address monitoring information gaps for oyster size. To-date, our project has sampled DAs from over 30 intertidal oyster reefs around Florida, radiocarbon dated most of the samples, and measured over 26,000 oyster shells. In the process, we found that C. virginica DAs are recent and high-resolution archives, with most samples from 15-35cm burial depth dating to within the last 80 years. We also developed a model to combine the DA data with real-time monitoring data on live oyster sizes from the same reefs to estimate reef- and locality-level size trends from as early as the 1960s to the present. This information is adding temporal context for our overwhelmingly short (~5-10 years) and recent (many post-2010) time series of live C. virginica size data. This case study demonstrates the potential utility of DA data for supplementing real-time monitoring data during the assessment and management of coastal habitats.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130094848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Cybulski, N. Duprey, S. Connolly, A. Foreman, Erin M. Dillon, H. Vonhof, A. Martínez-García, Brigida de Gracia, A. O’Dea
Along the coastal Tropical Eastern Pacific (TEP), regions of strong seasonal upwelling bring cold, nutrient-rich waters, controlling ecological conditions and sustaining millions of people through large-scale fisheries. The TEP is also important for the regulation of global climate and is affected by large-scale environmental processes such as ENSO. How the nutrient dynamics of this region will respond to climate change and what the implications will be for coastal ecology remains unknown. Environmental records are needed that capture intra and inter-decadal variation and extend over millennia where these biotic and abiotic processes interact. Here, we develop a new sampling approach and construct two coral skeleton records (n = >600) from reef matrix cores that extend six millennia, from the upwelling Gulf of Panamá and the non-upwelling Gulf of Chiriquí. We ask what effects millennial-scale climate patterns have on upwelling in the region, and how the magnitude of upwelled nutrients influences ecological productivity and even human habitation. We combined multiple proxies using climatic (carbonate δ18O), nutrient (skeletal-organic matrix δ15N), diagenetic (taphonomic scoring), ecological (benthic community composition), and temporal (U-Th dates) data. Using Generalised Additive Models to assess variability, we find strong divergences in the nutrient (δ15N; range >5 ‰) records between Gulfs, while δ18O (range ~2‰) is more stable. The greatest variation in δ15N values occurs during times of high reef accretion whereas δ18O is constant, suggesting that nutrients, not temperature, are driving reef productivity. Taphonomic, taxonomic, and age data reveal periodic shifts and collapses of coral communities that differ between Gulfs. We end by drawing connections between these ecological shifts to the episodic human habitation documented during the late-Holocene and hypothesize what this may mean for ecosystem resilience and environmental management under future climate.
{"title":"Coral Geochemical Records Track Millennial-Scale Ecosystem Change and Resilience in the Tropical Eastern Pacific","authors":"J. Cybulski, N. Duprey, S. Connolly, A. Foreman, Erin M. Dillon, H. Vonhof, A. Martínez-García, Brigida de Gracia, A. O’Dea","doi":"10.58782/flmnh.gitr2523","DOIUrl":"https://doi.org/10.58782/flmnh.gitr2523","url":null,"abstract":"Along the coastal Tropical Eastern Pacific (TEP), regions of strong seasonal upwelling bring cold, nutrient-rich waters, controlling ecological conditions and sustaining millions of people through large-scale fisheries. The TEP is also important for the regulation of global climate and is affected by large-scale environmental processes such as ENSO. How the nutrient dynamics of this region will respond to climate change and what the implications will be for coastal ecology remains unknown. Environmental records are needed that capture intra and inter-decadal variation and extend over millennia where these biotic and abiotic processes interact. Here, we develop a new sampling approach and construct two coral skeleton records (n = >600) from reef matrix cores that extend six millennia, from the upwelling Gulf of Panamá and the non-upwelling Gulf of Chiriquí. We ask what effects millennial-scale climate patterns have on upwelling in the region, and how the magnitude of upwelled nutrients influences ecological productivity and even human habitation. We combined multiple proxies using climatic (carbonate δ18O), nutrient (skeletal-organic matrix δ15N), diagenetic (taphonomic scoring), ecological (benthic community composition), and temporal (U-Th dates) data. Using Generalised Additive Models to assess variability, we find strong divergences in the nutrient (δ15N; range >5 ‰) records between Gulfs, while δ18O (range ~2‰) is more stable. The greatest variation in δ15N values occurs during times of high reef accretion whereas δ18O is constant, suggesting that nutrients, not temperature, are driving reef productivity. Taphonomic, taxonomic, and age data reveal periodic shifts and collapses of coral communities that differ between Gulfs. We end by drawing connections between these ecological shifts to the episodic human habitation documented during the late-Holocene and hypothesize what this may mean for ecosystem resilience and environmental management under future climate.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121557044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The multi-faceted impacts of the Anthropocene are increasingly modifying natural ecosystems and threatening biodiversity. Protected spaces in and adjacent to urban landscapes may be critical in protecting species in human-modified systems. Can small, protected spaces act as reservoirs for biodiversity across dynamic spatial and temporal gradients of human impact? To address this question, we identified small mammal remains from modern raptor pellets and Holocene archaeological sites along a human modification gradient in the San Francisco Bay Area, CA. We assessed small mammal alpha and beta diversity for both modern and Holocene sites. We tested for significant differences between sites and time bins using permutational multivariate analysis of variance (PERMANOVA) and visualized these differences using non-metric multidimensional scaling (NMDS). We found that alpha diversity decreased with increasing human modification in Anthropocene sites, with no corresponding change between Holocene sites. Additionally, the alpha diversity of modern sites with moderate/high levels of human modification was significantly lower than that of protected modern sites and all Holocene sites, driven by the dominance of human-commensal and disturbance-tolerant species. On the other hand, the small mammal communities from a small, protected area (Jasper Ridge Biological Preserve) retained Holocene levels of alpha diversity. Jasper Ridge has also changed less over time in terms of overall community composition than more modified sites. Despite this, both PERMANOVA and NMDS show that Holocene and Anthropocene communities are significantly distinct regardless of collection site and level of anthropogenic modification. Our results suggest that even relatively small, protected spaces within an urbanized matrix conserve native faunal communities, highlighting their important role in urban conservation.
{"title":"Small Biological Preserves and Smaller Mammals: Can Protected Areas in Our Most Populous Regions Conserve Historic Community Composition?","authors":"Maria C. Viteri, M. Stegner, E. Hadly","doi":"10.58782/flmnh.npfm3522","DOIUrl":"https://doi.org/10.58782/flmnh.npfm3522","url":null,"abstract":"The multi-faceted impacts of the Anthropocene are increasingly modifying natural ecosystems and threatening biodiversity. Protected spaces in and adjacent to urban landscapes may be critical in protecting species in human-modified systems. Can small, protected spaces act as reservoirs for biodiversity across dynamic spatial and temporal gradients of human impact? To address this question, we identified small mammal remains from modern raptor pellets and Holocene archaeological sites along a human modification gradient in the San Francisco Bay Area, CA. We assessed small mammal alpha and beta diversity for both modern and Holocene sites. We tested for significant differences between sites and time bins using permutational multivariate analysis of variance (PERMANOVA) and visualized these differences using non-metric multidimensional scaling (NMDS). We found that alpha diversity decreased with increasing human modification in Anthropocene sites, with no corresponding change between Holocene sites. Additionally, the alpha diversity of modern sites with moderate/high levels of human modification was significantly lower than that of protected modern sites and all Holocene sites, driven by the dominance of human-commensal and disturbance-tolerant species. On the other hand, the small mammal communities from a small, protected area (Jasper Ridge Biological Preserve) retained Holocene levels of alpha diversity. Jasper Ridge has also changed less over time in terms of overall community composition than more modified sites. Despite this, both PERMANOVA and NMDS show that Holocene and Anthropocene communities are significantly distinct regardless of collection site and level of anthropogenic modification. Our results suggest that even relatively small, protected spaces within an urbanized matrix conserve native faunal communities, highlighting their important role in urban conservation.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122366218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Species-environment interactions are integral to survivorship, especially when those environments test the extremes of organismal physiology. Large-bodied (>50kg) mammals, specifically artiodactyls and feliform carnivores, possess a specialized physiology known as carotid-rete-mediated selective brain cooling (CR-SBC), which has been established to be selectively advantageous in environments where water availability is limited and risk for dehydration is high. In this study, we investigate whether CR-SBC provides a release from physiological constraint imposed by the environment, specifically aridity. Using 18O values from tooth enamel as a proxy for water metabolism, we model the range in variance across 1265 individuals from species that possess a carotid rete against those without from three different environmental categories – arid, dry subhumid, and humid – using a non-parametric ANOVA. The results of the analysis indicate there is a comparatively higher, and statistically significant, amount of variance of 18O in mammals possessing CR-SBC than those without, especially within arid climates, that begins to equalize as environmental water availability increases. As environments become increasingly arid, understanding which species are more vulnerable to shifts in climate becomes more pertinent. The presence of CR-SBC provides a clear, binary feature by which to measure the relationship between the environment and species survivorship under varying levels of water availability, and is useful in informing and improving conservation tools, such as physiological distribution models.
{"title":"Variance of Carotid-Rete-Mediated Selective Brain Cooling Across Aridity Indices","authors":"Katherine Slenker, H. O'Brien, Lindsey T. Yann","doi":"10.58782/flmnh.hhfe1916","DOIUrl":"https://doi.org/10.58782/flmnh.hhfe1916","url":null,"abstract":"Species-environment interactions are integral to survivorship, especially when those environments test the extremes of organismal physiology. Large-bodied (>50kg) mammals, specifically artiodactyls and feliform carnivores, possess a specialized physiology known as carotid-rete-mediated selective brain cooling (CR-SBC), which has been established to be selectively advantageous in environments where water availability is limited and risk for dehydration is high. In this study, we investigate whether CR-SBC provides a release from physiological constraint imposed by the environment, specifically aridity. Using 18O values from tooth enamel as a proxy for water metabolism, we model the range in variance across 1265 individuals from species that possess a carotid rete against those without from three different environmental categories – arid, dry subhumid, and humid – using a non-parametric ANOVA. The results of the analysis indicate there is a comparatively higher, and statistically significant, amount of variance of 18O in mammals possessing CR-SBC than those without, especially within arid climates, that begins to equalize as environmental water availability increases. As environments become increasingly arid, understanding which species are more vulnerable to shifts in climate becomes more pertinent. The presence of CR-SBC provides a clear, binary feature by which to measure the relationship between the environment and species survivorship under varying levels of water availability, and is useful in informing and improving conservation tools, such as physiological distribution models.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128629619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In mangroves of South Florida, plant debris accumulates and humifies to form peat. The structure and composition of mangrove peat differs among mangal sub-habitats, leading to categorically distinct peat types reflective of the taphonomically active zone (TAZ). Here, taphonomic processes degrade and shape the peat until it is sequestered in the depth of final burial (DFB). Sequestered peats provide historical archives of the mangal depositional environment and the palaeoecological context of peat formation that are used to reconstruct mangal sub-habitats. However, as peat passes through the TAZ, information about the precursor mangal sub-habitat is reduced, which may skew mangrove community reconstructions. To better understand the influence of the TAZ on peat formation, we analyzed plant organ- and taxon-based measures by characterizing surficial mangrove peats from two contrasting mangal sub-habitats in Barnes Sound, Florida: a tidally influenced, Rhizophora-dominated fringe sub-habitat; and an inundated, interior mixed forest basin sub-habitat. We found (1) peats formed in basin sites have greater amounts of leaf litter, which correlates with reduced tidal activity and restricted detritivore access to the litter layer; (2) peats formed in fringe sites have higher root percentages, or root–shoot ratios, which provide a reliable method to differentiate between peats at depth, and (3) mangal sub-habitats differ in preserved organismal signals, such as foraminifera and insect parts. Further, we compare our surficial core samples to historical, deep core samples from other South Florida mangrove peat deposits to establish modern peat analogs needed to decipher preserved mangrove peats. These comparisons suggest that few aerial plant organs survive the TAZ and sequestered peats are biased towards root-rich peats characteristic of fringe sub-habitats; however, sequestered peats with lower root-shoot ratios indicate leaf litter-rich peats formed in basin sub-habitats.
{"title":"Establishing Modern Peat Analogs to Decipher Mangal Sub-Habitats From Historical Peats","authors":"Samuel H. Neely, A. Raymond","doi":"10.58782/flmnh.wyms3450","DOIUrl":"https://doi.org/10.58782/flmnh.wyms3450","url":null,"abstract":"In mangroves of South Florida, plant debris accumulates and humifies to form peat. The structure and composition of mangrove peat differs among mangal sub-habitats, leading to categorically distinct peat types reflective of the taphonomically active zone (TAZ). Here, taphonomic processes degrade and shape the peat until it is sequestered in the depth of final burial (DFB). Sequestered peats provide historical archives of the mangal depositional environment and the palaeoecological context of peat formation that are used to reconstruct mangal sub-habitats. However, as peat passes through the TAZ, information about the precursor mangal sub-habitat is reduced, which may skew mangrove community reconstructions. To better understand the influence of the TAZ on peat formation, we analyzed plant organ- and taxon-based measures by characterizing surficial mangrove peats from two contrasting mangal sub-habitats in Barnes Sound, Florida: a tidally influenced, Rhizophora-dominated fringe sub-habitat; and an inundated, interior mixed forest basin sub-habitat. We found (1) peats formed in basin sites have greater amounts of leaf litter, which correlates with reduced tidal activity and restricted detritivore access to the litter layer; (2) peats formed in fringe sites have higher root percentages, or root–shoot ratios, which provide a reliable method to differentiate between peats at depth, and (3) mangal sub-habitats differ in preserved organismal signals, such as foraminifera and insect parts. Further, we compare our surficial core samples to historical, deep core samples from other South Florida mangrove peat deposits to establish modern peat analogs needed to decipher preserved mangrove peats. These comparisons suggest that few aerial plant organs survive the TAZ and sequestered peats are biased towards root-rich peats characteristic of fringe sub-habitats; however, sequestered peats with lower root-shoot ratios indicate leaf litter-rich peats formed in basin sub-habitats.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128436154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alizé Hardin, Sahale N. Casebolt, A. Hyman, S. Barry, Katherine E. Cummings, T. Frazer, M. Kowalewski
Seagrass meadows are highly structured habitats of great socioeconomic value but are declining globally due to human impacts. The northern Gulf Coast of Florida contains one of the largest relatively unaltered seagrass habitats (~3,000 km2), making it a model system for acquiring baselines to better manage and monitor seagrass meadows. This project investigated spatial gradients in ecological and taphonomic attributes of surficial seagrass-associated benthic mollusk death assemblages. An updated analysis of water parameters (based on project COAST data) indicated that total dissolved phosphorous (TDP) and chlorophyll-a (CHL-a) concentrations increased steadily northward. To analyze the historical ecology of local seagrass meadows, mollusk assemblages were bulk sampled at 12 stations across multiple estuaries along the gradient. Radiocarbon dating of valves (n = 90) from several estuaries indicated that the assemblages represented a multi-millennial accumulation with a median shell age of 1760 AD. Focusing on two abundant bivalves found within all estuaries, Transennella spp and Crassostrea virginica, the study evaluated spatial trends in body size, traces of predation, and post-mortem shell alterations. The results, primarily focused on Transennella spp., indicated that ecological and taphonomic characteristics varied notably, both among and within estuaries. Relative abundance, body size, and taphonomic attributes did not appear to correlate significantly with productivity or drilling frequency. However, drilling frequency correlated significantly with TDP and CHL-a, suggesting that predator-prey interactions may co-vary tightly with productivity. These results suggest that spatial gradients in predation can be archived by drilling frequencies in death assemblages. Moreover, the consistency between the long-term record of predation and modern gradient conditions suggests that long-term spatial dynamics of predator-prey interactions may be hydrologically controlled.
{"title":"Concordant Spatial Gradients in Predation Intensity and Productivity Archived in Surficial Mollusk Shell Accumulations in Seagrass Meadows Along the Gulf Coast of Florida","authors":"Alizé Hardin, Sahale N. Casebolt, A. Hyman, S. Barry, Katherine E. Cummings, T. Frazer, M. Kowalewski","doi":"10.58782/flmnh.pyam8848","DOIUrl":"https://doi.org/10.58782/flmnh.pyam8848","url":null,"abstract":"Seagrass meadows are highly structured habitats of great socioeconomic value but are declining globally due to human impacts. The northern Gulf Coast of Florida contains one of the largest relatively unaltered seagrass habitats (~3,000 km2), making it a model system for acquiring baselines to better manage and monitor seagrass meadows. This project investigated spatial gradients in ecological and taphonomic attributes of surficial seagrass-associated benthic mollusk death assemblages. An updated analysis of water parameters (based on project COAST data) indicated that total dissolved phosphorous (TDP) and chlorophyll-a (CHL-a) concentrations increased steadily northward. To analyze the historical ecology of local seagrass meadows, mollusk assemblages were bulk sampled at 12 stations across multiple estuaries along the gradient. Radiocarbon dating of valves (n = 90) from several estuaries indicated that the assemblages represented a multi-millennial accumulation with a median shell age of 1760 AD. Focusing on two abundant bivalves found within all estuaries, Transennella spp and Crassostrea virginica, the study evaluated spatial trends in body size, traces of predation, and post-mortem shell alterations. The results, primarily focused on Transennella spp., indicated that ecological and taphonomic characteristics varied notably, both among and within estuaries. Relative abundance, body size, and taphonomic attributes did not appear to correlate significantly with productivity or drilling frequency. However, drilling frequency correlated significantly with TDP and CHL-a, suggesting that predator-prey interactions may co-vary tightly with productivity. These results suggest that spatial gradients in predation can be archived by drilling frequencies in death assemblages. Moreover, the consistency between the long-term record of predation and modern gradient conditions suggests that long-term spatial dynamics of predator-prey interactions may be hydrologically controlled.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116073744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The growth and maintenance of coral-reef structures built over 1000s of years serve as the foundation for the myriad ecosystem services reefs provide to society. Predicting how reef building will change in the future is, therefore, critical to designing effective coral-reef management strategies; however, it is challenging to accurately forecast the long-term process of reef accretion based on short-term ecological studies alone. Geological records, particularly those from sensitive, marginal reef environments such as the subtropical reef system of south Florida, are essential for projecting changes in reef accretion, and for optimizing strategies for coral-reef management. Using a combination of millennial-scale reconstructions of reef accretion and paleoecology from reef cores, and contemporary carbonate budget modeling, I evaluated the past, present, and a possible future of coral-reef development in south Florida. I will show that climate has been the primary control on the rate and extent of regional reef development and, by 3000 years ago, reef accretion was negligible throughout the region. This confined the ecosystem to an unstable equilibrium in which a veneer of living coral was the only barrier to catastrophic reef erosion. In recent decades, climate and other anthropogenic disturbances have pushed many reefs into a novel state characterized by a loss of reef-building corals that is unprecedented in the geological record. These changes have unbalanced Florida’s carbonate budgets, leading to increases in reef-framework erosion. I will show that there is hope for ongoing coral restoration efforts to revive reef growth on a local scale to levels comparable to long-term natural baselines; however, the central role of climate in both the millennial-scale declines in reef building and the modern decline in coral populations suggests that the efficacy of these local efforts will be limited without global-scale action to mitigate anthropogenic climate change.
{"title":"Geological Perspectives on the Degradation and Restoration of Coral Reefs","authors":"L. Toth","doi":"10.58782/flmnh.oxzv5621","DOIUrl":"https://doi.org/10.58782/flmnh.oxzv5621","url":null,"abstract":"The growth and maintenance of coral-reef structures built over 1000s of years serve as the foundation for the myriad ecosystem services reefs provide to society. Predicting how reef building will change in the future is, therefore, critical to designing effective coral-reef management strategies; however, it is challenging to accurately forecast the long-term process of reef accretion based on short-term ecological studies alone. Geological records, particularly those from sensitive, marginal reef environments such as the subtropical reef system of south Florida, are essential for projecting changes in reef accretion, and for optimizing strategies for coral-reef management. Using a combination of millennial-scale reconstructions of reef accretion and paleoecology from reef cores, and contemporary carbonate budget modeling, I evaluated the past, present, and a possible future of coral-reef development in south Florida. I will show that climate has been the primary control on the rate and extent of regional reef development and, by 3000 years ago, reef accretion was negligible throughout the region. This confined the ecosystem to an unstable equilibrium in which a veneer of living coral was the only barrier to catastrophic reef erosion. In recent decades, climate and other anthropogenic disturbances have pushed many reefs into a novel state characterized by a loss of reef-building corals that is unprecedented in the geological record. These changes have unbalanced Florida’s carbonate budgets, leading to increases in reef-framework erosion. I will show that there is hope for ongoing coral restoration efforts to revive reef growth on a local scale to levels comparable to long-term natural baselines; however, the central role of climate in both the millennial-scale declines in reef building and the modern decline in coral populations suggests that the efficacy of these local efforts will be limited without global-scale action to mitigate anthropogenic climate change.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115685116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. O’Dea, Brigida de Gracia, Julia K. Briand, J. Cybulski, Maybelline Ureña, Kimberly García-Méndez, J. Lueders-Dumont, Erin M. Dillon
Caribbean coral reefs started to deteriorate before systematic monitoring began and so questions remain about how reefs have changed since human impact and if they have transitioned into functionally ‘novel’ states. To explore these questions, we mapped and bulk-sampled several hectares of mid-Holocene reefs in Caribbean Panama and the Dominican Republic and compared the composition and ecological function of these pre-human impact reefs to nearby modern reefs. We quantified the remains of all major reef groups, but focus here on molluscs, corals, and fishes. Filter feeding molluscs are twice as abundant relative to other feeding modes on modern reefs, commensurate with eutrophication from land use changes. At the same time, large herbivorous gastropods declined significantly in size due to millennia of human selective harvesting. We observed the well-documented loss of Acroporid corals and a functional shift in coral communities towards weedier, slower growing, and brooding species. Some modern coral communities appear to retain some historical functions, and isolated Acropora refugia do persist, but the corals in them are less robust than those in the mid-Holocene, questioning their functional resilience to future change. Reef fish otolith assemblages suggest an 80% decline in non-harvested fish and a relative increase in planktotrophy—patterns best explained by the loss of coral structure and eutrophication. Counterintuitively, otolith sizes suggest that non-harvested fish are larger than they were in the past, a result that suggests lower mortality rates from reduced predation due to a loss of predators. This conclusion is supported by the estimated 71% decline in shark abundances and 400% increase in evidence of damselfish algal-gardening on modern reefs. These examples illustrate how both bottom-up and top-down processes have reshaped the structure, trophic interactions and ecosystem functions of Caribbean reefscapes.
{"title":"Baseline Caribbean Reefs","authors":"A. O’Dea, Brigida de Gracia, Julia K. Briand, J. Cybulski, Maybelline Ureña, Kimberly García-Méndez, J. Lueders-Dumont, Erin M. Dillon","doi":"10.58782/flmnh.tffb5439","DOIUrl":"https://doi.org/10.58782/flmnh.tffb5439","url":null,"abstract":"Caribbean coral reefs started to deteriorate before systematic monitoring began and so questions remain about how reefs have changed since human impact and if they have transitioned into functionally ‘novel’ states. To explore these questions, we mapped and bulk-sampled several hectares of mid-Holocene reefs in Caribbean Panama and the Dominican Republic and compared the composition and ecological function of these pre-human impact reefs to nearby modern reefs. We quantified the remains of all major reef groups, but focus here on molluscs, corals, and fishes. Filter feeding molluscs are twice as abundant relative to other feeding modes on modern reefs, commensurate with eutrophication from land use changes. At the same time, large herbivorous gastropods declined significantly in size due to millennia of human selective harvesting. We observed the well-documented loss of Acroporid corals and a functional shift in coral communities towards weedier, slower growing, and brooding species. Some modern coral communities appear to retain some historical functions, and isolated Acropora refugia do persist, but the corals in them are less robust than those in the mid-Holocene, questioning their functional resilience to future change. Reef fish otolith assemblages suggest an 80% decline in non-harvested fish and a relative increase in planktotrophy—patterns best explained by the loss of coral structure and eutrophication. Counterintuitively, otolith sizes suggest that non-harvested fish are larger than they were in the past, a result that suggests lower mortality rates from reduced predation due to a loss of predators. This conclusion is supported by the estimated 71% decline in shark abundances and 400% increase in evidence of damselfish algal-gardening on modern reefs. These examples illustrate how both bottom-up and top-down processes have reshaped the structure, trophic interactions and ecosystem functions of Caribbean reefscapes.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127361127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Modern ecosystems are almost universally degraded relative to their past counterparts, from the Pleistocene to the present day. Thus, modern ecosystems may serve as poor guides to conservation actions. Conservation paleobiology is well-suited to address this challenge through enhanced understanding of systems dynamics during past periods of greater species and functional diversity, abundances, and resilience. However, past and present ecosystem dynamics must be integrated to model the future impacts of conservation actions. Here we propose a three-step, Past-Present-Future (PPF) methodology rooted in mathematical modeling. First, construct a model of primary species and interactions of the present-day ecosystem, including biotic and abiotic components. Second, integrate historical and/or paleontological data into the model to investigate past states and processes of the ecosystem, with an emphasis on critical elements (e.g., ecological engineer species) that are no longer present. Third, integrate analyses from the first two steps to predict putative future dynamics and states, and use these to make testable predictions regarding specific conservation interventions. We illustrate this approach with a study investigating impacts of the now-extinct Steller’s sea cow on north Pacific giant kelp forests. The model indicates that the historical system was distinct from the modern, with differing abundances of giant kelp and understory algae. Furthermore, the familiar kelp-dominated state is metastable, capable of rapid transitions to an urchin-dominated state if perturbed by extreme hydrodynamic events, disease-driven reductions of seastar predation, or disease coupled to extreme warming events. We explore the possibility of increasing the resilience of modern forests by artificially recreating at least some of the ecological impacts of sea cows, accounting for metabolic requirements, estimates of abundance based on recent analyses of ancient DNA, and trophic impact.
{"title":"Steller’s Sea Cow and Kelp Forest Regeneration in the North Pacific","authors":"P. Roopnarine, Roxanne Banker, Scott D. Sampson","doi":"10.58782/flmnh.wtps7868","DOIUrl":"https://doi.org/10.58782/flmnh.wtps7868","url":null,"abstract":"Modern ecosystems are almost universally degraded relative to their past counterparts, from the Pleistocene to the present day. Thus, modern ecosystems may serve as poor guides to conservation actions. Conservation paleobiology is well-suited to address this challenge through enhanced understanding of systems dynamics during past periods of greater species and functional diversity, abundances, and resilience. However, past and present ecosystem dynamics must be integrated to model the future impacts of conservation actions. Here we propose a three-step, Past-Present-Future (PPF) methodology rooted in mathematical modeling. First, construct a model of primary species and interactions of the present-day ecosystem, including biotic and abiotic components. Second, integrate historical and/or paleontological data into the model to investigate past states and processes of the ecosystem, with an emphasis on critical elements (e.g., ecological engineer species) that are no longer present. Third, integrate analyses from the first two steps to predict putative future dynamics and states, and use these to make testable predictions regarding specific conservation interventions. We illustrate this approach with a study investigating impacts of the now-extinct Steller’s sea cow on north Pacific giant kelp forests. The model indicates that the historical system was distinct from the modern, with differing abundances of giant kelp and understory algae. Furthermore, the familiar kelp-dominated state is metastable, capable of rapid transitions to an urchin-dominated state if perturbed by extreme hydrodynamic events, disease-driven reductions of seastar predation, or disease coupled to extreme warming events. We explore the possibility of increasing the resilience of modern forests by artificially recreating at least some of the ecological impacts of sea cows, accounting for metabolic requirements, estimates of abundance based on recent analyses of ancient DNA, and trophic impact.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115627331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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