Geology Reports⌕ Search

Geology topics

Kimberly Yates

Publications and source records attributed to Kimberly Yates.

18 recordsLinked to original sources
USGS2026

Variable pH habitats could help prepare stone crabs for coastal acidification

Coastal acidification is being exacerbated by terrestrial organic inputs, especially after high precipitation events. Florida’s rainy season coincides with stone crab ( Menippe mercenaria) reproduction, and pH extremes could limit future harvests by reducing reproductive output. Populations that experience pH variability can serve as “natural laboratories” for estimating the tolerance of a species to coastal acidification. Here, we conducted a series of experiments to determine if ovigerous stone crabs conditioned in more variable pH habitats (seagrass) would result in faster embryonic development, greater hatching success, and higher larval survival relative to crabs conditioned in habitats with lower pH variability (sandy habitats). After field conditioning, crabs were transported to the laboratory and randomly acclimated to either a control pH (pH = ~ 7.90) or a reduced pH condition (pH = ~ 7.60) until larval release. The rate of embryo development was slower in the laboratory reduced pH treatment, however, there were no observable field condition effects on embryo development rate. Crabs conditioned in the more pH variable seagrass habitat did have greater hatching success and higher larval survival than crabs in less pH variable sandy habitats; however, larval survival was low across all treatments. These results suggest that the pH variability experienced in seagrass habitats during brooding may serve as a mechanism for stone crabs to acclimatize to extremes in seawater pH.

Marine Biology↗
USGS2026

Long- versus short-term changes in seafloor elevation and volume of the Upper Florida Keys Reef Tract: 1935–2002 and 2002–2016

Coral reefs provide immense ecosystem and economic value, supporting biodiversity, fisheries, tourism, and coastal protection worth billions annually. However, widespread degradation from thermal stress, storms, disease, and human impacts has caused significant coral cover and reef structure loss, increasing coastal vulnerability and economic risks. While coral loss is well-documented, degradation of underlying reef infrastructure and surrounding seafloor changes remain poorly understood. This study addresses this knowledge gap by quantifying seafloor elevation and volume changes across 234.2 km 2 of the Upper Florida Keys (UFK) reef tract using historical bathymetric and modern lidar (light detection and ranging) data collected from two periods with distinctly different disturbance regimes: 1935–2002 (frequent storms and major coral loss) and 2002–2016 (few storms and persistently low coral cover). Analysis of over 25,000 data points revealed substantial elevation and volume loss during 1935–2002 (−0.1 ± 0.8 m; 13.6 × 10 6 m 3 net loss), shifting to minimal gains by 2002–2016 (0.0 ± 0.3 m; 1.6 × 10 6 m 3 net gain). Despite this shift, benthic cover data showed continued declines in stony coral, with increases in macroalgae and octocorals, indicating that limited reef accretion persists even with reduced storm activity. Spatial analyses highlighted variable accretion and erosion patterns across habitats and subregions, underscoring the limitations of localized measurements for ecosystem-wide assessments. Our findings demonstrate the value of integrating historical and modern datasets for regional reef monitoring, establishing baselines for restoration planning, and emphasizing the need for continued high-resolution monitoring to guide adaptive management amid ongoing environmental change.

Florida↗
USGS2026

Coral reef protection may help avert risks to people, property, and economic activity caused by projected reef degradation

Degradation of coral reefs over the past several decades has caused regional-scale erosion of the shallow seafloor that serves as a protective barrier against coastal hazards along southeast Florida, USA. How future change in coral reefs may affect coastal flooding, however, has been less attended than other factors contributing to increasing risks such as sea-level rise and more intense storms. Here, the increased flooding hazard faced by Florida's coastal communities from the projected future degradation of its adjacent coral reefs is evaluated through oceanographic, coastal engineering, habitat, geospatial, and socioeconomic modeling. Risk-based valuation approaches were followed to map flood zones at 10-m 2 resolution along 430 km of Florida's reef-lined coast for the current and projected future coral reef conditions. The projected degradation of Florida's coral reefs can increase annual flooding to more than 8.77 km 2 of land and 4,980 km of roads, affecting more than 7,315 people, $412.5 million in damages to 1,400 buildings, and economic disruption of $438.1 million annually (2024 US dollars). The degradation of Florida's coral reefs would increase the annual risk to people and structures by more than 42% and 47%, respectively, but is spatially variable due to the heterogeneous alongshore nature and distribution of the reefs and communities: the increased risk exceeds $1 million/km annually to more than 17% of the coastline but also disproportionately would affect vulnerable populations. These results help identify areas where coral reef protection could help reduce the projected increased storm flooding risk to Florida's coastal communities.

Florida↗
USGS2024

Impact of Hurricane Irma on coral reef sediment redistribution at Looe Key Reef, Florida, USA

Understanding event-driven sediment transport in coral reef environments is essential to assessing impacts on reef species, habitats, restoration, and mitigation, yet a global knowledge gap remains due to limited quantitative studies. Hurricane Irma made landfall in the Lower Florida Keys with sustained 209 km h −1 winds and waves greater than 8 m on 10 September 2017, directly impacting the Florida Reef Tract (FRT) and providing an opportunity to perform a unique comprehensive, quantitative assessment of its impact on coral reef structure and sediment redistribution. We used lidar and multibeam derived digital elevation models (DEMs) collected before and after the passing of Hurricane Irma over a 15.98 km 2 area along the lower FRT including Looe Key Reef to quantify changes in seafloor elevation, volume, and structure due to storm impacts. Elevation change was calculated at over 4 million point locations across 10 habitat types within this study area for two time periods using data collected (1) approximately 1 year before the passing of Irma and 3 to 6 months following the storm's impact as well as (2) 3 to 6 months after and up to 16.5 months after the storm. Elevation change data were then used to generate triangulated irregular network (TIN) models in ArcMap to calculate changes in seafloor volume during each time period. Our results indicate that Hurricane Irma was primarily a depositional event that increased mean seafloor elevation and volume at this study site by 0.34 m and up to 5.4 Mm 3 , respectively. Sediment was transported primarily west-southwest (WSW) and downslope, modifying geomorphic seafloor features including the migration of sand waves and rubble fields, formation of scour marks in shallow seagrass habitats, and burial of seagrass and coral-dominated habitats. Approximately 16.5 months after Hurricane Irma (during a 13-month period between 2017 and 2019), net erosion was observed across all habitats with mean elevation change of −0.15 m and net volume change up to −2.46 Mm 3 . Rates of elevation change during this post-storm period were 1 to 2 orders of magnitude greater than decadal and multi-decadal rates of change in the same location, and changes showed erosion of approximately 50 % of sediment deposited during the storm event as seafloor sediment distribution began to re-equilibrate to non-storm sea-state conditions. Our results suggest that higher-resolution elevation change data collected over seasonal and annual time periods could enhance characterization and understanding of short-term and long-term rates and processes of seafloor change.

Florida↗
USGS2024

Nutrient and carbonate chemistry patterns associated with Karenia brevis blooms in three West Florida Shelf estuaries 2020-2023

Ocean acidification (OA) driven by eutrophication, riverine discharge, and other threats from local population growth that affect the inorganic carbonate system is already affecting the eastern Gulf of Mexico. Long-term declines in pH of ~ -0.001 pH units yr -1 have been observed in many southwest Florida estuaries over the past few decades. Coastal and estuarine waters of southwest Florida experience high biomass harmful algal blooms (HABs) of the dinoflagellate Karenia brevis nearly every year; and these blooms have the potential to impact and be impacted by seasonal to interannual patterns of carbonate chemistry. Sampling was conducted seasonally along three estuarine transects (Tampa Bay, Charlotte Harbor, Caloosahatchee River) between May 2020 and May 2023 to obtain baseline measurements of carbonate chemistry prior to, during, and following K. brevis blooms. Conductivity, temperature and depth data and discrete water samples for K. brevis cell abundance, nutrients, and carbonate chemistry (total alkalinity, dissolved inorganic carbonate (DIC), p CO 2, and pH T were evaluated to identify seasonal patterns and linkages among carbonate system variables, nutrients, and K. brevis blooms. Karenia brevis blooms were observed during six samplings, and highest p CO 2 and lowest pH T was observed either during or after blooms in all three estuaries. Highest average pH and lowest p CO 2 were observed in Tampa Bay. In all three estuaries, average DIC and pH T were higher and p CO 2 was lower during dry seasons than wet seasons. There was strong influence of net community calcification (NCC) and net community production (NCP) on the carbonate system; and NCC : NCP ratios in Tampa Bay, Charlotte Harbor, and the Caloosahatchee River were 0.83, 0.93, and 1.02, respectively. Linear relationships between salinity and dissolved ammonium, phosphate, and nitrate indicate strong influence of freshwater inflow from river input and discharge events on nutrient concentrations. This study is a first step towards connecting observations of high biomass blooms like those caused by K. brevis and alterations of carbonate chemistry in Southwest Florida. Our study demonstrates the need for integrated monitoring to improve understanding of interactions among the carbonate system, HABs, water quality, and acidification over local to regional spatial scales and event to decadal time scales.

Florida↗
USGS2023

An assessment of HgII to preserve carbonate system parameters in organic-rich estuarine waters

This work assesses the effectiveness of sample preservation techniques for measurements of pH T (total scale), total dissolved inorganic carbon (C T ), and total alkalinity (A T ) in organic-rich estuarine waters as well as the internal consistency of measurements and calculations (e.g., A T , pH T , and C T ) in these waters. Using mercuric chloride (HgCl 2 )-treated and untreated water samples, measurements of these carbonate system parameters were examined over a period of 3 months. Respiration of dissolved organic matter in untreated samples created large discrepancies in C T concentrations (~37 μ mol kg −1 increase, p < 0.0001), while C T was effectively constant in treated samples (3095.0 ± 1.14 μ mol kg −1 ). A T changes were observed for both treated and untreated samples, with HgCl 2 -treated samples showing the greatest variation (~ 26 μ mol kg −1 decrease, p < 0.001). In response to changing A T /C T ratios, pH T changes occurred in both treated and untreated samples but were relatively small in treated samples. Results in organic-rich estuarine waters that reflect the in situ carbonate system characteristics of the samples at the time of collection can be improved when samples obtained for C T and A T analysis are collected and stored separately. Accurate analyses of C T can be obtained by filtration and preservation with HgCl 2 . Accuracy of A T analyses can be improved by filtration and storage without adding HgCl 2 . The quality of pH T measurements can be improved by prompt analysis in the field and, if this cannot be accomplished, then samples can be preserved with HgCl 2 and measured in the laboratory within 1 week.

Limnology and Oceanography: Methods↗
USGS2006

Integration of coral reef ecosystem process studies and remote sensing

Worldwide, local-scale anthropogenic stress combined with global climate change is driving shifts in the state of reef benthic communities from coral-rich to micro- or macroalgal-dominated (Knowlton, 1992; Done, 1999). Such phase shifts in reef benthic communities may be either abrupt or gradual, and case studies from diverse ocean basins demonstrate that recovery, while uncertain (Hughes, 1994), typically involves progression through successional stages (Done, 1992). These transitions in benthic community structure involve changes in community metabolism, and accordingly, the holistic evaluation of associated biogeochemical variables is of great intrinsic value (Done, 1992). Effective reef management requires advance prediction of coral reef alteration in the face of anthropogenic stress and change in the global environment (Hatcher, 1997a). In practice, this goal requires techniques that can rapidly discern, at an early stage, sublethal effects that may cause long-term increases in mortality (brown, 1988; Grigg and Dollar, 1990). Such methods would improve our understanding of the differences in the population, community, and ecosystem structure, as well as function, between pristine and degraded reefs. This knowledge base could then support scientifically based management strategies (Done, 1992). Brown (1988) noted the general lack of rigor in the assessment of stress on coral reefs and suggested that more quantitative approaches than currently exist are needed to allow objective understanding of coral reef dynamics. Sensitive techniques for the timely appraisal of pollution effects or generalized endemic stress in coral reefs are sorely lacking (Grigg and Dollar, 1990; Wilkinsin, 1992). Moreover, monitoring methods based on population inventories, sclerochronology, or reproductive biology tend to myopic and may give inconsistent results. Ideally, an improved means of evaluating reef stress would discriminate mortality due to natural causes from morality to anthropogenic causes (Brown, 1988). Models of coral reef ecosystems, parameterized by process measurements and scaled in time-space using remote sensing, have the potential to address pressing research questions that are central to devising valid management strategies (Grigg el al., 1984; Hatcher, 1997b). To attain this goal, ecosystem-level models that integrate studies of physical and chemical forcing with observed biological and geological responses are required. This interdisciplinary approach to understanding reef biogeochemical dynamics can allow investigations that integrate the scales of time and space (Hatcher, 1997a), thereby enabling prediction of coral reef change (Andréfouët and Payri, 2001). In turn, prediction of holistic ecosystem function within various environmental focusing scenarios has substantial promise in mitigating future disturbance. Indeed, management of coral reefs at the ecosystem level has been suggested as the only meaningful approach to preserving coral reefs (Bohnsack and Ault, 1996; Christensen et al., 1996).

Florida↗
USGS2005

Gulf of Mexico Integrated Science - Tampa Bay Study: Examining the Impact of Urbanization on Seafloor Habitats

Seafloor habitats, such as seagrass beds, provide essential habitat for fish and marine mammals. For many years, the study of seagrass vitality has been a priority for scientists and resource managers working in Tampa Bay. Seafloor habitats are extremely sensitive to changes in water quality. Like a canary in a coal mine, seagrass can serve as an ecological indicator of estuary health. Between the 1940s and the 1970s, seagrass gradually died in Tampa Bay. This loss has been attributed to a rise in urbanization and an increase in nutrient loading into the bay. Better treatment of industrial wastewater and runoff beginning in the 1980s resulted in the continuous recovery of seagrass beds. However, in the mid-1990s, the recovery began to level off in areas where good water quality was expected to support continued seagrass recovery, demonstrating that nutrient loading may be only one factor impacting seagrass health. Researchers now are trying to determine what might be affecting the recovery of seagrass in these areas. Currently, little is understood about the effects that other aspects of urbanization and natural change, such as groundwater and sediment quality, might have on seagrass vitality. This segment of the Tampa Bay integrated science study is intended to identify, quantify, and develop models that illustrate the impact that urbanization may have on seafloor habitat distribution, health, and restoration.

Open-File Report↗
USGS2004

Gulf of Mexico Integrated Science - Tampa Bay Study Overview

The U.S. Geological Survey's Gulf of Mexico Integrated Science - Tampa Bay Study combines the expertise of federal, state, and local partners to address some of the most pressing ecological problems of the Tampa Bay estuary. This project serves as a template for integrated research projects in other coastal ecosystems in the nation. The Tampa Bay Study focuses on the scientific needs of the Bay, as identified by resource managers.

Open-File Report↗
USGS2001

Tampa Bay Integrated Science Pilot Study: wetland characterization

Coastal wetlands in Tampa Bay consist of mangrove forest and tidal salt marsh. Wetlands buffer storm surges, provide fish and wildlife habitat, and enhance water quality through the removal of water-borne nutrients and contaminants. Substantial areas of both mangrove and salt marsh have been lost to agricultural, residential and industrial development in this urban estuary. Wetlands restoration has been initiated in Tampa Bay. Baseline studies on the current condition of wetlands and historical and prehistorical information is needed for successful restoration planning and evaluation. A major objective of this component of the Tampa Bay pilot program was to characterize wetlands in Tampa Bay beginning with areas that differ in their degree of human-induced disturbance ( Fig. 1 ). The Alafia River area is urbanized, industrialized and dredged, whereas the Terra Ceia area has a history of agricultural use with associated soil berms and mosquito ditches, but has not been farmed for at least 20 years ( Fig. 2 ).

Open-File Report↗
USGS2001

Tampa Bay Integrated Science Pilot Study: Baseline mapping, land surface dynamics and predictive modeling, and hazards vulnerability studies

Tampa Bay and its environs have experienced phenomenal urban growth and significant changes in land cover and land-use practices over the past 50 years. This trend is expected to continue, with the impact of human activity broadening geographically and intensifying throughout the region. One of the immediate impacts of urban growth is the creation of additional impervious surfaces, which in turn, generate increased urban runoff that contributes to higher levels of nutrient loading in water bodies throughout the area. To better understand these and other anthropogenic affects on the ecology of the natural environment of the region, this component of the Tampa Bay Pilot Study took a broad basin-wide view. This regional view was intended to provide geographic and temporal context for the smaller intensely studied sample field site locations within the estuarine environment.

Open-File Report↗