Life Sciences Commons^™

Thermal Stress-Related Spatiotemporal Variations In High-Latitude Coral Reef Benthic Communities, Nicholas P. Jones, Joana Figueiredo, David S. Gilliam

Marine & Environmental Sciences Faculty Articles

High-latitude coral reef communities have been postulated as the first areas to undergo reorganisation under climate change. Tropicalisation has been identified in some high-latitude communities and is predicted in others, but it is unclear how the resident benthic taxa are affected. We conducted a long-term (2007–2016) assessment of changes to benthic community cover in relation to thermal stress duration on the Southeast Florida Reef Tract (SEFRT). Thermal stress events, both hot and cold, had acute (thermal stress duration affected benthic cover that year) and chronic (thermal stress duration affected benthic cover the following year) impacts on benthic cover. Chronic heat …

Uncovering The Role Of Symbiodiniaceae Assemblage Composition And Abundance In Coral Bleaching Response By Minimizing Sampling And Evolutionary Biases, Timothy D. Swain, Simon Lax, Vadim Backman, Luisa A. Marcelino

Marine & Environmental Sciences Faculty Articles

Background

Biodiversity and productivity of coral-reef ecosystems depend upon reef-building corals and their associations with endosymbiotic Symbiodiniaceae, which offer diverse functional capabilities to their hosts. The number of unique symbiotic partners (richness) and relative abundances (evenness) have been hypothesized to affect host response to climate change induced thermal stress. Symbiodiniaceae assemblages with many unique phylotypes may provide greater physiological flexibility or form less stable symbioses; assemblages with low abundance phylotypes may allow corals to retain thermotolerant symbionts or represent associations with less-suitable symbionts.

Results

Here we demonstrate that true richness of Symbiodiniaceae phylotype assemblages is generally not discoverable from …

Urgent Need For Coral Demography In A World Where Corals Are Disappearing, Peter J. Edmunds, Bernhard Riegl

Marine & Environmental Sciences Faculty Articles

Coral reefs have long attracted attention because of their biological and economic importance, but this interest now has turned to examining the possibility of functional extirpation. Widespread declines in coral abundances have fueled the shift in motivation for studying reefs and catalyzed the proliferation of monitoring to record the changes underway. Despite appreciation of monitoring as a scientific endeavor, its primary use has continued to be the quantification of cover of coral, macroalgae, and a few other space holders. The limitations of coral cover in evaluating the consequences of changing coral abundance were highlighted decades ago. Yet neglect of the …

Fallen Pillars: The Past, Present, And Future Population Dynamics Of A Rare, Specialist Coral–Algal Symbiosis, Andrea Chan, Cynthia L. Lewis, Karen L. Neely, Iliana B. Baums

Marine & Environmental Sciences Faculty Articles

With ongoing changes in climate, rare and ecologically specialized species are at increased risk of extinction. In sessile foundation fauna that reproduce asexually via fragmentation of existing colonies, the number of colonies does not reflect the number of genets and thus can obscure genotypic diversity. Colonies that are the product of fragmentation are not visually distinguishable from colonies that stem from sexual recruits. For this reason, molecular markers are necessary to assess genotypic variation and population structure in clonal organisms such as reef-building corals and their endosymbiotic dinoflagellates. For the rare Caribbean pillar coral, Dendrogyra cylindrus, and its endosymbiotic …

Indirect Legacy Effects Of An Extreme Climatic Event On A Marine Megafaunal Community, Robert Nowicki, Michael Heithaus, Jordan Thompson, Derek Burkholder, Kirk Gastrich, Aaron Wirsing

Marine & Environmental Sciences Faculty Articles

While extreme climatic events (ECEs) are predicted to become more frequent, reliably predicting their impacts on consumers remains challenging, particularly for large consumers in marine environments. Many studies that do evaluate ECE effects focus primarily on direct effects, though indirect effects can be equally or more important. Here, we investigate the indirect impacts of the 2011 “Ningaloo Niño” marine heatwave ECE on a diverse megafaunal community in Shark Bay, Western Australia. We use an 18‐year community‐level data set before (1998–2010) and after (2012–2015) the heatwave to assess the effects of seagrass loss on the abundance of seven consumer groups: sharks, …

Thresholds And Drivers Of Coral Calcification Responses To Climate Change, Niklas Kornder, Bernhard Riegl, Joana Figueiredo

Marine & Environmental Sciences Faculty Articles

Increased temperature and CO₂ levels are considered key drivers of coral reef degradation. However, individual assessments of ecological responses (calcification) to these stressors are often contradicting. To detect underlying drivers of heterogeneity in coral calcification responses, we developed a procedure for the inclusion of stress–effect relationships in ecological meta‐analyses. We applied this technique to a dataset of 294 empirical observations from 62 peer‐reviewed publications testing individual and combined effects of elevated temperature and pCO₂ on coral calcification. Our results show an additive interaction between warming and acidification, which reduces coral calcification by 20% when pCO₂ levels exceed …

Climate Change, One Health And Mercury, L. K. Duffy, T. Vertigan, B. Dainowski, K. Dunlap, Amy Hirons

Marine & Environmental Sciences Faculty Articles

Climate change is occurring on both regional and global scales. The use and global distribution of toxic metals is increasing and affecting environmental, animal and human health as a result of air, water and food contamination. Mercury (Hg) in major forms Hg°, Hg²⁺ and methyl mercury (CH₃Hg⁺) are increasingly available around the globe. Both metal and organic contaminants are impacting the health of all species on the planet. Mercury is an example of a metal that can cause or aggravate a disease state, for example, diabetes. Habitat stewardship is needed to maintain a healthy system, …

Biogeochemical Analysis Of Ancient Pacific Cod Bone Suggests Hg Bioaccumulation Was Linked To Paleo Sea Level Rise And Climate Change, Maribeth S. Murray, C. Peter Mcroy, L. K. Duffy, Amy Hirons, J. M. Schaaf, Robert P. Trocine, John Trefry

Marine & Environmental Sciences Faculty Articles

Deglaciation at the end of the Pleistocene initiated major changes in ocean circulation and distribution. Within a brief geological time, large areas of land were inundated by sea-level rise and today global sea level is 120 m above its minimum stand during the last glacial maximum. This was the era of modern sea shelf formation; climate change caused coastal plain flooding and created broad continental shelves with innumerable consequences to marine and terrestrial ecosystems and human populations. In Alaska, the Bering Sea nearly doubled in size and stretches of coastline to the south were flooded, with regional variability in the …

Water Column Productivity And Temperature Predict Coral Reef Regeneration Across The Indo-Pacific, Bernhard Riegl, Peter W. Glynn, Evie A. Wieters, Samuel J. Purkis, C. D'Angelo, Joerg Wiedenmann

Marine & Environmental Sciences Faculty Articles

Predicted increases in seawater temperatures accelerate coral reef decline due to mortality by heat-driven coral bleaching. Alteration of the natural nutrient environment of reef corals reduces tolerance of corals to heat and light stress and thus will exacerbate impacts of global warming on reefs. Still, many reefs demonstrate remarkable regeneration from past stress events. This paper investigates the effects of sea surface temperature (SST) and water column productivity on recovery of coral reefs. In 71 Indo-Pacific sites, coral cover changes over the past 1-3 decades correlated negative-exponentially with mean SST, chlorophyll a, and SST rise. At six monitoring sites …

Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre

Marine & Environmental Sciences Faculty Articles

Physical uptake of anthropogenic CO₂ is the dominant driver of ocean acidification (OA) in the open ocean. Due to expected decreases in calcification and increased dissolution of CaCO₃ framework, coral reefs are thought to be highly susceptible to OA. However, biogeochemical processes can influence the pCO₂ and pH of coastal ecosystems on diel and seasonal time scales, potentially modifying the long‐term effects of increasing atmospheric CO₂. By compiling data from the literature and removing the effects of short‐term variability, we show that the average pCO₂ of coral reefs throughout the globe has increased ~3.5‐fold …

Severe 2010 Cold-Water Event Caused Unprecedented Mortality To Corals Of The Florida Reef Tract And Reversed Previous Survivorship Patterns, Diego Lirman, Stephanie Schopmeyer, Derek Manzello, Lewis J. Gramer, William F. Precht, Frank E. Muller-Karger, Kenneth Banks, Brian Barnes, Erich Bartels, Amanda Bourque, James Byrne, Scott Donahue, Janice Duquesnel, Louis Fisher, David S. Gilliam, James C. Hendee, Meaghan E. Johnson, Kerry Maxwell, Erin Mcdevitt, Jamie Monty, Digna Rueda, Rob Ruzicka, Sara Thanner

Marine & Environmental Sciences Faculty Articles

Background

Coral reefs are facing increasing pressure from natural and anthropogenic stressors that have already caused significant worldwide declines. In January 2010, coral reefs of Florida, United States, were impacted by an extreme cold-water anomaly that exposed corals to temperatures well below their reported thresholds (16°C), causing rapid coral mortality unprecedented in spatial extent and severity.

Methodology/Principal Findings

Reef surveys were conducted from Martin County to the Lower Florida Keys within weeks of the anomaly. The impacts recorded were catastrophic and exceeded those of any previous disturbances in the region. Coral mortality patterns were directly correlated to in-situ and satellite-derived …

Climate Change, Coral Reef Ecosystems, And Management Options For Marine Protected Areas, Brian D. Keller, Daniel F. Gleason, Elizabeth Mcleod, Christa M. Woodley, Satie Airame, Billy D. Causey, Alan M. Friedlander, Rikki Grober-Dunsmore, Johanna E. Johnson, Steven Miller, Robert S. Steneck

Marine & Environmental Sciences Faculty Articles

Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an …