Symmetrical Brain Coral (Pseuododiploria strigosa) emersed during low tide along the shoreline of PortMiami.

Read ‘Coral persistence despite marginal conditions in the Port of Miami‘:

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Read news coverage on the paper from WLRN Miami.

Symmetrical Brain Coral (Pseuododiploria strigosa) emersed during low tide along the shoreline of PortMiami.

We found that the Symmetrical Brain Corals (Pseuododiploria strigosa) living in the urban environment (specifically alongside MacArthur Causeway and Star Island in Miami) were predominantly colonized by the Durusdinium sp. strain of symbiotic algae (zooxanthellae) that provides the coral with photosynthetic energy during daylight hours. Durusdinium is known to be a heat-tolerant genus of zooxanthellae, and has long been investigated by scientists seeking to create bleaching-resistant ‘super corals’. However, until this study, the Symmetrical Brain Coral had rarely been observed hosting this species of zooxanthellae elsewhere in the region, making these observations here in Miami quite remarkable.

Beyond the helpful symbionts, the Symmetrical Brain Corals living in the urban environment were also found to be producing proteins and enzymes known to identify and digest pathogenic invaders. These proteins could be a two-fold benefit to the coral since disease-causing microbes can be digested as food before they can infect the coral. The urban marine environments around Miami often have high concentrations of phytoplankton and turbidity in the water, along with high bacterial concentrations that frequently require ‘no swim’ public health advisories. The ability to capture and extract more energy from food could enhance its health and provide sustenance during times of bleaching.

These findings from a single species of urban coral in Miami’s coastal environment suggest further investigation is warranted in the variety of other reef-building species that have self-recruited to the City’s concrete and riprap shorelines. It also demonstrates how the human-made hydrogeologic conditions around PortMiami serve as an evolutionary gauntlet selecting for corals better adapted for life in the Anthropocene.

Read ‘Molecular Mechanisms of Coral Persistence Within Highly Urbanized Locations in the Port of Miami, Florida‘:

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On November 27th we embarked on the first field trip with researchers from NOAA and University of Miami for the next phase of Coral Morphologic’s long-term project to document, study, and conserve Miami’s unusually resilient ‘urban corals’. That is, the corals that have pioneered into Miami’s intercoastal waterways as larvae and settled onto man-made infrastructure. It is precisely Miami’s legacy of anthropogenic disturbance that led Coral Morphologic to recognize that the City was a real-world window in which to understand how corals may adapt and evolve to anthropogenic impacts.

Studying genetic variation and the underlying causes of these variations is at the heart of a global effort to identify more resilient coral genotypes capable of restoring degraded coral habitat. Most of this research has focused on traditionally healthy, offshore reef habitats and identifying corals that show more resilience to stress than neighbors, or in experimental lab settings with distinct coral colonies of the same species subjected to stressful conditions. However, our project proposes to sample the tissue of healthy coral colonies (specifically Pseudodiploria strigosa and Porites asteroides) living in less than ideal ‘urban’ conditions, as well as healthy coral living offshore in ‘natural’ conditions, to determine if the genetic variation between sites is significant. The sample sites will also be surveyed and scientifically described by community assessment and seasonal changes through photo mosaics, monitoring of water chemistry, temperature, pH, and light levels, to quantify and compare site conditions. The final phase of this project will involve transplanting corals to the tip of PortMiami from each of the ‘urban’ sites, along with fragments from the offshore, natural reef to compare how each is able to adapt, and eventually developing an ‘urban coral’ nursery to grow the most resilient coral genotypes for restoration of reefs and laboratory research.

But the first task in this year-long study was to characterize each of the study sites through photo-mosaics that create three dimensional maps using a pair of GoPro cameras. These maps will serve as our detailed baseline imagery to better understand the forces of coral recruitment, growth, mortality, competition from macroalgae, and the accumulation of trash/ debris over time. Watch the video above to see each of the three urban coral research sites and the techniques used to document them. We look forward to providing updates over the course of the year as we document the sites, analyze transcriptomes, transplant corals, and characterize range of water quality and chemical conditions that Miami’s urban corals endure.

Read Part 2 (& Part 1) of our essay on super corals: ‘On Super Corals and Where to Find Them (A Closer Look at Miami’s Urban Coral Ecosystem)’ on Medium or click the link below:

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