Once one of the predominant reef-building corals in the region,Acropora cervicornisis now a focal species of coral restoration efforts in Florida and the western Caribbean. Scientists and restoration practitioners have been independently collecting phenotypic data on genets ofA. cervicornisgrown in restoration nurseries. While these data are important for understanding the intraspecific response to varying environmental conditions, and thus the potential genetic contribution to phenotypic variation, in isolation these observations are of limited use for large-scale, multi- institution restoration efforts that are becoming increasingly necessary. Here, we present theAcropora cervicornisData Coordination Hub, a web-accessible relational database to align disparate datasets to compare genet-specific performance. In this data descriptor, we release data for 248 genets evaluated across 38 separate traits. We present a framework to align datasets with the ultimate goal of facilitating informed, data-driven restoration throughout the Caribbean.
Corals throughout the Caribbean have experienced major declines since the 1970s. In response, many agencies have focused their conservation and restoration efforts on outplanting nursery-grown coral fragments onto degraded reefs. Predation on newly outplanted corals can be an important but often unmonitored factor contributing to the declining health and survival of these fragments. In this study, we outplanted 360 boulder coral fragments (Montastraea cavernosa, Orbicella faveolata, Pseudodiploria clivosa), sourced from both ex situ and in situ nurseries, at three locations in the Florida Keys. Each location included one inshore and one offshore site. Ten fragments of each species and source were outplanted at each site (60 corals per site). Transplants were monitored for finfish predation, live tissue area, and survival at 1, 2, 6, and 12 wks post-outplanting. We found the highest finfish predation for all species during the 1 wk monitoring period. Predation during this first week varied by location and reef type, with two locations showing higher predation on offshore sites and one location experiencing increased predation on the inshore site. We also found that coral fragments produced in the ex situ nursery experienced higher initial predation compared to fragments produced in the in situ nursery. However, overall coral survival at 12 wks post-outplanting was 96%, suggesting there was no effect of initial predation on survival. Our results indicate that coral restoration efforts may be affected by intense, initial predation on newly-outplanted boulder coral colonies, but this initial predation may not lead to an increase in mortality.
Stony coral tissue loss disease (SCTLD) is an emergent and often lethal coral disease that was first reported near Miami, FL (USA) in 2014. Our objective was to determine if coral colonies showing signs of SCTLD possess a specific microbial signature across five susceptible species sampled in Florida’s Coral Reef. Three sample types were collected: lesion tissue and apparently unaffected tissue of diseased colonies, and tissue of apparently healthy colonies. Using 16S rRNA high-throughput gene sequencing, our results show that, for every species, the microbial community composition of lesion tissue was significantly different from healthy colony tissue and from the unaffected tissue of diseased colonies. The lesion tissue of all but one species (Siderastrea siderea) had higher relative abundances of the order Rhodobacterales compared with other types of tissue samples, which may partly explain why S. siderea lesions often differed in appearance compared to other species. The order Clostridiales was also present at relatively high abundances in the lesion tissue of three species compared to healthy and unaffected tissues. Stress often leads to the dysbiosis of coral microbiomes and increases the abundance of opportunistic pathogens. The present study suggests that Rhodobacterales and Clostridiales likely play an important role in SCTLD.
The rapid loss of reef-building corals owing to ocean warming is driving the development of interventions such as coral propagation and restoration, selective breeding and assisted gene flow. Many of these interventions target naturally heat-tolerant individuals to boost climate resilience, but the challenges of quickly and reliably quantifying heat tolerance and identifying thermotolerant individuals have hampered implementation. Here, we used coral bleaching automated stress systems to perform rapid, standardized heat tolerance assays on 229 colonies of Acropora cervicornis across six coral nurseries spanning Florida's Coral Reef, USA. Analysis of heat stress dose-response curves for each colony revealed a broad range in thermal tolerance among individuals (approx. 2.5°C range in Fv/Fm ED50), with highly reproducible rankings across independent tests (r = 0.76). Most phenotypic variation occurred within nurseries rather than between them, pointing to a potentially dominant role of fixed genetic effects in setting thermal tolerance and widespread distribution of tolerant individuals throughout the population. The identification of tolerant individuals provides immediately actionable information to optimize nursery and restoration programmes for Florida's threatened staghorn corals. This work further provides a blueprint for future efforts to identify and source thermally tolerant corals for conservation interventions worldwide.
In recent decades, the Florida reef tract has lost over 95% of its coral cover. Although isolated coral assemblages persist, coral restoration programs are attempting to recover local coral populations. Listed as threatened under the Endangered Species Act, Acropora cervicornis is the most widely targeted coral species for restoration in Florida. Yet strategies are still maturing to enhance the survival of nursery‐reared outplants of A. cervicornis colonies on natural reefs. This study examined the survival of 22,634 A. cervicornis colonies raised in nurseries along the Florida reef tract and outplanted to six reef habitats in seven geographical subregions between 2012 and 2018. A Cox proportional hazards regression was used within a Bayesian framework to examine the effects of seven variables: (1) coral‐colony size at outplanting, (2) coral‐colony attachment method, (3) genotypic diversity of outplanted A. cervicornis clusters, (4) reef habitat, (5) geographical subregion, (6) latitude, and (7) the year of monitoring. The best models included coral‐colony size at outplanting, reef habitat, geographical subregion, and the year of monitoring. Survival was highest when colonies were larger than 15 cm (total linear extension), when outplanted to back‐reef and fore‐reef habitats, and when outplanted in Biscayne Bay and Broward–Miami subregions, in the higher latitudes of the Florida reef tract. This study points to several variables that influence the survival of outplanted A. cervicornis colonies and highlights a need to refine restoration strategies to help restore their population along the Florida reef tract.
Along the Florida reef tract, stony-coral-tissue-loss disease (SCTLD) has caused extensive mortality of more than 20 scleractinian coral species. The pathogen is unknown, but its epizoology indicates that the disease, facilitated by water currents, has progressed linearly along the tract, affecting reefs at the scale of hundreds of kilometers. To inform ongoing disease mitigation efforts, we examined the small-scale spatial and temporal epidemiology of SCTLD. We established a series of sites in the middle Florida Keys at offshore and inshore locations that had not yet shown signs of SCTLD. We then conducted high-frequency monitoring from February 2018 through September 2019 and documented the onset of SCTLD and its progression through the sites. SCTLD was first observed at one site during early February 2018 and by early March 2018 all sites showed signs of the disease. A dynamic multistate model suggested that disease transmission was independent of coral density and found little evidence of a positive association between a colony showing signs of SCTLD and the condition or distance to its neighboring colonies. The model did, however, indicate that the probability of a colony showing signs of SCTLD increased with increasing colony surface area. These results are consistent with the water-borne transmission of a pathogen that progressed rapidly through the survey area. However, by the end of our survey the progression of SCTLD had slowed, particularly at inshore sites. Many affected colonies no longer exhibited progressive tissue mortality typical of the disease, suggesting the existence of differentially resilient colonies or coral communities, meriting their use for future coral rescue and propagation and disease research. These results are useful for refining ongoing SCTLD mitigation strategies, particularly by determining when disease rates are sufficiently low for direct intervention efforts designed to arrest disease progression on individual coral colonies will be most effective.
Reef restoration programs in Florida, US, focused initially on Acropora, but there is now a need to include other species that have also experienced declines. An outplanting experiment using Acropora cervicornis, Montastraea cavernosa, and Orbicella faveolata was conducted to compare performance among species and evaluate the impacts of contact interactions with macroalgae and the zoanthid Palythoa caribaeorum. Montastraea cavernosa and O. faveolata showed high survivorship (78% and 92%, respectively) over 18 mo. However, surviving colonies had limited growth and lost tissue due to factors like predation and disease. In contrast, A. cervicornis showed exponential growth. Colonies in contact with macroalgae showed the lowest survivorship. Removing macroalgae provided no long-term benefits in growth and a slight improvement in colony survivorship. Acropora cervicornis in contact with Palythoa grew 45% less than controls. Our study showed that: (1) coral taxa with massive morphologies (40–130 cm2) can be transplanted with low colony mortality but that their slow growth is not enough to balance partial tissue mortality caused by multiple chronic stressors; (2) removal of macroalgae at the time of outplanting improves colony survivorship; (3) periodic removal of macroalgae does not enhance growth; and (4) contact with Palythoa should be avoided. The impacts of contact competition were variable among species with different colony morphologies, with A. cervicornis showing the highest susceptibility to competition from algae and Palythoa. While restoration can rapidly increase coral abundance, long-term success will require a multifaceted approach to reduce the impacts of chronic reef stressors on wild and outplanted corals alike.
Samples from eight species of corals (Colpophyllia natans, Dendrogyra cylindrus, Diploria labyrinthiformis, Meandrina meandrites, Montastraea cavernosa, Orbicella faveolata, Pseudodiploria strigosa, and Siderastrea siderea) that exhibited gross clinical signs of acute, subacute, or chronic tissue loss attributed to stony coral tissue loss disease (SCTLD) were collected from the Florida Reef Tract during 2016–2018 and examined histopathologically. The hallmark microscopic lesion seen in all eight species was focal to multifocal lytic necrosis (LN) originating in the gastrodermis of the basal body wall (BBW) and extending to the calicodermis, with more advanced lesions involving the surface body wall. This was accompanied by other degenerative changes in host cells such as mucocyte hypertrophy, degradation and fragmentation of gastrodermal architecture, and disintegration of the mesoglea. Zooxanthellae manifested various changes including necrosis (cytoplasmic hypereosinophilia, pyknosis); peripheral nuclear chromatin condensation; cytoplasmic vacuolation accompanied by deformation, swelling, or atrophy; swollen accumulation bodies; prominent pyrenoids; and degraded chloroplasts. Polyhedral intracytoplasmic eosinophilic periodic acid–Schiff-positive crystalline inclusion bodies (∼1–10 μm in length) were seen only in M. cavernosa and P. strigosa BBW gastrodermis in or adjacent to active lesions and some unaffected areas (without surface lesions) of diseased colonies. Coccoidlike or coccobacilloidlike structures (Gram-neutral) reminiscent of microorganisms were occasionally associated with LN lesions or seen in apparently healthy tissue of diseased colonies along with various parasites and other bacteria all considered likely secondary colonizers. Of the 82 samples showing gross lesions of SCTLD, 71 (87%) were confirmed histologically to have LN. Collectively, pathology indicates that SCTLD is the result of a disruption of host–symbiont physiology with lesions originating in the BBW leading to detachment and sloughing of tissues from the skeleton. Future investigations could focus on identifying the cause and pathogenesis of this process.
Coral gardening plays an important role in the recovery of depleted populations of threatened Acropora cervicornis in the Caribbean. Over the past decade, high survival coupled with fast growth of in situ nursery corals have allowed practitioners to create healthy and genotypically diverse nursery stocks. Currently, thousands of corals are propagated and outplanted onto degraded reefs on a yearly basis, representing a substantial increase in the abundance, biomass, and overall footprint of A. cervicornis. Here, we combined an extensive dataset collected by restoration practitioners to document early (1–2 yr) restoration success metrics in Florida and Puerto Rico, USA. By reporting region-specific data on the impacts of fragment collection on donor colonies, survivorship and productivity of nursery corals, and survivorship and productivity of outplanted corals during normal conditions, we provide the basis for a stop-light indicator framework for new or existing restoration programs to evaluate their performance. We show that current restoration methods are very effective, that no excess damage is caused to donor colonies, and that once outplanted, corals behave just as wild colonies. We also provide science-based benchmarks that can be used by programs to evaluate successes and challenges of their efforts, and to make modifications where needed. We propose that up to 10% of the biomass can be collected from healthy, large A. cervicornis donor colonies for nursery propagation. We also propose the following benchmarks for the first year of activities for A. cervicornis restoration: (1) >75% live tissue cover on donor colonies; (2) >80% survivorship of nursery corals; and (3) >70% survivorship of outplanted corals. Finally, we report productivity means of 4.4 cm yr−1 for nursery corals and 4.8 cm yr−1 for outplants as a frame of reference for ranking performance within programs. Such benchmarks, and potential subsequent adaptive actions, are needed to fully assess the long-term success of coral restoration and species recovery programs.
Abstract Threatened Caribbean coral communities can benefit from high‐resolution genetic data used to inform management and conservation action. We use Genotyping by Sequencing (GBS) to investigate genetic patterns in the threatened coral, Acropora cervicornis, across the Florida Reef Tract (FRT) and the western Caribbean. Results show extensive population structure at regional scales and resolve previously unknown structure within the FRT. Different regions also exhibit up to threefold differences in genetic diversity (He), suggesting targeted management based on the goals and resources of each population is needed. Patterns of genetic diversity have a strong spatial component, and our results show Broward and the Lower Keys are among the most diverse populations in Florida. The genetic diversity of Caribbean staghorn coral is concentrated within populations and within individual reefs (AMOVA), highlighting the complex mosaic of population structure. This variance structure is similar over regional and local scales, which suggests that in situ nurseries are adequately capturing natural patterns of diversity, representing a resource that can replicate the average diversity of wild assemblages, serving to increase intraspecific diversity and potentially leading to improved biodiversity and ecosystem function. Results presented here can be translated into specific goals for the recovery of A. cervicornis, including active focus on low diversity areas, protection of high diversity and connectivity, and practical thresholds for responsible restoration.
Fisheries managers worldwide are increasingly using no-take marine reserves (NTMR) to bolster the sustainability of fisheries. Within the Florida Keys National Marine Sanctuary (FKNMS), the Western Sambo Ecological Reserve (WSER) was created to protect a natural area for spawning and a permanent residence area for marine life by eliminating recreational and commercial harvest of resident species. To evaluate whether WSER is meeting these design criteria, we assessed the age structure and potential egg production of the Caribbean spiny lobster (Panulirus argus) population in WSER and in a nearby, unprotected, fished area. Concentration of the age-pigment neurolipofuscin in eyestalks of P. argus was quantified histologically to determine age. We used Monte Carlo simulations to compare the age structure between the two populations of lobster. Lobsters in WSER were older than those in the fished area. Analyses suggested that more than 90% of the lobsters in the fished area were younger than 1.9 years, whereas half of the lobsters in WSER were older than 1.9 years. Moreover, some lobsters may have been the same age (5-6 years) as was WSER itself at the time of the survey, suggesting that they were long-term residents of WSER. Evident in this age-based study was the retention of female lobsters in WSER, as confirmed by the presence of older females, whereas large and thus likely protected females were uncommon during surveys in which only size and sex data were collected. Also, as expected in an older population, the frequency of female lobsters with evidence of maturity was higher in WSER than in the fished areas of the Florida Keys. This research indicates that WSER is functioning as an NTMR, which has resulted in the development of a multiple-year-class lobster population and increased egg production of female lobsters. (C) 2013 Elsevier B.V. All rights reserved.
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 cold-temperature metrics. These impacts rival, in spatial extent and intensity, the impacts of the well-publicized warm-water bleaching events around the globe. The mean percent coral mortality recorded for all species and subregions was 11.5% in the 2010 winter, compared to 0.5% recorded in the previous five summers, including years like 2005 where warm-water bleaching was prevalent. Highest mean mortality (15%–39%) was documented for inshore habitats where temperatures were <11°C for prolonged periods. Increases in mortality from previous years were significant for 21 of 25 coral species, and were 1–2 orders of magnitude higher for most species. Conclusions/Significance The cold-water anomaly of January 2010 caused the worst coral mortality on record for the Florida Reef Tract, highlighting the potential catastrophic impacts that unusual but extreme climatic events can have on the persistence of coral reefs. Moreover, habitats and species most severely affected were those found in high-coral cover, inshore, shallow reef habitats previously considered the “oases” of the region, having escaped declining patterns observed for more offshore habitats. Thus, the 2010 cold-water anomaly not only caused widespread coral mortality but also reversed prior resistance and resilience patterns that will take decades to recover.
During an unusual cold‐water event in January 2010, reefs along the Florida Reef Tract suffered extensive coral mortality, especially in shallow reef habitats in close proximity to shore and with connections to coastal bays. The threatened staghorn coral, Acropora cervicornis, is the focus of propagation and restoration activities in Florida and one of the species that exhibited high susceptibility to low temperatures. Complete mortality of wild staghorn colonies was documented at 42.9% of donor sites surveyed after the cold event. Remarkably, 72.7% of sites with complete A. cervicornis mortality had fragments surviving within in situ coral nurseries. Thus, coral nurseries served as repositories for genetic material that would have otherwise been completely lost from donor sites. The location of the coral nurseries at deeper habitats and distanced from shallow nearshore habitats that experienced extreme temperature conditions buffered the impacts of the cold‐water event and preserved essential local genotypes for future Acropora restoration activities.
Accurate age estimates for Panulirus argus, the commercially important Caribbean spiny lobster, would greatly enhance life history and population analyses. Most age approximations of P. argus are based on size and growth data, but size is generally considered a poor proxy for age of crustaceans in the field because of numerous environmental, density-dependent, and fishery-related factors. An established technique for aging crustaceans, employing histologically determined lipofuscin content in the nervous system, was investigated using known-age lobsters reared in the laboratory at ambient temperatures. We verified the presence of lipofuscin in eyestalk neural tissue by using autofluorescence and Sudan black staining and described its distribution in cell cluster A of the hemiellipsoid body. Neurolipofuscin accumulated with age; the overall trend was linear with indications of seasonal oscillation, whereas growth began to approach an asymptote after 3 years. Differences in the neurolipofuscin concentrations in the two eyestalks from the same animal were statistically insignificant. There was also no difference in the neurolipofuscin concentrations of males and females of the same age. The present data suggest a maximum potential lifespan for P. argus of about 20 years. These results also suggest that the neurolipofuscin technique will be valuable for estimating age of wild-caught specimens of P. argus.
For many species of lobsters, size at sexual maturity varies across spatially separated populations. This is so for two populations of Caribbean spiny lobster, Panulirus argus, in southern Florida, where females from open-fishing areas around the Dry Tortugas mature at a larger size than females from open-fishing areas in the Florida Keys. Variations in onset of maturity between populations of lobsters have been attributed to different environmental conditions, lobster density, and/or fishing pressure. We used age as estimated by histologically expressed neurolipofuscin to examine differences in size at maturity in P. argus. Neurolipofuscin content measured in known-age, laboratory-reared animals in a previous study was used to estimate age in wild-caught P. argus. We show that lobsters from the Florida Keys are significantly smaller than lobsters of the same age from the Dry Tortugas. This difference in growth rates between lobsters from the two locations likely explains the differences in size at onset of maturation. High rates of injury from fishery practices in the Florida Keys and differential predation on slow-growing lobsters in the Dry Tortugas may account for these differences in growth rates. Additionally, we compared the ages of reproductive females collected from breeding grounds of the Florida Keys to same-sized nonreproductive females from an area in the Florida Keys where there was no evidence of breeding. We found that females possessing eggs early in the breeding season were significantly older than females that bore eggs later in the breeding season or that did not produce eggs. Older females also produced more clutches of eggs. Our research indicates that reproduction is related to age in P. argus. The intense fishery and the methods used to fish lobsters are the most likely causes of the reduction in spiny lobster population size structure and size at maturity.
Abstract Commercial fishers report finding their lobster traps often great distances from their original location following major hurricanes. But traps also move during lesser wind events, such as during winter cold fronts. To assess trap impact on coral communities following winter storms, lobster traps were placed in hardbottom and reef habitats commonly used by commercial fishers in the Florida Keys, United States. Trap movement, percentage benthic faunal cover, and benthic faunal damage were assessed after 26 wind events occuring over three winters. Traps moved when storms with sustained winds greater than 15 knots (27.8 km/h) persisted for more than 2 days. Winter storms above this threshold moved buoyed traps a mean (±SE) distance of 3.63 ± 0.62 m, 3.21 ± 0.36 m, and 0.73 ± 0.15 m per trap and affected a mean area of 4.66 ± 0.76 m2, 2.88 ± 0.29 m2, and 1.06 ± 0.17 m2, per trap at 4‐m, 8‐m, and 12‐m depths, respectively. Unbuoyed traps, simulating derelict traps, moved a mean distance of 0.43 ± 0.08 m and 0.44 ± 0.02 m, and affected a mean area of 0.77 ± 0.06 m2 and 0.90 ± 0.08 m2 per trap at 4‐m and 8‐m depths, respectively. Injuries caused by trap movement included scraped, fragmented, and dislodged sessile fauna, resulting in significant damage to stony coral, octocoral, and sponges. Overall, sessile fauna cover along the trap movement path was reduced from 45% to 31%, 51% to 41%, and 41% to 35% at the 4‐m, 8‐m, and 12‐m sites, respectively. Because of the large numbers of traps deployed and reported lost each season, damage to sessile fauna and loss of benthic faunal cover caused by traps needs to be considered to effectively protect coral reefs and manage essential fishery habitat in the future.