Live coral cover has declined precipitously on Caribbean reefs in recent decades. Acropora cervicornis coral has been particularly decimated, and few Western Atlantic Acropora spp. refugia remain. ...Coral Gardens, Belize, was identified in 2020 as a long-term refugium for this species. This study assesses changes in live A. cervicornis coral abundance over time at Coral Gardens to monitor the stability of A. cervicornis corals, and to explore potential threats to this important refugium. Live coral cover was documented annually from 2012-2019 along five permanent transects. In situ sea-surface temperature data were collected at Coral Gardens throughout the study period and compared with calibrated satellite data to calculate Maximum Monthly Mean (MMM) temperatures and Degree Heating Weeks (DHW). Data on bathymetry, sediment, substrate, herbivore abundance, and macroalgal abundance were collected in 2014 and 2019 to assess potential threats to Coral Gardens. Live coral cover declined at all five transect sites over the study period. The greatest loss of live coral occurred between 2016 and 2017, coincident with the earliest and highest maximum average temperatures recorded at the study site, and the passage of a hurricane in 2016. Structural storm damage was not observed at Coral Gardens, though live coral cover declined after the passage of the storm. Uranium-thorium (230Th) dating of 26 dead in situ fragments of A. cervicornis collected in 2015 from Coral Gardens revealed no correlation between coral mortality and tropical storms and hurricanes in the recent past. Our data suggest that several other common drivers for coral decline (i.e. herbivory, predation, sedimentation, pH) may likely be ruled out for Coral Gardens. At the end of the study period, Coral Gardens satisfied most criteria for refugium status. However, the early onset, higher mean, and longer duration of above-average temperatures, as well as intermittent temperature anomalies likely played a critical role in the stability of this refugium. We suggest that temperature stress in 2016 and perhaps 2015 may have increased coral tissue vulnerability at Coral Gardens to a passing hurricane, threatening the status of this unique refugium.
Caribbean Acropora spp. corals have undergone a decline in cover since the second half of the twentieth century. Loss of these architecturally complex and fast-growing corals has resulted in ...significant, cascading changes to the character, diversity, and available eco-spaces of Caribbean reefs. Few thriving Acropora spp. populations exist today in the Caribbean and western North Atlantic seas, and our limited ability to access data from reefs assessed via long-term monitoring efforts means that reef scientists are challenged to determine resilience and longevity of existing Acropora spp. reefs. Here we used multiple dating methods to measure reef longevity and determine whether Coral Gardens Reef, Belize, is a refuge for Acropora cervicornis against the backdrop of wider Caribbean decline. We used a new genetic-aging technique to identify sample sites, and radiocarbon and high-precision uranium-thorium (U-Th) dating techniques to test whether one of the largest populations of extant A. cervicornis in the western Caribbean is newly established after the 1980s, or represents a longer-lived, stable population. We did so with respect for ethical sampling of a threatened species. Our data show corals ranging in age from 1910 (.sup.14 C) or 1915 (.sup.230 Th) to at least November 2019. While we cannot exclude the possibility of short gaps in the residence of A. cervicornis earlier in the record, the data show consistent and sustained living coral throughout the 1980s and up to at least 2019. We suggest that Coral Gardens has served as a refuge for A. cervicornis and that identifying other, similar sites may be critical to efforts to grow, preserve, conserve, and seed besieged Caribbean reefs.
New δ13C data are presented from 10 coral skeletons collected from Florida and elsewhere in the Caribbean (Dominica, Dominican Republic, Puerto Rico, and Belize). These corals range from 96 to 200 ...years in age and were collected between 1976 and 2002. The change in the δ13C of the skeletons from these corals between 1900 and 1990 has been compared with 27 other published coral records from the Atlantic, Pacific, and Indian Oceans. The new data presented here make possible, for the first time, a global comparison of rates of change in the δ13C value of coral skeletons. Of these records, 64% show a statistically significant (p < 0.05) decrease in δ13C towards the modern day (23 out of 37). This decrease is attributable to the addition of anthropogenically derived CO2 (13C Suess effect) to the atmosphere. Between 1900 and 1990, the average rate of change of the δ13C in all the coral skeletons living under open oceanic conditions is approximately −0.01‰ yr−1. In the Atlantic Ocean the magnitude of the decrease since 1960,−0.019 yr−1 ±0.015‰, is essentially the same as the decrease in the δ13C of atmospheric CO2 and the δ13C of the oceanic dissolved inorganic carbon (−0.023 to −0.029‰ yr−1), while in the Pacific and Indian Oceans the rate is more variable and significantly reduced (−0.007‰ yr−1 ±0.013). These data strongly support the notion that (i) the δ13C of the atmosphere controls ambient δ13C of the dissolved inorganic carbon which in turn is reflected in the coral skeletons, (ii) the rate of decline in the coral skeletons is higher in oceans with a greater anthropogenic CO2 inventory in the surface oceans, (iii) the rate of δ13C decline is accelerating. Superimposed on these secular variations are controls on the δ13C in the skeleton governed by growth rate, insolation, and local water masses.
Acropora cervicornis
and
A. palmata
have experienced substantial losses in coral cover throughout the Caribbean, but their hybrid (
A. prolifera
) appears to be increasing at some sites. The shifts ...in relative abundance could result from hybridization with subsequent asexual fragmentation, recent increased hybridization, or a disproportionate loss in the parental species. Here, acroporid taxa from three U.S. Virgin Islands sites were genotyped revealing 35 hybrid genotypes, suggesting multiple hybridization events. Genotypic richness in
A. cervicornis
(0.62),
A. prolifera
(0.64), and
A. palmata
(0.68) was not significantly different across sites. To further explore acroporid dynamics at these sites, we analyzed existing photo transects from 2009 to 2017 to reveal significant losses of
A. cervicornis
but stable hybrid percent cover. High genotypic richness and stable populations suggest acroporid hybrids may become the primary shallow reef-builders in some locations previously occupied by the parental species.
Foundation species such as redwoods, seagrasses and corals are often long‐lived and clonal. Genets may consist of hundreds of members (ramets) and originated hundreds to thousands of years ago. As ...climate change and other stressors exert selection pressure on species, the demography of populations changes. Yet, because size does not indicate age in clonal organisms, demographic models are missing data necessary to predict the resilience of many foundation species. Here, we correlate somatic mutations with genet age of corals and provide the first, preliminary estimates of genet age in a colonial animal. We observed somatic mutations at five microsatellite loci in rangewide samples of the endangered coral, Acropora palmata (n = 3352). Colonies harboured 342 unique mutations in 147 genets. Genet age ranged from 30 to 838 years assuming a mutation rate of 1.195−04 per locus per year based on colony growth rates and 236 to 6500 years assuming a mutation rate of 1.542−05 per locus per year based on sea level changes to habitat availability. Long‐lived A. palmata genets imply a large capacity to tolerate past environmental change, and yet recent mass mortality events in A. palmata suggest that capacity is now being frequently exceeded.
The corals
Acropora palmata
and
A. cervicornis
are important Caribbean reef-builders that have faced significant mortality in recent decades. While many studies have focused on the recent demise of ...these species, data from areas where
Acropora
spp. have continued to thrive are limited. Understanding the genetic diversity, recruitment, and temporal continuity of healthy populations of these threatened
Acropora
spp. and the hybrid they form (“
Acropora prolifera
”) may provide insights into the demographic processes governing them. We studied three reef sites with abundant
A. cervicornis
,
A. palmata
, and hybrid
Acropora
populations offshore of Ambergris Caye, Belize at Coral Gardens, Manatee Channel, and Rocky Point. Samples were collected from all three
Acropora
taxa. We used microsatellite markers to determine: (1) genotypic diversity; (2) dominant reproductive mode supporting local recruitment; (3) minimum and maximum genet age estimates for all three acroporids; and (4) the history of hybrid colonization at these sites. We found that
Acropora
populations were highly clonal with local recruitment primarily occurring through asexual fragmentation. We also estimated the ages of 10
Acropora
genets using recent methodology based on somatic mutation rates from genetic data. Results indicate minimum ages of 62–409 yr for
A. cervicornis,
187–561 yr for
A. palmata
, and 156–281 yr for the
Acropora
hybrids at these sites. Our data indicate that existing
A. cervicornis, A. palmata,
and
Acropora
hybrid genets persisted during the 1980s Caribbean-wide
Acropora
spp. collapse, suggesting that these sites have been a refuge for Caribbean
Acropora
corals. Additionally, our data suggest that formation of extant hybrid
Acropora
genets pre-dates the widespread collapse of the parent taxa.
The major difficulties with diabetic treatment root in self-management, patient tolerance, and compliance with treatments. A new medication class, glucagon-like peptide-1 (GLP-1) analogs, has ...evidence of combining weight loss and glucose control with minimal side effects and cardiovascular benefit. For years, the standard therapy was adding insulin for patients with suboptimal response to oral agents. This method takes advanced education and lifestyle modifications to elicit adequate response. New injectable options allow initiation of a simpler regimen. The focus of this systematic review is to evaluate available evidence about the effect of GLP-1 analog therapy on patient compliance and quality of life.
Live coral cover has declined precipitously on Caribbean reefs in recent decades. Acropora cervicornis coral has been particularly decimated, and few Western Atlantic Acropora spp. refugia remain. ...Coral Gardens, Belize, was identified in 2020 as a long-term refugium for this species. This study assesses changes in live A. cervicornis coral abundance over time at Coral Gardens to monitor the stability of A. cervicornis corals, and to explore potential threats to this important refugium. Live coral cover was documented annually from 2012–2019 along five permanent transects. In situ sea-surface temperature data were collected at Coral Gardens throughout the study period and compared with calibrated satellite data to calculate Maximum Monthly Mean (MMM) temperatures and Degree Heating Weeks (DHW). Data on bathymetry, sediment, substrate, herbivore abundance, and macroalgal abundance were collected in 2014 and 2019 to assess potential threats to Coral Gardens. Live coral cover declined at all five transect sites over the study period. The greatest loss of live coral occurred between 2016 and 2017, coincident with the earliest and highest maximum average temperatures recorded at the study site, and the passage of a hurricane in 2016. Structural storm damage was not observed at Coral Gardens, though live coral cover declined after the passage of the storm. Uranium-thorium (230Th) dating of 26 dead in situ fragments of A. cervicornis collected in 2015 from Coral Gardens revealed no correlation between coral mortality and tropical storms and hurricanes in the recent past. Our data suggest that several other common drivers for coral decline (i.e. herbivory, predation, sedimentation, pH) may likely be ruled out for Coral Gardens. At the end of the study period, Coral Gardens satisfied most criteria for refugium status. However, the early onset, higher mean, and longer duration of above-average temperatures, as well as intermittent temperature anomalies likely played a critical role in the stability of this refugium. We suggest that temperature stress in 2016 and perhaps 2015 may have increased coral tissue vulnerability at Coral Gardens to a passing hurricane, threatening the status of this unique refugium.
To compare 2.0 mg ranibizumab (RBZ) injections with 0.5 mg RBZ for eyes with center-involved diabetic macular edema (DME).
Randomized, controlled, double-masked (to the dose), interventional, ...multicenter clinical trial.
A total of 152 patients (152 eyes) with DME.
Eligible eyes were randomized in a 1:1 ratio to 0.5 mg (n = 77) or 2.0 mg (n = 75) RBZ. Study eyes received 6 monthly mandatory injections followed by as-needed injections until month 24.
The primary efficacy end point of the study was mean change in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) at month 6. Secondary outcomes included the mean change in BCVA and CFT at month 24, and incidence and severity of systemic and ocular adverse events through month 24.
A total of 152 eyes were randomized in the study. At month 24, the mean improvement from baseline BCVA was +11.06 letters in the 0.5 mg RBZ group (n = 59) and +6.78 letters in the 2.0 mg RBZ group (n = 54) (P = 0.02). The mean numbers of RBZ injections through month 24 were 18.4 and 17.3 in the 0.5 mg and 2.0 mg RBZ groups, respectively (P = 0.08). The mean change in CFT was -192.53 μm in the 0.5 mg RBZ group and -170.64 μm in the 2.0 mg RBZ group (P = 0.41). By month 24, 3 deaths had occurred in the 0.5 mg RBZ group and 3 deaths had occurred in the 2.0 mg RBZ group; 5 of these 6 deaths occurred secondary to cardiovascular causes, and 1 death occurred as the result of severe pneumonia. All 5 patients with a cardiovascular cause of death had a history of coronary heart disease.
At month 24, there were significant visual and anatomic improvements in both groups, with subjects in the 0.5 mg RBZ group gaining more vision. Visual and anatomic gains achieved at month 6 were largely maintained through month 24. No new safety events were identified. In this study population, 2.0 mg RBZ does not appear to provide additional benefit over 0.5 mg RBZ.
Caribbean Acropora spp. corals have undergone a decline in cover since the second half of the twentieth century. Loss of these architecturally complex and fast-growing corals has resulted in ...significant, cascading changes to the character, diversity, and available eco-spaces of Caribbean reefs. Few thriving Acropora spp. populations exist today in the Caribbean and western North Atlantic seas, and our limited ability to access data from reefs assessed via long-term monitoring efforts means that reef scientists are challenged to determine resilience and longevity of existing Acropora spp. reefs. Here we used multiple dating methods to measure reef longevity and determine whether Coral Gardens Reef, Belize, is a refuge for Acropora cervicornis against the backdrop of wider Caribbean decline. We used a new genetic-aging technique to identify sample sites, and radiocarbon and high-precision uranium-thorium (U-Th) dating techniques to test whether one of the largest populations of extant A. cervicornis in the western Caribbean is newly established after the 1980s, or represents a longer-lived, stable population. We did so with respect for ethical sampling of a threatened species. Our data show corals ranging in age from 1910 (14C) or 1915 (230Th) to at least November 2019. While we cannot exclude the possibility of short gaps in the residence of A. cervicornis earlier in the record, the data show consistent and sustained living coral throughout the 1980s and up to at least 2019. We suggest that Coral Gardens has served as a refuge for A. cervicornis and that identifying other, similar sites may be critical to efforts to grow, preserve, conserve, and seed besieged Caribbean reefs.
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