Human-induced salinity changes impact marine organisms and ecosystems.

Climate change is fundamentally altering marine and coastal ecosystems on a global scale. While the effects of ocean warming and acidification on ecology and ecosystem functions and services are being comprehensively researched, less attention is directed toward understanding the impacts of human-driven ocean salinity changes. The global water cycle operates through water fluxes expressed as precipitation, evaporation, and freshwater runoff from land. Changes to these in turn modulate ocean salinity and shape the marine and coastal environment by affecting ocean currents, stratification, oxygen saturation, and sea level rise. Besides the direct impact on ocean physical processes, salinity changes impact ocean biological functions with the ecophysiological consequences are being poorly understood. This is surprising as salinity changes may impact diversity, ecosystem and habitat structure loss, and community shifts including trophic cascades. Climate model future projections (of end of the century salinity changes) indicate magnitudes that lead to modification of open ocean plankton community structure and habitat suitability of coral reef communities. Such salinity changes are also capable of affecting the diversity and metabolic capacity of coastal microorganisms and impairing the photosynthetic capacity of (coastal and open ocean) phytoplankton, macroalgae, and seagrass, with downstream ramifications on global biogeochemical cycling. The scarcity of comprehensive salinity data in dynamic coastal regions warrants additional attention. Such datasets are crucial to quantify salinity-based ecosystem function relationships and project such changes that ultimately link into carbon sequestration and freshwater as well as food availability to human populations around the globe. It is critical to integrate vigorous high-quality salinity data with interacting key environmental parameters (e.g., temperature, nutrients, oxygen) for a comprehensive understanding of anthropogenically induced marine changes and its impact on human health and the global economy.

Going with the flow: How corals in high-flow environments can beat the heat.

Coral reefs are experiencing unprecedented declines in health on a global scale leading to severe reductions in coral cover. One major cause of this decline is increasing sea surface temperature. However, conspecific colonies separated by even small spatial distances appear to show varying responses to this global stressor. One factor contributing to differential responses to heat stress is variability in the coral's micro-environment, such as the amount of water flow a coral experiences. High flow provides corals with a variety of health benefits, including heat stress mitigation. Here, we investigate how water flow affects coral gene expression and provides resilience to increasing temperatures. We examined host and photosymbiont gene expression of Acropora cf. pulchra colonies in discrete in situ flow environments during a natural bleaching event. In addition, we conducted controlled ex situ tank experiments where we exposed A. cf. pulchra to different flow regimes and acute heat stress. Notably, we observed distinct flow-driven transcriptomic signatures related to energy expenditure, growth, heterotrophy and a healthy coral host-photosymbiont relationship. We also observed disparate transcriptomic responses during bleaching recovery between the high- and low-flow sites. Additionally, corals exposed to high flow showed "frontloading" of specific heat-stress-related genes such as heat shock proteins, antioxidant enzymes, genes involved in apoptosis regulation, innate immunity and cell adhesion. We posit that frontloading is a result of increased oxidative metabolism generated by the increased water movement. Gene frontloading may at least partially explain the observation that colonies in high-flow environments show higher survival and/or faster recovery in response to bleaching events.

Corals as canaries in the coalmine: Towards the incorporation of marine ecosystems into the 'One Health' concept.

'One World - One Health' is a developing concept which aims to explicitly incorporate linkages between the environment and human society into wildlife and human health care. Past work in the field has concentrated on aspects of disease, particularly emerging zoonoses, and focused on terrestrial systems. Here, we argue that marine environments are crucial components of the 'One World - One Health' framework, and that coral reefs are the epitome of its underlying philosophy. That is, they provide vast contributions to a wide range of ecosystem services with strong and direct links to human well-being. Further, the sensitivity of corals to climate change, and the current emergence of a wide range of diseases, make coral reefs ideal study systems to assess links, impacts, and feedback mechanisms that can affect human and ecosystem health. There are well established protocols for monitoring corals, as well as global networks of coral researchers, but there remain substantial challenges to understanding these complex systems, their health and links to provisioning of ecosystem services. We explore these challenges and conclude with a look at how developing technology offers potential ways of addressing them. We argue that a greater integration of coral reef research into the 'One World - One Health' framework will enrich our understanding of the many links within, and between, ecosystems and human society. This will ultimately support the development of measures for improving the health of both humans and the environment.

Reliable eDNA detection and quantification of the European weather loach (Misgurnus fossilis).

The European weather loach (Misgurnus fossilis) is a cryptic and poorly known fish species of high conservation concern. The species is experiencing dramatic population collapses across its native range to the point of regional extinction. Although environmental DNA (eDNA)-based approaches offer clear advantages over conventional field methods for monitoring rare and endangered species, accurate detection and quantification remain difficult and quality assessment is often poorly incorporated. In this study, we developed and validated a novel digital droplet PCR (ddPCR) eDNA-based method for reliable detection and quantification, which allows accurate monitoring of M. fossilis across a number of habitat types. A dilution experiment under laboratory conditions allowed the definition of the limit of detection (LOD) and the limit of quantification (LOQ), which were set at concentrations of 0.07 and 0.14 copies µl-1 , respectively. A series of aquarium experiments revealed a significant and positive relationship between the number of individuals and the eDNA concentration measured. During a 3 year survey (2017-2019), we assessed 96 locations for the presence of M. fossilis in Flanders (Belgium). eDNA analyses on these samples highlighted 45% positive detections of the species. On the basis of the eDNA concentration per litre of water, only 12 sites appeared to harbour relatively dense populations. The other 31 sites gave a relatively weak positive signal that was typically situated below the LOQ. Combining sample-specific estimates of effective DNA quantity (Qe ) and conventional field sampling, we concluded that each of these weak positive sites still likely harboured the species and therefore they do not represent false positives. Further, only seven of the classified negative samples warrant additional sampling as our analyses identified a substantial risk of false-negative detections (i.e., type II errors) at these locations. Finally, we illustrated that ddPCR outcompetes conventional qPCR analyses, especially when target DNA concentrations are critically low, which could be attributed to a reduced sensitivity of ddPCR to inhibition effects, higher sample concentrations being accommodated and higher sensitivity obtained.

Prospective assessment of Clostridioides (formerly Clostridium) difficile colonization and acquisition in hematopoietic stem cell transplant patients.

BACKGROUND: Patients undergoing hematopoietic stem cell transplant (HSCT) possess numerous risk factors for Clostridioides (formerly Clostridium) difficile infection (CDI) and experience a high rate of diarrhea. Colonization rates of Clostridium difficile vary greatly among subgroup analyses with recent studies demonstrating colonization rates in the blood and marrow transplant units up to nine times that of the general population. METHODS: The primary objectives of this study were to identify the rate of C difficile colonization and acquisition in HSCT patients admitted to the blood and marrow transplant unit. This was a prospective study that included all adult patients admitted for hematopoietic stem cell transplantation. Stool specimens were routinely collected on admission and weekly thereafter for a maximum of six samples per patient. RESULTS: Forty-two patients met inclusion criteria and had baseline samples available for analysis. The rate of C difficile colonization on admission was 24%, and an additional 9% of patients acquired the organism during admission. Twelve percent of patients developed CDI that was diagnosed clinically. Univariate analysis showed an increased risk of colonization for patients with three or more prior chemotherapy cycles. CONCLUSIONS: Given high colonization rates coupled with high risk of CDI in this population, providers must be judicious when testing for CDI and interpreting test results for HSCT patients.

Mass mortality hits gorgonian forests at Montecristo Island.

Mediterranean gorgonian forests are species-rich habitats, and like many other marine habitats they are threatened by anthropogenic disturbances and mass mortality events. These mortality events have often been linked to anomalies in the temperature profiles of the Mediterranean region. On 5 September 2017, colonies of the gorgonians Eunicella singularis and Eunicella cavolini exhibited rapid tissue loss, down to a depth of 30 m along the steep cliffs of Montecristo Island, Tuscan Archipelago National Park, Tyrrhenian Sea, Italy. Interestingly, Montecristo has previously been identified as a reference site for the ecological quality assessment of the western Mediterranean benthic assemblages on rocky bottoms. The observed mortality event occurred during a period of increased sea temperature. By utilising a combination of high-resolution oceanographic analysis, forecast models and citizen science initiatives, we propose that an early warning system for the concomitance of heat waves and mortality events can be put in place. A temperature-based coral disease surveillance tool could then be established for the entire Mediterranean Sea. Such a tool would allow for the timely study of mass mortality phenomena and the implementation of prompt mitigation and/or restoration initiatives. Finally, this specific mortality event, in a Marine Protected Area, offers a unique opportunity to monitor and assess the resilience of gorgonian populations and associated benthic assemblages in the absence of other, more directly, anthropogenic disturbances such as pollution and land runoff.

The role of viruses in coral health and disease.

Metagenomic and electron microscopy studies confirm that the coral microbiome contains a rich diversity and abundance of viruses. While there have been no definitive tests of disease causation by viruses in corals, viruses have been implicated as coral pathogens in a number of studies. Growing evidence also indicates that latent viral infections can compromise the algal symbionts under environmental stress and may be involved in the coral bleaching response. Conversely, bacteriophages and archaeal phage viruses are abundant in the microbiome of healthy corals and are likely to be involved in complex ecological networks, genetic material transfer and selective co-evolution within the surface mucus layers and tissues. The relative importance of viral control of bacterial and archaeal populations is unknown, but they are almost certain to be exerting some level of control on the composition and maintenance of the coral microbiome. While rapid leaps in the capability to detect viruses have been made due to advances in metagenomics and bioinformatics, these approaches need now to be integrated with in vitro culture and challenge experiments to assess the functional roles of viruses in health and disease, and it is imperative that interactions with other members of the coral microbiome are taken into account when assessing disease causation.

Prospective, Controlled Study of Acyclovir Pharmacokinetics in Obese Patients.

The current recommendations for intravenous (i.v.) acyclovir dosing in obese patients suggest using ideal body weight (IBW) rather than total body weight (TBW). To our knowledge, no pharmacokinetic analysis has validated this recommendation. This single-dose pharmacokinetic study was conducted in an inpatient oncology population. Enrollment was conducted by 1:1 matching of obese patients (>190% of IBW) to normal-weight patients (80 to 120% of IBW). All patients received a single dose of i.v. acyclovir, 5 mg/kg, infused over 60 min. Consistent with current recommendations, IBW was used for obese patients and TBW for normal-weight patients. Serial plasma concentrations were obtained and compared. Seven obese and seven normal-weight patients were enrolled, with mean body mass indexes of 45.0 and 22.5 kg/m(2), respectively. Systemic clearance was substantially higher in the obese than normal-weight patients (mean, 19.4 ± 5.3 versus 14.3 ± 5.4 liters/h; P = 0.047). Area under the concentration-time curve was lower in the obese patients (15.2 ± 2.9 versus 24.0 ± 9.4 mg · h/liter; P = 0.011), as was maximum concentration (5.8 ± 0.9 versus 8.2 ± 1.3 mg/liter; P = 0.031). Utilization of IBW for dose calculation of i.v. acyclovir in obese patients leads to lower systemic exposure than dosing by TBW in normal-weight patients. While not directly evaluated in this study, utilization of an adjusted body weight for dose determination appears to more closely approximate the exposure seen in normal-weight patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT01714180.).

Metabolome-mediated biocryomorphic evolution promotes carbon fixation in Greenlandic cryoconite holes.

Microbial photoautotrophs on glaciers engineer the formation of granular microbial-mineral aggregates termed cryoconite which accelerate ice melt, creating quasi-cylindrical pits called 'cryoconite holes'. These act as biogeochemical reactors on the ice surface and provide habitats for remarkably active and diverse microbiota. Evolution of cryoconite holes towards an equilibrium depth is well known, yet interactions between microbial activity and hole morphology are currently weakly addressed. Here, we experimentally perturbed the depths and diameters of cryoconite holes on the Greenland Ice Sheet. Cryoconite holes responded by sensitively adjusting their shapes in three dimensions ('biocryomorphic evolution') thus maintaining favourable conditions for net autotrophy at the hole floors. Non-targeted metabolomics reveals concomitant shifts in cyclic AMP and fucose metabolism consistent with phototaxis and extracellular polymer synthesis indicating metabolomic-level granular changes in response to perturbation. We present a conceptual model explaining this process and suggest that it results in remarkably robust net autotrophy on the Greenland Ice Sheet. We also describe observations of cryoconite migrating away from shade, implying a degree of self-regulation of carbon budgets over mesoscales. Since cryoconite is a microbe-mineral aggregate, it appears that microbial processes themselves form and maintain stable autotrophic habitats on the surface of the Greenland ice sheet.

Reprint of 'Diseases in marine invertebrates associated with mariculture and commercial fisheries'.

Diseases in marine invertebrates are increasing in both frequency and intensity around the globe. Diseases in individuals which offer some commercial value are often well documented and subsequently well studied in comparison to those wild groups offering little commercial gain. This is particularly the case with those associated with mariculture or the commercial fisheries. Specifically, these include many Holothuroidea, and numerous crustacea and mollusca species. Pathogens/parasites consisting of both prokaryotes and eukaryotes from all groups have been associated with diseases from such organisms, including bacteria, viruses, fungi and protozoa. Viral pathogens in particular, appear to be an increasingly important group and research into this group will likely highlight a larger number of diseases and pathogens being described in the near future. Interestingly, although there are countless examples of the spread of disease usually associated with transportation of specific infected hosts for development of aquaculture practices, this process appears to be continuing with no real sign of effective management and mitigation strategies being implicated. Notably, even in well developed countries such as the UK and the US, even though live animal trade may be well managed, the transport of frozen food appears to be less well so and as evidence suggests, even these to have the potential to transmit pathogens when used as a food source for example.

White syndrome in Acropora muricata: nonspecific bacterial infection and ciliate histophagy.

Selective antibiotic treatment of white syndrome (WS)-affected corals (Acropora muricata) from Fiji was used to identify 3 potential bacterial pathogens of the disease. Interestingly, the suite of bacterial associates of the disease was different to that recently identified using identical primer sets for WS on the GBR and in the Solomon Islands. In addition to the three bacterial pathogenic candidates and as previously shown for WS and more recently for white band disease (WBD) in the Caribbean, all samples of the disease were specifically associated with the histophagous ciliate Philaster lucinda. From the pattern of disease progression and histopathology in relation to the selective elimination of microbial groups, we conclude that these 'white' diseases are a result of a nonspecific bacterial infection and a 'secondary' infection by the P. lucinda ciliate. Although we have not observed the initiation of infection, a nonspecific, multispecies bacterial infection appears to be a corequirement for WS lesion progression and we hypothesize that the bacterial infection occurs initially, weakening the defences of the host to predation by the ciliates. Such ciliate histophagy gives rise to the characteristic white band of denuded coral skeleton that gives these diseases their names. The characteristics of the microbial communities of WBD and WS appear identical, and since the bacterial associates of WS vary geographically (and/or temporally), there appears to be no logical distinction between WS in the Indo-Pacific and WBD in the Caribbean.

Identification of a bacterial pathogen associated with Porites white patch syndrome in the Western Indian Ocean.

Porites white patch syndrome (PWPS) is a coral disease recently described in the Western Indian Ocean. This study aimed to isolate and identify potential pathogens associated with PWPS utilizing both culture and nonculture screening techniques and inoculation trials. A total of 14 bacterial strains (those dominant in disease lesions, absent or rare in healthy tissues and considered potential pathogens in a previous study) were cultured and used to experimentally inoculate otherwise healthy individuals in an attempt to fulfil Henle-Koch's postulates. However, only one (P180R), identified as closely related (99-100% sequence identity based on 1.4 kb 16S RNA sequence) to Vibrio tubiashii, elicited signs of disease in tank experiments. Following experimental infection (which resulted in a 90% infection rate), the pathogen was also successfully re-isolated from the diseased tissues and re-inoculated in healthy corals colonies, therefore fulfilling the final stages of Henle-Koch's postulates. Finally, we report that PWPS appears to be a temperature-dependent disease, with significantly higher tissue loss (anova: d.f. = 2, F = 39.77, P < 0.01) occurring at 30 °C [1.45 ± 0.85 cm(2) per day (mean ± SE)] compared to ambient temperatures of 28 and 26 °C (0.73 ± 0.80 cm(2) per day (mean ± SE) and 0.51 ± 0.50 cm(2) per day (mean ± SE), respectively).

Diseases in marine invertebrates associated with mariculture and commercial fisheries.

Diseases in marine invertebrates are increasing in both frequency and intensity around the globe. Diseases in individuals which offer some commercial value are often well documented and subsequently well studied in comparison to those wild groups offering little commercial gain. This is particularly the case with those associated with mariculture or the commercial fisheries. Specifically, these include many Holothuroidea, and numerous crustacea and mollusca species. Pathogens/parasites consisting of both prokaryotes and eukaryotes from all groups have been associated with diseases from such organisms, including bacteria, viruses, fungi and protozoa. Viral pathogens in particular, appear to be an increasingly important group and research into this group will likely highlight a larger number of diseases and pathogens being described in the near future. Interestingly, although there are countless examples of the spread of disease usually associated with transportation of specific infected hosts for development of aquaculture practices, this process appears to be continuing with no real sign of effective management and mitigation strategies being implicated. Notably, even in well developed countries such as the UK and the US, even though live animal trade may be well managed, the transport of frozen food appears to be less well so and as evidence suggests, even these to have the potential to transmit pathogens when used as a food source for example.

Reduction in time to first action as a result of electronic alerts for early sepsis recognition.

The use of an electronic alerting system to notify practitioners when a patient meets modified systemic inflammatory response syndrome criteria was hypothesized to decrease the time to goal-directed therapy initiation. This retrospective, before-and-after study analyzed adult patients identified with sepsis or septic shock and compared 30 patients prior to electronic alert initiation with 30 patients after initiation. The primary endpoint was time to any sepsis-related intervention. Patients in the post-alert group demonstrated a shorter time to any sepsis-related intervention by a median difference of 3.5 hours (P = .02). Using computerized medical records to create an electronic alerting system has the potential to identify high-risk patients and initiate interventions sooner. At our institution, the creation of an alerting system with real-time data has decreased the time it takes to begin sepsis workup and treatment.

Hemodynamic comparison of mitral valve repair: techniques for a flail anterior leaflet.

BACKGROUND AND AIM OF THE STUDY: Anterior leaflet flail resulting from elongated or ruptured marginal chordae is frequently diagnosed among adults, and is amenable to surgical repair. The study aim was to investigate the efficacy of three surgical techniques, namely neochordoplasty, limited triangular resection and edge-to-edge repair, to correct anterior leaflet flail in an in-vitro experimental model. METHODS: Seven porcine mitral valves were evaluated in a pulsatile heart simulator before surgical manipulation, after anterior marginal chordae transection, and with each surgical repair. Marginal chordal transection induced leaflet flail with moderate mitral regurgitation (MR). Following the confirmation of MR via direct flow measurements, it was corrected by three repairs: neochordoplasty with ePTFE sutures, limited triangular resection, and edge-to-edge repair. The post-repair valve hemodynamics were quantified under pulsatile conditions of 120 mmHg peak transmitral pressure and 5 l/min cardiac output at 70 beats/min. Hemodynamic, geometric and echocardiographic indices were also measured. RESULTS: Transecting the marginal chordae induced A2 prolapse and produced the regurgitant fraction to 18.7 +/- 10.2%. Surgical repair effectively reduced the regurgitant fraction to 6.9 +/- 6.3% (p = 0.019 to prolapse, p = 0.0117 to baseline) with neochordae, to 5.8 +/- 7.0% (p = 0.03 to prolapse, p = 0.0378 to baseline) with triangular resection, and to 13.3 +/- 10.2% (p = 0.2091 to prolapse, p = 0.0045 to baseline) with edge-to-edge repair. Remnant regurgitation was largest with edge-to-edge repair compared to limited leaflet resection and neochordoplasty, though central leaflet coaptation was restored equally by the three repairs, with mild systolic leaflet restriction after repair. CONCLUSION: Anterior leaflet repair and a reduction in MR is achievable with the three techniques, although neochordoplasty and triangular resection proved superior to edge-to-edge repair in eliminating MR.

Cocoa and Polyphenol-Rich Cocoa Fractions Fail to Improve Acute Colonic Inflammation in Dextran Sulfate Sodium-Treated Mice.

SCOPE: A study is conducted to determine the anti-inflammatory effects of cocoa and polyphenol-rich cocoa fractions in the dextran sulfate sodium (DSS)-induced mouse model of acute colonic inflammation. METHODS AND RESULTS: Male C57BL/6J mice are treated with dietary cocoa powder, an extractable cocoa polyphenol fraction, or a non-extractable cocoa polyphenol fraction for 2 weeks prior to treatment with 2.5% DSS in the drinking water for 7 days to induce colonic inflammation. Cocoa treatment continues during the DSS period. Cocoa and/or cocoa fractions exacerbate DSS-induced weight loss and fail to mitigate DSS-induced colon shortening but do improve splenomegaly. Cocoa/cocoa fraction treatment fails to mitigate DSS-induced mRNA and protein markers of inflammation. Principal component analysis shows overlap between cocoa or cocoa fraction-treated mice and DSS-induced controls, but separation from mice not treated with DSS. CONCLUSION: The results suggest cocoa and cocoa polyphenols may not be useful in mitigating acute colonic inflammation.

Ready or Not: A Crossover Study of (Un)graded Individual Readiness Assurance Tests in Team-Based Learning.

OBJECTIVE: This study aimed to measure the effects of graded vs ungraded individual readiness assurance tests (iRATs) on the students' test scores and achievement goals in a team-based learning classroom. METHODS: A 2 × 2 crossover study was conducted in a required second-year pharmacotherapy course. Teams 1 to 8 were assigned to a UG iRAT during the first half of the course, followed by a G iRAT the second half of the course (G/UG group). Teams 9 to 16 were assigned to the opposite grading sequence (ie, UG/G). A multivariate analysis of variance was used to analyze the differences in test scores, as measured using iRAT and examination scores. A separate multivariate analysis of variance was used to examine the differences in achievement goals. RESULTS: There was a significant difference in test scores based on the iRAT grading condition. Individual readiness assurance tests were higher in the G condition (72.51% vs 67.99%); however, the examination scores were similar in the G and UG conditions (81.07% vs 80.32%). There was no statistically significant difference in the achievement goals based on the iRAT grading condition. CONCLUSION: In a required second-year pharmacotherapy course that uses team-based learning, student performance on the iRAT was modestly lower in the UG iRAT condition; however, the students' examination scores were unchanged. Achievement goals were unchanged based on the iRAT grading condition.

Horizon scanning the application of probiotics for wildlife.

The provision of probiotics benefits the health of a wide range of organisms, from humans to animals and plants. Probiotics can enhance stress resilience of endangered organisms, many of which are critically threatened by anthropogenic impacts. The use of so-called 'probiotics for wildlife' is a nascent application, and the field needs to reflect on standards for its development, testing, validation, risk assessment, and deployment. Here, we identify the main challenges of this emerging intervention and provide a roadmap to validate the effectiveness of wildlife probiotics. We cover the essential use of inert negative controls in trials and the investigation of the probiotic mechanisms of action. We also suggest alternative microbial therapies that could be tested in parallel with the probiotic application. Our recommendations align approaches used for humans, aquaculture, and plants to the emerging concept and use of probiotics for wildlife.

Yeast two-hybrid junk sequences contain selected linear motifs.

Yeast two-hybrid (Y2H) screenings result in identification of many out-of-frame (OOF) clones that code for short (2-100 amino acids) peptides with no sequence homology to known proteins. We hypothesize that these peptides can reveal common short linear motifs (SLiMs) responsible for their selection. We present a new protocol to address this issue, using an existing SLIM detector (TEIRESIAS) as a base method, and applying filters derived from a mathematical model of SLiM selection in OOF clones. The model allows for initial analysis of likely presence of SLiM(s) in a collection of OOF sequences, assisting investigators with the decision of whether to invest resources in further analysis. If SLiM presence is detected, it estimates the length and number of amino acid residues involved in binding specificity and the amount of noise in the Y2H screen. We demonstrate that our model can double the prediction sensitivity of TEIRESIAS and improve its specificity from 0 to 1.0 on simulated data and apply the model to seven sets of experimentally derived OOF clones. Finally, we experimentally validate one SLiM found by our method, demonstrating its utility.

The Effect of Pollen on Coral Health.

Corals are facing a range of threats, including rises in sea surface temperature and ocean acidification. Some now argue that keeping corals ex situ (in aquaria), may be not only important but necessary to prevent local extinction, for example in the Florida Reef Tract. Such collections or are already becoming common place, especially in the Caribbean, and may act as an ark, preserving and growing rare or endangered species in years to come. However, corals housed in aquaria face their own unique set of threats. For example, hobbyists (who have housed corals for decades) have noticed seasonal mortality is commonplace, incidentally following months of peak pollen production. So, could corals suffer from hay fever? If so, what does the future hold? In short, the answer to the first question is simple, and it is no, corals cannot suffer from hay fever, primarily because corals lack an adaptive immune system, which is necessary for the diagnosis of such an allergy. However, the threat from pollen could still be real. In this review, we explore how such seasonal mortality could play out. We explore increases in reactive oxygen species, the role of additional nutrients and how the microbiome of the pollen may introduce disease or cause dysbiosis in the holobiont.