Environmental DNA (eDNA) metabarcoding has transformed spatial biodiversity assessments, although its capacity to distinguish persistent from dynamic elements of ecological communities through time remains largely unknown. We asked to what degree eDNA signals on coral reefs are temporally consistent representations of community composition or are dominated by short-lived fluctuations, and how this distinction influences interpretation of biodiversity data through time. We assessed these questions in Hawaiian coral reef communities over 2 years, replicated with two universal eDNA markers (nuclear 18S and mitochondrial COI). Our analyses revealed that community composition differed strongly among sites, while within-site assemblages were relatively stable through time. Despite high per-sample richness, a smaller core of reef taxa, including sponges, annelids, and red algae, were consistently detected across sites and sampling dates, indicating that eDNA reliably captures dominant community members despite natural variability in DNA production, degradation, and transport. This core assemblage anchored site distinctiveness, while temporal variation was driven by the appearance and disappearance of a comparatively large number of rare or transient taxa. This temporal variation was detectable but smaller in magnitude and associated with environmental factors such as wind, waves, tides, and lunar cycles, highlighting their role in modulating patterns of taxon detectability. Overall, eDNA signals primarily reflect underlying spatial heterogeneity rather than transient fluctuations, demonstrating that routine eDNA surveys can robustly track community dynamics across space and time. By identifying the ecological and environmental correlates of eDNA signal variation, our study demonstrates that spatially structured community differences dominate eDNA profiles on coral reefs and allow persistent biodiversity patterns to be distinguished from short-term temporal variability. Although eDNA integrates biological and physical processes distinct from direct observation, the resulting patterns are highly similar to those generated by visual reef surveys, in which strong site-level differentiation is maintained by a small set of persistent taxa, while a large pool of rare species contributes to transient variability. The convergence between molecular and observational approaches links eDNA-derived biodiversity patterns to underlying community assembly processes and enhances ecological interpretation of molecular data in tropical reef ecosystems.

Background:Environmental DNA (eDNA) has transformed biodiversity monitoring, but its application for long-term ecological assessment remains limited by uncertainty in the temporal stability and consistency of eDNA signals, as well as by specialized workflows that limit accessibility for community-led programs. Expanding participation in biomonitoring requires approaches that are both logistically feasible and scientifically robust. Here, we evaluated eDNA tools for coral reef monitoring in Hawai i by comparing (1) coral-specific genetic markers for tracking benthic community dynamics through time, and (2) passive eDNA samplers (PEDS) as a low-effort alternative to active filtration. This research was conducted with local stewardship organizations on O ahu, Hawai i, positioning eDNA as a complementary tool to place-based ecological knowledge that can inform conservation strategies and enhance ecological monitoring. Results:Across five broad taxonomic markers, we detected diverse reef communities spanning 17 phyla, with consistent regional differences in community composition, including clear differentiation in algal assemblages. Passive samplers recovered comparable taxonomic richness to active filtration when sampling effort was standardized, but showed greater variability among replicates, whereas active methods more consistently detected rare and transient taxa. Despite this, passive samplers captured similar broad-scale community patterns with reduced logistical effort. For coral monitoring, all three markers (12S, 16S, ITS2) showed strong correlations with visual cover and detected more genera than visual surveys. Among these, 16S showed the strongest and most consistent performance across temporal replicates, while ITS2 showed greater temporal variability. Conclusions:Accessible eDNA approaches can generate ecologically meaningful data for reef monitoring when matched to specific objectives. Passive samplers provide a scalable, low-barrier option for widespread community biomonitoring, while active filtration remains important for detecting rare taxa. A multimarker approach enabled detection of native, endemic, and nuisance taxa, offering an ecosystem-level perspective for management. Given the relatively slow pace of change in coral assemblages, periodic eDNA surveys may provide a useful and practical longer-term complement to rapid visual assessments of coral cover. Integrating these tools with local stewardship efforts can expand participation in eDNA biomonitoring while supporting conservation in urbanized, culturally significant reef systems.

Distinguishing native from non-native species is complicated by cryptogenic taxa, whose native or non-native status remains uncertain, and cryptic species, which are genetically distinct yet morphologically indistinguishable taxa. These challenges can intersect when molecular tools uncover hidden diversity and inadvertently confound efforts to trace species origins. In marine systems, environmental DNA (eDNA) has transformed biodiversity monitoring, but reliance on short, single-locus markers makes it vulnerable to false-positive detections of cryptic sibling species with markers lacking sufficient taxonomic resolution. Extending previous investigations into the occurrence and spread of Chondria tumulosa, we conducted eDNA screening in multiple island regions to evaluate possible range connectivity. A quantitative polymerase chain reaction assay developed from a Northwestern Hawaiian Islands barcode produced a novel eDNA detection at Majuro in the Marshall Islands. However, subsequent multilocus sequencing (cytochrome c oxidase subunit I, ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit, 18S small subunit ribosomal RNA, Universal Plastid Amplicon) of collected material revealed consistent sequence divergence, suggesting independently evolving lineages. Our findings suggest that the Hawaiian C. tumulosa and the Majuro lineage are sibling taxa with a broader Pacific distribution, shaped by historical allopatry and possible human-mediated dispersal. This case highlights the need to confirm eDNA matches using informative multilocus barcoding regions and emphasizes the need to integrate genetic, morphological and ecological data to resolve the identity and origins of cryptogenic taxa.

Early detection of nuisance species is crucial for managing threatened ecosystems and preventing widespread establishment. Environmental DNA (eDNA) data can increase the sensitivity of biomonitoring programs, often at minimal cost and effort. However, eDNA analyses are prone to errors that can complicate their use in management frameworks. To address this, eDNA studies must consider imperfect detections and estimate error rates. Detecting nuisance species at low abundances with minimal uncertainty is vital for successful containment and eradication. We developed a novel eDNA assay to detect a nuisance marine macroalga across its colonization front using surface seawater samples from Papahānaumokuākea Marine National Monument (PMNM), one of the world's largest marine reserves. Chondria tumulosa is a cryptogenic red alga with invasive traits, forming dense mats that overgrow coral reefs and smother native flora and fauna in PMNM. We verified the eDNA assay using site-occupancy detection modeling from quantitative polymerase chain reaction (qPCR) data, calibrated with visual estimates of benthic cover of C. tumulosa that ranged from < 1% to 95%. Results were subsequently validated with high-throughput sequencing of amplified eDNA and negative control samples. Overall, the probability of detecting C. tumulosa at occupied sites was at least 92% when multiple qPCR replicates were positive. False-positive rates were 3% or less and false-negative errors were 11% or less. The assay proved effective for routine monitoring at shallow sites (less than 10 m), even when C. tumulosa abundance was below 1%. Successful implementation of eDNA tools in conservation decision-making requires balancing uncertainties in both visual and molecular detection methods. Our results and modeling demonstrated the assay's high sensitivity to C. tumulosa, and we outline steps to infer ecological presence-absence from molecular data. This reliable, cost-effective tool enhances the detection of low-abundance species, and supports timely management interventions.

The cryptogenic marine red alga Chondria tumulosa was first observed in 2016 in subtidal habitats at Manawai (Pearl and Hermes Atoll) in the Papahānaumokuākea Marine National Monument (PMNM), Hawai'i. Without molecular or morphological matches to any known species, it was described in 2020 and declared cryptogenic. This alga has substantially increased in benthic cover and has been discovered on two additional atolls in PMNM: Kuaihelani (Midway) and Hōlanikū (Kure). It exhibits several characteristics indicative of non-native origins including putative prior absence in the region, persistence in high densities over nearly a decade, apparent lack of native herbivore pressure, and strong tetrasporophytic bias. Importantly, it is negatively impacting the culturally and ecologically valuable reefs of PMNM. The geographical origin of this putative invasion is unknown, and there are no published reports of the species occurring anywhere other than PMNM. The central Pacific location of Hawai'i allows a broad range of potential sources for the origin of C. tumulosa. Taxonomic ambiguities within the genus Chondria and challenges associated with sampling necessitate the development of a narrowed set of search locations and efficient search strategies to detect the species outside of PMNM. Attachment to floating debris is a potential introduction vector for C. tumulosa into PMNM, and an oceanographic model was used to identify the most likely source locations for this pathway between 2000 and 2015, including Japan in the western Pacific, Johnston Atoll, the Line Islands including Palmyra Atoll in the central Pacific, and Clipperton Atoll and the Galápagos Islands in the eastern Pacific. We used a recently developed and validated eDNA assay for detecting C. tumulosa from three of the regions of interest to screen for C. tumulosa with no samples yielding positive detections. We provide a framework for investigating positive eDNA field detections using in-water surveys, microscopy, and DNA barcoding. A parallel sampling effort targeting preserved specimens stored in global herbaria is also presented, which did not yield any detections. Several Chondria species remain targets for sequencing from global herbaria. Identification of the native range of C. tumulosa is a critical step that will allow for an evaluation of its evolutionary ecology and any shifts that may have occurred that facilitated its putative invasion and subsequent spread, offering insights crucial for the development of mitigation strategies to safeguard PMNM against further risk.

ABSTRACT Non‐indigenous species (NIS) have far‐reaching economic, ecological and cultural impacts on native biota. Early detection of nuisance species is crucial for preventing their widespread establishment and conserving threatened ecosystems. Acanthophora spicifera is a red alga that has successfully colonized tropical and subtropical waters around the globe, out‐competing native flora and fauna and is among the most common non‐indigenous algae of shallow Hawaiian coral reefs. To assist early detection and eradication efforts of NIS, we developed a qPCR assay for the non‐indigenous A. spicifera. Assay sensitivity and specificity were validated with species‐specific primers targeting a 131 base‐pair region of the ribulose‐1,5‐bisphosphate carboxylase/oxygenase large subunit (rbcL) gene. Using environmental DNA (eDNA) collected from surface seawater samples across the Hawaiian Archipelago, we then estimated A. spicifera site occupancy across sites where its presence was visually confirmed, as well as a large number of sites where its presence is unknown. Through occupancy modelling of eDNA and opportunistic visual survey data, A. spicifera eDNA was estimated to be present at 17% of surveyed sites, including one in the remote Papahānaumokuākea National Marine Sanctuary (PNMS), a world heritage site that is home to numerous endemic species. Thorough investigation of control samples, high‐throughput sequencing data and visual surveys suggest that the presence of A. spicifera eDNA within PNMS is associated with an emerging colonization front in the region. Our results indicate that the eDNA assay is sensitive to the presence of A. spicifera and is a cost‐effective method for monitoring its distribution on impacted coral reefs.

Efficient detection and management of non-indigenous species are critical for mitigating their ecological impacts. Environmental DNA (eDNA) techniques have transformed biodiversity monitoring by enabling sensitive and cost-effective surveys. This study compares the efficacy of passive eDNA samplers (PEDS) to conventional active filtration methods for detecting the cryptogenic macroalga Chondria tumulosa within the Papahānaumokuākea Marine National Monument, Hawaiʻi, USA. Three components of the species-specific eDNA assay were evaluated: clinical sensitivity, DNA yield, and overall performance. Site-level detection sensitivity of 15-minute PEDS deployments matched that of 2-L active filtration, with both methods detecting C. tumulosa in all cases where it was known to present. Site-occupancy models provided a robust framework for evaluating overall performance, offering critical insights into the tradeoffs of PEDS for detecting rare taxa. The success of PEDS is largely dependent on the increased number of qPCR replicates employed in this study compared to the previously developed eDNA assay for C. tumulosa. Passive method performance resulted in lower qPCR detection rates with higher probabilities of false-positives and false-negatives. Model estimates for C. tumulosa eDNA occupancy were similar between PEDS affixed to stationary buoys and PEDS attached to roving SCUBA divers. There was, however, a decrease in the eDNA capture rate among samples collected while on SCUBA. We also tested two passive membrane types—research-grade mixed cellulose ester filters and low-cost cotton rounds. The absorbent cotton rounds yielded greater target eDNA yields and were more reliable for inferring the presence of C. tumulosa. However, DNA yields from PEDS were consistently lower than actively filtered samples, indicating the importance of optimizing sampling and processing protocols to balance erroneous detections. Despite these limitations, passive sampling successfully detected C. tumulosa at low abundances (<1%), demonstrating its utility for uncovering cryptic taxa. PEDS are a cost-effective, versatile, and scalable alternative to active filtration, particularly in remote or resource-limited settings.

Climate change is causing shifts in the spatial distribution of species and a reshuffling of the composition of multiple community types. On coral reefs, deep water can act as both refuges and refugia for corals from the combined negative effects of heat and light stress. Phenotypically plastic generalists that can tolerate both low and high light environments could be disproportionately important on future reefs, persisting in refugia and colonizing vacant shallow reefs. We performed a common garden experiment to investigate the effect of light on three different wild-collected genotypes of the abundant, depth-generalist coral Pavona varians. We measured the growth response and reaction norms of six other morphological and functional traits in full sunlight, 75%, and 90% shade. We also modeled the combined effects of light and temperature on growth. P. varians had positive growth in all three treatments, but increased both skeletal mass and 2-D colony footprint most in 90% shade, with a higher density of corallites, and a less rugose skeleton that may enhance light capture. Areas of the colony corresponding to new growth had greater fluorescence of Symbiodiniaceae communities in the darkest treatment. Light did not alter the functional lipid ratio, nor did communities of Symbiodiniaceae vary with light treatments. The model revealed additively negative, but not synergistic, effects of light and temperature on growth. This additively negative relationship in the model is consistent with the hypothesis that reductions in bleaching at depth could be the product of reduced light stress at depth rather than reduced temperature stress. Light-associated plasticity likely allows P.varians to live in a wide variety of habitats and across a broad depth gradient. In reduced light conditions, this species may mitigate some of the negative effects of bleaching temperatures on growth. We predict that P. varians is likely one of a minority of species that may benefit from deep reef refugia.

The analysis of environmental DNA (eDNA) is a powerful tool for rapidly assessing biodiversity across aquatic ecosystems. Its implementation remains limited, however, by the logistical complexity of standard eDNA workflows, which often require specialized equipment and expertise. This protocol presents passive environmental DNA samplers (PEDS) as a simplified, low‐cost alternative to conventional active water filtration methods. PEDS are designed for ease of use, enabling ambient eDNA capture without pumps or filtration systems, and allowing for rapid deployment and retrieval with short field exposures (∼15 min). We detail procedures for construction, deployment, and retrieval, alongside recommendations for minimizing contamination and optimizing DNA recovery. DNA is extracted from cotton membranes housed within the PEDS unit using a modified Qiagen DNeasy Blood & Tissue protocol. The protocol was validated at the Papahānaumokuākea Marine National Monument, Hawaiʻi, where PEDS were used to detect Chondria tumulosa , a cryptogenic nuisance alga, as part of ongoing conservation efforts. The use of simplistic PEDS and cotton membranes provides a cost‐effective and scalable method for researchers seeking to implement eDNA‐based monitoring in marine and other aquatic environments. © 2025 Wiley Periodicals LLC. Basic Protocol 1 : Assembly and deployment of PEDS on stationary buoys Alternate Protocol : Assembly and deployment of PEDS on roving surveyors Basic Protocol 2 : Processing and storage of sample membranes Support Protocol 1 : Extraction of DNA from PEDS membranes Support Protocol 2 : Amplification of extracted DNA by PCR

The European eel ( Anguilla anguilla ) has declined by over 90% since the early 1980s and has been listed as critically endangered. Yet, despite strict export bans from the European Union, the European eel is still sold illegally in many countries. Efforts to monitor the trade of European eels have been primarily concentrated in Asian markets where concerningly high rates of European eel have been reported. Comparably fewer studies have assessed the identities of eel samples from the United States (US), despite the obvious implications for eel conservation. To address this knowledge gap, we purchased 137 eel products (134 freshwater eels and three saltwater eels) from grocers, sushi bars, and restaurants in nine states across the US from 2019 to 2021. Seven samples (5.2%) labeled as freshwater eels (or “unagi”) were identified as European eels using a combination of mitochondrial (cytochrome b) and nuclear (18S rRNA) restriction digestion assays, a fast and inexpensive molecular tool for seafood identification that can identify hybrids between European eels ( A. anguilla ) and American eels ( A. rostrata ). No hybrids between European and American eels were found and all seven samples identified with restriction digestion as European eels were confirmed by sequencing of cytochrome b and 18S rRNA. Frequency of European eels in US markets did not significantly correlate with state or retail type. Although illegal eel exports are likely reaching US consumers, the frequency of European eel samples in this study of the US market is much lower than found in other non-European countries.

Ecological patterns in biodiversity are primarily based on conspicuous organisms. Few methods are used to survey the taxonomically rich cryptobiome, which is made up of inhabitants from within microhabitats. One way that cryptic marine biodiversity can be non- invasively surveyed is by analyzing environmental DNA (eDNA) present in seawater. Using coral reefs as a model system, here we compare estimates of cryp tic diversity among community biomass and eDNA metabarcoding sampling methods with a broad eukaryotic marker (COI). First, contributions to eDNA were investigated across cryptobiomes through a comparison of community metabarcoded biomass from standardized autonomous reef monitoring structures (ARMS) to eDNA acquired from seawater in which individual ARMS were soaked. Second, we compared these results to those from eDNA samples taken from within reef crevices and the am bient water column. Metabarcoding of community biomass from ARMS and eDNA from the two types of water samples revealed significantly different communities of cryptic coral reef habitat with little overlap between methods. Taxa that were unique to metabarcoding of ARMS biomass were predominantly from chitinous and calcify ing groups (polychaetes, palaemonid shrimp, mollusks, brittle stars, and red algae), which suggests that these taxa are underrepresented in eDNA surveys. Other than the corals themselves, sponges and red algae were significant drivers of reef crevice community differences, while ambient seawater samples detected mostly planktonic organisms and reef fishes. Our data indicate that both eDNA and ARMS provide in complete accounting of cryptic diversity. Direct sampling of biomass is best suited for building taxonomies and improving databases, whereas eDNA methods offer rapid insights into the composition of cryptobiomes. Because each method likely captures different taxa, multiple targeted assays can be used to provide the greatest estimates of metazoan and macroalgal richness.

ABSTRACT We describe, for the first time, egg masses and larval developmental mode of a recently described Antarctic philinoid snail, Waegelea antarctica. Egg masses resembled the gelatinous, attached masses of many temperate philinoid species and contained very large offspring that hatched as developmentally advanced veligers with many juvenile features. Like other Antarctic heterobranch egg masses, development in the masses of W. antarctica appeared to be largely synchronous despite low internal oxygen levels. Hatched larvae could both swim and crawl, and we did not observe metamorphosis over several days. Molecular barcoding using cytochrome c oxidase subunit I (COI) showed an almost perfect (<0.002% difference) match between our specimens from McMurdo Sound in the Ross Sea and a single sequence from a specimen collected >8,000 km away in the Weddell Sea, suggesting either high realized larval dispersal or a recent range expansion. We also describe the egg mass of the related Antarctophiline alata (identified using COI barcoding) from the Ross Sea, which differed from published descriptions in having considerably smaller embryos.

Synopsis Pair-living is a common social system found across animal taxa, and the relationship between pair-living and reproduction varies greatly among species. Siphonaria gigas, hermaphroditic pulmonate gastropods, often live in pairs in the rocky intertidal zone of the tropical Eastern Pacific. Combining genetic parentage analysis using four polymorphic microsatellite loci with behavioral observations from a 10-week field study, we provide the first description of the mating system of a Siphonaria species incorporating genetic data. S. gigas mated both within-pair and extra-pair and three out of four paired S. gigas individuals produced egg masses with extra-pair paternity. Multiple paternity was detected, but at a relatively low frequency (19% of egg masses) compared to other marine gastropods. Behavioral data indicate one potential advantage of pair-living: paired S. gigas produced almost twice as many egg masses as their solitary counterparts over four reproductive cycles. These observations, together with constraints on the movement of S. gigas, suggest that pairing may ensure mate access and increase reproductive success.

Aquatic vegetation provides a wide range of benefits and services for ecosystems such as the production of oxygen, improvement of water quality, sheltering of important species, prevention of shoreline erosion by damping waves and storm surges, reduction of the oscillatory velocity inside the canopy, and the increasing of turbulence at stem length scales. Besides, the generation of a shear layer in the velocity profile at the canopy top increases the wave stress term, the mechanism in charge of releasing a mean current shoreward by a balance against the form drag force. However, the effects due to other factors such as the wave decay throughout the canopy, and/or the vertical gradient of the turbulent stress are not yet well understood. In this study, dimensional analysis of the momentum equation is performed at the wavelength (λ) and water depth (h) spatial scales over a long period (t) to develop a depth-dependent wave-induced steady current as a function of the incoming wave characteristics and submerged canopy properties. The analytical model is compared with laboratory data for rigid stems and with numerical data for flexible elements presenting a good agreement, allowing the model to be extended to coastal scale and real-field applications. Abstract At the mouth of the Magdalena River Estuary (MRE), the tidal range only reaches 0.60 m during spring tides. When comparing the tides with the mean freshwater discharge of 7000 m^3/s of the Magdalena River, it is easy to understand why the effect of the tides in the hydrodynamics of the MRE has been systematically neglected in the scientific literature. However, a recent inter-institutional Abstract Anthropogenic forcing generates observable climate changes in sea surface temperature (SST) and sea level (SL) across the planet. Since the Caribbean and Pacific coasts of Colombia are vulnerable to this forcing, in this article we use the results of the Max Planck Institute Ocean Model (MPIOM) to describe the SST and SL in the study areas by the year 2100. The SST and SL, which were run by MPIOM under Representative Pathways of Concentration (RCP) 4.5 and 8.5, allowed to obtain climatologies of 30 years every 10 years during the period 2010-2100. These climatologies were analyzed statistically and graphically to find relationships between the variables and factors that influence the Colombian climate, such as the Caribbean Low-Lev-el Jet (CLLJ), the Chocó Low-Level Jet (ChLLJ), and the Intertropical Convergence Zone (ITCZ). The SST and SL of RCP 4.5 and 8.5 showed different characteristics on the Colombian Caribbean and Pacific coasts, taking into account factors that affect differentially SST and SL in each sector for the year 2100: 1- the SST is higher in the Caribbean Sea, which showed a unimodal SL regime; 2- the SL is higher in the Pacific Ocean with a bimodal regime; 3- the SST showed a positive trend and higher amplitudes of climatological oscillation in RCP 8.5; 4- the SL showed more extreme values and a slight decrease at the end of the century in the RCP 8.5. Abstract The research project systematic observation of vegetation regarding the zonal occurrence, growth, density, and biomechanical properties is conducted. Simultaneous measurements of environmental parameters covering waves, currents, and soil properties yield a comprehensive data set for analysis, numerical and analytical modeling purposes. Hydraulic experiments modeling the wave-vegetation-soil interaction will be devised based on field data, developing dynamically and geometrically scaled vegetation surrogates. Besides vegetation properties aboveground, previously overlooked root system effects that are hypothesized to govern erosional processes in salt marshes and dunes will be of particular interest. At present, two field laboratory sites are selected based on a site assessment matrix for the coastline, thus incorporating expert feedback. The first surrogate model designs are under development and field methods are being evaluated. Abstract The salt balance between the Pacific and the Atlantic Oceans is essential for the Global circulation belt. Differences in salinity between the Pacific and the Atlantic are maintained by the humidity transport from the Atlantic to the Pacific through the atmosphere. Most of this transport occurs in the tropical region of the SW Caribbean (Colombian basin), North of South America, Central America, and Panama basin (Pacific), with several low-level jets. As a result, the Eastern Pacific Fresh Water Pool is formed. This work aims to represent the circulation of atmospheric water in this region and its connection with ocean salinity. To achieve this, we quantified the atmospheric water flows on the Caribbean and Pacific catchment areas (including the continent and the ocean) and the balance between their inflows and outflows on different time scales (mean, seasonal, and interannual). Since the excess or insuf-ficient water for each balance is received or lost (respectively) by the ocean, the results were compared with the surface salinity of the Colombian and Panama basins over the different time scales. The atmospheric mean balance is consistent with the ocean’s mean salinity, i.e., Abstract This study seeks to determine the influence of the roughness associated with a coral species ( Stylophora pistillata ) on the hydrodynamics of the incident flow by analyzing the turbulent motions generated around the coral structure. The experiment was carried out in a laboratory flume, where the coral was exposed to stationary flow with Reynolds numbers of 5624,11249,16863 and 22497. Velocity measurements were taken in two scenarios: coral with and without living tissue. Turbulent motions were studied via quadrant analysis, divided into four types: transport away from the bottom with an increase of upper layers velocity (outward interactions), transport away from the bottom with a decrease of upper layers velocity (ejections), transport towards the bottom with a decrease of lower layers velocity (inward interactions), and transport towards the bottom with an increase of lower layers velocity (sweeps). Results indicate that the predominant motions for both scenarios are ejections and sweeps, increasing its dominance as the Reynolds numbers increase. However, the behavior of each motion varies depending on the coral state. For the coral with living tissue, the motions were dominated by the ejections and a little less by the sweeps, showing that, in this case, the more energetic motions generate a transport away from the coral delaying the upper layers, followed in importance by motions towards the bottom. On the other hand, for the coral without living tissue, the occurrence of these two types of events and how energetic they are was more balanced, especially for the lowest Reynolds numbers. Abstract The transformation of surface gravity waves across a barrier reef at San Andrés Island in the Colombian Caribbean Sea was examined through field measurements. Pressure sensors were located offshore the reef crest, at the northeast side of the fit, obtaining fw = 0.56 ± 0.021 (R^2=0.75). Using the parameterization proposed by Swart (1974) and the equivalent bottom roughness scale, the KN varied from 0.01 - 1.42 m, which are qualitatively consistent with the scales of variability of the reef observed during the field campaign. The study suggests that healthy reefs with high coral cover may provide greater coastal protection than degraded reefs with low coral cover. It also highlights the importance of obtaining more field data to better correlate the bottom reef surface and coral species distribution with KN values, which is still an open research question. Abstract Mesoscale eddies are ubiquitous features in the ocean that typically exhibit different properties regarding their surroundings. They transport passive tracers such as heat, salt, and carbon, and are relevant structures for the redistribution of energy and mass around all the oceans. Eddies also play an important role in supplying nutrients to the shelf-slope and to the upper layers where plankton blooms may result. In this work, the main statistical characteristics of mesoscale eddies in the Caribbean Sea were studied, as well as the seasonal and inter-annual variability in the number of eddy observations. Key descriptors of mesoscale eddies from satellite-based sea level anomalies (SLA) such as their lifetime, size, and amplitude were assessed for the period between 1993 and 2016. Additionally, the spatio-temporal variability in the number of eddy observations was evaluated in relation to the Sea Surface Temperature (SST), the surface wind-curl, and the main climatic index of variability in the area. Eddy-observations were correlated with the wind-curl at the annual cycle, whereas their density was influenced at the inter-annual scale ENSO. Abstract During every year’s hurricane season, the Atlantic and the Caribbean are exposed to the economic, social, and environmental impacts of these phenomena. The analysis of variables such as wind and waves generated by these extreme events is essential to determine their possible impacts, as well as their multiple scientific and engineer-20 ing applications. Available information such as satellite data and reanalysis databases present significant problems of low temporal and spatial resolution preventing a good representation of the asymmetry of the maximum winds around the eye, as well as a tendency to underestimate some of these phenomena, respectively. A modified parametric model is proposed to represent the asymmetry of the maximum velocity field more adequately, according to the hurricane category. The proposed methodology uses the information of 13 years of data –available from flying airplanes- of the Hurricane Research Division (HRD), the HURDAT2 database of the National Hurricane Center (NHC), and automatic scripts for the detection of the variability of the maximum wind speeds around the eye

Seafood mislabeling misleads consumers about the abundance of commercially harvested and cultured species, hinders consumer choice, and allows overfished and threatened species to reach the marketplace. Despite the importance of seafood in local culture and in the tourist-driven economy of Hawai'i, no studies of seafood label accuracy have been conducted in the state. Here, we use mitochondrial DNA barcoding to investigate patterns of seafood mislabeling in restaurants, groceries, and sushi bars in the greater Honolulu area. Our results revealed an overall mislabeling rate of 21 % (+9.3%). Sushi bars had the highest rate (27 %), followed by restaurants (23 %) and groceries (17 %). The most common mislabeled fish was Swai (Pangasianodon hypophthalmus), sold as more expensive fish under a variety of names. The overall mislabeling rate in Honolulu was lower than the national rate (33 %) found in the largest study from the U.S. mainland by Oceana, but similar to a more recent, but smaller national Oceana survey (21 %). However, comparisons of overall rates across studies can be misleading because much of the geographic variation in mislabeling is confounded by varying proportions of samples obtained from different kinds of retailers. Finally, the widespread use of acceptable – but generic – market names in Hawai'i concealed the true diversity of species for sale, including endangered species. Two species in our study (Anguilla anguilla and Thunnus maccoyii) labeled with generic but acceptable market names are considered "Critically Endangered" by the International Union for Conservation of Nature.

The ability of an organism to respond to a changing climate is an important issue for the future of coastal ecosystems worldwide. Coral bleaching is a stress response to elevated seawater temperatures, which are projected to increase as a result of a warming climate. Coral populations adjust their thermal sensitivity through adaptation or individual colony acclimatization, but identifying acclimatization of individual colonies requires long-term ecological observation in the field. Consecutive bleaching events in Hawai'i in 2014 and 2015 provided an unprecedented natural experiment for comparing bleaching susceptibilities of coral communities as well as assessing acclimatization. Individual colonies were monitored for 15 mo encompassing the periods before, during, and after both bleaching events. Metrics of bleaching, recovery, and mortality were calculated to investigate responses between bleaching events. Initial colony responses varied by species, with only Porites evermanni exhibiting significantly less bleaching in the second year despite a 27 % increase in accumulated thermal stress and low partial mortality overall. In contrast, P. lobata and Pocillopora meandrina experienced similar bleaching responses both years, with P. lobata experiencing significantly less mortality the second year, and P. meandrina having similar mortality both years. This study demonstrates the importance of monitoring individual colonies to fully understand reef bleaching dynamics and points to the influence of species composition when assessing the potential for reef acclimatization. Given that thermal stress is predicted to be a major stressor for coral reefs in the future, acclimatization may serve as a critical mechanism that limits mass mortality, allowing time for populations to adapt.

Coral reefs support the most diverse assemblages of marine life on Earth, yet are declining due to local and global stressors. Rapid and widespread monitoring is essential for tracking ecosystem responses, but assessment of coral communities traditionally relies on time-consuming visual estimates of coral cover, the percentage of substrate occupied by living corals. The analysis of environmental DNA (eDNA) offers fast and efficient insights into the abundance and distribution of species, yet it remains untested to monitor coral biomass. Here, we demonstrate that visual estimates are highly correlated with the abundance of coral eDNA on reefs in Hawai'i measured with a relatively simple, rapid, but replicated PCR-based metabarcoding approach. Target sequence length was also tested by amplifying short (~120 base-pairs) and long (~400 base-pairs) fragments from the same region of two mitochondrial DNA genes, 16S ribosomal DNA, and cytochrome oxidase-1 using primers designed to preferentially amplify Hawaiian coral genera. Careful primer selection and target sequence lengths play an important role in determination of coral abundance from eDNA biomass. Given its broad applicability and ease of use, eDNA metabarcoding can provide complementary analytical support for biomonitoring programs and management initiatives tracking changes in coral cover caused by climate change and other disturbances on coral reefs.

ABSTRACT Antarctic animals share many traits that are attributed to evolution in a stable, extremely cold climate. Among invertebrates, development is exceptionally slow, making observational studies of development logistically challenging, particularly when conducted under natural conditions in the field. Using multiple deployments to McMurdo Station, Antarctica, we characterized the development, in the field, of an unidentified buccinoidean gastropod species with encapsulated development. Thirteen egg capsules collected at Granite Harbor, McMurdo Sound, Ross Sea, were attached to natural rock and outplanted at a depth of ~25 m at the base of the McMurdo Intake Jetty on 2 December 2007, photographed on 5 October 2011 and 6 September 2012 and then returned to the laboratory on 27 November 2015. In 2015, four capsules were open and empty, five were open and contained a single large hatchling and the remaining four capsules were intact but not open, each containing a single large juvenile snail. To identify the developing embryos, we sequenced mitochondrial cytochrome c oxidase subunit I (COI) from two hatchlings and compared those sequences with those from adults collected near the egg mass, as well as with sequences of other buccinoideans from GenBank. Based on the close match between hatchling and adult COI sequences (hatchling sequences differed from those of an adult at only 2 of 658 nucleotide positions), we identified the embryos as Antarctodomus thielei (Powell, 1958)). The egg mass morphology and development of this species have not been previously described. Our study shows that A. thielei has a development time of more than 8 years, which is the longest measured for any gastropod.