Extreme spatial heterogeneity in carbonate accretion potential on a Caribbean fringing reef linked to local human disturbance gradients

This is the final version. Available on open access from Wiley via the DOI in this recordThe capacity of coral reefs to maintain their structurally complex frameworks and to retain the potential for vertical accretion is vitally important to the persistence of their ecological functioning and the ecosystem services they sustain. However, datasets to support detailed along-coast assessments of framework production rates and accretion potential do not presently exist. Here we estimate, based on gross bioaccretion and bioerosion measures, the carbonate budgets and resultant maximum accretion potential (RAPmax) of the shallow reef zone of leeward Bonaire – between 5 to 12 m depth – at unique fine spatial resolution along this coast (115 sites). Whilst the fringing reef of Bonaire is often reported to be in a better ecological condition than most sites throughout the wider Caribbean region, our data show that the carbonate budgets of the reefs and derived RAPmax rates varied3 considerably across this ~58 km long fringing reef complex. Some areas, in particular the marine reserves, were indeed still dominated by structurally complex coral communities with high net carbonate production (> 10 kg CaCO3 m-2 year-1 35 ), high live coral cover and complex structural topography. The majority of the studied sites, however, were defined by relatively low budget states (< 2 kg CaCO3 m-2 year-1 36 ) or were in a state of net erosion. These data highlight the marked spatial heterogeneity that can occur in budgets states, and thus in reef accretion potential, even between quite closely spaced areas of individual reef complexes. This heterogeneity is linked strongly to the degree of localized land-based impacts along the coast, and resultant differences in the abundance of reef framework building coral species. The major impact of this variability is that those sections of reef defined by low-accretion potential will have limited capacity to maintain their structural integrity and to keep pace with current projections of climate change induced sea-level rise (SLR), thus posing a threat to reef functioning, biodiversity and trophic cascades. Since many Caribbean reefs are more severely degraded than those found around Bonaire, it is to be expected that the findings presented here are rather the rule than the exception, but the study also highlights the need for similar high spatial resolution (along-coast) assessments of budget states and accretion potential to meaningfully explore increasing coastal risk at the country level. The findings also more generally underline the significance of reducing local anthropogenic disturbance and restoring framework-building coral assemblages. Appropriately focussed local preservation efforts may aid in averting future large-scale submergence of Caribbean coral reefs and will constrain the social and economic implications associated with the loss of reef goods and services.Ministry of Economic AffairsWageningen UniversityRoyal Netherlands Institute for Sea Researc

Facies and faunal assemblage changes in response to the Holocene transgression in the Lagoon of Mayotte (Comoro Archipelago, SW Indian Ocean)

This paper documents the facies change in response to the Holocene transgression within five sediment cores taken in the lagoon of Mayotte, which contain a Type-1 depositional sequence (lowstand, transgressive and highstand deposits underlain by an erosive sequence boundary). Quantitative compositional analysis and visual examination of the bioclasts were used to document the facies changes. The distribution of the skeletal and non-skeletal grains in the lagoon of Mayotte is clearly controlled by (1) the rate and amplitude of the Holocene sea-level rise, (2) the pre-Holocene basement topography and (3) the growth-potential of the barrier reef during sea-level rise, and the changes in bathymetry and continuity during this period. The sequence boundary consists of the glacial karst surface. The change-over from the glacial lowstand is marked by the occurrence of mangrove deposits. Terrigenous and/or mixed terrigenous-carbonate muds to sandy muds with a mollusc or mollusc-ostracod assemblage dominate the transgressive deposits. Mixed carbonate-siliciclastic or carbonate sand to gravel with a mollusc-foraminifer or mollusc-coral-foraminifer assemblage characterize the early highstand deposits on the inner lagoonal plains. The early highstand deposits in the outer lagoonal plains consist of carbonate muds with a mollusc-foraminifer assemblage. Late highstand deposits consist of terrigenous muds in the nearshore bays, mixed terrigenous-carbonate sandy muds to sands with a mollusc-foraminifer assemblage on the inner lagoonal plains and mixed muds with a mollusc-foraminifer assemblage on the outer deep lagoonal plains. The present development stage of the individual lagoons comprises semi-enclosed to open lagoons with fair or good water exchange with the open ocean

Effectiveness of simulation training and assessment of PICU nurses' resuscitation skills: A mixed methods study from the Netherlands

Purpose: The quality of resuscitation and effective leadership are decisive for the outcome of a resuscitation. Nurses are usually the first responders upon cardiac arrest. Therefore, we started the “proficiency check” project, which aims to improve nurses' resuscitation and teamwork skills. This article describes the effectiveness of the proficiency check and nurses' experiences with it. Design and methods: This study was done among intensive care nurses working on a pediatric ICU (PICU) in the Netherlands. It was designed as a mixed-methods study combining a quantitative and a qualitative approach. Quantitative data were obtained through a pre-posttest comparison of nurses' resuscitation and teamwork skills, in a simulation setting. Qualitative data on nurses' experiences were collected through semi-structured individual interviews. Results: Both resuscitation and teamwork skills improved significantly. In 39 nurses (32%), the improvement of both resuscitation and teamwork skills after the intervention was large (effect size >0.8). The experiences of nu

Assessing health-related quality-of-life changes in informal caregivers: an evaluation in parents of children with major congenital anomalies

Purpose: Relatively few attempts to measure the effects on the health-related quality of life (HRQoL) of informal caregivers within the context of economic evaluations have been reported. This paper is an exploratory attempt to find suitable methods to assess caregi

Can we improve outcome of congenital diaphragmatic hernia?

This review gives an overview of the disease spectrum of congenital diaphragmatic hernia (CDH). Etiological factors, prenatal predictors of survival, new treatment strategies and long-term morbidity are described. Early recognition of problems and improvement of treatment strategies in CDH patients may increase survival and prevent secondary morbidity. Multidisciplinary healthcare is necessary to improve healthcare for CDH patients. Absence of international therapy guidelines, lack of evidence of many therapeutic modalities and the relative low number of CDH patients calls for cooperation between centers with an expertise in the treatment of CDH patients. The international CDH Euro-Consortium is an example of such a collaborative network, which enhances exchange of knowledge, future research and development of treatment protocols

Whiting–related sediment export along the Middle Miocene carbonate ramp of Great Bahama Bank.

International audienc

Coral climate proxy data from a marginal reef area, Kuwait, northern Arabian-Persian Gulf

We present the first coral climate proxy data (Sr / Ca, δ18O, δ13C) from the Persian–Arabian Gulf using a Porites lutea coral collected offshore Kuwait. Both oxygen isotope- and Sr / Ca-ratios of the coral core investigated are statistically correlated with instrumental sea surface temperatures (SST) for the area from 1980–2002. However, the temperature calibration curve for Sr / Ca differs from other published curves in that its slope is much lower. The correlation coefficient between δ18Ocoral and instrumental SST is at the lower limit as compared to other sites. These differences most likely relate to insufficient data representation of cold winters and hot summers, and indicates that much higher sampling resolution is needed in marginal reef areas such as Kuwait with extreme environmental fluctuations, i.e., intra-annual SST-variation of 16–34 °C, as compared to low latitude locations with relatively low SST variation. Variations of carbon isotopes of the coral skeleton do not exhibit climate control, however, a negative excursion in 1991 might be attributed to the massive oil field fires of the II. Gulf War

Facies variations in response to Holocene sea-level and climate change on Bora Bora, French Polynesia: Unravelling the role of synsedimentary siderite in a tropical marine, mixed carbonate-siliciclastic lagoon

International audienceFive mixed carbonate-siliciclastic sedimentary facies were identified in the barrier-reef lagoon of Bora Bora using microfacies and statistical analyses of 70 sediment samples taken at high resolution from two vibrocores. Fades and fades successions were interpreted with respect to Holocene sea-level and climate changes. The windward lagoon core is characterized by sideritic marly wackestones and foraminifera-sideritic wackestones, deposited around 7700 years BP (years before present) during the early-mid Holocene transgression. At that time, extensive weathering and erosion of iron-bearing minerals from the volcanic island, due to a wetter climate, were expressed in the formation of synsedimentary siderite in lagoonal sediments. The enrichment in delta O-18 (+ 032 to + 0.54 parts per thousand) in the siderite grains indicates marine to mixed marine-meteoric conditions during precipitation. Siderite formation resulted from microbial degradation of organic material, indicated by depleted delta C-13 values (- 13.61 to - 14.48160) that led to reducing conditions in lagoonal sediments, and resulted in iron reduction in the presence of dissolved bicarbonate. The chemical compositions of the siderites changes upcore, from relatively high Fe (91-95 mol%) and low Mn (5-6 mol%) at the core base to relatively low Fe (83-88 mol%) and high Mn (11-16 mol%) at the core top. The substitutions of Fe by Mn, Ca and Mg at grain margins illustrate changes in pore-water chemistry towards more oxygenated conditions and reflect sea-level rise and elevated rainfall during the early-mid Holocene. A drier climate during the mid-late Holocene was accompanied by reduced iron input and the proportion of siderite decreased, approaching zero in the upper section of the core. In the leeward lagoon core, siderite is again common in the lower section, and decreases in abundance upcore. Mollusc-foraminifera many packstones and mollusc wackestones accumulated similar to 5400-3500 years BP during the mid-Holocene in the windward core. Early in this period rotalid and miliolid foraminifera dominated. These are tolerant of environmental stress such as changes in water quality, nutrients or salinity. From the mid-Holocene to the present, textularid foraminifera are common in both cores, and indicate normal marine lagoonal conditions. Since the mid-late Holocene sea-level highstand and fall to modern level, mudstones have dominated in both cores. During the last 1000 years coral fragments have increased in abundance in the windward lagoon, presumably as a result of lagoonward progradation of fringing reefs in the mid-late Holocene. Since the late Holocene, motus on the windward side of Bora Bora have hampered sediment transport and lagoonward pro gradation of sand aprons. Increasing numbers of peloids, largely hardened faecal pellets, in the windward core in the last 1000 years may reflect early submarine lithification within the lagoon. Our study shows that during the Holocene, sea-level and climate change have influenced sediment import, composition and distribution in the Bora Bora lagoon. The sensitive response of the environment to external changes demonstrates the potential of tropical reef lagoons as archives of climate and sea-level changes