A 2 week field experiment was conducted to measure surface wave dissipation on a barrier reef at Kaneohe Bay, Oahu, Hawaii. Wave heights and velocities were measured several locations the fore flat, which used estimate rates of by breaking bottom friction. Dissipation flat found be dominated friction that are significantly larger than those typically observed sandy beach sites. This is attributed rough generated organisms, makes highly efficient dissipating energy Results compared spectral...

Abstract Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal subtidal naturally Kimberley region in northwest Australia. Here tides up to 10 m cause aerial exposure corals temperatures as high 37 °C that fluctuate daily by 7 °C. Control were maintained at ambient nearshore which varied diurnally 4-5 °C, while treatment...

Abstract The response of the circulation a coral reef system in Kaneohe Bay, Hawaii, to incident wave forcing was investigated using field data collected during 10-month experiment. Results from study revealed that dominant mechanism driving over much Bay. As predicted theoretically, setup generated near crest resulting breaking established pressure gradient drove flow and out two channels. Maximum found be roughly proportional offshore energy flux above threshold root-mean-square height 0.7...

A coupled wave‐circulation numerical model was used to simulate the distribution of wave energy, as well circulation induced by breaking, wind, and tidal forcing, within a coral reef system in Kaneohe Bay, Oahu, Hawaii. Modeled wave, current, setup fields were compared with field measurements collected on forereef, flat, channels lagoon over 4‐week period. The predicted height transformation across reef‐lagoon good agreement observations, using single‐parameter (spatially uniform) values...

Abstract Coral calcification is dependent on the mutualistic partnership between endosymbiotic zooxanthellae and coral host. Here, using newly developed geochemical proxies (δ 11 B B/Ca), we show that Porites corals from natural reef environments exhibit a close ( r 2 ∼0.9) antithetic relationship dissolved inorganic carbon (DIC) pH of corals’ calcifying fluid (cf). The highest DIC cf (∼ × 3.2 seawater) found during summer, consistent with thermal/light enhancement metabolically...

We present a three-dimensional hydrodynamic-biogeochemical model of wave-driven coral-reef lagoon system using the circulation ROMS (Regional Ocean Modeling System) coupled with wave transformation SWAN (Simulating WAves Nearshore). Simulations were used to explore sensitivity water column carbonate chemistry across reef variations in benthic metabolism, forcing, sea level, and geomorphology. Our results show that changes reef-water depend primarily on ratio metabolism square root onshore...

Maximum rates of phosphate, nitrate, and ammonium uptake by a reef flat community were estimated from frictional dissipation that calculated the attenuation waves propagating over Kaneohe Bay Barrier Reef flat. Time‐averaged flow speeds across entire study area ranged 0.08 to 0.22 m s −1 . Observed decreases in wave energy fluxes near‐bottom orbital velocities gave mean estimate for bottom friction coefficient ( c f ) ± 0.03. Friction coefficients used nutrient mass‐transfer 5–9 d phosphate...

Communities of benthic organisms can form very rough surfaces (canopies) on the seafloor. Previous studies have shown that an oscillatory flow induced by monochromatic surface waves will drive more inside a canopy than comparable unidirectional current. This paper builds these previous investigating how wave energy is attenuated within canopies under spectral conditions, or random fields defined many frequencies. A theoretical model first developed to predict attenuation varies among...

Both canopy flow and porous media theories have been developed independent of one another to predict through submerged structures. These approaches are very similar, albeit with some key differences in how resistance forces parameterized. Canopy models provide a means parameterizing the shear stresses that occur at top canopy, whereas can often simpler more tractable way turbulent form drag based on simple morphological metrics empirical relationships already hydrology literature. We set...

Rates of net production, calcification, and nutrient uptake were measured in a coral‐dominated reef flat community on Ningaloo Reef northwestern Australia under seasonally minimum maximum light levels. Daily integrated decreased twofold while water temperatures remained relatively constant increasing by only 1°C average from summer to winter. daily gross primary production ( GPP ) 33% ± 9% higher than winter (1400 70 versus 1050 60 mmol C m −2 d −1 ), far less the seasonal changes reported...

Significance In situ free ocean CO 2 enrichment (FOCE) experiments and geochemical analyses (δ 11 B, Sr/Ca) conducted on corals ( Porites cylindrica ) from the highly dynamic Heron Island reef flat of Great Barrier Reef show that this species exerts strong physiological controls pH their calcifying fluid (pH cf ). Over an ∼6-mo period, mid-winter to early summer, we these maintained at near constant elevated levels independent variable temperatures FOCE-controlled carbonate chemistries which...

3D imaging exposes deformities and shows how ocean acidification can change the way juvenile corals build their skeletons.

Nitrate and nitrite (NO x ) phosphate (PO 4 dynamics over Ningaloo Reef, Western Australia, are shown to depend on oceanographic forcing of coupled mass transfer limited (MTL) gross uptake release from remineralized oceanic particulate organic matter (POM). Estimates rates increased significantly with increasing POM were the same order as rates. Gross concentrations wave energy dissipation, 35–80% higher reef crest (7–9 mmol NO m −2 d −1 4–5 PO ), correlated independent estimates...

Mass transfer rates from submerged canopies constructed arrays of vertical cylinders were investigated for a range different cylinder spacings under both unidirectional and oscillatory flow. Individual canopy elements made gypsum dissolved in fresh water to simulate the mass metabolites living benthic organisms. flow up three times higher than values measured comparable current. This enhancement was shown be strong function element spacing. A model developed predict on basis in‐canopy speed...

We made continuous measurements of the flux dissolved oxygen over an algal‐dominated reef flat community on Kaneohe Bay Barrier Reef, Hawaii as a proxy for net production ( NP ) organic carbon. Fluxes were calculated from and current profiles taken moored sensors acoustic Doppler profilers (ADCPs) located at points defining vertices triangular control volume 250 m in length each side. Surface cruciform drifters well dye patches tracked across to get independent Lagrangian currents. While...

A 2 week field experiment investigated the hydrodynamics of a strongly tidally forced tropical intertidal reef platform in Kimberley region northwestern Australia, where spring tidal range exceeds 8 m. At this site, flat and wide (∼1.4 km) is located slightly above mean sea level, such that during low tide offshore water level can fall 4 m below platform. While always remained submerged over each cycle, there were dramatic asymmetries both levels velocities on reef, i.e., flood duration...

We investigated the influence of hydrodynamic forcing (waves, tides, alongshore currents and winds) net calcification by coral reef organisms on spatial distribution total alkalinity (TA) in a fringing system through combination field measurements numerical modeling. A experiment was conducted over 10 days Coral Bay (Ningaloo Reef, Western Australia) during which we measured wave heights, currents, tides as well TA across fore reef, crest, lagoon. used observed changes adjacent flat, along...