A5012063820- Coral and Marine Ecosystems Studies
- Marine and fisheries research
- Oceanographic and Atmospheric Processes
- Coastal and Marine Dynamics
- Marine and coastal plant biology
- Tropical and Extratropical Cyclones Research
- Remote Sensing and LiDAR Applications
- Ocean Waves and Remote Sensing
- Fish Ecology and Management Studies
- Underwater Acoustics Research
- 3D Surveying and Cultural Heritage
- Coastal wetland ecosystem dynamics
- Crustacean biology and ecology
- Hydrology and Sediment Transport Processes
- Meteorological Phenomena and Simulations
- Aeolian processes and effects
- Satellite Image Processing and Photogrammetry
- Marine and coastal ecosystems
- Coastal and Marine Management
- Marine animal studies overview
- Marine Biology and Ecology Research
- Ocean Acidification Effects and Responses
- Underwater Vehicles and Communication Systems
- Target Tracking and Data Fusion in Sensor Networks
- Arctic and Antarctic ice dynamics
Duke University
2014-2024
University of South Carolina Beaufort
2018-2023
Marine Conservation Institute
2010-2021
Stanford University
2006-2013
Mechanics' Institute
2006-2008
University of North Carolina at Chapel Hill
1999-2005
Coral bleaching is the detrimental expulsion of algal symbionts from their cnidarian hosts, and predominantly occurs when corals are exposed to thermal stress. The incidence severity often spatially heterogeneous within reef-scales (<1 km), therefore not predictable using conventional remote sensing products. Here, we systematically assess relationship between in situ measurements 20 environmental variables, along with seven remotely sensed SST stress metrics, 81 observed events at coral...
We examined the role of wave‐driven circulation relative to wind and buoyancy forcing in a coral reef‐lagoon system. Circulation measurements Paopao Bay, Moorea, French Polynesia, during austral summer show importance waves driving flows over reef crest, through lagoon, out pass. Tides were comparatively weak, due proximity amphidromic points, exhibited an unusual spring‐neap cycle where major lunar tide modulated solar tide, overall tidal phase stayed approximately constant. Wind had only...
Abstract Coral bleaching is the single largest global threat to coral reefs worldwide. Integrating diverse body of work on critical understanding and combating this problem. Yet investigating drivers, patterns, processes poses a major challenge. A recent review published experiments revealed wide range experimental variables used across studies. Such approaches enhances discovery, but without full transparency in analytical methods used, can also make comparisons among studies challenging....
[1] In a hydrodynamic sense, coral reef is complex array of obstacles that exerts net drag force on water moving over the reef. This typically parameterized in ocean circulation models using coefficients (CD) or roughness length scales (z0); however, published CD for reefs span two orders magnitude, posing challenge to predictive modeling. Here we examine reasons large range reported and assess limitations z0 parameterize reefs. Using formal framework based 3-D spatially averaged momentum...
Abstract Observations of waves, setup, and wave-driven mean flows were made on a steep coral forereef its associated lagoonal system the north shore Moorea, French Polynesia. Despite complex geometry forereef, wave amplitudes that are nearly equal to water depth, linear theory showed very good agreement with data. Measurements across reef illustrate importance including both transport (owing Stokes drift), as well Eulerian when computing fluxes over reef. Finally, observed setup closely...
Abstract The loss of functional and accreting coral reefs reduces coastal protection resilience for tropical coastlines. Coral restoration has potential recovering healthy that can mitigate risks from hazards increase sustainability. However, scaling up to the large extent needed requires integrated application principles engineering, hydrodynamics, ecology across multiple spatial scales, as well filling missing knowledge gaps disciplines. This synthesis aims identify how scientific...
Very high resolution (VHR) airborne data enable detection and physical measurements of individual coral reef colonies. The bathymetric LiDAR system, as an active remote sensing technique, accurately computes the ecosystem's surface reflectance using a single green wavelength at decimetre scale over 1-to-100 km2 areas. A passive multispectral camera mounted on drone can build blue-green-red (BGR) orthorectified mosaic centimetre 0.01-to-0.1 combination these technologies is used for first...
An analysis of transient momentum balances is carried out to elucidate circulation, dynamics, and exchange mechanisms at shallow barotropic tidal inlets. Circulation computed using a depth-integrated, fully nonlinear, time-stepping, finite-element model with variably spaced grids having horizontal resolution down 50 m. Velocity elevation fields from the are used directly evaluate contribution each term in equations overall balance. A transformation x–y terms into an s–n coordinate system...
Planktonic, filamentous, heterocystous cyanobacteria form blooms in certain nitrogen‐limited ecosystems but are absent or rare others that seem to have suitable environmental conditions. We tested the hypothesis small scale shear affects physiological activities and morphology of high turbulence environments. Using Taylor‐Couette flow generate small‐scale shear, we conducted one set experiments on cultures two strains Baltic Sea Nodularia a complementary using natural phytoplankton...
Abstract A field experiment was conducted to examine stratified and unstratified curvature-generated lateral circulation momentum balances in an estuarine tidal channel. Conductivity, temperature, depth, current profiler data were collected vertically laterally across the channel at a sharp bend over fortnightly period measure terms of budget. Well-mixed conditions allow development classic two-layer helical flow around bend. Stratification strengthens curvature-induced circulation, but...
Although small‐scale spatial flow variability can affect both larger‐scale circulation patterns and biological processes on coral reefs, there are few direct measurements of across horizontal scales <100 m. Here a shallow reef flat were measured at from single colony to several adjacent colonies using an array acoustic Doppler velocimeters diver‐operated traverse. We observed recirculation zones immediately behind colonies, reduced currents elevated dissipation rates in turbulent wakes up...
Owing to the shallowness of waters, vast areas, and spatial complexity, reefscape mapping requires Digital Depth Models (DDM) at a fine scale but over large areas. Outperforming waterborne surveys limited by shallow water depths costly airborne campaigns, recently launched satellite sensors, endowed with high spectral very capabilities, can adequately address raised issues. Doubling number bands, innovative eight band WorldView-2 (WV2) imagery is susceptible enhance DDM retrieved from...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 605:135-150 (2018) - DOI: https://doi.org/10.3354/meps12714 Understanding differential patterns in coral reef recovery: chronic hydrodynamic disturbance as a limiting mechanism for colonization T. Shay Viehman1,2,*, James L. Hench2, Sean P. Griffin3, Amit Malhotra1,4, Katharine Egan1,4, Patrick N. Halpin5...
Fish species such as Atlantic menhaden ( Brevoortia tyrannus ) must often transit relatively small barrier island inlets to move from their continental shelf spawning grounds estuarine nurseries, where they spend juvenile phase. Physical transport through these is strongly influenced by tides, winds, local geometry and bathymetry, can be very different that occurring on the shelf. In March 1996, an extensive multidisciplinary field experiment was conducted identify larval pathways in...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 370:127-141 (2008) - DOI: https://doi.org/10.3354/meps07622 Reef structure regulates small-scale spatial variation in coral bleaching Hunter S. Lenihan1,*, Mehdi Adjeroud2,3, Matthew J. Kotchen1, James L. Hench4, Takashi Nakamura5 1Bren School of Environmental Science and Management, University California,...
Analysis of five‐year records temperatures and currents collected at Moorea reveal strong internal wave activity predominantly semi‐diurnal frequencies impacting reef slopes depths ≥30 m around the entire island. Temperature changes 1.5°C to 3°C are accompanied by surges upward onshore flow vertical shear in currents. Superimposed on annual temperature approximately 3°C, is high from Oct–May markedly lower Jun–Sep. The offshore pycnocline broadly distributed with continuous stratification...
Hydrodynamic conditions can influence the distribution and abundance of aquatic species in many ways, including directly through disturbance resource delivery, indirectly by altering environmental cues interactions. In coral reef ecosystems, corallivory is an important top‐down control populations, while water motion enhance performance via autotrophic and/or heterotrophic pathways. Using a large‐scale field assay Mo‘orea, French Polynesia, we measured extent to which growth branching...
Marine heatwaves are increasing in frequency and duration, threatening tropical reef ecosystems through intensified coral bleaching events. We examined a strikingly variable spatial pattern of Moorea, French Polynesia following heatwave that lasted from November 2018 to July 2019. In 2019, four months after the onset bleaching, we surveyed > 5000 individual colonies two dominant genera, Pocillopora Acropora, at 10 m 17 water depths, six forereef sites around island where temperature was...
We present measurements of flows and fluxes phytoplankton to Conch Reef, Florida, a Caribbean reef dominated by sponges soft corals, located in 15 m water offshore Key Largo. Vertical profiles chlorophyll a, proxy for biomass, showed near-bed depletion, indicating the existence concentration boundary layers. Along with simultaneous velocity profiles, turbulence, temperature stratification, these were used compute α, mass transfer bed (i.e., flux normalized concentration). The α value ranged...
Populations of marine organisms on coral reef islands (CRI) are connected in space and time by seawater that transports propagules plants, animals, algae. Yet, despite this reality, it is often assumed routine replenishment populations CRI supported locally-sourced (hereafter, larvae). Following large disturbances, however, distantly-sourced larvae from less disturbed within a regional meta-population likely to be important for local population recovery, but evaluating the roles locally-...