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Recent Publications

  • Koslow JA, Miller E.F, McGowan J.A.  2015.  Dramatic declines in coastal and oceanic fish communities off California. Marine Ecology Progress Series. 538:221-227.
    Abstract Summary:

    The California Cooperative Oceanic Fisheries Investigations (CalCOFI) ichthyoplankton surveys and systematic sampling of southern California power plant cooling-water intakes (PPI) provide independent, complementary time series to assess fish communities off southern California from nearshore to oceanic environments. The PPI program has sampled the shallow nearshore fish community at 5 sites along the coast of southern California since 1972,...

  • Nordstrom M.C, Demopoulos A.WJ, Whitcraft C.R, Rismondo A., McMillan P., Gonzalez J.P, Levin L.A.  2015.  Food web heterogeneity and succession in created saltmarshes. Journal of Applied Ecology. 52:1343-1354.
    Abstract Summary:

    Ecological restoration must achieve functional as well as structural recovery. Functional metrics for re-establishment of trophic interactions can be used to complement traditional monitoring of structural attributes. In addition, topographic effects on food web structure provide added information within a restoration context; often, created sites may require spatial heterogeneity to effectively match structure and function of natural...

  • Askarizadeh A., Rippy MA, Fletcher T.D, Feldman D.L, Peng J., Bowler P., Mehring A.S, Winfrey B.K, Vrugt J.A, AghaKouchak A. et al..  2015.  From rain tanks to catchments: Use of low-impact development to address hydrologic symptoms of the urban stream syndrome. Environmental Science & Technology. 49:11264-11280.
    Abstract Summary:

    Catchment urbanization perturbs the water and sediment budgets of streams, degrades stream health and function, and causes a constellation of flow, water quality, and ecological symptoms collectively known as the urban stream syndrome. Low-impact development (LID) technologies address the hydrologic symptoms of the urban stream syndrome by mimicking natural flow paths and restoring a natural water balance. Over annual time scales, the volumes...

  • Grimes D.J, Cortale N., Baker K., McNamara D.E.  2015.  Nonlinear forecasting of intertidal shoreface evolution. Chaos. 25
    Abstract Summary:

    Natural systems dominated by sediment transport are notoriously difficult to forecast. This is particularly true along the ocean coastline, a region that draws considerable human attention as economic investment and infrastructure are threatened by both persistent, long-term and acute, event driven processes (i.e., sea level rise and storm damage, respectively). Forecasting the coastline's evolution over intermediate time (daily) and space (...

  • Fang H.Z, de Callafon R.A, Franks PJS.  2015.  Smoothed estimation of unknown inputs and states in dynamic systems with application to oceanic flow field reconstruction. International Journal of Adaptive Control and Signal Processing. 29:1224-1242.
    Abstract Summary:

    Forward-backward smoothing based unknown input and state estimation for dynamic systems is studied in this paper, motivated by reconstruction of an oceanographic flow field using a swarm of buoyancy-controlled drifters. The development is conducted in a Bayesian framework. A Bayesian paradigm is constructed first to offer a probabilistic view of the unknown quantities given the measurements. Then a maximum a posteriori is established to build...

  • Kaniewska P., Chan C.KK, Kline D., Ling E.YS, Rosic N., Edwards D., Hoegh-Guldberg O., Dove S..  2015.  Transcriptomic changes in coral holobionts provide insights into physiological challenges of future climate and ocean change. Plos One. 10
    Abstract Summary:

    Tropical reef-building coral stress levels will intensify with the predicted rising atmospheric CO2 resulting in ocean temperature and acidification increase. Most studies to date have focused on the destabilization of coral-dinoflagellate symbioses due to warming oceans, or declining calcification due to ocean acidification. In our study, pH and temperature conditions consistent with the end-of-century scenarios of the Intergovernmental...

  • Highlighted Publication Intraseasonal altimetric SSH (cm) from delayed-time AVISO product
    Gasparin F., Roemmich D., Gilson J., Cornuelle B..  2015.  Assessment of the upper-ocean observing system in the equatorial Pacific: The role of Argo in resolving intraseasonal to interannual variability*. Journal of Atmospheric and Oceanic Technology. 32:1668-1688.
    Abstract Summary:

    Using more than 10 years of Argo temperature and salinity profiles (2004-14), a new optimal interpolation (OI) of the upper ocean in the equatorial Pacific is presented. Following Roemmich and Gilson's procedures, which were formulated for describing monthly large-scale anomalies, here every 5 days anomaly fields are constructed with improvements in the OI spatial covariance function and by including the time domain. The comparison of Argo...

  • Lee Z.P, Marra J., Perry M.J, Kahru M.  2015.  Estimating oceanic primary productivity from ocean color remote sensing: A strategic assessment. Journal of Marine Systems. 149:50-59.
    Abstract Summary:

    It has long been realized that approaches using satellite ocean-color remote sensing are the only feasible means to quantify primary productivity (PP) adequately for the global ocean. Through decades of dedicated efforts and with the help of various satellite ocean-color missions, great progresses have been achieved in obtaining global PP as well as its spatial and temporal variations. However, there still exist wide differences between...

  • Raman A.V, Damodaran R., Levin L.A, Ganesh T., Rao Y.KV, Nanduri S., Madhusoodhanan R..  2015.  Macrobenthos relative to the oxygen minimum zone on the East Indian margin, Bay of Bengal. Marine Ecology-an Evolutionary Perspective. 36:679-700.
    Abstract Summary:

    The Bay of Bengal remains one of the least studied of the world's oxygen minimum zones (OMZs). Here we offer a detailed investigation of the macrobenthos relative to oxygen minimum zone [OMZ - DO (dissolved oxygen), concentration <0.5ml1(-1)] at 110 stations off the North East Indian margin (16(0) and 20(0)N) featuring coastal, shelf and slope settings (10-1004m). Macrobenthos (>0.5mm) composition, abundance and diversity were studied...

  • Bromirski PD, Diez A., Gerstoft P, Stephen R.A, Bolmer T., Wiens D.A, Aster R.C, Nyblade A..  2015.  Ross Ice Shelf vibrations. Geophysical Research Letters. 42:7589-7597.
    Abstract Summary:

    Broadband seismic stations were deployed across the Ross Ice Shelf (RIS) in November 2014 to study ocean gravity wave-induced vibrations. Initial data from three stations 100km from the RIS front and within 10km of each other show both dispersed infragravity (IG) wave and ocean swell-generated signals resulting from waves that originate in the North Pacific. Spectral levels from 0.001 to 10Hz have the highest accelerations in the IG band (0....

  • Gocke C., Janussen D., Reiswig H.M, Jarrell SC, Dayton PK.  2015.  Rossella podagrosa Kirkpatrick, 1907: A valid species after all. Zootaxa. 4021:169-177.
    Abstract Summary:

    In this study we provide evidence that the species Rossella podagrosa Kirkpatrick, 1907, commonly considered a synonym of Rossella racovitzae Topsent, 1901, is truly a valid species. We show that it can be clearly distinguished from other species especially when taking into consideration the in situ habitus of the sponge in combination with the spicules. Furthermore we demonstrate the weaknesses in the so far published synonymy concept for...

  • Hally-Rosendahl K., Feddersen F, Clark D.B, Guza RT.  2015.  Surfzone to inner-shelf exchange estimated from dye tracer balances. Journal of Geophysical Research-Oceans. 120:6289-6308.
    Abstract Summary:

    Surfzone and inner-shelf tracer dispersion are observed at an approximately alongshore-uniform beach. Fluorescent Rhodamine WT dye, released near the shoreline continuously for 6.5 h, is advected alongshore by breaking-wave- and wind-driven currents, and ejected offshore from the surfzone to the inner-shelf by transient rip currents. Novel aerial-based multispectral dye concentration images and in situ measurements of dye, waves, and currents...

  • Winters KB.  2015.  Tidally driven mixing and dissipation in the stratified boundary layer above steep submarine topography. Geophysical Research Letters. 42:7123-7130.
    Abstract Summary:

    A tidally driven, stratified boundary layer over supercritical topography is simulated numerically. The near-boundary flow is characterized by quasiperiodic, bore-like motions and episodic expulsion events where fluid is ejected into the stratified interior. The character of the bores is compared to the high-resolution ocean mooring data of van Haren (2006). The diffusivity of the flow near the boundary is estimated by means of a synthetic...

  • Gieskes JM, Han S, Rathburn A, Rothwell G, M. Pérez E, Porrachia M, Barbanti A, Deheyn DD.  2015.  Anthropogenic contaminants in Venice Lagoon sediments and their pore fluids: Results from the SIOSED Project. Marine Chemistry. 174:73-84.
    Abstract Summary:

    Investigations of sediment geochemistry and interstitial water chemistry during SIOSED (Scripps Institution of Oceanography Sediment Research Project) revealed information about the characteristics and depth range of contamination in sediments associated with dredging operations in the Venice Lagoon, Italy. Results from gravity cores indicate that contamination ranges larger and deeper in sediments associated with Porto Marghera and the...

  • Ulloa HN, Winters KB, de la Fuente A, Niño Y.  2015.  Degeneration of internal Kelvin waves in a continuous two-layer stratification. Journal of Fluid Mechanics. 777:68-96.
    Abstract Summary:

    We explore the evolution of the gravest internal Kelvin wave in a two-layer rotating cylindrical basin, using direct numerical simulations (DNS) with a hyper-viscosity/diffusion approach to illustrate different dynamic and energetic regimes. The initial condition is derived from Csanady’s (J. Geophys. Res., vol. 72, 1967, pp. 4151–4162) conceptual model, which is adapted by allowing molecular diffusion to smooth the discontinuous idealized...

  • Neal B.P, Lin T.H, Winter R.N, Treibitz T., Beijbom O., Kriegman D., Kline DI, Mitchell B.G.  2015.  Methods and measurement variance for field estimations of coral colony planar area using underwater photographs and semi-automated image. Environmental Monitoring and Assessment. 187
    Abstract Summary:

    Size and growth rates for individual colonies are some of the most essential descriptive parameters for understanding coral communities, which are currently experiencing worldwide declines in health and extent. Accurately measuring coral colony size and changes over multiple years can reveal demographic, growth, or mortality patterns often not apparent from shortterm observations and can expose environmental stress responses that may take...

  • Bertrand E.M, McCrow J.P, Moustafa A., Zheng H., McQuaid J.B, Delmont T.O, Post A.F, Sipler R.E, Spackeen J.L, Xu K. et al..  2015.  Phytoplankton-bacterial interactions mediate micronutrient colimitation at the coastal Antarctic sea ice edge. Proceedings of the National Academy of Sciences of the United States of America. 112:9938-9943.
    Abstract Summary:

    Southern Ocean primary productivity plays a key role in global ocean biogeochemistry and climate. At the Southern Ocean sea ice edge in coastal McMurdo Sound, we observed simultaneous cobalamin and iron limitation of surface water phytoplankton communities in late Austral summer. Cobalamin is produced only by bacteria and archaea, suggesting phytoplankton-bacterial interactions must play a role in this limitation. To characterize these...

  • Chenillat F, Franks PJS, Riviere P, Capet X, Grima N., Blanke B.  2015.  Plankton dynamics in a cyclonic eddy in the Southern California Current System. Journal of Geophysical Research-Oceans. 120:5566-5588.
    Abstract Summary:

    The California Current System is an eastern boundary upwelling system (EBUS) with high biological production along the coast. Oligotrophic offshore waters create cross-shore gradients of biological and physical properties, which are affected by intense mesoscale eddy activity. The influence of eddies on ecosystem dynamics in EBUS is still in debate. To elucidate the mechanisms that influence the dynamics of ecosystems trapped in eddies, and...

  • Suanda SH, Barth JA.  2015.  Semidiurnal baroclinic tides on the central Oregon inner shelf. Journal of Physical Oceanography.
    Abstract Summary:

    Semidiurnal velocity and density oscillations are examined over the mid and inner continental shelf near Heceta Bank on the Oregon coast. Measurements from two long-term observation networks with sites on and off the submarine bank reveal that both baroclinic velocities and displacements are dominated by the first mode, with larger velocities on the mid shelf and northern parts of the bank. Mid-shelf sites have current ellipses that are near...

  • Ramirez-Llodra E., Trannum H.C, Evenset A., Levin L.A, Andersson M., Finne T.E, Hilario A., Flem B., Christensen G., Schaanning M. et al..  2015.  Submarine and deep-sea mine tailing placements: A review of current practices, environmental issues, natural analogs and knowledge gaps in Norway and internationally. Marine Pollution Bulletin. 97:13-35.
    Abstract Summary:

    The mining sector is growing in parallel with societal demands for minerals. One of the most important environmental issues and economic burdens of industrial mining on land is the safe storage of the vast amounts of waste produced. Traditionally, tailings have been stored in land dams, but the lack of land availability, potential risk of dam failure and topography in coastal areas in certain countries results in increasing disposal of...

  • Levin LA, Mendoza GF, Grupe BM, Gonzalez JP, Jellison B, Rouse G, Thurber AR, Waren A.  2015.  Biodiversity on the rocks: Macrofauna inhabiting authigenic carbonate at Costa Rica methane seeps. Plos One. 10:e0131080.
    Abstract Summary:

    The activity of anaerobic methane oxidizing microbes facilitates precipitation of vast quantities of authigenic carbonate at methane seeps. Here we demonstrate the significant role of carbonate rocks in promoting diversity by providing unique habitat and food resources for macrofaunal assemblages at seeps on the Costa Rica margin (400–1850 m). The attendant fauna is surprisingly similar to that in rocky intertidal shores, with numerous...

  • Asch R.G.  2015.  Climate change and decadal shifts in the phenology of larval fishes in the California Current ecosystem. Proceedings of the National Academy of Sciences of the United States of America. 112:E4065-E4074.
    Abstract Summary:

    Climate change has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such changes are occurring in Eastern Boundary Current Upwelling ecosystems, because these regions are subject to natural decadal climate variability, and regional climate models predict seasonal delays in upwelling. To answer this question, the phenology of 43 species of larval fishes was investigated between 1951 and 2008 off southern...

  • Brzezinski M.A, Krause J.W, Bundy R.M, Barbeau K.A, Franks P., Goericke R, Landry MR, Stukel M.R.  2015.  Enhanced silica ballasting from iron stress sustains carbon export in a frontal zone within the California Current. Journal of Geophysical Research-Oceans. 120:4654-4669.
    Abstract Summary:

    Nutrient dynamics, phytoplankton rate processes, and export were examined in a frontal region between an anticyclone and a pair of cyclones 120 km off the coast in the southern California Current System (sCCS). Low silicic acid: nitrate ratios (Si:N) and high nitrate to iron ratios (N: Fe) characteristic of Fe-limiting conditions in the sCCS were associated with the northern cyclone and with the transition zone between the cyclones and the...

  • Highlighted Publication Schematic viewof dielcycle of dissipation
    Franks PJS.  2015.  Has Sverdrup's critical depth hypothesis been tested? Mixed layers vs. turbulent layers Ices Journal of Marine Science. 72:1897-1907.
    Abstract Summary:

    Sverdrup (1953. On conditions for the vernal blooming of phytoplankton. Journal du Conseil International pour l'Exploration de la Mer, 18: 287295) was quite careful in formulating his critical depth hypothesis, specifying a "thoroughly mixed top layer" with mixing "strong enough to distribute the plankton organisms evenly through the layer". With a few notable exceptions, most subsequent tests of the critical depth hypothesis have ignored...

  • Jeong H.J, Lim A.S, Franks PJS, Lee K.H, Kim J.H, Kang N.S, Lee M.J, Jang S.H, Lee S.Y, Yoon E.Y et al..  2015.  A hierarchy of conceptual models of red-tide generation: Nutrition, behavior, and biological interactions. Harmful Algae. 47:97-115.
    Abstract Summary:

    Red tides - discolorations of the sea surface due to dense plankton blooms - occur regularly in coastal and offshore waters along much of the world's coastline. Red tides often cause large-scale mortalities of fish and shellfish and significant losses to the aquaculture and tourist industries of many countries. Therefore, understanding and predicting the mechanisms controlling the outbreak, persistence, spread, and decline of red tides are...

  • Spydell M.S, Feddersen F, Olabarrieta M., Chen J.L, Guza RT, Raubenheimer B., Elgar S..  2015.  Observed and modeled drifters at a tidal inlet. Journal of Geophysical Research-Oceans. 120:4825-4844.
    Abstract Summary:

    Material transport and dispersion near the mouth of a tidal inlet (New River Inlet, NC) are investigated using GPS-tracked drifters and numerical models. For ebb tide releases, velocities are largest (> 1 ms(-1)) in two approximately 30 m wide channels that bisect the 1-3 m deep ebb shoal. In the channels, drifter and subsurface current meter velocities are similar, consistent with strong vertical mixing and 2-D hydrodynamics. Drifters...

  • Kahru M, Jacox M.G, Lee Z., Kudela R.M, Manzano-Sarabia M., Mitchell B.G.  2015.  Optimized multi-satellite merger of primary production estimates in the California Current using inherent optical properties. Journal of Marine Systems. 147:94-102.
    Abstract Summary:

    Building a multi-decadal time series of large-scale estimates of net primary production (NPP) requires merging data from multiple ocean color satellites. The primary product of ocean color sensors is spectral remote sensing reflectance (Rrs). We found significant differences (13-18% median absolute percent error) between Rrs estimates at 443 nm of different satellite sensors. These differences in Rrs are transferred to inherent optical...

  • de Verneil A., Franks PJS.  2015.  A pseudo-Lagrangian method for remapping ocean biogeochemical tracer data: Calculation of net Chl-a growth rates. Journal of Geophysical Research-Oceans. 120:4962-4979.
    Abstract Summary:

    A key goal in understanding the ocean's biogeochemical state is estimation of rates of change of critical tracers, particularly components of the planktonic ecosystem. Unfortunately, because ship survey data are not synoptic, it is difficult to obtain spatially resolved estimates of the rates of change of tracers sampled in a moving fluid. Here we present a pseudo-Lagrangian transformation to remap data from under-way surveys to a pseudo-...

  • Suanda SH, Feddersen F.  2015.  A self-similar scaling for cross-shelf exchange driven by transient rip currents. Geophysical Research Letters. 42:5427-5434.
    Abstract Summary:

    Transient rip currents, episodic offshore flows from the surf zone to the inner shelf, present a recreational beach hazard and exchange material across the nearshore ocean. The magnitude and offshore extent of transient rip-current-induced exchange and its relative importance to other inner shelf exchange processes are poorly understood. Here 120 model simulations with random, normally incident, directionally spread waves spanning a range of...

  • Highlighted Publication Unit source locations generating the largest amplitude waves at target sites on the U.S. West Coast.
    Rasmussen L., Bromirski PD, Miller AJ, Arcas D., Flick RE, Hendershott M.C.  2015.  Source location impact on relative tsunami strength along the US West Coast. Journal of Geophysical Research-Oceans. 120:4945-4961.
    Abstract Summary:

    Tsunami propagation simulations are used to identify which tsunami source locations would produce the highest amplitude waves on approach to key population centers along the U.S. West Coast. The reasons for preferential influence of certain remote excitation sites are explored by examining model time sequences of tsunami wave patterns emanating from the source. Distant bathymetric features in the West and Central Pacific can redirect tsunami...

  • Sperling E.A, Wolock C.J, Morgan A.S, Gill B.C, Kunzmann M., Halverson G.P, Macdonald F.A, Knoll A.H, Johnston D.T.  2015.  Statistical analysis of iron geochemical data suggests limited late Proterozoic oxygenation. Nature. 523:451-454.
    Abstract Summary:

    Sedimentary rocks deposited across the Proterozoic-Phanerozoic transition record extreme climate fluctuations, a potential rise in atmospheric oxygen or re-organization of the seafloor redox landscape, and the initial diversification of animals(1,2). It is widely assumed that the inferred redox change facilitated the observed trends in biodiversity. Establishing this palaeoenvironmental context, however, requires that changes in marine redox...

  • Beijbom O., Edmunds P.J, Roelfsema C., Smith J., Kline DI, Neal B.P, Dunlap M.J, Moriarty V., Fan TY, Tan C.J et al..  2015.  Towards automated annotation of benthic survey images: Variability of human experts and operational modes of automation. Plos One. 10
    Abstract Summary:

    Global climate change and other anthropogenic stressors have heightened the need to rapidly characterize ecological changes in marine benthic communities across large scales. Digital photography enables rapid collection of survey images to meet this need, but the subsequent image annotation is typically a time consuming, manual task. We investigated the feasibility of using automated point-annotation to expedite cover estimation of the 17...

  • Breitburg D.L, Salisbury J., Bernhard J.M, Cai W.J, Dupont S., Doney SC, Kroeker K.J, Levin L.A, Long W.C, Milke L.M et al..  2015.  And on top of all that... Coping with ocean acidification in the midst of many stressors. Oceanography. 28:48-61.
    Abstract Summary:

    Oceanic and coastal waters are acidifying due to processes dominated in the open ocean by increasing atmospheric CO2 and dominated in estuaries and some coastal waters by nutrient-fueled respiration. The patterns and severity of acidification, as well as its effects, are modified by the host of stressors related to human activities that also influence these habitats. Temperature, deoxygenation, and changes in food webs are particularly...

  • Levin L.A, Honisch B., Frieder C.A.  2015.  Geochemical proxies for estimating faunal exposure to ocean acidification. Oceanography. 28:62-73.
    Abstract Summary:

    Growing concern over the impacts of modern ocean acidification (OA) and interest in historical pH excursions have intensified the development of geochemical proxies for organism exposure to acidification and other components of the carbonate system. The use of carbonate structures produced by foraminifers, coccolithophores, corals, mollusks, brachiopods, echinoderms, ostracods, and fish for paleoreconstructions is an active area of study, and...

  • Mehring A.S, Kuehn K.A, Thompson A., Pringle C.M, Rosemond A.D, First M.R, Lowrance R.R, Vellidis G..  2015.  Leaf litter nutrient uptake in an intermittent blackwater river: influence of tree species and associated biotic and abiotic drivers. Functional Ecology. 29:849-860.
    Abstract Summary:

    1. Organic matter may sequester nutrients as it decomposes, increasing in total N and P mass via multiple uptake pathways. During leaf litter decomposition, microbial biomass and accumulated inorganic materials immobilize and retain nutrients, and therefore, both biotic and abiotic drivers may influence detrital nutrient content. We examined the relative importance of these types of nutrient immobilization and compared patterns of nutrient...

  • Kumar N., Feddersen F, Uchiyama Y., McWilliams J., O'Reilly W..  2015.  Midshelf to surfzone coupled ROMS-SWAN model data comparison of waves, currents, and temperature: Diagnosis of subtidal forcings and response. Journal of Physical Oceanography. 45:1464-1490.
    Abstract Summary:

    A coupled wave and circulation model that includes tide, wind, buoyancy, and wave processes is necessary to investigate tracer exchange in the shelf region. Here, a coupled Regional Ocean Model System (ROMS)-Simulating Waves Nearshore (SWAN) model, resolving midshelf to the surfzone region of the San Pedro Bay, California, is compared to observations from the 2006 Huntington Beach experiment. Waves are well modeled, and surfzone cross- and...

  • Kline DI, Teneva L., Hauri C., Schneider K., Miard T., Chai A., Marker M., Dunbar R., Caldeira K., Lazar B. et al..  2015.  Six month in situ high-resolution carbonate chemistry and temperature study on a coral reef flat reveals asynchronous pH and temperature anomalies. Plos One. 10
    Abstract Summary:

    Understanding the temporal dynamics of present thermal and pH exposure on coral reefs is crucial for elucidating reef response to future global change. Diel ranges in temperature and carbonate chemistry parameters coupled with seasonal changes in the mean conditions define periods during the year when a reef habitat is exposed to anomalous thermal and/or pH exposure. Anomalous conditions are defined as values that exceed an empirically...

  • Winters KB.  2015.  Tidally-forced flow in a rotating, stratified, shoaling basin. Ocean Modelling. 90:72-81.
    Abstract Summary:

    Baroclinic flow of a rotating, stratified fluid in a parabolic basin is computed in response to barotropic tidal forcing using the nonlinear, non-hydrostatic, Boussinesq equations of motion. The tidal forcing is derived from an imposed, boundary-enhanced free-surface deflection that advances cyclonically around a central amphidrome. The tidal forcing perturbs a shallow pycnocline, sloshing it up and down over the shoaling bottom....

  • Davison P.C, Koslow JA, Kloser R.J.  2015.  Acoustic biomass estimation of mesopelagic fish: backscattering from individuals, populations, and communities. Ices Journal of Marine Science. 72:1413-1424.
    Abstract Summary:

    Acoustic survey methods are useful to estimate the distribution, abundance, and biomass of mesopelagic fish, a key component of open ocean ecosystems. However, mesopelagic fish pose several challenges for acoustic biomass estimation based on their small size, wide depth range, mixed aggregations, and length-dependent acoustic reflectance, which differentiate them from the larger epipelagic and neritic fish for which these methods were...

  • Abstract Summary:

    We report cross-frontal changes in the characteristics of plankton proxy variables measured by autonomous Spray ocean gliders operating within the Southern California Current System (SCCS). A comparison of conditions across the 154 positive frontal gradients (i.e., where density of the surface layer decreased in the offshore direction) identified from six years of continuous measurements showed that waters on the denser side of the fronts...

  • Jackson G.A, Checkley DM, Dagg M..  2015.  Settling of particles in the upper 100 m of the ocean detected with autonomous profiling floats off California. Deep-Sea Research Part I-Oceanographic Research Papers. 99:75-86.
    Abstract Summary:

    We have deployed an autonomous profiling float, the SOLOPC, to sample the concentration of particles larger than 100 mu m off the California coast at approximately hourly intervals down to at least 100 m for periods as long as 12 d. We used the data to estimate total aggregate concentrations hourly at 2-m depth intervals, studying the dynamics of particle sedimentation in this difficult-to-sample region. We find that even over time scales of...

  • Gallo N.D, Cameron J., Hardy K., Fryer P., Bartlett DH, Levin L.A.  2015.  Submersible- and lander-observed community patterns in the Mariana and New Britain trenches: Influence of productivity and depth on epibenthic and scavenging communities. Deep-Sea Research Part I-Oceanographic Research Papers. 99:119-133.
    Abstract Summary:

    Deep-sea trenches remain one of the least explored ocean ecosystems due to the unique challenges of sampling at great depths. Five submersible dives conducted using the DEEPSEA CHALLENGER submersible generated video of undisturbed deep-sea communities at bathyal (994 m), abyssal (3755 m), and hadal (8228 m) depths in the New Britain Trench, bathyal depths near the Ulithi atoll (1192 m), and hadal depths in the Mariana Trench Challenger Deep (...

  • Maloney J.M, Grupe B.M, Pasulka A.L, Dawson K.S, Case D.H, Frieder C.A, Levin L.A, Driscoll NW.  2015.  Transpressional segment boundaries in strike-slip fault systems offshore southern California: Implications for fluid expulsion and cold seep habitats. Geophysical Research Letters. 42:4080-4088.
    Abstract Summary:

    The importance of tectonics and fluid flow in controlling cold seep habitats has long been appreciated at convergent margins but remains poorly understood in strike-slip systems. Here we present geophysical, geochemical, and biological data from an active methane seep offshore from Del Mar, California, in the inner California borderlands (ICB). The location of this seep appears controlled by localized transpression associated with a step in...

  • Bromirski PD, Cayan DR.  2015.  Wave power variability and trends across the North Atlantic influenced by decadal climate patterns. Journal of Geophysical Research-Oceans. 120:3419-3443.
    Abstract Summary:

    Climate variations influence North Atlantic winter storm intensity and resultant variations in wave energy levels. A 60 year hindcast allows investigation of the influence of decadal climate variability on long-term trends of North Atlantic wave power, P-W, spanning the 1948-2008 epoch. P-W variations over much of the eastern North Atlantic are strongly influenced by the fluctuating North Atlantic Oscillation (NAO) atmospheric circulation...

  • Karas BJ, Diner RE, Lefebvre SC, McQuaid J, Phillips APR, Noddings CM, Brunson JK, Valas RE, Deerinck TJ, Jablanovic J et al..  2015.  Designer diatom episomes delivered by bacterial conjugation. Nat Commun. 6
    Abstract Summary:

    Eukaryotic microalgae hold great promise for the bioproduction of fuels and higher value chemicals. However, compared with model genetic organisms such as Escherichia coli and Saccharomyces cerevisiae, characterization of the complex biology and biochemistry of algae and strain improvement has been hampered by the inefficient genetic tools. To date, many algal species are transformable only via particle bombardment, and the introduced DNA is...

  • Parnell P.E.  2015.  The effects of seascape pattern on algal patch structure, sea urchin barrens, and ecological processes. Journal of Experimental Marine Biology and Ecology. 465:64-76.
    Abstract Summary:

    Seascapes are the marine analog of terrestrial landscapes, and their importance for ecological processes in marine ecosystems is generally poorly known. This is especially true for giant kelp (Macrocystis pyrifera) forests for which the acquisition of high resolution acoustic terrain data is problematic due to canopy cover. The goal of this study was to determine the effects of geologically forced seascape structure on algal patch structure,...

  • Highlighted Publication Scanning electronic micrographs illustrating different types of shell dissolution.
    Bednarsek N., Ohman MD.  2015.  Changes in pteropod distributions and shell dissolution across a frontal system in the California Current System. Marine Ecology Progress Series. 523:93-103.
    Abstract Summary:

    We tested the sensitivity of the vertical distributions and shell dissolution patterns of thecosome pteropods to spatial gradients associated with an eddy-associated front in the southern California Current System. The aragonite saturation horizon (Omega(arag) = 1.0) shoaled from > 200 to <75 m depth across the front. The vertical distribution of thecosome pteropods tracked these changes, with all 5 species showing reduced occurrence at...

  • Helly J.J, Vernet M, Murray A.E, Stephenson G.R.  2015.  Characteristics of the meltwater field from a large Antarctic iceberg using delta O-18. Journal of Geophysical Research-Oceans. 120:2259-2269.
    Abstract Summary:

    Large tabular icebergs represent a disruptive influence on a stable water column when drifting in the open ocean. This is a study of one iceberg, C18A, encountered in the Powell Basin in the Weddell Sea in March 2009, formed from iceberg C18 ( 76x7km) originating from the Ross Ice Shelf in May 2002. C18A was lunate in shape with longest dimensions of 31kmx7kmx184m. The meltwater field from C18A was characterized using 18O from water samples...

  • Luo M, Dale AW, Wallmann K, Hensen C, Gieskes J, Yan W, Chen D.  2015.  Estimating the time of pockmark formation in the SW Xisha Uplift (South China Sea) using reaction-transport modeling. Marine Geology. 364:21-31.
    Abstract Summary:

    Carbon cycling and fluid seepage in marine sediments over the late Quaternary were investigated at a now-extinct pockmark located in a mega-pockmark field in the SW Xisha Uplift (NW South China Sea). Measured particulate organic carbon (POC) content, and porewater sulfate (SO42 −), dissolved inorganic carbon (DIC) concentrations and δ34S-SO42 − distributions were used to constrain a non-steady-state reaction-transport model and quantify POC...

  • Gallien T.W, O'Reilly W.C, Flick RE, Guza RT.  2015.  Geometric properties of anthropogenic flood control berms on southern California beaches. Ocean & Coastal Management. 105:35-47.
    Abstract Summary:

    Coastal flood riskfrom coincident high tides' and energetic waves is concentrated around low-lying urban areas. Municipalities construct temporary sand berms (also known as sacrificial dunes) to manage potential flooding, however the relationships between berm geometry (e.g., height, width and length) and performance are not understood. Concomitant pressures of sea level rise and urbanization will increase active beach berming. Effective...