Monterey Bay Aquarium Research Institute

About: Monterey Bay Aquarium Research Institute is a nonprofit organization based out in Castroville, California, United States. It is known for research contribution in the topics: Upwelling & Population. The organization has 630 authors who have published 2068 publications receiving 119899 citations. The organization is also known as: Monterey Bay Aquarium and Research Institute & MBARI.

Three‐dimensional acoustic monitoring and modeling of a deep‐sea CO2 droplet cloud

Abstract: [1] We show that release of 5 liters of liquid CO2 at 1000 m depth can be readily detected acoustically, and tracked for over 30 minutes, and 150 m of ascent, with both surface ship (38 kHz) and ROV (675 kHz) sonars. The released liquid broke up into droplets covered with a hydrate film. The remarkably sensitive acoustic response of the droplets may be attributed to the high sound speed contrast between CO2 (300 m/sec) and sea water (1500 m/sec), the near spherical shape of the droplets created by the hydrate shell, and the high compressibility of the liquid. The observed cloud conformed closely to models of CO2 disposal, allowing for reasonable predictions of larger scale processes. This offers a remarkably sensitive technique for examination in real time of engineered releases of CO2, volcanic sea floor liquid CO2 plumes, or leakage from geologic CO2 storage.

The Role of Carrion Supply in the Abundance of Deep-Water Fish off California

Abstract: Few time series of deep-sea systems exist from which the factors affecting abyssal fish populations can be evaluated. Previous analysis showed an increase in grenadier abundance, in the eastern North Pacific, which lagged epibenthic megafaunal abundance, mostly echinoderms, by 9–20 months. Subsequent diet studies suggested that carrion is the grenadier's most important food. Our goal was to evaluate if changes in carrion supply might drive the temporal changes in grenadier abundance. We analyzed a unique 17 year time series of abyssal grenadier abundance and size, collected at Station M (4100 m, 220 km offshore of Pt. Conception, California), and reaffirmed the increase in abundance and also showed an increase in mean size resulting in a ~6 fold change in grenadier biomass. We compared this data with abundance estimates for surface living nekton (pacific hake and jack mackerel) eaten by the grenadiers as carrion. A significant positive correlation between Pacific hake (but not jack mackerel) and grenadiers was found. Hake seasonally migrate to the waters offshore of California to spawn. They are the most abundant nekton species in the region and the target of the largest commercial fishery off the west coast. The correlation to grenadier abundance was strongest when using hake abundance metrics from the area within 100 nmi of Station M. No significant correlation between grenadier abundance and hake biomass for the entire California current region was found. Given the results and grenadier longevity, migration is likely responsible for the results and the location of hake spawning probably is more important than the size of the spawning stock in understanding the dynamics of abyssal grenadier populations. Our results suggest that some abyssal fishes' population dynamics are controlled by the flux of large particles of carrion. Climate and fishing pressures affecting epipelagic fish stocks could readily modulate deep-sea fish dynamics.

Linking Direct Measurements of Turbidity Currents to Submarine Canyon-Floor Deposits

Abstract: Submarine canyons are conduits for episodic and powerful sediment density flows (commonly called turbidity currents) that move globally significant amounts of terrestrial sediment and organic carbon into the deep sea, forming some of the largest sedimentary deposits on Earth. The only record available for most turbidity currents is the deposit they leave behind. Therefore, to understand turbidity current processes, we need to determine the degree to which these flows are represented by their deposits. However, linking flows and deposits is a major long-standing scientific challenge. There are few detailed measurements from submarine turbidity currents in action, and even fewer direct measurements that can be compared to resulting seabed deposits. Recently, an extensive array of moorings along Monterey Canyon, offshore California, took measurements and samples during sediment density flow events, providing the most comprehensive dataset to date of turbidity current flows and their deposits. Here, we use sediment trap samples, velocity measurements, and seafloor cores to document how sand is transported through a submarine canyon, and how the transported sediment is represented in seafloor deposits. Sediment trap samples from events contain primarily fine to medium-grained sand with sharp bases, normal grading, and muddy tops. Sediment captured from the water column during the flow shows normal grading, which is broadly consistent with the initial peak and waning of flow velocities measured at a single height within the flow, and may be enhanced by collapsing flows. Flow events contain coarser sand concentrated toward the seafloor and larger grain sizes on the seafloor or in the dense near-bed layer, possibly representative of stratified flows. Although flow velocity varies, sand grain sizes in sediment traps are similar over distances of 50 km down-canyon, suggesting that grain size is an unfaithful record of down-canyon changes in maximum flow speeds. Sand transported within flow events and sampled in sediment traps is similar to sand sampled from the seafloor shortly after the events, but traps do not contain pebbles and gravel common in seabed deposits. Seabed deposits thus appear to faithfully record the sand component that is transported in the water column during sub-annual turbidity currents.

Monitoring of cold and light stress impact on photosynthesis by using the laser induced fluorescence transient (LIFT) approach

Abstract: Chlorophyll fluorescence measurements have been widely applied to quantify the photosynthetic efficiency of plantsnon-destructively.Themostcommonlyusedpulseamplitudemodulated(PAM)techniqueprovidesasaturatinglight pulse,whichisnotpracticalatthecanopyscale.Wereporthereonarecentlydevelopedtechnique,laserinduced fluorescence transient (LIFT),whichiscapableofremotelymeasuring thephotosyntheticefficiencyofselected leavesatadistance of up to50m.TheLIFTapproachcorrelatedwellwithgasexchangemeasurementsunderlaboratoryconditionsandwastestedin a field experiment monitoring the combined effect of low temperatures and high light intensity on a variety of plants during the early winter in California. We observed a reduction in maximum and effective quantum yield in electron transport for Capsicum annuum L., Lycopersicon esculentum L. and Persea americana Mill. as the temperatures fell, while a grass community was not affected by combined low temperature and high light stress. The ability to make continuous, automatic and remote measurements of the photosynthetic efficiency of leaves with the LIFT system provides a new approach for studying and monitoring of stress effects on the canopy scale.