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Published journal articles by MLML faculty, staff and students. Full text is included when copyright allows.


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Temporal variation in seaweed and invertebrate assemblages in shallow rhodolith beds of Baja California Sur, México
Temporal variation in seaweed and invertebrate assemblages in shallow rhodolith beds of Baja California Sur, México
We assessed temporal variation (2013-2015) in rhodolith (non-geniculate corallines) size and cover, as well as variability in associated macroalgae and invertebrates in one rhodolith bed from the Gulf of California and two on the Pacific Coast of Baja California Sur, México. While rhodoliths persisted at all sites, those in the Gulf were less abundant (Lithothamnion muelleri: 10-14% cover) compared to Pacific sites (Lithophyllum margaritae: 40-64% cover). Rhodoliths from Pacific sites were influenced by storms and tidal currents that shifted beds and redistributed fine sediments. At the Gulf site, 30 macroalgal taxa were encountered and abundance peaked during spring (76-78% cover) and early summer (73-97% cover), then declined following extreme summer heat (22-25% cover) suggesting algae cycle in response to seasonal temperature changes. At Pacific sites, 14 macroalgal taxa were encountered with highest covers observed in winter 2014 (44%) and spring 2015 (26%). Seasonality was potentially masked by algal blooms or inter-annual temperature variation. Sessile invertebrate cover was low at the Gulf site (typically <7%) and ranged from 3-21% at Pacific sites, while mobile invertebrates were dominated by arthropods (Gulf: 1-3 ind m−2, Pacific: 1-91 ind m−2) and molluscs (Gulf: 0-2 ind m−2, Pacific: 9-470 ind m−2). Invertebrate assemblages did not vary seasonally at any site and were likely impacted by episodic recruitment as well as other biotic and abiotic factors. Detailed life history studies and more complete environmental data are needed to better connect relationships between biological patterns observed in rhodolith beds worldwide and associated environmental factors.
Temporal variation in the artisanal elasmobranch fishery of Sonora, Mexico
Temporal variation in the artisanal elasmobranch fishery of Sonora, Mexico
Baseline, species-specific information is largely unavailable for artisanal elasmobranch fisheries, but is essential for the monitoring of exploited populations and the development of effective management plans. Seasonal surveys were conducted during 1998-1999 in Sonora, Mexico to determine the extent and activities of artisanal elasmobranch fisheries operating in the eastern Gulf of California. Nineteen fishing sites were documented, the majority of which (84.2%) targeted elasmobranchs during some part of the year. Most small demersal sharks and rays were landed in bottom set gillnet fisheries that also targeted demersal teleosts, whereas large sharks were usually taken in directed surface longline or, to a lesser extent, drift gillnet fisheries. Rays numerically dominated sampled landings in Sonora (63.4%, n = 100,136), and catch rates exceeded those of sharks during spring and summer months. The shovelnose guitarfish, Rhinobatos productus, was the primary fishery target during these seasons. During autumn, small sharks, especially mustelids (Mustelus spp.) were numerically dominant, but rays (e.g., Dasyatis dipterura) were also caught in large numbers. Winter landings in Sonora were principally composed of mustelid sharks, which represented the greatest seasonal catch rates of all elasmobranch taxa during this study. Large sharks were of comparably minor importance, with a limited summer fishery operating in the southern part of the state. Variation in catch composition was evident in association with differential interannual environmental conditions (El Niño and La Niña) and seasonal temperature fluctuations. Size composition of landings varied greatly by species, but relatively small size classes of sharks and rays were abundant and large, often gravid females of several ray species (e.g., R. productus and Narcine entemedor) supported spring and summer fisheries in nearshore waters. Populations of many large shark species (e.g., Carcharhinus leucas, Carcharhinus limbatus, Carcharhinus obscurus and Galeocerdo cuvier) have likely been overfished, prompting a shift in effort towards coastal populations of smaller elasmobranchs. © 2009 Elsevier B.V. All rights reserved., Cited By (since 1996):13, Fish and Fisheries, CODEN: FISRD
Ten years of-induced ocean warming causes comprehensive changes in marine benthic communities
Ten years of-induced ocean warming causes comprehensive changes in marine benthic communities
One of the most commonly predicted effects of global ocean warming on marine communities is a poleward shift in the distributional boundaries of species with an associated replacement of cold-water species by warm-water species. However, these types of predictions are imprecise and based largely on broad correlations in uncontrolled studies that examine changes in the distribution or abundances of species in relation to seawater temperature. Our study used an 18-year sampling program in intertidal and subtidal habitats and before-after, control-impact analyses. We show that a 3.5°C rise in seawater temperature, induced by the thermal outfall of a power-generating station, over 10 years along 2 km of rocky coastline in California resulted in significant community-wide changes in 150 species of algae and invertebrates relative to adjacent control areas experiencing natural temperatures. Contrary to predictions based on current biogeographic models, there was no trend toward warmer-water species with southern geographic affinities replacing colder-water species with northern affinities. Instead, the communities were greatly altered in apparently cascading responses to changes in abundance of several key taxa, particularly habitat-forming subtidal kelps and intertidal foliose red algae. Many temperature-sensitive algae decreased greatly in abundance, whereas many invertebrate grazers increased. The responses of these benthic communities to ocean warming were mostly unpredicted and strongly coupled to direct effects of temperature on key taxa and indirect effects operating through ecological interactions., Cited By (since 1996):91, Seaweeds, CODEN: ECOLA
Tephrochronology of marine tephra adjacent to Central America
Tephrochronology of marine tephra adjacent to Central America
Geochemical analyses performed on volcanic ash layers from the 3 ocean basins surrounding Central America revealed 11 distinct tephra horizons during the past 300 000 yr, and the distribution of each tephra was delineated. The age of each layer was determined by correlation to oxygen isotope and calcium carbonate stratigraphy in marine cores or by interpolation or extrapolation of ages from that stratigraphy. Geochemical correlation of the marine tephra to other terrestrial sources will facilitate dating of explosive volcanic eruptions in southern Mexico, Central America, and northern South America. -from Author, Cited By (since 1996):15, Rocks and Cores
Tephrochronology of the western Gulf of Mexico for the last 185,000 years
Tephrochronology of the western Gulf of Mexico for the last 185,000 years
Tephra in 31 piston cores from the western Gulf of Mexico and 7 piston cores from the equatorial Pacific were analyzed by electron microprobe. Six ash layers in the western Gulf of Mexico were easily distinguished by TiO2, FeO, and CaO contents and correlated by geochemistry in order to determine the distribution pattern for each ash layer. Correlation by geochemistry is an easier, more accurate method than biostratigraphic correlation; some of the tephras were miscorrelated by biostratigraphy. The six tephras were dated by geochemical identification in a piston core with oxygen-isotope stratigraphy and the ages are Y5 (30,000 yr B.P.), Y6 (65,000 yr B.P.), Y8 (84,000 yr B.P.), X2 (110,000 yr B.P.), W1 (136,000 yr B.P.), and W2 (185,000 yr B.P.). Data from this study corroborated correlations of the Y8 tephra in the western Gulf of Mexico with the D layer in the eastern equatorial Pacific Ocean. None of the other five layers in the Gulf of Mexico, however, were found in the Pacific Ocean. The limited distribution of the Y5, Y6, X2, and W2 ash layers close to Mexico indicates possible sources in Mexico. Tephra from the late Pleistocene La Primavera pumice in Mexico, however, does not correlate with the marine tephra. © 1985., Cited By (since 1996):7, Rocks and Cores
Terminal deoxynucleotidyl transferases from elasmobranchs reveal structural conservation within vertebrates
Terminal deoxynucleotidyl transferases from elasmobranchs reveal structural conservation within vertebrates
The DNA polymerase (pol) X family is an ancient group of enzymes that function in DNA replication and repair (pol β), translesion synthesis (pol λ and pol μ) and terminal addition of non-templated nucleotides. This latter terminal deoxynucleotidyl transferase (TdT) activity performs the unique function of providing diversity at coding joins of immunoglobulin and T-cell receptor genes. The first isolated full-length TdT genes from shark and skate are reported here. Comparisons with the three-dimensional structure of mouse TdT indicate structural similarity with elasmobranch orthologues that supports both a template-independent mode of replication and a lack of strong nucleotide bias. The vertebrate TdTs appear more closely related to pol μ and fungal polymerases than to pol λ and pol β. Thus, unlike other molecules of adaptive immunity, TdT is a member of an ancient gene family with a clear gene phylogeny and a high degree of similarity, which implies the existence of TdT ancestors in jawless fishes and invertebrates., Cited By (since 1996):10, Fish and Fisheries, CODEN: IMNGB
Testing tag attachments to increase the attachment duration of archival tags on baleen whales
Testing tag attachments to increase the attachment duration of archival tags on baleen whales
As biologging technology has advanced to study whale behavior, various tag attachment methods have been developed. Suction cup attachments were developed for short-term (<24 h) studies using high-resolution archival tags, and implantable or dart attachments were developed for long-term (months) studies using coarse-resolution satellite tags. The purpose of this study was to test various tag attachment configurations to increase the deployment duration of archival tags while minimizing potential physical impacts to the whale.
Testing the iron hypothesis in ecosystems of the equatorial Pacific Ocean
Testing the iron hypothesis in ecosystems of the equatorial Pacific Ocean
The idea that iron might limit phytoplankton growth in large regions of the ocean has been tested by enriching an area of 64 km 2 in the open equatorial Pacific Ocean with iron. This resulted in a doubling of plant biomass, a threefold increase in chlorophyll and a fourfold increase in plant production. Similar increases were found in a chlorophyll-rich plume down-stream of the Galapagos Islands, which was naturaly enriched in iron. These findings indicate that iron limitation can control rates of phytoplankton productivity and biomass in the ocean., Cited By (since 1996):749, Oceanography, CODEN: NATUA
Tetronarce cowleyi, sp. nov., a new species of electric ray from southern Africa
Tetronarce cowleyi, sp. nov., a new species of electric ray from southern Africa
A new species of torpedo ray, Tetronarce cowleyi, sp. nov., is described from specimens collected from the southeastern Atlantic Ocean. The new species is placed in the genus Tetronarce based on a uniform dorsal coloration and absence of papillae around the spiracles. The new species is distinguished from its closest congeners, the North Atlantic Tetronarce nobiliana Bonnaparte, 1835, and southwestern Atlantic Tetronarce puelcha Lahille, 1926, by a combination of morphological characteristics including a shorter spiracular length, a proportionally greater head length as measured between snout margin and fifth gill openings, a proportionally greater preoral snout length, a uniform shiny black or dark gray dorsal surface, lacking any prominent markings, and a creamy white ventral color with dark edges in juveniles but fading with growth. Teteronarce cowleyi, sp. nov., is further distinguished from T. nobiliana by its more circular anterior disc shape (vs. relatively straight in T. nobiliana), fewer tooth rows (32/28 vs. 38-53/38-52 in T. nobiliana), greater mouth width (1.5-1.7 times as great as interorbital width vs. 0.5-0.6 times interorbital width in T. nobiliana), smaller distance between second dorsal and caudal fins (3.5-4.9% vs. 6.6-6.8% in T. nobiliana), and a clasper length extending nearly to lower caudal fin origin (claspers in T. nobiliana that extend only two-thirds distance between second dorsal and caudal fins). Teteronarce cowleyi, sp. nov., is known from Walvis Bay, Namibia to Algoa Bay, Eastern Cape, South Africa, at depths of 110 to 457 m. Copyright © 2015 Magnolia Press., Export Date: 26 June 2015
Thallium concentrations in seawater
Thallium concentrations in seawater
Measurements of the concentration of thallium in seawater collected from numerous ocean locations ranged from 12 to 16 ng kg-1. Variations between the Atlantic and Pacific Oceans, between the northern and southern hemispheres of the Pacific Ocean, and between surface and deep waters of both the Pacific and Atlantic oceans were comparable with the precision of the analyses. This relatively constant distribution indicates that the element's cycle in seawater may be similar to those of the alkali metals which are its principal biogeochemical analogues. © 1985., Cited By (since 1996):34, Oceanography, CODEN: MRCHB
The 154-year record of sea level at San Francisco: Extracting the long-term trend, recent changes, and other tidbits
The 154-year record of sea level at San Francisco: Extracting the long-term trend, recent changes, and other tidbits
A data adaptive method called ensemble empirical mode decomposition (EEMD) is used to examine the 154-year record of monthly sea level at San Francisco. The mode that is lowest in frequency corresponds to the long-term trend. The next highest mode corresponds to an oscillation with a period of ~100 years and may be related to solar variability. When this mode is combined with the long-term trend, the rate of increase in sea level starts to decrease by ~1980. The next lower mode corresponds to interdecadal time scales and thus includes the Pacific Decadal Oscillation. When combined with the two lower modes, sea level itself starts to decrease by the mid-1990s. These results are consistent with the most recent results from the intergovernmental panel on climate change (IPCC), and may be the first obtained from a tidal record. Prior to conducting EEMD, corrections for glacial isostatic adjustment (GIA) and the inverse barometer (IB) effect were applied. The effect of applying the GIA correction was relatively small, but the IB correction reduced the slope of the long-term trend in sea level by almost 15%. This reduction is due to a long-term increase in the variance of sea level pressure. To determine if the 10-15 year ENSO modulation cycle could be detected from the decomposition we first compared the envelope from the mode associated with ENSO, with the two adjacent modes that were lower in frequency. Spectral analysis revealed no significant maxima in the ENSO mode envelope, but a major peak in the spectrum for the two adjacent modes, with a period of 12. 8 years. This is consistent with a local response to El Niño warming for the ENSO mode, but a non-local response for the two adjacent modes. A similar analysis was performed for the Southern Oscillation Index and a spectral maximum was found between 12 and 16 years, consistent with our non-local interpretation of the previous two modes. © 2010 Springer-Verlag., Cited By (since 1996):5, Oceanography
The ARTEMIS under-ice AUV docking system
The ARTEMIS under-ice AUV docking system
The ARTEMIS docking system demonstrates autonomous docking capability applicable to robotic exploration of sub-ice oceans and sub-glacial lakes on planetary bodies, as well as here on Earth. In these applications, melted or drilled vertical access shafts restrict vehicle geometry as well as the in-water infrastructure that may be deployed. The ability of the vehicle to return reliably and precisely to the access point is critical for data return, battery charging, and/or vehicle recovery. This paper presents the mechanical, sensor, and software components that make up the ARTEMIS docking system, as well as results from field deployment of the system to McMurdo Sound, Antarctica in the austral spring of 2015. The mechanical design of the system allows the vehicle to approach the dock from any direction and to pitch up after docking for recovery through a vertical access shaft. It uses only a small volume of in-water equipment and may be deployed through a narrow vertical access shaft. The software of the system reduces position estimation error with a hierarchical combination of dead reckoning, acoustic aiding, and machine vision. The system provides critical operational robustness, enabling the vehicle to return autonomously and precisely to the access shaft and latch to the dock with no operator input.
The Academic Fleet - Past, Present and Future
The Academic Fleet - Past, Present and Future
The University-National Oceanographic Laboratory System (UNOLS) is a consortium of 57 academic institutions with significant marine programs that either operate or use the U.S. academic research fleet. The goal of UNOLS is to optimize scientific and economic efficiency of the Fleet and to ensure that national planning for new ships is undertaken. As a result of this planning and coordination, the 28 research vessels in the UNOLS Fleet stand as the largest and most capable fleet of oceanographic research vessels in the world. The UNOLS Fleet is utilized by scientists from all across the country and many institutions beyond those that are UNOLS members. These seagoing facilities provide the platforms on which the bulk of American oceanographic research is performed. The Fleet is made up of different ships with different operational management and different funding profiles yet commonly seeking to provide state-of-the-art, cost effective, seagoing science platforms. This paper will review the history of UNOLS and the process by which it has evolved. It will explain the unique relationships between the UNOLS institutions and their relationship with the federal agencies funding oceanographic science., Vessels & Voyages, CODEN: MTSJB
The Experimental Economy of Geoengineering
The Experimental Economy of Geoengineering
Will the practical application of geoengineering technologies inadvertently bring about the catastrophic futures they are meant to pre-empt? And is such elicitation of unpredictability as unintended as it might appear ? the accidental consequence of the extension of a modernist attitude to control and domesticate nature? To grasp what is at stake in such questions, this paper traces out the marginal history of ocean geoengineering, its correlative ?green? economy, and through the deployment of algae as an inventive world-remaking device, their co-formation of the earth as a site of unbounded experimentation ? of what I call experiment earth. My argument here is that such methods of geoengineering inject disturbances into the algae-ocean-earth system that do not seek control, but to elicit surprise and explicate the mechanisms of the complex permutations of their unpredictability, where new forms of knowledge and value are created not through the application of preconceived ideas or a process of commensuration, but through the harnessing of anticipation and the generation of surprise. How, I ask, are we to understand the lineaments of a pre-emptive ?green? economy that is premised on not just managing, but speculatively materially recomposing the non-linear chemical and ecological constitution of the earth?s metabolism? And what, from this vantage point, is the earth becoming?
The History of Jelly Husbandry at the Monterey Bay Aquarium
The History of Jelly Husbandry at the Monterey Bay Aquarium
The Monterey Bay Aquarium (MBA) has been exhibiting jellyfish since 1985. Mr. David Powell, MBA's first Curator, learned culturing techniques for moon jellies (Aurelia aurita) from Mr. Yoshitaka Abe, who was then Curator at Ueno Zoo. Abe-san sent Mr. Powell and his staff their first Aurelia aurita polyps, and they used his tank design to build MBA's first moon jelly exhibit. Since those early days, a number of passionate aquarists have sought to find new gelatinous species to culture and new ways to interpret them to the public. After the first moon jelly exhibit, MBA next exhibited jellyfish in the temporary exhibitions Living Treasures of the Pacific (1989) and Planet of the Jellies (1992), testing out not only the ability to maintain a jellyfish gallery long term but also the public's interest in these ill-known creatures. In 1996, MBA committed to a permanent jellyfish gallery. The construction of the Outer Bay Wing included the Drifters Gallery, which exhibits jellyfish species local to Monterey Bay and the California coast. In the subsequent years, MBA continued to work with tropical and other exotic species in temporary exhibitions, including Jellies: Living Art and The Jellies Experience. These exhibitions gave the team opportunities to experiment with new ways to culture and exhibit unique species. In addition, MBA has been able to contribute to science by describing the life cycles of several jellyfish species and discovering new jellyfish species in the Monterey Submarine Canyon. MBA's work has not been conducted in a vacuum, however, as we have collaborated with institutions in the United States, Japan, and around the world to expand our collective knowledge of jellyfish husbandry.
The Marine Optical Buoy (MOBY) radiometric calibration and uncertainty budget for ocean color satellite sensor vicarious calibration
The Marine Optical Buoy (MOBY) radiometric calibration and uncertainty budget for ocean color satellite sensor vicarious calibration
For the past decade, the Marine Optical Buoy (MOBY), an autonomous radiometric buoy stationed in the waters off Lanai, Hawaii, has been the primary in-water oceanic observatory for the vicarious calibration of U. S. satellite ocean color sensors, including the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate Resolution Imaging Spectrometer (MODIS) instruments on the National Aeronautics and Space Administration's (NASA's) Terra and Aqua satellites. The MOBY vicarious calibration of these sensors supports international efforts to develop a global, multi-year time series of consistently calibrated ocean color data products. A critical component of the MOBY program is establishing radiometric traceability to the International System of Units (SI) through standards provided by the U. S. National Institute of Standards and Technology (NIST). A detailed uncertainty budget is a core component of traceable metrology. We present the MOBY uncertainty budget for up-welling radiance and discuss approaches in new instrumentation to reduce the uncertainties in in situ water-leaving radiance measurements., Cited By (since 1996):10, Oceanography, Art. No.: 67441M, CODEN: PSISD
The Santa Barbara oil spill Part 1
The Santa Barbara oil spill Part 1
The quantity of oil which came ashore during the early stages of the Santa Barbara oil spill has been estimated from intertidal oil samples and aeirial photographs. These methods indicate that 4500 metric tons of crude oil were deposited on nearly 90 km of coast by 8 February 1969, 11 days after the spill began. Dosages in the intertidal zone varied from 2·7 to 118·1 metric tons/km. These dosage estimates suggest that the flow rate at the well was around 5000 barrels (726 metric tons)/day during the early stages of the spill. A large quantity of oil was held for varying periods of time in the surface canopies of offshore kelp beds. The interaction of wind, wave action, tides, and substrate determined the pattern of oil distribution within the intertidal zone.
The Santa Barbara oil spill Part 2
The Santa Barbara oil spill Part 2
The initial effects of the Santa Barbara oil spill on intertidal and kelp bed organisms were studied. Based on earlier surveys, the greatest negative biological change at a sample station after the spill was the loss of 16 plant species. However, losses in species were correlated in most cases with sand movement, and may have been related to the severe storms which occurred before and during the oil spill. Although gross species changes were not correlated with oil dosage, severe damage occurred in intertidal surf grass and barnacle populations as a result of the oil pollution. Potential long-term biological effects of the continuing pollution are discussed.
The Santa Barbara oil spill ‑ an ecological disaster?
The Santa Barbara oil spill ‑ an ecological disaster?
In its initial stages, the 1969 Santa Barbara oil spill released over 70,000 barrels of crude oil into the Santa Barbara Channel. This oil eventually polluted the entire channel and over 230 km of mainland and Channel Islands shore. The greates known damage occured in surfgrass communities and barnacle and bird populations; an estimated 9,000,000 barnacles and 9,000 birds were killed, and over 14 tonnes of surfgrass blades and associated organisms were lost. The oil also affected other populations, but, in general total damage cannot be determined. Cleanup procedures resulted in additional damage on both rocky shores and sandy beaches. Although some populations have recovered, the lack of prespill and postspill information makes it impossible to determine adequately the long-term effects. In addition, the side of the spill, diversity of habitats affected, and lack of ecological information combine to make an overall "disaster" assessment impossible. The inherent difficulties in assessing biological damage and recovery resulting from such a pollution incident suggest that every effort must be made to prevent and contain future spills.

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