Modern Ocean Research Articles

Storm and fair-weather wave base: A relevant distinction?

Surface waves are an important mechanism for the redistribution of sediment on shallow marine shelves, and are commonly interpreted as comprising two distinct populations: fairweather waves and storm waves, the latter of which are generally thought to penetrate to greater water depths. Here we used >2.3 ! 10 6 spectral density estimates for the surface ocean collected between 1996 and 2008 from 32 buoys in the Caribbean, the Gulf of Mexico, and the western Atlantic to test the hypothesis that surface waves in the modern ocean comprise two size modes. Although distinct wave size classes occur in some individual measurements and over the time scales of some individual storms, time-averaged frequency distributions of wave size are unimodal. Thus, there is no empirical basis for presupposing a distinct bimodal separation in the size of fair-weather and storm waves, or in the manifestation of such differences in stratigraphic successions. Instead, there is a continuously increasing probability that a wave will reach the bottom with decreasing water depth and a separate probability that describes the hydrodynamic state of the sediment-water interface. Wave size does, however, exhibit signifi cant geographic bimodality. Locations in the relatively protected Gulf of Mexico and Caribbean regions have modal wavelengths that are ~50 m less than waves at locations along the western Atlantic. Time-integrated estimates of the depth of wave penetration provide empirical constraints on the paleo-water depths of ancient sedimentary deposits and highlight differences between sheltered shelf environments, such as those that characterized many ancient epeiric seas, and open-ocean‐facing, narrow continental shelves.

Origin of first cells at terrestrial, anoxic geothermal fields.

All cells contain much more potassium, phosphate, and transition metals than modern (or reconstructed primeval) oceans, lakes, or rivers. Cells maintain ion gradients by using sophisticated, energy-dependent membrane enzymes (membrane pumps) that are embedded in elaborate ion-tight membranes. The first cells could possess neither ion-tight membranes nor membrane pumps, so the concentrations of small inorganic molecules and ions within protocells and in their environment would equilibrate. Hence, the ion composition of modern cells might reflect the inorganic ion composition of the habitats of protocells. We attempted to reconstruct the "hatcheries" of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells. These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K(+), Zn(2+), Mn(2+), and phosphate. Thus, protocells must have evolved in habitats with a high K(+)/Na(+) ratio and relatively high concentrations of Zn, Mn, and phosphorous compounds. Geochemical reconstruction shows that the ionic composition conducive to the origin of cells could not have existed in marine settings but is compatible with emissions of vapor-dominated zones of inland geothermal systems. Under the anoxic, CO(2)-dominated primordial atmosphere, the chemistry of basins at geothermal fields would resemble the internal milieu of modern cells. The precellular stages of evolution might have transpired in shallow ponds of condensed and cooled geothermal vapor that were lined with porous silicate minerals mixed with metal sulfides and enriched in K(+), Zn(2+), and phosphorous compounds.

“Tremendous Damage” or “Mere Pinpricks”: The Costs of Piracy

Abstract In the voluminous literature on historical piracy there is no convincing analysis of the actual impact of piracy on sea trade. This article attempts, in a preliminary way, such an analysis. Fragmentary data from the early modern Indian Ocean suggests that the cost of piracy was a minor imposition as compared with many other charges and dangers, some of them predictable, others not.

The molybdenum isotopic composition of the modern ocean

Natural variations in the isotopic composition of molybdenum (Mo) are showing increasing potential as a tool in geochemistry. Although the ocean is an important reservoir of Mo, data on the isotopic composition of Mo in seawater are scarce. We have recently developed a new method for the precise determination of Mo isotope ratios on the basis of preconcentration using a chelating resin and measurement by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), which allows us to measure every stable Mo isotope (Nakagawa et al., 2008). In this study, 172 seawater samples obtained from 9 stations in the Pacific, Atlantic, and Southern Oceans were analyzed, giving global coverage and the first full depth-profiles. The average isotope composition in δA/95Mo (relative to a Johnson Matthey Mo standard solution) was as follows: δ92/95Mo = -2.54 ± 0.16‰ (2SD), δ94/95Mo = -0.73 ± 0.19‰, δ96/95Mo = 0.85 ± 0.07‰, δ97/95Mo = 1.68 ± 0.08‰, δ98/95Mo = 2.48 ± 0.10‰, and δ100/95Mo = 4.07 ± 0.18‰. The δ values showed an excellent linear correlation with atomic mass of AMo (R2 = 0.999). Three-isotope plots for the Mo isotopes were fitted with straight lines whose slopes agreed with theoretical values for mass-dependent isotope fractionation. These results demonstrate that Mo isotopes are both uniformly distributed and follow a mass-dependent fractionation law in the modern oxic ocean. In addition, Mo isotopic analysis revealed that δ98/95Mo of the standard used in this study was 0.117 ± 0.009‰ lighter than the Mo standard that was used by Archer and Vance (2008). A common Mo standard is urgently required for the precise comparison of Mo isotopic compositions measured in different laboratories. On the other hand, our results strongly support the possibility of seawater as an international reference material for Mo isotopic composition.

Feedback Interactions between Trace Metal Nutrients and Phytoplankton in the Ocean

In addition to control by major nutrient elements (nitrogen, phosphorus, and silicon) the productivity and species composition of marine phytoplankton communities are also regulated by a number of trace metal nutrients (iron, zinc, cobalt, manganese, copper, and cadmium). Of these, iron is most limiting to phytoplankton growth and has the greatest effect on algal species diversity. It also plays an important role in limiting di-nitrogen (N2) fixation rates, and thus is important in controlling ocean inventories of fixed nitrogen. Because of these effects, iron is thought to play a key role in regulating biological cycles of carbon and nitrogen in the ocean, including the biological transfer of carbon to the deep sea, the so-called biological CO2 pump, which helps regulate atmospheric CO2 and CO2-linked global warming. Other trace metal nutrients (zinc, cobalt, copper, and manganese) have lesser effects on productivity; but may exert an important influence on the species composition of algal communities because of large differences in metal requirements among species. The interactions between trace metals and ocean plankton are reciprocal: not only do the metals control the plankton, but the plankton regulate the distributions, chemical speciation, and cycling of these metals through cellular uptake and recycling processes, downward flux of biogenic particles, biological release of organic chelators, and mediation of redox reactions. This two way interaction has influenced not only the biology and chemistry of the modern ocean, but has had a profound influence on biogeochemistry of the ocean and earth system as a whole, and on the evolution of marine and terrestrial biology over geologic history.

Blood Ties: Exile, Family, and Inheritance across the Indian Ocean in the Early Nineteenth Century

Historians are rarely privy to why any one document ends up in a certain file kept in a particular archive, but the happenstance of discovering an unexpected source that yields an interesting tangent to one's main topic is undoubtedly one of the pleasures of research. This story tracing marginal centers across the Indian Ocean involves a document in the Indonesian National Archives in Jakarta that caught my eye because it was “out of place” amongst the Dutch East India Company (VOC) records that constitute the archives for my research on the Company's network of forced migration. My research focused specifically on the circuit of penal transportation and political exile between Batavia, the Indonesian archipelago and the Cape of Good Hope and draws on the VOC archives in The Netherlands, South Africa and Indonesia. The fragmentary overlap between Dutch and British colonial records on Madura in the Indonesian National Archives that provides the basis for this chapter included the translation of a letter dated May 26, 1813, written to the Governor-General of India at Fort William in Calcutta, Lord Minto, from three Madurese princes who were officers of the Bugis Corps commissioned by the English East India Company (EIC) at Fort Marlborough in Bencoolen on the west coast of Sumatra. The file reflects the letter authors' attempt to pursue their interests by shrewd observation of rivalries between these European colonial powers. The princes were staking a claim to the throne of Madura based on the exile to the Cape of Good Hope of their grandfather, Pangeran Cakraningrat IV, by the Dutch East India Company in the 1740s. 1 This “momentary drama” sheds insight into the intersection between various imperial and indigenous political networks that constituted the early modern Indian Ocean. The immediate political context of the letter was the British invasion and conquest of Java, and by proximity the neighboring island of Madura, which displaced the Dutch as the major European power negotiating with the Javanese states over control of the island and its surrounding territories. Behind this

Molybdenum evidence for expansive sulfidic water masses in ~ 750 Ma oceans

The Ediacaran appearance of large animals, including motile bilaterians, is commonly hypothesized to reflect a physiologically enabling increase in atmospheric and oceanic oxygen abundances (pO 2). To date, direct evidence for low oxygen in pre-Ediacaran oceans has focused on chemical signatures in the rock record that reflect conditions in local basins, but this approach is both biased to constrain only shallower basins and statistically limited when we seek to follow the evolution of mean ocean chemical state through time. Because the abundance and isotopic composition of molybdenum (Mo) in organic-rich euxinic sediments can vary in response to changes in global redox conditions, Mo geochemistry provides independent constraints on the global evolution of well-oxygenated environments. Here, we establish a theoretical framework to access global marine Mo cycle in the past from the abundance and isotope composition of ancient seawater. Further, we investigate the ~ 750 Ma Walcott Member of the Chuar Group, Grand Canyon, which accumulated in a rift basin with open connection to the ocean. Iron speciation data from upper Walcott shales indicate that local bottom waters were anoxic and sulfidic, consistent with their high organic content (up to 20 wt.%). Similar facies in Phanerozoic successions contain high concentrations of redox-sensitive metals, but in the Walcott Member, abundances of Mo and U, as well as Mo/TOC (~ 0.5 ppm/wt.%) are low. δ 98 Mo values also fall well below modern equivalents (0.99 ± 0.13‰ versus ~ 2.35‰ today). These signatures are consistent with model predictions where sulfidic waters cover ~ 1–4% of the global seafloor, corresponding to a ~ 20–80 fold increase compared to the modern ocean. Therefore, our results suggest globally expansive sulfidic water masses in mid-Neoproterozoic oceans, bridging a nearly 700 million-year gap in previous Mo data. We propose that anoxic and sulfidic (euxinic) conditions governed Mo cycling in the oceans even as ferruginous subsurface waters re-appeared 800–750 Ma, and we interpret this anoxic ocean state to reflect a markedly lower atmospheric and oceanic O 2 level, consistent with the hypothesis that pO 2 acted as an evolutionary barrier to the emergence of large motile bilaterian animals prior to the Ediacaran Period.

Sensitivity of seawater oxygen isotopes to climatic and tectonic boundary conditions in an early Paleogene simulation with GISS ModelE‐R

An isotope‐enabled ocean‐atmosphere general circulation model (GISS ModelE‐R) is used to estimate the spatial gradients of the oxygen isotopic composition of seawater (δ18Osw, where δ is the deviation from a known reference material in per mil) during the early Paleogene (45–65 Ma). Understanding the response of δ18Osw to changes in climatic and tectonic boundary conditions is important because records of carbonate δ18O document changes in hydrology, as well as changes in temperature and global ice‐volume. We present results from an early Paleogene configuration of ModelE‐R which indicate that spatial gradients of surface ocean δ18Osw during this period could have been significantly different to those in the modern ocean. The differences inferred from ModelE‐R are sufficient to change early Paleogene sea surface temperature estimates derived from primary carbonate δ18O signatures by more than ±2°C in large areas of the ocean. In the North Atlantic, Indian, and Southern Oceans, the differences in δ18Osw inferred from our simulation with ModelE‐R are in direct contrast with those from another δ18O‐tracing model study which used different, but equally plausible, early Paleogene boundary conditions. The large differences in δ18Osw between preindustrial and early Paleogene simulations, and between models, emphasizes the sensitivity of δ18Osw to climatic and tectonic boundary conditions. For this reason, absolute estimates of Eocene/Paleocene temperature derived from carbonate δ18O alone are likely to have larger uncertainties than are usually assumed.

Modern Oceans, Ancient Sites: Archaeology and Marine Conservation on San Miguel Island, California by Todd J. Braje

Modern Oceans, Ancient Sites: Archaeology and Marine Conservation on San Miguel Island, California by Todd J. Braje

Molybdenum isotopic records across the Precambrian-Cambrian boundary

Molybdenum (Mo) isotopic data from early Cambrian formations in southern China demonstrate the importance of non-euxinic sediments as a promising archive for coeval seawater Mo records. For the first time, in analogue to noneuxinic, nonskeletal carbonates, we report that the pristine phosphorites also can preserve the ambient fluid, which make the pristine phosphorites a new potential fingerprinting tool to record the coeval paleoseawater. Pristine phosphorite and dolomite samples of two early Cambrian formations in southern China suggest that early Cambrian seawater may have had δ 97/95 Mo values of at least 1.4‰, similar to modern oceans. Low δ 97/95 Mo (as low as −0.5‰) values were obtained from reworked phosphorite, but evidence suggests that these are reflecting Mo related to Fe oxyhydroxide minerals rather than the coeval seawater. In contrast, late Precambrian dolomite just below the transition to the Cambrian would indicate a δ 97/95 Mo of coeval seawater slightly heavier than that of the Mesoproterozoic (0.9‰–1‰ versus 0.8‰), suggesting that oceanic circulation patterns may have been thoroughly reorganized by that time, and may have triggered biological diversification from the Ediacaran to the early Cambrian.

Glacial marine nutrient and carbon redistribution: Evidence from the tropical ocean

The nature and timing of marine nutrient and carbon redistribution through a glacial cycle remains unclear. Understanding transfers to and from the surface and deep ocean reservoirs is important to explaining Pleistocene variation in atmospheric CO2 content. Observations in the modern ocean show that the nutrient supply to the tropical upwelling regions depends on content of deep reservoirs and vertical mixing in the Southern and subantarctic oceans. Previous work in the Pacific demonstrated that nutrient supply to the tropics was reduced during the Glacial, consonant with reduced vertical mixing in the Southern Ocean. We examine the glacial record of the tropical Atlantic with the same methods used in the Pacific (N. dutertrei carbon isotope data combined with export production estimates to evaluate changes in thermocline nutrient content). In contrast to the Pacific, we find evidence for an increase in tropical Atlantic nutrient supply under glacial conditions. The source of nutrients can be traced to subantarctic surface waters and ultimately to an enriched abyssal reservoir. Bathymetrically forced vertical mixing could account for the transfer of nutrients from this reservoir in the S. Atlantic. The enriched reservoir developed in early MIS 4 (75 ka) and persisted until about 14.5 ka (Bolling/Allerod). This timing corresponds to shifts in atmospheric CO2 content from intermediate to minimum (full glacial) levels at 75 ka and from intermediate to Holocene concentrations near 14.5 ka.

Silicon uptake by sponges: a twist to understanding nutrient cycling on continental margins

About 75% of extant sponge species use dissolved silicon (DSi) to build a siliceous skeleton. We show that silicon (Si) uptake by sublittoral Axinella demosponges follows an enzymatic kinetics. Interestingly, maximum uptake efficiency occurs at experimental DSi concentrations two orders of magnitude higher than those in the sponge habitats, being unachievable in coastal waters of modern oceans. Such uptake performance appears to be rooted in a former condition suitable to operate at the seemingly high DSi values characterizing the pre-Tertiary (>65 mya) habitats where this sponge lineage diversified. Persistence of ancestral uptake systems causes sponges to be outcompeted by the more efficient uptake of diatoms at the low ambient DSi levels characterizing Recent oceans. Yet, we show that sublittoral sponges consume substantial coastal DSi (0.01–0.90 mmol Si m−2 day−1) at the expenses of the primary-production circuit. Neglect of that consumption hampers accurate understanding of Si cycling on continental margins.

Lateral-Line-Inspired Sensor Arrays for Navigation and Object Identification

AbstractThe lateral line is a critical component of fish sensory systems, found to affect numerous aspects of behavior, including maneuvering in complex fluid environments with poor visibility. This sensory organ has no analog in modern ocean vehicles, despite its utility and ubiquity in nature, and could fill the gap left by sonar and vision systems in turbid, cluttered environments.To emulate the lateral line and characterize its object-tracking and shape recognition capabilities, a linear array of pressure sensors is used along with analytic models of the fluid in order to determine position, shape, and size of various objects in both passive and active sensing schemes. We find that based on pressure information, tracking a moving cylinder can be effectively achieved via a particle filter. Using principal component analysis, we are also able to reliably distinguish between cylinders of different cross section and identify the critical flow signature information that leads to the shape identification. In a second application, we employ pressure measurements on an artificial fish and an unscented Kalman filter to successfully identify the shape of an arbitrary static cylinder.Based on the experiments, we conclude that a linear pressure sensor array for identifying small objects should have a sensor-to-sensor spacing of less than 0.03 (relative to the length of the sensing body) and resolve pressure differences of at least 10 Pa. These criteria are used in the development of an artificial lateral line adaptable to the curved hull of an underwater vehicle, employing conductive polymer technologies to form a flexible array of small pressure sensors.

Terrestrial influences on carbon burial at sea

Over geologic time, a primary driver for change in atmospheric concentrations of gases such as methane, CO2, and O2 is burial of organic matter in marine sediments. After photosynthetic organisms produce organic matter and O2, these compounds are typically respired to CO2 in short order. However, burial of organic matter in sediments sequesters carbon for eons, allowing O2 to build up and playing a small role in reducing CO2 in the atmosphere. The exact mechanisms and rates of organic matter burial are therefore significant terms that need to be understood to fully comprehend earth processes. Organic matter preservation is linked to the burial of minerals, many of which are terrestrially derived. The favored hypothesis explaining organic–mineral associations is that the abundance of mineral surface area somehow protects organic matter from degradation. In this way, ocean sediments containing fine-grained minerals bury more organic matter than coarse-grained sediments. The mechanistic details of this remain poorly elucidated, but the relationship in the modern ocean is reasonably well described: ≈1 mg of C is buried along with each square meter of external mineral surface. This approach excludes the internal surfaces of expandable clay minerals, which have previously been thought to be relatively unimportant (1). The one notable exception to this generality occurs in suboxic and anoxic portions of the ocean, where organic matter is preserved in excess of 1 mg C per external square meter. It has generally been assumed that external mineral surface area controls “baseline” amounts of organic matter burial and that anoxia enhances burial. In PNAS, Kennedy and Wagner. (2) bring a unique perspective to this paradigm. They show that mineralogy, not just surface area, can play a large role in controlling organic matter burial. By measuring the internal surface area of expandable clays and relating that to changes in organic matter burial in Cretaceous black shales, they illustrate a process whereby both mineralogy and anoxia amplify carbon storage. The amplification effect seems to occur rapidly, on a temporal scale of decades rather than millenia.

Development of the Cretaceous Greenhouse Climate and the Oceanic Thermal Structure

Abstract. The development of the climate during the Cretaceous greenhouse interval is reviewed based on geological and paleontological records, geochemical proxy records for paleotemperature and atmospheric carbon-dioxide concentration (pCO2), the production rate of oceanic crust, and the timing and scale of emplacement of large igneous provinces. Geological and paleontological evidence, and paleotemperature records indicate that the Early Cretaceous climate was relatively cool, possibly accompanied by the development of continental ice sheets. Subsequent warming reached a peak in the Turonian, when sea surface temperatures in equatorial and high-latitude regions exceeded 36° C and 20° C, respectively. The possibility of a maximum temperature above 36° C at the equator is inconsistent with the cirrus cloud negative-feedback hypothesis proposed for the modern ocean, which may indicate that the hypothesis is not valid for an ice-free greenhouse system. Although elevated levels of pCO2 are thought to be resp...

Whole‐genome expression analysis reveals a role for death‐related genes in stress acclimation of the diatom Thalassiosira pseudonana

Low iron (Fe) availability critically limits diatom distribution and productivity in vast regions of the modern ocean, such as open-ocean, high nutrient low chlorophyll areas and coastal regimes characterized as Fe limitation 'mosaics'. While unique strategies of Fe uptake and storage confer competitive advantages to pennate diatoms, the molecular determinants of low Fe acclimation are largely unknown in centric diatoms. We combined genome-wide and targeted comparative transcriptomic analysis with diagnostic biochemistry and in vivo cell staining as a platform to identify the suite of genes involved in acclimation to Fe and associated oxidative stress in Thalassiosira pseudonana. A total of 1312 genes, nearly 12% of the total genome content, responded to Fe starvation in growing cells characterized by low photosynthetic efficiency and enhanced oxidative stress, caspase activity and metacaspase expression. While 82% of the most highly upregulated genes were also represented in EST libraries derived from diverse diatoms grown under various stress conditions (e.g. silicon, CO(2) and nitrogen limitation), our analysis suggests that T. pseudonana mounts a unique molecular response to Fe starvation that includes a number of genes distinct from those of the model pennate diatom, Phaeodactylum tricornutum, which diverged ~90 million years ago. Homologues to ~50% of the upregulated genes were also identified in a metatranscriptome of eukaryotic phytoplankton communities from a chronically Fe-limited region in the Northeast Pacific. Furthermore, we provide experimental evidence that a subset of putative death-related genes participate in the cellular acclimation to low Fe and associated oxidative damage, suggesting that they co-evolved with other metabolic pathways and play adaptive roles in the success of diatoms.

Silicate:nitrate ratios of upwelled waters control the phytoplankton community sustained by mesoscale eddies in sub-tropical North Atlantic and Pacific

Abstract. Mesoscale eddies in sub-tropical gyres physically perturb the water column and can introduce macronutrients to the euphotic zone, stimulating a biological response in which phytoplankton communities can become dominated by large phytoplankton. Mesoscale eddies may therefore be important in driving export in oligotrophic regions of the modern ocean. However, the character and magnitude of the biological response sustained by eddies is variable. Here we present data from mesoscale eddies in the Sargasso Sea (Atlantic) and the waters off Hawai'i (Pacific), alongside mesoscale events that affected the Bermuda Atlantic Time-Series Study (BATS) over the past decade. From this analysis, we suggest that the phytoplankton community structure sustained by mesoscale eddies is predetermined by the relative abundance of silicate over nitrate (Si*) in the upwelled waters. We present data that demonstrate that mode-water eddies (MWE) in the Sargasso Sea upwell locally formed waters with relatively high Si* to the euphotic zone, and that cyclonic eddies in the Sargasso Sea introduce waters with relatively low Si*, a signature that originated in the iron-limited Southern Ocean. We propose that this phenomenon can explain the observed dominance of the phytoplankton community by large-diatom species in MWE and by small prokaryotic phytoplankton in cyclonic features. In contrast to the Atlantic, North Pacific Intermediate Water (NPIW) with high Si* may influence the cyclonic eddies in waters off Hawai'i, which also appear capable of sustaining diatom populations. These observations suggest that the structure of phytoplankton communities sustained by eddies may be related to the chemical composition of the upwelled waters in addition to the physical nature of the eddy.

A Review of Canada's Implementation of the Oceans Act since 1997—From Leader to Follower?

With the passage of the Oceans Act in 1997, Canada was considered a global leader in modern oceans management. With provisions for marine protected areas (MPAs) and integrated oceans management, the Oceans Act was meant to address the existing piecemeal approach to oceans management, by moving to a new approach founded in the concepts of sustainable development and ecosystem-based management. However, the past 13 years of implementation of the Act have highlighted a number of challenges that are affecting the degree to which oceans management is actually changing “in the water.” Most fundamental is the lack of adequate governance mechanisms that will ensure compliance by all parts of the Fisheries and Oceans Canada, and by other federal departments, and enhanced collaboration with all levels of government, including provinces, territories and First Nations. Coupled with inadequate funding, no timelines for completion of plans for MPAs, and the lack of accountability mechanisms, Canada's ocean estate continues to be managed on the piecemeal, sector-by-sector approach that the Oceans Act was meant to replace. More recently, global best practice in MPA establishment is moving to networks and huge MPAs that are fully protected from all human activities, while broader oceans management is moving from an integrated approach to one that includes marine spatial planning and ocean zoning. Canada is just beginning to explore how these new practices could be implemented in its ocean estate, and needs to move more rapidly in order to better conserve and manage ocean ecosystems.

Design of Ocean Data Buoys Based on CFD

Ocean Data Buoy with fixed-point, real-time, long-term, continuous and accurate data collection capabilities is a modern ocean observing tools and instruments. Therefore, the reliability of information is essential, which depends on the stability of the working buoy. While the waves are acting, the buoys are difficult to maintain their stability. Based on Computational Fluid Dynamics, the force situations of buoy at wave conditions are simulated by using Variable Operating Frequency method and Fluent software. The variation of lift and drag forces and the changing trend of movement of buoy are obtained. And then the numerical value of force is adjusted by changing the height of waterline. At last, the digital design of shell structure is carried out with SolidWorks to improve the stability of buoys in surface wave.

Phosphorus imbalance in the global ocean?

The phosphorus budget of the prehuman modern ocean is constrained applying the most recent estimates of the natural riverine, eolian, and ice‐rafted input fluxes; the phosphorus burial in marine sediments; and the hydrothermal removal of dissolved phosphate from the deep ocean. This review of current flux estimates indicates that the phosphorus budget of the ocean is unbalanced since the accumulation of phosphorus in marine sediments and altered oceanic crust exceeds the continental input of particulate and dissolved phosphorus. The phosphorus mass balance is further tested considering the dissolved phosphate distribution in the deep water column, the marine export production of particulate organic matter, rain rates of phosphorus to the seafloor, benthic dissolved phosphate fluxes, and the organic carbon to phosphorus ratios in marine particles. These independent data confirm that the phosphate and phosphorus budgets were not at steady state in the prehuman global ocean. The ocean is losing dissolved phosphate at a rate of ≥11.6 × 1010 mol yr−1 corresponding to a decline in the phosphate inventory of ≥4.5% kyr−1. Benthic data show that phosphate is preferentially retained in pelagic deep‐sea sediments where extended oxygen exposure times favor the degradation of particulate organic matter and the uptake of phosphate in manganese and iron oxides and hydroxides. Enhanced C: P regeneration ratios observed in the deep water column (>400 m water depth) probably reflect the preferential burial of phosphorus in pelagic sediments. Excess phosphate is released from continental margin sediments deposited in low‐oxygen environments. The dissolved oxygen threshold value for the enhanced release of dissolved phosphate is ∼20 μM. Benthic phosphate fluxes increase drastically when oxygen concentrations fall below this value.