scispace - formally typeset
Search or ask a question

Showing papers by "Woods Hole Oceanographic Institution published in 1978"


Journal ArticleDOI
TL;DR: In this paper, the levels of four sets of pollutants (heavy-metals, artificial radionuclides, petroleum components, and halogenated hydrocarbons) have been measured in U.S. coastal waters, using bivalves as sentinel organisms.
Abstract: The levels of four sets of pollutants (heavy-metals, artificial radionuclides, petroleum components, and halogenated hydrocarbons), have been measured in U.S. coastal waters, using bivalves as sentinel organisms. The strategies of carrying out this programme are outlined and the results from the first year's work are given. Varying degrees of pollution in U.S. coastal waters have been indicated by elevated levels of pollutants in the bivalves, which comprised certain species of mussels and oysters and were collected at over one hundred localities.

859 citations


Book ChapterDOI
01 Jan 1978
TL;DR: For example, it is evident that organisms have aggregated, patchy distributions of abundance on a wide variety of space and time scales as mentioned in this paper, which can be easily seen in the terrestrial and littoral environments.
Abstract: It is evident that organisms have aggregated, patchy distributions of abundance on a wide variety of space and time scales. This can easily be seen in the terrestrial and littoral environments. It has been more difficult to observe in the pelagic realm simply because we cannot see into the ocean. Thus we must depend upon sampling to gain an impression of the space-time scales of pattern in this habitat. Despite the difficulties, enough sampling of the right sort has now been done so that we can make some very general statements about the nature of pattern in the ocean, particularly with regard to pattern in the distribution and abundance of planktonic organisms. All the evidence indicates that plankton is patchy on a broad spectrum of scales. Because this aggregated spatial pattern is such a general phenomenon, there is little question of its ecological and evolutionary importance. Further, because we assume our samples represent a larger universe, patchiness strongly affects our efforts to obtain estimates of the abundance of organisms and our ability to detect significant spatial and temporal changes in abundance. It is therefore of great importance that we understand its nature, causes, and effects.

625 citations


Journal ArticleDOI
TL;DR: In this paper, the sulphur isotopic composition of ocean water sulphate was determined using the SF 6 method for samples from various depths of the Geosecs Stations II and 3 and for a single Pacific Ocean surface sample.

582 citations


Journal ArticleDOI
TL;DR: Trace element analyses have been carried out on hydrothermally altered pillow basalts of greenschist facies dredged from the median valley of the Mid-Atlantic Ridge as mentioned in this paper.

425 citations


Journal ArticleDOI
TL;DR: Waterborne nutrients enter the Great Sippewissctt Marsh through groundwater, rain, and tidal flooding as discussed by the authors, and the amount of waterborne nutrients entering the marsh provides primarily ammonium, nitrate, nitrite, dissolved organic (don) and particulate (PN) nitrogen, particulate carbon (PC), and phosphate.
Abstract: Waterborne nutrients enter Great Sippewissctt Marsh through groundwater, rain, and tidal flooding. The ebb of tidal water removes nutrients. During summer, uptake by marsh biota leads to net import of nutrients. The increased export of ammonium in August may be due to leaching from senescent marsh plants. There is a net annual export of ammonium, nitrate, nitrite, dissolved organic (DON) and particulate (PN) nitrogen, particulate carbon (PC), and phosphate. Ammonium, DON, and PN are the major forms of nitrogen exported. Nutrient concentrations in coastal and marsh water are correlated, and marsh exports could contribute substantially to nutrient supplies of coastal waters. Groundwater entering the marsh provides primarily N03-N and DON. Nutrient inputs through precipitation consist primarily of DON, NO,-N, and NIIcN. Particulate materials in rain have a high C:N ratio, contributing little to enrichment of the nitrogen-limited salt marsh. Groundwater carries over 20 times the amount of nutrients brought in by rain. The nitrogen provided by both sources is more than enough to support annual plant growth. Inputs of nitrogen by groundwater are therefore important to the nitrogen economy of a salt marsh. About half the dissolved inorganic nitrogen brought into the marsh by groundwater is converted to and exported as PN. The marsh thus transforms the nitrogen that would have been used by primary producers into a form suitable for consumers such as shellfish. Large amounts of apparently refractory DON enter the marsh in groundwater and similar amounts are exported by tides. PC exported to coastal water is equivalent to 40% of the net annual production of Spartina alterniflora, the dominant marsh plant.

357 citations


Journal ArticleDOI
18 May 1978-Nature
TL;DR: In situ 14C and 45Ca uptake experiments show that when photosynthesis increases, more light metabolic CO2 is incorporated in the skeleton, explaining the non-equilibrium isotopic compositions previously reported for hermatypic corals and associated benthonic foraminifera.
Abstract: Stable-isotope composition of carbonate precipitated by hermatypic corals and associated benthonic foraminifera is strongly influenced by photosynthesis of symbiotic algae. In situ 14C and 45Ca uptake experiments show that when photosynthesis increases, more light metabolic CO2 is incorporated in the skeleton. This mechanism explains the non-equilibrium isotopic compositions previously reported for these organisms (as well as for planktonic foraminifera), and have important implications for palaeoenvironmental determinations based on stable-isotope analysis.

352 citations


Journal ArticleDOI
TL;DR: It is suggested that many red tides in New England and eastern Canadian waters are initiated through the displacement of motile estuarine populations into nearshore area by tidal advection and surface runoff, although the potential existence and importance of offshore cyst reservoirs cannot be discounted.
Abstract: Thick-walled, nonmotile cysts (termed hypnocysts) of two dinoflagellates were isolated from estuarine sediments in Cape Cod, Massachusetts, and germinated to produce their respective motile, thecate stages. Hypnocysts from Orleans district were identified as Gonyaulax excuvata (Braarud) Balech sensu Loeblich & Loeblich. Visually identical hypnocysts from Falmouth district were provisionally identified as Gonyaulax tamarensis Lebour. Both species were toxic. A geographic survey in September detected hypnocysts in only the sediments of locations where toxic blooms developed the preceding and following Spring. Laboratory incubation (16 C) of hypnocysts from sediment samples stored in the dark (5 C) for 6 mo initiated excystment by the temperature increase, with no appreciable effect from light regime, nutrient, or chelator concentrations. Motility of excysted germlings was optimum in highly chelated medium and in the presence of light. We conclude that hypnocysts of both tasa are important in seeding recurrent annual blooms, synchronizing early bloom development with vernal warning of seawater and increasing the geographic range of the species. We suggest that many red tides in New England and eastern Canadian waters are initiated through the displacement of motile estuarine populations into nearshore area by tidal advection and surface runoff, although the potential existence and importance of offshore cyst reservoirs cannot be discounted. Evidence is presented that hypnocysts are probable sexual zygotes whereas the thin-walled cysts readily formed in laboratory cultures (pellicle cyst) are asexual. Pellicle cysts are of limited durability, do not overwinter in nature, and therefore do not play a significant role in initiating toxic blooms.

345 citations


Journal ArticleDOI
TL;DR: In this paper, the authors considered the problem of topographic wave generation by wind, where the effects of wind stress or of freshwater influx are felt only over the forward portion of a long shelf (i.e., that portion to which topographic waves propagate from the source region).
Abstract: The mean circulation in a coastal zone of variable depth may under certain circumstances be modeled by linear equations, including a bottom friction linear in the depth-averaged velocity. The resulting steady-state problem is similar to the problem of topographic wave generation by wind. The equation governing the pressure field has the form of a one-dimensional heat conduction equation, with longshore distance in the direction of topographic wave propagation playing the role of time. The effects of wind stress or of freshwater influx are felt only over the forward portion of a long shelf (i.a., that portion to which topographic waves propagate from the source region). Various simple solutions can be written down for the arrested topographic wave problem in virtue of the heat conduction analogy. They generally show the presence of a pressure field trapped in a nearshore band. For periodic wind stress, for example, the scale width of the trapped pressure field is L=(2r/fks)1/2, where r is a bottom...

336 citations



Journal ArticleDOI
TL;DR: Changing capacity for NH4+ uptake with N content appears to be a mechanism whereby excessive accumulation of N was avoided by N‐deficient plants but a large accumulation was possible for N‐depleted plants.
Abstract: Similar NH4+ and NO3−.uptake kinetic patterns were observed in Neoagardhiella baileyi (Harvey ex Kiitzing) Wyinne & Taylor and Gracilaria foliifera (Forssk?l) Borgesen. NO3− was taken up in a rate-sturating fashion described by the Michaelis-Menten equation. NH4+ uptake was multicomponent: a saturable component was accompanied by a diffusive or a high K component showing no evidence of saturation (at ≤50 μM [NH4+]). Nitrogen starved plantsi(C/N atom ratios > ca. 10) showed higher transient rates of NH4+ uptake at a given concentration than plants not N-Iimited. Only plants with high N content exhibited diel changes inNH4+ uptake rates, and showed transient rates of NH4+ accumulation which did not greatly exceed the capacity to incorporate N in steady-state growth. NH4+ was preferred over NO3−even in plants preconditioned on NO3−as the sole N. source, NO3− uptake was suppressed at 5μM [NH4+], but simultaneous uptake occurred at unsurpressed rates at lower concentrations. Potential for N accumulation was greater via NH4+uptake than via NO3−uptake. Changing capacity for NH4+ uptake with N content appears to be a mechanism whereby excessive accumulation of N was avoided by N-.satiated plants but a large accumulation was possible for N-depleted plants.

252 citations


Journal ArticleDOI
01 Nov 1978-Nature
TL;DR: In this paper, the zinc ion activity (rather than the total zinc concentration) can limit the growth rate of a coastal diatom Thalassiosira weissflogii (Grun. = T. fluviatalis).
Abstract: THE total zinc concentration in unpolluted marine waters has been reported to be in the 10−10 M range1. Such low concentration of an essential micronutrient suggests that the growth of some phytoplankton may be zinc limited. Of the trace metals necessary for phytoplankton growth, only iron has been considered a potential limiting micronutrient in the marine environment2,3. On the basis of laboratory work which focused mostly on copper, it is well known that the toxicity of a trace metal depends on its chemical speciation and can be related uniquely to its free ion activity4,5. However, it has not been established unequivocally that the availability of some metals may also be controlled by their free ion activities and may thus be depressed by organic complexation. Here we report laboratory experiments demonstrating that the zinc ion activity (rather than the total zinc concentration) can limit the growth rate of a coastal diatom Thalassiosira weissflogii (Grun. = T. fluviatalis Hust.) and that the limitation occurs at zinc ion activities which would be present in unpolluted seawater if any organic complexation of zinc were taking place.

Journal ArticleDOI
TL;DR: In this paper, a fast growing marine diatom Thalassiosira pseudonana (3H) was grown under NH4+-limited steady state conditions in continuous culture.
Abstract: A fast-growing marine diatom Thalassiosira pseudonana (3H) was grown under NH4+-limited steady state conditions in continuous culture. Growth rate could not be described as a function of external or residual NH,+ because of analytical limitations in measuring NHd+ concentrations co.03 pg-atom N * liter -‘. Neither did the data fit the internal nutrient model of Droop because the washout growth rate (I;) under N limitation is substantially less than the maximum growth rate term used in the Droop expression (p). The ratio of the minimum (ka) to the maximum ( Qm) cell quota was the key term in determining the ratio fi:&, and hence the applicability of the Droop expression. For limiting nutrients such as vitamin Blz and P, @ - p, and the expression is applicable; but, when fi < pi, as for N and Si, the usefulness of the expression is diminished, and when p + 00, as for inorganic carbon, the Droop equation is completely invalid. In a general sense the usefulness of the Droop expression diminishes as the limiting nutrient:cell weight ratio increases. The generality of the concept of cell “shift UP, ” or increasing k, and p with increasing growth rate, is questioned as no evidence for this phenomenon was found in T. pseudonana. Moreover, the demonstration of discontinuities in kinetic curves of Q vs. /.L does not a priori imply that the coefficients kR and I; are variable.

Journal ArticleDOI
01 Mar 1978-Nature
TL;DR: In this article, the authors summarise 37 measurements of excess helium in hydrothermal waters sampled using the Alvin deep submersible at the Galapagos Spreading Centre during February and March of 1977.
Abstract: SINCE the discovery of excess 3He in Pacific deep waters1, it has been argued that the source of this anomaly is the mid-depth injection of primordial helium from seafloor spreading centres1,2. This hypothesis is consistent with the spatial distribution of excess 3He in the deep waters3–5, its presence in the glassy (rapidly quenched) margins of extruded ocean basalts6,7, and the detection of a large 3He excess in a ‘thermal plume’ (thermal anomaly ∼0.1 °C, sampled using a deep-tow sled) over the Galapagos Spreading Centre8–10. In this report, we summarise 37 measurements of excess helium in hydrothermal waters sampled using the Alvin deep submersible at the Galapagos Spreading Centre during February and March of 1977.

Journal ArticleDOI
TL;DR: In this article, the authors have suggested that the Luzon arc has underthrust the Central Range of Taiwan, to at least 40 km west of the longitud nal valley.
Abstract: During the middle and late Miocene the northern continuation of the Luzon volcanic arc approached the Asian continental margin through subduction of oceanic crust on its western side. Collision deformation began in late Miocene time because middle Miocene marine fossils are present in the slate belt of Taiwan. South Taiwan, the crust-crust contact between the Philippine and Asia plates occurs at the large negative free-air gravity anomaly over the deformed accretionary wedge of the Manila Trench. The deformed sediment wedge has been uplifted to shallower depths toward Taiwan and forms part of the southernmost peninsula of Taiwan. The pattern of gravity anomalies suggests that the Luzon arc has underthrust the Central Range of Taiwan, to at least 40 km west of the longitud nal valley. Thus the west edge of the Philippine plate at Taiwan appears to be chisel shaped in cross section. Recent transcurrent faulting along the longitudinal valley is being superimposed on this collisional suture. The Ilan plain is a landward extension of the Okinawa Trough and forms the southwestern end of that extensional back-arc structure of the Ryukyu Island arc. The crust-crust contact between the Ryukyu arc and the Philippine plate occurs at the negative free-air anomaly of the accretionary wedge. On the west this contact abuts the northward end of the longitudinal valley fault. We speculate that the Luzon arc convergence zone in the region of Taiwan has been sealing southward and that concomitantly a new plate boundary may be developing on the east side of Luzon and progres ing northward. Magnetic anomalies trending N70°E in the China basin west of Luzon are associated with the crest of an extinct spreading ridge which formed the deep part of the China basin by separating older but shallower crust. Magnetic anomalies in the westernmost Philippine basin suggest the existence of north-trending anomalies. The consistency of the skewness, the small amplitude factor, and to a lesser extent the bathymetric cross sections in the westernmost Philippine basin compared with those of the Central Basin Ridge region on the southeast support the view that the Gagua Ridge may be an extinct spreading center and that the adjacent topography was formed by seafloor-spreading.

Journal ArticleDOI
TL;DR: Oceanic ctenophores show a great diversity in feeding biology, ranging from Leucothea multicornis, which can eat only small copepods, to species of Ocyropsis , which can capture and ingest small fish and euphausiids.

Journal ArticleDOI
TL;DR: Growth rate appeared to follow saturation‐type nutrient uptake kinetics for plants receiving ammonium, nitrate, urea of sewage effluent enrichments, and this indicates that both species possess the ability to utilize very low concentrations of N.
Abstract: Gracilaria foliifera (Forsskal) Borgesen and Neoagardhiella bailiyi (Harvey ex Kiitzing) Wynne & Taylor were grown in continuous-flow culture under controlled environmental conditions in 15 liter experimental chambers. Growth rate was related to the source and concentration of nitrogen enrichment supplied to the plants, Growth rate appeared to follow saturation-type nutrient uptake kinetics for plants receiving ammonium, nitrate, urea of sewage effluent enrichments. Ammonium enrichment produced higher growth rates than nitrate of sewage enrichment. The lowest growth rates occurred in the chambers receiving unenriched seawater or urea. The low estimated constants (K) for growth were in the range of 0.2–0.4 (M N for all N enrichments examined. The low estimated values of K compare closely with those found for microalgae and indicate that both species possess the ability to utilize very low concentrations of N.

Journal ArticleDOI
01 Mar 1978-Nature
TL;DR: In this paper, the Murchison meteorite was found to contain seven α-hydroxy carboxylic acids (hydroxy acids) in a type II carbonaceous chondrite, and the presence of these acids would provide evidence in support of the Strecker mechanism responsible for the natural extraterrestrial synthesis of amino acids found in meteorites.
Abstract: A VARIETY of indigenous organic compounds have been detected in carbonaceous meteorites1–6, and of these, the amino acids have been the most extensively studied1,7–11. In addition to the amino acids commonly found in the proteins of terrestrial organisms, a large number of nonprotein amino acids have also been detected8. Moreover, the amino acids in meteorites exist as a racemic mixture, demonstrating their abiotic origin1,8–10. The general abundance pattern of amino acids in the Murchison meteorite is similar to that obtained in a typical prebiotic electric discharge experiment12. The mechanism of formation of amino acids in the electric discharge is by way of the Strecker synthesis, that is, the reaction of hydrogen cyanide, aldehydes and ammonia in aqueous solution, producing amino nitriles, which yield amino acids following acid hydrolysis13,14. In the electric discharge experiment, in addition to amino acid formation, the corresponding α-hydroxycarboxylic acids (hydroxy acids) are also produced by the reaction of hydrogen cyanide and aldehydes (the cyanohydrin synthesis). The ratio of hydroxy to amino acids depends on the amount of ammonia present in the system13,14. At high ammonia concentrations, amino acids are preferentially synthesised, whereas if ammonia is absent, only hydroxy acids are produced. Thus, the detection of hydroxy acids in carbonaceous meteorites would provide evidence in support of the hypothesis that the Strecker mechanism is responsible for the natural extraterrestrial synthesis of amino acids found in meteorites. In addition, the ratio of hydroxy to amino acids would provide some indication as to the ammonia content of the environment in which these compounds were synthesised. We report here the presence of seven α-hydroxycarboxylic acids in the Murchison meteorite, a type II carbonaceous chondrite.

Journal ArticleDOI
TL;DR: The growth and yield of Gracilaria tikvahiae was independent of nutrient concentration, nutrient loading, nitrogen loading, or whether nitrogen was in the form of NH 4 + N or NO 3 − N, but was highly dependent upon flow rate.

Book ChapterDOI
01 Jan 1978
TL;DR: In this paper, the authors consider the food chain relations between organisms as a factor affecting spatial structure and this involves aspects such as the size distribution of the plants and animals and the numbers of different species within each trophic grouping.
Abstract: The title of this volume mentions only the spatial patterns of plankton, but the populations we are concerned with have other types of variation which cannot be ignored. They have different life spans which must have an effect on their spatial distributions. Also, we must consider the food chain relations between organisms as a factor affecting spatial structure and this involves aspects such as the size distribution of the plants and animals and the numbers of different species within each trophic grouping.

Journal ArticleDOI
TL;DR: Atlantic salmon parr and brook trout in July showed “nip” as the commonest agonistic act, but in September and October “approach” and “charge and chase” were more common, possibly due to aggression associated with spawning.
Abstract: Atlantic salmon parr and brook trout were observed in stream tanks at the Matamek Research Station, Quebec. In the autumn, at 10 C Atlantic salmon parr began sheltering in rubble, and at 9 C the majority had disappeared into hiding. Brook trout also had this tendency to hide at cold temperatures, but not as strongly as the salmon. In slow water flows (<5 cm/s), Atlantic salmon parr tended to hide in the rubble substrate at any temperature, and aggression decreased. In both slow and faster water velocities during summer and autumn the commonest agonistic act by Atlantic salmon parr was “charge and chase”. Brook trout in July showed “nip” as the commonest agonistic act, but in September and October “approach” and “charge and chase” were more common, possibly due to aggression associated with spawning. Shade was attractive to both species in shallow water, but given the choice of a shallow (30 cm) tank with a shade cover, and a deeper (50 cm) tank with no shade, the majority of brook trout and Atlan...

Journal ArticleDOI
13 Jul 1978-Nature
TL;DR: In this paper, the rare earth elements (REE) LaLu are generally considered to be unaffected by weathering and are thus often used to characterise variations in basalt and magma composition.
Abstract: DREDGED oceanic basalts and those sampled by deep-ocean drilling have commonly undergone some weathering with subsequent changes in their chemical composition1–7. The rare-earth elements (REE) La–Lu are generally considered to be unaffected by weathering and are thus often used to characterise variations in basalt and magma composition. When considered relative to chondritic abundances8, the overall REE distribution is a critical diagnostic tool. In particular, the relative depletion of light-REE is used to discriminate between magma types. We present here new findings which show that REE are affected by low-temperature weathering processes. In particular, the light-REE show enrichments which may result in a basalt with a primary light-REE depleted pattern showing a flat or enriched light-REE pattern.

Book ChapterDOI
01 Jan 1978
TL;DR: Marine sharks, skates, and rays are endowed with an electric sense that enables them to detect voltage gradients as low as 0.01 μV/cm within the frequency range of direct current (DC) up to about 8 Hz.
Abstract: Marine sharks, skates, and rays are endowed with an electric sense that enables them to detect voltage gradients as low as 0.01 μV/cm within the frequency range of direct current (DC) up to about 8 Hz. Their electroreceptor system comprises the ampullae of Lorenzini, which are delicate sensory structures in the snouts of these elasmobranch fishes. Sharks, skates, and rays use their electric sense in predation, sharply cueing in on the DC and low-frequency bioelectric fields of their prey. Swimming through the earth’s magnetic field, they also induce electric fields that may provide them with the physical basis of an electromagnetic compass sense. Their ability to orient magnetically has in fact been demonstrated in recent training experiments.

Journal ArticleDOI
TL;DR: In this paper, the formation of Sterenes from sterols via microbiological processes or chemical auto-oxidation, followed by subsequent dehydration mechanisms and double bond isomerization is postulated.

Journal ArticleDOI
TL;DR: In this article, it was shown that both methane and oxygen are rapidly consumed in “young” water but, while oxygen consumption continues at a low rate throughout the deep ocean, methane consumption virtually ceases within about 100 years of isolation from the surface ocean.
Abstract: Oceanic dissolved methane concentrations are normally in excess of atmospheric equilibrium values in surface waters but show a rapid decrease with depth. Deep North Atlantic waters have only ca. 30% of their atmospheric equilibrium values of methane and deep North Pacific waters have only ca. 10%. Methane consumption rates calculated from methane analyses and water mass ages derived from published data on SII/3He ages, r4C ages, and model calculations show that both methane and oxygen are rapidly consumed in “young” water but, while oxygen consumption continues at a low rate throughout the deep ocean, methane consumption virtually ceases within about 100 years of isolation from the surface ocean.

Journal ArticleDOI
TL;DR: Significant changes in grain size along the beach are found, which represent coarsening in the direction of net wave-driven transport as mentioned in this paper, and the cause is ascribed to progressive winnowing out of the finer fraction and its dispersal offshore by tidal currents.

Journal ArticleDOI
TL;DR: The continental shelf off the Nile Delta is covered by terrigenous sands on the shore face, by terrenous muds on the middle shelf and by algal carbonates on the outer shelf.

Journal ArticleDOI
TL;DR: In this article, a recent cruise in the Arabian Sea showed a clear association of the secondary nitrite maximum with the intermediate salinity maximum originating in the Persian Gulf and Gulf of Oman.

Journal ArticleDOI
01 Apr 1978-Nature
TL;DR: Mantle convection studies indicate that large-scale shear beneath plates acts together with the buoyant uplift of the lower density plume material to produce a succession of discrete plumes and consequently island chains such as Hawaii as discussed by the authors.
Abstract: Mantle convection studies indicate that large-scale shear beneath plates acts together with the buoyant uplift of the lower density plume material to produce a succession of discrete plumes and consequently island chains such as Hawaii. The spacing of the Hawaiian Islands requires that its low viscosity shear zone is less than 80 km thick.

Journal ArticleDOI
TL;DR: In this paper, an in-situ water circulator (ISWAC) was developed to allow accurate measurement of dissolution rates of various carbonate particles with minimal stagnation and mechanical weight loss.

Journal ArticleDOI
TL;DR: In this paper, the authors found that a greater than 50% increase in the amount of particulate organic carbon and chlorophyll per square meter occurred in a 13m water column of Buzzards Bay during tidal cycles.