Moss Landing Marine Laboratories Research Articles

The bulk fluorescein diacetate assay (FDA) as a technique for evaluating biotic impacts of crude oil to coastal sediments

This study adapted the bulk fluorescein diacetate (FDA) assay to evaluate the impact of crude oil on biological activity levels in marine sediments. Sediment cores from the Elkhorn Slough, California were incubated with different levels of sweet crude oil (Deepwater Horizon, Macondo Prospect) in the Moss landing Marine Laboratories aquarium facility over a 30-day period. During this period, the amount of fluorescein released, concentration of oxygen in overlying waters, and flux of oxygen into the sediments were monitored. For all treatments a strong negative correlation between added oil and FDA production was observed (p < 0.05). The concentration of oxygen in the first 2 mm of sediment cores decreased linearly with the addition of crude oil and correlated positively with fluorescein released (p < 0.05). A linear increase in sediment oxygen flux was also observed upon crude oil addition. The miniaturized bulk FDA assay could be powerful in evaluating oil spill impacts in coastal systems.

Early-career researchers: an interview with Brooke Flammang.

Brooke Flammang is an Assistant Professor at the New Jersey Institute of Technology, where she investigates how organisms interact with their environment and how these interactions drive the evolutionary selection of morphology and function. She received her Bachelor's degree in Marine Biology from Fairleigh Dickinson University before moving to Moss Landing Marine Laboratories for her Master's degree and completing her PhD with George Lauder at Harvard University in 2010. She was awarded the Dorothy H. Skinner award in 2013 and the Carl Gans award in 2017 by the Society for Integrative and Comparative Biology.

The Hunt Fellowship: Inspiring acoustics professionals of the future

Students may exit a Ph.D. program feeling fatigued, and sometimes a bit directionless professionally. These feelings combined with the challenging academic job market could be part of the reason for this time period being one of the biggest “leaks in the pipeline,” for women scientists in particular. The flexibility and generosity of the Hunt Fellowship can be inspiring at this crossroads of a young scientist’s career. As the 2009–2010 Hunt Postdoctoral Research Fellowship recipient, I studied the acoustic behavior of humpback whales on their Antarctic feeding grounds, working under the mentorship of Dr. Whitlow Au (University of Hawaii) and Dr. Douglas Nowacek (Duke University). This project followed seamlessly from my dissertation, yet brought me to new ecosystems and reinvigorated my research questions with surprising data. The signal processing skills I gained in acoustic and animal movement analysis solidified my interest in quantitative acoustic behavior research and I made strong connections with several interdisciplinary research groups. This all fueled my career path toward my current Research Faculty position at Moss Landing Marine Laboratories, using similar sound and movement tags to study the effects of anthropogenic noise on cetaceans in general.

Bomb radiocarbon analyses validate and inform age determination of longnose skate (Raja rhina) and big skate (Beringraja binoculata) in the north Pacific Ocean

Age and growth estimates based on growth band counts of sectioned vertebrae have been produced for longnose skate (Raja rhina) and big skate (Beringraja binoculata [formerly Raja binoculata]) populations in the Gulf of Alaska, British Columbia and California. Previous growth studies involving estimates from different laboratories in the USA (Alaska Fisheries Science Center, AFSC; Pacific Shark Research Center, PSRC at Moss Landing Marine Laboratories) and Canada (Fisheries and Oceans Canada, DFO) have produced dissimilar results for either species, highlighting the need for development of a consistent age determination protocol and more importantly an age validation study. Archived large specimens of longnose skate and big skate collected in Monterey Bay, CA, in 1980 and 1981 had minimum preliminary age estimates from vertebral growth band counts old enough to suggest that radiocarbon (14C) signals from bomb testing conducted in the late-1960s could be used to establish dates of growth band formation. To this end, we micro-milled skate vertebral thin sections, measured Δ14C using mass spectrometry, and estimated year of growth band formation based on the estimated age from growth band counts using both unstained and stained preparation methods Non-linear random effects modeling, implemented in a Markov Chain Monte Carlo (MCMC) simulation, was used to compare the skate Δ14C data set to a marine teleost otolith reference chronology for the California Current System. Results showed Δ14C measurements for big skate were non-informative as none of the archived samples were old enough for comparison to the reference curve, hence validation of the age estimation approach was not possible. However, for longnose skate, Δ14C data were more informative to fit pulse function models and compare results to the reference chronology. Modeling results indicated longnose skate age estimates based on unstained vertebral thin sections were less biased (overestimated to a smaller degree) than estimates based on stained vertebral thin sections. The degree of bias depended on agency ageing criteria, with the least biased age estimates produced by age readers from the AFSC. The AFSC age estimates had about a 70% probability that age estimates of longnose skate was within+/− 2 years of the expected age based on the radiocarbon assays. We were able to validate the age estimation methodology for longnose skate and establish criteria for growth band counts, which should now be useful to generate region-specific accurate growth and life history parameters required for more reliable stock assessment approaches.

Living carbonate habitats in temperate California (USA) waters: distribution, growth, and disturbance of Santa Catalina Island rhodoliths

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 560:135-145 (2016) - DOI: https://doi.org/10.3354/meps11919 Living carbonate habitats in temperate California (USA) waters: distribution, growth, and disturbance of Santa Catalina Island rhodoliths Paul A. Tompkins*, Diana L. Steller Moss Landing Marine Laboratories, 8272 Moss Landing Rd., Moss Landing, California 95039, USA *Corresponding author: ptompkins25@gmail.com ABSTRACT: Rhodoliths are globally widespread, free-living coralline red algal nodules (Rhodophyta). Living beds of rhodoliths create carbonate-based biogenic benthic habitats, which are sensitive to human disturbance and slow to recover. Despite their ecological importance, few quantitative assessments of the distribution and anthropogenic impacts on rhodoliths exist for the eastern Pacific Ocean. Following historical reports of beds in the Channel Islands off California, USA, we mapped bed distributions, examined rhodolith habitat sensitivity to human disturbance, and determined seasonal growth rates to assess rhodolith recovery potential at Santa Catalina Island. Rhodolith material from 7 beds covering 23000 m2 of live rhodoliths and 43000 m2 of dead rhodolith sediment were mapped. Beds were patchy, dominated by small Lithothamnion australe rhodoliths (mean ± SD: 10.6 ± 0.8 mm in diameter), and 6 beds were disturbed by mooring arrays. Surveys of mooring frequency and experimental manipulation of mooring chains showed that the cover of live rhodoliths, their physical structure, and the diversity and abundance of associated benthic species were negatively related to this prevalent anthropogenic disturbance. Axial growth rates of Santa Catalina Island rhodoliths were relatively slow, seasonally variable, and similar to those reported in other rhodolith studies (annual mean: 1.25 ± 0.62 mm yr-1). Due to their importance as biogenic habitat, sensitivity to disturbance, and slow recovery potential, California rhodolith beds should be considered a priority for monitoring efforts and restoration and should be included within marine protected area planning. KEY WORDS: Rhodophyta · Disturbance · Lithothamnion australe · Coralline algae · Maerl · Channel Islands Full text in pdf format PreviousNextCite this article as: Tompkins PA, Steller DL (2016) Living carbonate habitats in temperate California (USA) waters: distribution, growth, and disturbance of Santa Catalina Island rhodoliths. Mar Ecol Prog Ser 560:135-145. https://doi.org/10.3354/meps11919 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 560. Online publication date: November 24, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

Whisker growth dynamics in two North Pacific pinnipeds: implications for determining foraging ecology from stable isotope analysis

Whisker growth dynamics in two North Pacific pinnipeds: implications for determining foraging ecology from stable isotope analysis McHuron, EA. 1* , Walcott, S.M. 2,3 , Zeligs, J. 4 , Skrovan, S. 4 , Costa, D.P 1 , Reichmuth, C. 2 Department of Ecology & Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA Institute of Marine Sciences, Long Marine Laboratory, Santa Cruz, CA 95060, USA Department of Biological Sciences, University of Alaska, Anchorage, AK 99508, USA Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA *Corresponding author, emchuron@ucsc.edu Abstract Stable isotope analysis (SIA) of whiskers is increasingly used to investigate the foraging ecology of pinnipeds. An understanding of whisker growth dynamics is lacking for most species, yet is necessary for study design and interpretation of isotope data. Here we present measurements of whisker growth in five California sea lions (Zalophus californianus) and two spotted seals (Phoca largha) obtained using photogrammetry. Data were collected from captive individuals for at least one year, resulting in serial measurements of 321 sea lion and 153 spotted seal whiskers. The sea lion whiskers exhibited linear growth, with growth rates that ranged from <0.01 to 0.18 mm day -1 . In contrast, spotted seal whiskers exhibited asymptotic growth characterized by rapid initial growth of up to 1.40 mm day -1 ; whiskers reached 75% and 95% of their asymptotic length after an average of 48 and 105 days, respectively. Over half of the spotted seal whiskers were lost annually during a period that coincided with the annual pelage molt, whereas the estimated lifespan of sea lion whiskers was 10+ years. Our data indicate that sea lion whisker growth rates can be used to reliably determine time periods of tissue deposition and link isotope values with ecological events over multiple years. In contrast, spotted seal whiskers archive dietary information over a period of months, and interpretation of isotope values is complicated by growth and shedding patterns of whiskers, and physiological changes associated with the annual pelage molt. Keywords: Vibrissae, Phocid, Otariid, Growth rate, Foraging behavior

John Holland Martin: From Picograms to Petagrams and Copepods to Climate: The Class of MS 280, Moss Landing Marine Laboratories

John Holland Martin: From Picograms to Petagrams and Copepods to Climate: The Class of MS 280, Moss Landing Marine Laboratories

John Holland Martin From Picograms to Petagrams and Copepods to Climate: The Class of MS 280, Moss Landing Marine Laboratories

John Holland Martin From Picograms to Petagrams and Copepods to Climate: <i>The Class of MS 280, Moss Landing Marine Laboratories</i>

Stomach Contents of a Cuvier's Beaked Whale (Ziphius cavirostris) Stranded in Monterey Bay, California

From 1942 to 2010 there were 23 reported strandings of Cuvier’s Beaked Whale, Ziphius cavirostris (Odontoceti: Ziphiidae), in the Pacific Northwest (Oregon and Washington), and 25 reported strandings in California between 1982 and 2010 (Moore and Barlow 2013). Although Z. cavirostris appears to be the most cosmopolitan of the beaked whales, occurring in all oceans except in high polar regions (Leatherwood and Reeves 1983; Heyning 1989), global phylogenetic analyses reveal low maternal gene flow among populations confined to isolated ocean basins (Dalebout and others 2005). Extensive surveys throughout the California Current System (CCS) show that Z. cavirostris is distributed offshore over the continental slope, occurring more frequently closer to shore and aggregated in areas of complex bathymetry (for example, Monterey Bay, California and within the Southern California Bight, see Fig. 2 in Moore and Barlow 2013). In the northern CCS, Moore and Barlow (2013) estimated that the Z. cavirostris population likely has decreased by approximately 30% from 10,771 in 1991 to approximately 7550 individuals in 2008, and they suggested that one potential cause could be ecosystem change, thus highlighting the need for additional information on food habits. Heyning (1989) first summarized prey information for Z. cavirostris from around the world, a list that included 10 cephalopod families (16 genera), gadiform and atheriniform fishes, and 2 accounts of crustacean prey. Santos and others (2001) reported prey remains from 3 Z. cavirostris stranded in the eastern Atlantic and provided a review of known prey remains for the species. MacLeod and others (2003) extended the review of Santos and others (2001) to include comparison of Z. cavirostris with 2 additional beaked whales: Mesoplodon spp. and Hyperoodon planifrons. Combining these records with 7 Z. cavirostris stomachs evaluated by Santos and others (2007), the known diet of Z. cavirostris is based on prey remains recovered from only 45 individuals world-wide; diets consisted of 46 cephalopod species (15 families), infrequent crustacean remains, and rare representation among mostly unidentified fishes (MacLeod and others 2003). Compared with records from the Atlantic, food habits of Z. cavirostris off Alaska and in the eastern North Pacific are less well known (n 5 5 individuals, and only 1 from California). Fiscus (1997) identified 6 cephalopod families (11 genera) from a subset of the stomach remains collected and described by Kenyon (1961) from a mature female Z. cavirostris that stranded in March 1959 on Amchitka Island, Aleutian Islands, Alaska. Foster and Hare (1990) identified 3 of the same cephalopod families (4 genera) as reported by Fiscus (1997) from a Z. cavirostris stranded in Kodiak, Alaska. In the Gulf of Mexico, Fertl and others (1997) identified a single beak of Loligo peali from an individual that stranded in Texas. An adult female Z. cavirostris (Moss Landing Marine Laboratory Museum [MLMLM] #499, standard length 600 cm) stranded dead on 15 January 1998 at Marina State Beach, California (UTM: Zone 10S, 607191E, 4062264N, WGS84). During a 2-d field necropsy, to minimize the loss of contents, we tied-off both the esophageal and duodenal ends of the stomach before removing it on 16 January 1998. Prey remains were also collected from the whale’s oral cavity. The stomach contents from 5 pyloric compartments (see Kenyon 1961 for a description of the stomach of an adult female Z. cavirostris) were gently rinsed and sifted through a 500-mm sieve. Cephalopod remains (whole beaks, beak fragments, and eye lenses) and fish remains (bones and eye lenses) were preserved in 50% isopropyl alcohol and fish otoliths were stored dry. Cephalopods were identified to lowest taxon using the GENERAL NOTES

Biology and Management of Dogfish Sharks. Based on a symposium held in Seattle, Washington, 13–15 June 2005. Edited by Vincent F. Gallucci, Gordon A. McFarlane, and, Gregory G. Bargmann. Bethesda (Maryland): American Fisheries Society. $69.00. xvi + 435 p.; ill.; index. ISBN: 978‐1‐934874‐07‐3. 2009.

Previous articleNext article No AccessNew Biological BooksBiology and Management of Dogfish Sharks. Based on a symposium held in Seattle, Washington, 13–15 June 2005. Edited by Vincent F. Gallucci, Gordon A. McFarlane, and, Gregory G. Bargmann. Bethesda (Maryland): American Fisheries Society. $69.00. xvi + 435 p.; ill.; index. ISBN: 978‐1‐934874‐07‐3. 2009.David. A. EbertDavid. A. EbertPacific Shark Research Center, Moss Landing Marine Laboratories, Moss Landing, California Search for more articles by this author Pacific Shark Research Center, Moss Landing Marine Laboratories, Moss Landing, CaliforniaPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 85, Number 4December 2010 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/656886 Views: 8Total views on this site Copyright © 2010 by The University of Chicago Press. All rights reserved.PDF download Crossref reports no articles citing this article.

James W. Nybakken: September 16, 1936 – June 20, 2009 An Appreciation

A long-time member of AMU/AMS, President in 1986, and distinguished teacher, marine biologist, and researcher, James W. Nybakken (Fig. 1) died of leukemia June 20, 2009 at the age of 72. Jim did his graduate work at the University of Wisconsin, completing his Ph.D. in 1965 with a dissertation on the ecology of Three Saints Bay on Kodiak Island, Alaska. Shortly after his study, an earthquake elevated much of the bay’s intertidal zone several meters, and Jim’s thesis, published by the University of Alaska (1969) provided invaluable baseline data to assess the ecological effects of the earthquake. In September 1965, Jim joined the faculty of California State University Hayward (now CSU East Bay). In January 1966, he began teaching at the CSU system’s Moss Landing Marine Laboratories (MLML), where he was a member of the founding faculty and where he spent the rest of his career. He served as acting director of the Laboratories in the mid-1990s. “Throughout his tenure at MLML he witnessed the transformation of a small fi eld station cobbled together in an old cannery building to a modern marine institution with an international reputation for excellence in marine science.” (www.mlml. calstate.edu/announcements/news/6-24-09). I fi rst met Jim when he was a graduate student participating in a three-month International Indian Ocean Expedition (IIOE) cruise on the then Stanford University teaching and research vessel Te Vega in 1963. This ship facilitated inshore and coral reef studies in the western Indian Ocean, from Singapore through the Strait of Malacca and Malaysia to northern Thailand, and then through the islands off the south coast of Sumatra, ending rather ignominiously with an irrevocably broken drive shaft off Padang. The scientifi c personnel consisted of six faculty members and museum curators and six graduate students from diverse universities. Jim and I worked together on comparative ecology of the important reef-associated gastropod Conus, discovering in the process the most species-rich assemblages known at the time. Fig. 2 shows Jim, as well as Joe Rosewater, who also served as AMU president, in 1969, aboard the Te Vega during the IIOE cruise. In 1968-69, Jim, together with his wife Bette and their two small sons, Kent and Scott, spent a year’s leave of absence from MLML in Seattle, where Jim and I analyzed the fi eld data from the IIOE cruise and worked on writing up the results. We were able to obtain ecological data on 48 species, and we found up to 27 of them on a single reef. Co-occurring Conus species typically specialize differentially on prey species, but those in more diverse assemblages proved not to be more specialized. Rather, they consumed a wider array of prey taxa, and they specialized more on different microhabitats than did those in habitats that support fewer species. We also demonstrated size-selective predation, that only the largest individuals of prey species may be large enough to repay foraging effort, and that Conus individuals shift their diets to larger prey species as they grow (Kohn and Nybakken 1975). During that year, we also collaborated on the fi rst scanning electron microscopic morphological study of the harpoonlike Conus radular tooth (Kohn et al. 1972), and Jim embarked on studies of the ecology and radular morphology of Eastern Pacifi c Conus (Nybakken 1970a, 1970b, 1971, 1979a, 1979b). While Jim’s biological interests were broad, most but not all of his research focused on molluscs. His other notable contribution to the biology of Conus was the fi rst study ever made of ontogeny of radular teeth (Nybakken and Perron 1988,

Contaminant Loads And Hematological Correlates In The Harbor Seal (Phoca vitulina) Of San Francisco Bay, California

An expanding body of research indicates that exposure to contaminants may impact marine mammal health, thus possibly contributing to population declines. The harbor seal population of the San Francisco Bay (SFB), California, has suffered habitat loss and degradation, including decades of environmental contamination. To explore the possibility of contaminant-induced health alterations in this population, blood levels of polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and polybrominated diphenyl ethers (PBDEs) were quantified in free-ranging seals; relationships between contaminant exposure and several key hematological parameters were examined; and PCB levels in the present study were compared with levels determined in SFB seals a decade earlier. PCB residues in harbor seal blood decreased during the past decade, but remained at levels great enough that adverse reproductive and immunological effects might be expected. Main results included a positive association between leukocyte counts and PBDEs, PCBs, and DDE in seals, and an inverse relationship between red blood cell count and PBDEs. Although not necessarily pathologic, these responses may serve as sentinel indications of contaminant-induced alterations in harbor seals of SFB, which, in individuals with relatively high contaminant burdens, might include increased rates of infection and anemia.We thank staff, students, and volunteers from Moss Landing Marine Laboratories, the Richmond Bridge Harbor Seal Survey/San Francisco State University, and the Marine Mammal Center for assistance with seal capture and handling. We gratefully acknowledge Judy Lawrence (Marine Mammal Center) for running CBCs and serum chemistries. D. Anderson, B. Sacks, and two anonymous reviewers provided helpful critiques of the article. This project was supported in part by grants to J. Neale from the University of California Marine Council (02 T CEQI 03 0104) and the NIH (5 T32 ES07059-25 Traineeship in Environmental Toxicology).

Papers Posit Grave Impact of Trawling

Papers Posit Grave Impact of Trawling

Behavior of a fine-grained soil during the Loma Prieta earthquake

Results of an investigation into the behavior of a fine-grained clayey soil at Moss Landing during the 1989 Loma Prieta earthquake are presented. A deposit of this soil underlies portions of the Moss Landing Marine Laboratory that experienced up to 1.3 m of lateral spreading deformations during this magnitude 7 earthquake. Silty clay from the deposit erupted to the surface in a "soil boil" characteristic of liquefaction, during and immediately after the earthquake. A sample from the silty clay boil had a liquid limit of 38, a plasticity index of 17, and a &lt;5 µm fraction of 24%, and thus would be considered nonliquefiable according to commonly used criteria. Analysis of cyclic triaxial test data suggests that portions of the silty clay deposit likely developed high residual excess pore pressures (ru,r approx 80-90%) and significant shear strains during the earthquake and thus likely contributed to the observed lateral deformations. The field and laboratory data show that commonly used criteria for identifying "liquefiable" clayey soils should be applied with caution and should not be indiscriminately viewed as a substitute for detailed laboratory and in situ testing of low plasticity fine-grained soils.Key words: liquefaction, cyclic loading, silt, clay, earthquake, case history.

Behavior of a fine-grained soil during the Loma Prieta earthquake

Results of an investigation into the behavior of a fine-grained clayey soil at Moss Landing during the 1989 Loma Prieta earthquake are presented. A deposit of this soil underlies portions of the Moss Landing Marine Laboratory that experienced up to 1.3 m of lateral spreading deformations during this magnitude 7 earthquake. Silty clay from the deposit erupted to the surface in a "soil boil" characteristic of liquefaction, during and immediately after the earthquake. A sample from the silty clay boil had a liquid limit of 38, a plasticity index of 17, and a <5 µm fraction of 24%, and thus would be considered nonliquefiable according to commonly used criteria. Analysis of cyclic triaxial test data suggests that portions of the silty clay deposit likely developed high residual excess pore pressures (ru,r approx 80-90%) and significant shear strains during the earthquake and thus likely contributed to the observed lateral deformations. The field and laboratory data show that commonly used criteria for identifying "liquefiable" clayey soils should be applied with caution and should not be indiscriminately viewed as a substitute for detailed laboratory and in situ testing of low plasticity fine-grained soils.Key words: liquefaction, cyclic loading, silt, clay, earthquake, case history.

What controls dissolved iron concentrations in the world ocean?

Dissolved (< 0.4 μm) iron has been measured in 354 samples at 30 stations in the North and South Pacific, Southern Ocean and North Atlantic by the Trace Metals Laboratory at Moss Landing Marine Laboratories. These stations are all more than 50 km from a continental margin. The global distribution of dissolved iron, which is derived from these profiles, is remarkable for several reasons. The dissolved iron profiles have a uniform shape with a nutrient-like profile at each station. Concentrations at the surface are all < 0.2 nmol kg −1 and average 0.07 nmol kg −1 . Below 500 m, the average concentration is 0.76 nmol kg −1 . The largest value in the data set is 1.38 nmol kg −1 . There is no inter-ocean fractionation, which is unique for an element with a nutrient-like profile. Published estimates of the iron residence time are on the order of 100 to 200 yr, indicative of rapid removal. Other elements with such short residence times are characterized by vertical profiles that decrease with depth and deep concentrations that decrease with age as water passes from the Atlantic to the Pacific. This is not the case for iron. The largest horizontal changes in dissolved iron are observed in gradients from the continental margin. There is only a factor of three difference between the minimum (0.4 nmol kg −1 ) and maximum (1.3 nmol kg −1 ) value in the data set at a depth near 750 m, where variability is at a maximum. The minimum concentrations are found at stations in the remote central Pacific and the maximum values occur at stations adjacent to the continental margin. The major source of iron in the deep sea is generally aeolian deposition. Integrated (surface to 500 m) concentrations of iron at each station are only weakly correlated with the aeolian iron deposition flux, however. This contrasts with other elements such as lead that also have strong atmospheric sources. These observations lead us to conclude that the nutrient-like profile is maintained by a mechanism that reduces the scavenging rate of dissolved iron at concentrations less than 0.6 nmol kg −1 . This mechanism may be complexation by strong iron binding ligands, which have been found in both the Atlantic and Pacific at concentrations near 0.6 nM. This apparent solubility would act to diminish inter-ocean fractionation. It would allow a nutrient-like profile to develop before scavenging began to remove iron. In order to test the concept, we developed a numerical model to make quantitative predictions of dissolved iron concentrations from place to place. The dissolved iron source in the ocean interior is remineralization from sinking particulate organic matter. Scavenging removes dissolved iron only at concentrations greater than the apparent solubility. The only geographically variable parameter in the model is the export flux of carbon from the surface layer, which carries iron with it. The model generated dissolved iron profiles, based on measured or estimated values of the carbon export flux, are in remarkable agreement with the observed profiles at all stations from the North Atlantic through the Southern Ocean to the North Pacific.

Adding iron to ocean spurs photosynthesis

Experiments in the equatorial Pacific Ocean demonstrate that lack of iron is what keeps large ocean areas from being biologically productive. This makes iron great candidate as the agent that leads to the temperature changes that produce ice ages, says Kenneth S. Johnson, professor of oceanography at Moss Landing Marine Laboratories in California, one of the principal investigators. But the experiments also point out problems with a proposal first floated about six years ago: to alleviate some of the global warming effects caused by huge increases in atmospheric carbon dioxide by fertilizing the oceans with iron. The work was conducted by a team of oceanographers from nine institutions in the U.S., the U.K., and Mexico [ Nature , 383 , 495, 508, 511, and 513 (1996)]. The researchers added iron sulfate and a biologically inert tracer molecule, sulfur hexafluoride, to a patch of ocean some 800 miles west of the Galapagos Islands, then monitored the effect on ...

Did Plutarch Get Archimedes' Wishes Right?

Les Lange, Fellow of the California Academy of Sciences, Special Advisor to the Director of the Moss Landing Marine Laboratories on Monterey Bay, is Emeritus Professor of Mathe? matics and Emeritus Dean of Science of San Jose State Univer? sity. He learned mathematics at Berkeley, Valparaiso, Stanford (M.S. with George Polya), and Notre Dame (Ph.D. with Wladimir Seidel). He shared an MAA Lester R. Ford Sr. Award with Don Chakerian for a geometry paper, and an MAA George Polya Award with James W. Miller for a linear algebra paper. With G. L. Alexanderson he wrote the London Mathematical Society's extensive Polya obituary.

Tubicolous polychaetes as substrates for epizoic foraminifera

Abstract. Associations of epizoic foraminifera and invertebrates are widespread and have been reported from polar to tropical and shallow to bathyal environments (Zumwalt &amp;amp; DeLaca, 1980). Their fossil record stretches far back into Palaeozoic times as documented by agglutinated foraminifera attached to crinoids in Silurian and Devonian reef deposits of Morocco and Gotland (Franzen, 1974). Strong preferences for filter-feeding hosts suggest that epizoic foraminifera benefit from increased nutritional resources accumulated in the immediate flow microhabitat (Langer &amp;amp; Long, 1994).In the course of a broader study on foraminifera/invertebrate associations, several hundred foraminifera attached to the outer wall of agglutinated tubes of various polychaetes (e.g. Sabella sp., Potamilla sp.) were collected from sediment samples dredged at 61 m depth off the University of California, Moss Landing Marine Laboratory (NW Pacific). Attached foraminifera display a remarkable mode to obtain and differentially cement grains from the host tube that previously has not been reported. Agglutinated polychaete tubes and fragments thereof may reach 2 cm or more in length and are composed of fine sand, silt and micas cemented together by secreted organic material (Fig. 1). Tubes are typically orientated vertically in the mud and project above the sediment surface into the water column.NEW OBSERVATIONSExamination of agglutinated polychaete tubes revealed that their outer walls were commonly colonized by one to three foraminiferans (Figs 1–3, tube diameter 1.5–2.0 mm). The epizoic foraminiferal fauna comprised exclusively agglutinated taxa and included the following species: Alveophragmium advenum (Cushman), Textularia abbreviata Lalicker &amp;amp; McCulloch, Textularia schencki . . .

Notes on the JGOFS North Atlantic Bloom Experiment—dissolved organic carbon intercomparison

Using high temperature catalytic oxidation (HTCO), personnel from four laboratories analyzed water samples collected during the JGOFS North Atlantic Bloom study for their dissolved organic carbon (DOC) content. In general, good agreement was obtained. Values obtained on samples filtered and frozen compared well with those analyzed immediately after collection. DON analyses of the same frozen samples did not co-vary with DOC; thus far, DON results have only been reported by Moss Landing Marine Laboratories.