Benthic macrofauna and habitat monitoring on the Continental Shelf of the northeastern United States: I. Biomass

Information on long-term temporal variability of and trends in benthic community-structure variables, such as biomass, is needed to estimate the range of normal variability in comparison with the effects of environmental change or disturbance. Fishery resource distribution and population growth will be influenced by such variability. This study examines benthic macrofaunal biomass and related data collected annually between 1978 and 1985 at 27 sites on the continental shelf of the northwestern Atlantic, from North Carolina to the southern Gulf of Maine. The study was expanded at several sites with data from other studies collected at the same sites prior to 1978. Results indicate that although there was interannual and seasonal variability, as expected, biomass levels over the study period showed few clear trends. Sites exhibiting trends were either in pollution-stressed coastal areas or influenced by the population dynamics of one or a few species, especially echinoderms. (PDF file contains 34 pages.)

Ichthyoplankton of the continental shelf near Kodiak Island, Alaska

Eleven ichthyoplankton surveys were conducted (1 in 1972 and 10 between 1977 and 1979) in the northeastern Pacific Ocean over the continental shelf off Kodiak Island, Alaska. In the 677 neuston and 632 bongo tows, eggs or larvae of more than 80 fish taxa were found. They were present in every season and throughout the survey area, although more taxa and more individuals were found in summer than in other seasons. Among the more abundant species were the gadid Theragra chalcogramma and several hexagrammids and pleuronectids. The hexagrammids and several coUids were abundant in the neustonic layer, where they spent close to a year as larvae and prejuvenlles. Although the seasonal and geographic distribution of most taxa was complex, two patterns emerged: Late summer-fall spawners produce demersal eggs and have neustonic larvae that remain pelagic for several months (hexagrammids and some cottlds), and spring-summer spawners have pelagic eggs and larvae that spend several weeks in the plankton but are not closely associated with the surface (Theragra chalcogramma, pleuronectlds). (PDF file contains 95 pages.)

I. Geology of the Southwest quarter of the Elsinore Quadrangle. II. Geochemical properties of the waters of the Elsinore Quadrangle [= Geology of the Lake Elsinore Quadrangle, California. Mineral deposits of Lake Elsinore Quadrangle, California]

The Lake Elsinore quadrangle covers about 250 square miles and includes parts of the southwest margin of the Perris Block, the Elsinore trough, the southeastern end of the Santa Ana Mountains, and the Elsinore Mountains.

The oldest rocks consist of an assemblage of metamorphics of igneous effusive and sedimentary origin, probably, for the most part, of Triassic age. They are intruded by diorite and various hypabyssal rocks, then in turn by granitic rocks, which occupy over 40 percent of the area. Following this last igneous activity of probable Lower Cretaceous age, an extended period of sedimentation started with the deposition of the marine Upper Cretaceous Chico formation and continued during the Paloecene under alternating marine and continental conditions on the margins of the blocks. A marine regression towards the north, during the Neocene, accounts for the younger Tertiary strata in the region under consideration.

Outpouring of basalts to the southeast indicates that igneous activity was resumed toward the close of the Tertiary. The fault zone, which characterizes the Elsinor trough, marks one of the major tectonic lines of southem California. It separates the upthrown and tilted block of the Santa Ana Mountains to the south from the Perris Block to the north.

Most of the faults are normal in type and nearly parallel to the general trend of the trough, or intersect each other at an acute angle. Vertical displacements generally exceed the horizontal ones and several periods of activity are recognized.

Tilting of Tertiary and older Quaternary sediments in the trough have produced broad synclinal structures which have been modified by subsequent faulting.

Five old surfaces of erosion are exposed on the highlands.

The mineral resources of the region are mainly high-grade clay deposits and mineral waters.

Flood risk management: What are the main drivers of prevention?

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Effects of a flash-flood on channel morphology and some insects of a small stony stream in the Peak District, Derbyshire

In this paper, some observations are made following a flash-flood that occurred in Stake Clough, a small tributary of the River Goyt, during the evening of 6 August 1996. The site was visited eight times between 8 August - 30 October 1996 to take samples and make observations on the stream. The flood scoured the bed of Stake Clough but more significantly, caused it to change course along the middle part of the floodplain. Initially after the flood, the numbers of insects in all stretches of the stream channel were low (100-200 m super(2)), but then gradually rose to population densities approaching ten times this figure. The benthos was dominated by the Chironomidae and also leuctrid stoneflies (Leuctra nigra, L. hippopus and L. inermis). On 8th August 1996, 12 mesh bags, each containing oak leaves, were placed in the stream and collected after 24 hours. These were also dominated by chironomids, and contained relatively high numbers of the caddis, Potamophylax cingulatus.

I. Foehn winds of southern California. II. Foehn wind cyclo-genesis. III. Weather conditions associated with the Akron disaster. IV. The Los Angeles storm of December 30, 1933 to January 1, 1934

I. Foehn winds of southern California.
An investigation of the hot, dry and dust laden winds occurring in the late fall and early winter in the Los Angeles Basin and attributed in the past to the influences of the desert regions to the north revealed that these currents were of a foehn nature. Their properties were found to be entirely due to dynamical heating produced in the descent from the high level areas in the interior to the lower Los Angeles Basin. Any dust associated with the phenomenon was found to be acquired from the Los Angeles area rather than transported from the desert. It was found that the frequency of occurrence of a mild type foehn of this nature during this season was sufficient to warrant its classification as a winter monsoon. This results from the topography of the Los Angeles region which allows an easy entrance to the air from the interior by virtue of the low level mountain passes north of the area. This monsoon provides the mild winter climate of southern California since temperatures associated with the foehn currents are far higher than those experienced when maritime air from the adjacent Pacific Ocean occupies the region.

II. Foehn wind cyclo-genesis.
Intense anticyclones frequently build up over the high level regions of the Great Basin and Columbia Plateau which lie between the Sierra Nevada and Cascade Mountains to the west and the Rocky Mountains to the east. The outflow from these anticyclones produce extensive foehns east of the Rockies in the comparatively low level areas of the middle west and the Canadian provinces of Alberta and Saskatchewan. Normally at this season of the year very cold polar continental air masses are present over this territory and with the occurrence of these foehns marked discontinuity surfaces arise between the warm foehn current, which is obliged to slide over a colder mass, and the Pc air to the east. Cyclones are easily produced from this phenomenon and take the form of unstable waves which propagate along the discontinuity surface between the two dissimilar masses. A continual series of such cyclones was found to occur as long as the Great Basin anticyclone is maintained with undiminished intensity.

III. Weather conditions associated with the Akron disaster.
This situation illustrates the speedy development and propagation of young disturbances in the eastern United States during the spring of the year under the influence of the conditionally unstable tropical maritime air masses which characterise the region. It also furnishes an excellent example of the superiority of air mass and frontal methods of weather prediction for aircraft operation over the older methods based upon pressure distribution.

IV. The Los Angeles storm of December 30, 1933 to January 1, 1934.
This discussion points out some of the fundamental interactions occurring between air masses of the North Pacific Ocean in connection with Pacific Coast storms and the value of topographic and aerological considerations in predicting them. Estimates of rainfall intensity and duration from analyses of this type may be made and would prove very valuable in the Los Angeles area in connection with flood control problems.

Flood circulation in oligomictic lakes: an undervalued reason for restriction of zooplankton production [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 22 9-52, 1967]

Dormancy has been observed in several species of Cyclops. Animals in dormancy are characterised by almost complete inactivity of the main appendages and sluggish intestinal peristalsis. In Cyclops vicinus dormancy can take place in copepod stages III (19%), IV (78%) and V (3%) but one and the same animal only in one developmental stage. The author gives his own results between frequency of dormancy and photoperiod (20 C, 1000 lux). He concludes that dormancy in C. vicinus can be influenced by day length and can be ended prematurely by short day length.

Origem e composição da matéria orgânica sedimentar na margem continental próximo a Cabo Frio (RJ), porção sul da Bacia de Campos, costa sudeste do Brasil

Lipídios como marcadores moleculares (ácidos graxos, esterois e n- alcoois) e COT foram analisados em 48 amostras de sedimento superficial (0-2 cm) em dois períodos (inverno de 2008/2009 e verão de 2009) ao longo de 12 isóbatas em 2 transectos (25 a 3000 m) na principal região de ressurgência da costa sudeste do Brasil, onde a influência do aporte fluvial é mínima. O objetivo foi (i) avaliar as fontes, transporte e regiões de acúmulo da matéria orgânica (MO) (ii) identificar a fração da MO potencialmente disponível para os orgânismos bentônicos. Este estudo faz parte do Projeto Habitats Heterogeneidade Ambiental da Bacia de Campos coordenado pelo CENPES/PETROBRAS. Lipídios derivados da produção primária (0.058 - 3.1 mg gCOT-1) e secundária (0.015 - 2.2 mg gCOT-1) representaram a maior fração da MO sedimentar, enquanto lipídios derivados de fontes alóctonas (0.043 - 0.40 mg gCOT-1) e bactérias (<0.01 - 0.43 mg gCOT-1) foram menos representativos. O padrão de transporte e acúmulo da MO no sedimento depende da associação entre fatores físicos (hidrodinâmicos) e biológicos (resposta a ressurgência), e não é influenciado sazonalmente como observado em dados prévios na mesma região. Verificou-se que regiões restritas da plataforma continental apresentam acúmulo de MO lábil e esse material é exportado para regiões do talude (400 a 1000 m de profundidade), o que representa uma fonte importante de MO biodisponível para a comunidade bentônica desta região.

O uso do boto-cinza (Sotalia guianensis) como sentinela da poluição continental por compostos organoclorados (DDT, PCB, HCH, HCB e Mirex) em baías costeiras do Estado do Rio de Janeiro

Concentrações de compostos organoclorados (DDTs, PCBs, HCHs, Mirex e HCB) foram determinadas em camadas externas e internas do tecido adiposo subcutâneo de 17 botos-cinza (Sotalia guianensis) da região Sudeste do Brasil. Não houve diferenças estatísticas significativas entre os estratos, relativo aos 37 compostos determinados, assim como ΣDDT, ΣPCB, ΣHCH, e as razões p,p-DDE/ΣDDT e ΣDDT/ΣPCB. Entretanto, foram observadas diferenças significativas nas concentrações de alguns compostos organoclorados de animais encalhados ou capturados acidentalmente quando comparados com animais biopsiados remotamente, sendo assim as comparações entre esses dois conjuntos de dados, devem ser vistas com cuidado. No presente estudo, as concentrações dos compostos organoclorados foram determinadas em biópsias de botos-cinza obtidas de 2007 a 2009, nas baías de Sepetiba (n=13) e Ilha Grande (n=11), Sudeste do Brasil. As concentrações (ng/g de lipídio) variaram de Paranaguá, apresentaram padrões distintos de acumulação dos compostos organoclorados. O último achado demonstra a existência de separações ecológicas entre os botoscinza a partir de diferentes áreas, o que constitui informação de grande importância para a conservação e o manejo da espécie

Studies of noble gases in meteorites and in the earth

The isotopic and elemental abundances of noble gases in the solar system are investigated, using simple mixing models and mass-spectrometric measurements of the noble gases in meteorites and terrestrial rocks and minerals.

Primordial neon is modeled by two isotopically distinct components from the interstellar gas and dust. Neon from the gas dominates solar neon, which contains about ten times more ²⁰Ne than ²²Ne. Neon from the dust is represented in meteorites by neon-E, with ²⁰Ne/²²Ne less than 0.6. Isotopic variations in meteorites require neon from both dust and gas to be present. Mixing dust and gas without neon loss generates linear correlation lines on three-isotope and composition-concentration diagrams. A model for solar wind implantation predicts small deviations from linear mixing, due to preferential sputtering of the lighter neon isotopes.

Neon in meteorites consists of galactic cosmic ray spallation neon and at least two primordial components, neon-E and neon-S. Neon was measured in several meteorites to investigate these end- members. Cosmogenic neon produced from sodium is found to be strongly enriched in ²²Ne. Neon measurements on sodium-rich samples must be interpreted with care so not to confuse this source of ²²Ne with neon-E, which is also rich in ²²Ne.

Neon data for the carbonaceous chondrite Mokoia show that the end member composition of neon-Si in meteorites is ²⁰Ne/²²Ne = 13.7, the same as the present solar wind. The solar wind composition evidently has remained constant since before the compaction of Mokoia.

Ca, Al-rich inclusions from the Allende meteorite were examined for correlation between neon-E and oxygen or magnesium isotopic anomalies. ²²Ne and ³⁶Ar enrichments found in some inclusions are attributed to cosmic- ray-induced reactions on Na and Cl, not to a primordial component. Neon-E is not detectably enriched in Allende.

Measurements were made to determine the noble gas contents of various terrestrial rocks and minerals, and to investigate the cycling of noble gases between different terrestrial reservoirs. Beryl crystals contain a characteristic suite of magmatic gases including nucleogenic ²¹Ne and ²²Ne from (α,n) reactions, radiogenic ⁴⁰Ar, and fissiogenic ^131-136Xe from the decay of K and U in the continental crust. Significant concentrations of atmospheric noble gases are also present in beryl.

Both juvenile and atmospheric noble gases are found in rocks from the Skaergaard intrusion. The ratio ⁴⁰Ar/³⁶Ar (corrected for in situ decay of ⁴⁰K) correlates with δ¹⁸O in plagioclase. Atmospheric argon has been introduced into samples that have experienced oxygen-isotope exchange with circulating meteoric hydrothermal fluids. Unexchanged samples contain juvenile argon with ⁴⁰Ar/³⁶Ar greater than 6000 that was trapped from the Skaergaard magma.

Juvenile and atmospheric gases have been measured in the glassy rims of mid-ocean ridge (MOR) pillow basalts. Evidence is presented that three samples contain excess radiogenic ¹²⁹Xe and fission xenon, in addition to the excess radiogenic ⁴⁰Ar found in all samples. These juvenile gases are being outgassed from the upper-mantle source region of the MOR magma. No isotopic evidence has been found here for juvenile primordial noble gases accompanying the juvenile radiogenic gases in the MOR glasses. Large argon isotopic variations in a single specimen provide a clear indication of the late-stage addition of atmospheric argon, probably from seawater.

The Skaergaard data demonstrate that atmospheric noble gases dissolved in ground water can be transferred into crustal rocks. Subduction of oceanic crust altered by seawater can transport atmospheric noble gases into the upper mantle. A substantial portion of the noble gases in mantle derived rocks may represent subducted gases, not a primordial component as is often assumed.

Observação do transporte de sedimentos em suspensão ao longo do Canal Norte do rio Amazonas durante condições de baixa descarga (outubro 2008)

The Amazon river, located in northernBrazil, discharges between 80,000 and 250,000 m3s-1 of water onto the adjacent shelf, creating a plume of brackish water that extends hundreds of kilometers away from the river mouth. This river also carries a large amount of fine sediments to the ocean where fluid mud has been found in the topset and upper foreset layers of the subaqueous delta formed on the mid-shelf. One of the main goals of this dissertation is to describe how turbulence and suspended sediment concentration vary along the Northern Channel of the Amazon river. Water column measurements were carried out in October 2008 at six anchor stations (P1, P3, P5, P6, P8 e P9) located seaward of the river mouth; P1 and P9 were 125 km apart. Each station was occupied during 13 hours during which current speed and direction were continuously sampled with a 600 kHz Teledyne-RDI ADCP; hourly profiles of temperature, salinity, turbidity and depth were also obtained. Water samples were collected for determination of Suspended Particulate Matter (SPM) concentration and calibration of the turbidity sensor. Current speed reached values above 1.5 m s1 in the along-channel direction (NE-SW); a remarkable ebb-flood asymmetry was observed and flows were strongly ebb-dominated. Throughout the water column, SPM concentration at stations P1 and P3 varied between 100 and 300 mg L1 in association with the presence of freshwater. In contrast, a strong salinity gradient was observed between stations P6 and P9, coinciding with the occurrence of concentrations of SPM above 10 g L-1 (fluid mud). At stations P3, P5 and P6, interface between freshwater from the Amazon river and salt water from the continental shelf, shear stresses wereestimated through four diferents methods: Reynolds, Turbulent Kinetic Energy (TKE), modified TKE and Quadratic Law; in the nearbed region (3 mab) the computed values varied between 0 and 3 Pa. At the three stations (P3, P5 and P6) the lowest and the highest shear stress values were obtained through, respectively, the Reynolds and the TKE methods. Over the whole water column turbulence intensity was estimated through the standard deviation of the turbulent component of the along-channel current velocity (root-mean square of u); from these values, it was estimated the turbulent dissipation of energy (G), whose values at 3 mab varied between zero and 20 s1.

Lipídios como indicadores de processos biogeoquímicos em sedimentos da margem continental do Estado do Rio de Janeiro

Este estudo constitui parte do Projeto Habitats Heterogeneidade Ambiental da Bacia de Campos coordenado pelo CENPES/Petrobras, um projeto multidisciplinar de caracterização ambiental que considera as diferentes feições e habitats da margem continental do sudeste brasileiro. O objetivo desta tese foi investigar os processos relacionados com a origem, o transporte e o acúmulo de matéria orgânica (MO) em sedimentos da margem continental da Bacia de Campos (RJ). Para isso, foram determinados a composição elementar da matéria orgânica (carbono e nitrogênio) por combustão a seco e os lipídios (esteróis, álcoois e ácidos graxos) por CG-MS e CG-DIC. Foram analisadas 215 amostras de sedimento superficial (0-2 cm de profundidade), coletadas em duas amostragens (períodos seco e chuvoso de 2008/2009), distribuídas sobre 12 isóbatas (de 25 a 3000 m) ao longo de 9 transectos de norte a sul da bacia. Além disto, foram ainda consideradas as isóbatas de 400 a 1900 m em dois cânions submarinos no norte da bacia (Almirante Câmara e Grussaí). Com base nos resultados obtidos, a MO sedimentar na plataforma e talude da bacia revelou-se essencialmente autóctone, derivada de produtores primários e secundários. Com isto, a MO contém uma fração reativa significativa e, portanto, é potencialmente biodisponível para os organismos bentônicos. No entanto, foram observados gradientes espaciais significativos na qualidade e na quantidade da MO sedimentar. Na plataforma continental (25 m a 150 m de profundidade) as concentrações de lipídios foram intermediárias e houve predomínio de MO sedimentar lábil. Exceções foram as áreas influenciadas por ressurgência costeira e/ou intrusão sub-superficial (próximo à Cabo Frio, Cabo de São Tomé e no limite norte da bacia), onde as concentrações foram altas. No talude superior e médio (400 a 1300 m) as concentrações de MO foram notadamente mais elevadas, mas com maior influência de processos bacterianos de alteração de sua composição original. E no talude inferior (1900 a 3000 m) as concentrações de MO estiveram muito baixas e apenas os lipídios mais resistentes à degradação bacteriana foram encontrados em concentrações mensuráveis. Isto sugeriu a exportação de materiais da plataforma ao longo do gradiente batimétrico, possivelmente decorrente da ação de meandros e vórtices da Corrente do Brasil e das correntes de fundo atuantes na região. Além disto, por ser lábil e biodisponível, a MO no sedimento apresenta uma fração biodisponível que pode ter uma influência na ecologia das comunidades bentônicas, particularmente aquelas localizadas no talude superior. Os cânions Grussaí e Almirante Câmara se revelaram regiões de acúmulo de MO e importantes no transporte da MO com valor nutritivo para comunidades bentônicas do talude médio e inferior.

Massa corporal e morfometria de Conopophaga melanops (Aves: Conopophagidae): uma comparação intrasexual e entre áreas continental e insular de Mata Atlântica, na região da Baía da Ilha Grande, RJ

A forma e o tamanho de um determinado organismo devem caracterizar aspectos ecológicos, uma vez que a morfometria é resultado da evolução. Diferenças nos caracteres morfológicos podem ter sido causadas por isolamento geográfico, mesmo em períodos de tempo relativamente curtos. O estudo da morfologia ecológica é uma tentativa de compreender a relação funcional entre variação morfológica e a ecologia dos animais. A variação nos atributos morfométricos de tamanho corpóreo entre os sexos pode ser um resultado da ação da seleção sexual. O presente estudo aborda uma comparação intrasexual e entre área continental e insular da morfologia de Conopophaga melanops (Vieillot, 1818), tendo sido realizado em uma área na Ilha Grande e em outra área na Reserva Ecológica Rio das Pedras (ReRP), RJ. A espécie, endêmica de Mata Atlântica e estritamente florestal, apresenta dimorfismo sexual, contudo indivíduos jovens possuem plumagem similar a de fêmeas. As aves foram capturadas com redes neblina, e doze medidas morfométricas foram obtidas de 51 indivíduos. A confirmação do sexo foi realizada por métodos moleculares baseados no DNA em 69 amostras. O percentual de erro na identificação do sexo em campo, pela plumagem, foi de 9,7%. A confirmação molecular do sexo é uma importante ferramenta que têm potencial de revelar padrões demográficos em estudos comportamentais e reprodutivos desta espécie. Na ReRP o comprimento da asa e a variável distância da cabeça até a ponta do bico apresentaram uma diferença significativa, sendo maior para machos do que para fêmeas. Já na Ilha Grande, as únicas variáveis que apresentaram diferença significativa foram comprimento da cauda (maior em machos) e altura do bico na base (maior em fêmeas). As diferenças de tamanho da asa entre os sexos corroboram com padrões de diversas outras espécies Neotropicais. A diferença morfométrica do bico pode estar associada à ecologia alimentar desta espécie. Tanto fêmeas quanto machos foram maiores na ilha do que no continente com relação ao comprimento total e comprimento da asa, além de comprimento da cauda maior para os machos.

Alimentación de la merluza en la región del talud continental argentino, época invernal (Merlucciidae, Merluccius merluccius hubbsi)

In the present paper the first results on the food and feeding habityas of hake in the region of the Argentinean continental slope are given. The data were obtained from the hake sampling made on board of the German research ship "Walther Herwig" during his first fishing exploratory trip in the Southwest Atlantic and from the investigation on the collected hake's stomachs.

Distribuição espacial do pico e ultraplâncton na plataforma continental e talude entre Cabo Frio (RJ) e Ubatuba (SP) e sua relação com a hidrodinâmica local: inverno de 2010

O picoplâncton (0,2 - 2,0 m) e ultraplâncton (> 2,0 - 5,0 m) despertam interesse por utilizarem ativamente a matéria orgânica dissolvida, estabelecendo a alça microbiana. Responsáveis por 50-80% da produção primária em águas oligotróficas, essas frações apresentam elevadas eficiência luminosa e razão superfície/volume que as permitem alcançar alto desenvolvimento mesmo sob baixas luminosidade e disponibilidade de nutrientes. Buscando relacionar a distribuição espacial e composição da comunidade pico e ultraplanctônica aos controles bottom-up na plataforma continental e talude ao largo dos Estados do Rio de Janeiro e São Paulo (22S a 26S), foram coletadas amostras de água em 39 estações oceanográficas e utilizadas as imagens dos sensores MODIS Terra e Aqua, bem como dados de hidrografia, para a descrição dos fenômenos oceanográficos de mesoescala. A abundância total de ambas as frações de tamanho, assim como a dominância do picoplâncton, reduziu em função do distanciamento da costa. Os organismos autotróficos foram em média (102 cél.mL-1 a 104 cél.mL-1 ) majoritariamente uma ordem de grandeza inferiores aos heterotróficos (103 cél.mL-1 a 105 cél.mL-1). A Água Central do Atlântico Sul (ACAS) e as plumas das baías de Guanabara e Sepetiba (RJ) permaneceram na plataforma interna favorecendo o aumento na concentração dos macronutrientes e refletindo na mudança da estrutura da comunidade através do aumento da contribuição de autótrofos no centro da plataforma, principalmente do ultraplâncton à superfície (cerca de 21%) e na profundidade do máximo de clorofila (44%). O transporte de águas costeiras carreadas por uma corrente de origem sul gerou o vórtice de plataforma identificado nas imagens de satélite para a região da plataforma interna de Ubatuba (SP), onde concentrações mais elevadas de amônio (0,28 M) e fosfato (9,64 M) a partir dos 50 m sustentaram maior densidade do ultra autótrofo (2,89 x 103 cél.mL-1) que superou a densidade de heterótrofos (2,50 x 103 cél.mL-1) no máximo de clorofila. Os resultados destacaram um forte gradiente nerítico-oceânico na distribuição dos organismos. Sugerem ainda a predominância do metabolismo heterotrófico na maior parte das águas oligotróficas da plataforma e talude entre o Rio de Janeiro e São Paulo, bem como a presença de caráter autotrófico naquelas regiões influenciadas por feições de mesoescala, como plumas estuarinas e vórtices de plataforma.