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At least 1,729 records · Page 96Linked to original sources
USGS1994

Re-Os isotopic evidence for an enriched-mantle source for the Noril'sk-type, ore-bearing intrusions, Siberia

Magmatic Cu-Ni sulfide ores and spatially associated ultramafic and mafic rocks from the Noril'sk I, Talnakh, and Kharaelakh intrusions are examined for Re-Os isotopic systematics. Neodymium and lead isotopic data also are reported for the ultramafic and mafic rocks. The Re-Os data for most samples indicate closed-system behavior since the ca. 250 Ma igneous crystallization age of the intrusions. There are small but significant differences in the initial osmium isotopic compositions of samples from the three intrusions. Ores from the Noril'sk I intrusion have γ Os values that vary from +0.4 to +8.8, but average +5.8. Ores from the Talnakh intrusion have γ Os values that range from +6.7 to +8.2, averaging +7.7. Ores from the Kharaelakh intrusion have γ Os values that range from +7.8 to +12.9, with an average value of +10.4. The osmium isotopic compositions of the ore samples from the Main Kharaelakh orebody exhibit minimal overlap with those for the Noril'sk I and Talnakh intrusions, indicating that these Kharaelakh ores were derived from a more radiogenic source of osmium than the other ores. Combined osmium and lead data for major orebodies in the three intrusions plot in three distinct fields, indicating derivation of osmium and lead from at least three isotopically distinct sources. Some of the variation in lead isotopic compositions may be the result of minor lower-crustal contamination. However, in contrast to most other isotopic and trace element data, Os-Pb variations are generally inconsistent with significant crustal contamination or interaction with the subcontinental lithosphere. Thus, the osmium and lead isotopic compositions of these intrusions probably reflect quite closely the compositions of their mantle source, and suggest that these two isotope systems were insensitive to lithospheric interaction. Ultramafic and mafic rocks have osmium and lead isotopic compositions that range only slightly beyond the compositions of the ores. These rocks also have relatively uniform ϵ Nd values that range only from −0.8 to + 1.1. This limited variation in neodymium isotopic composition may reflect the characteristics of the mantle sources of the rocks, or it may indicate that somehow similar proportions of crust contaminated the parental melts. The osmium, lead, and neodymium isotopic data for these rocks most closely resemble the mantle sources of certain ocean island basalts (OIB), such as some Hawaiian basalts. Hence, these data are consistent with derivation of primary melts from a mantle source similar to that of some types of hotspot activity. The long-term Re/Os enrichment of this and similar mantle sources, relative to chondritic upper mantle, may reflect 1. incorporation of recycled oceanic crust into the source more than 1 Ga ago, 2. derivation from a mantle plume that originated at the outer core-lower mantle interface, or 3. persistence of primordial stratification of rhenium and osmium in the mantle.

Siberia↗
USGS1992

Experimental evidence for the effects of polyphenolic compounds from Dictyoneurum californicum Ruprecht (Phaeophyta: Laminariales) on feeding rate and growth in the red abalone Haliotus rufescens Swainson

The effects of polyphenolic compounds from brown algae on grazing and growth rate of the California red abalone Haliotis rufescens Swainson were examined. Abalone consumed three phenolic-poor algal species, Laminaria sinclarii (Harvey) Farlow, Macrocystis pyrifera Agardh, and Nereocystis luetkeana Postels et Ruprecht (mean phenolic content = 0.52% dry mass), at a greater rate than two phenolic-rich species, Dictyoneurum californicum Ruprecht and Cystoseira osmundacea Agardh (mean phenolic content = 4.60% dry mass). This inverse relationship between phenolic content and consumption rate also existed after the algae were macerated and the liquid portion of the blended slurry incorporated in agar discs. However, the correlation between grazing rate and phenolic content imprpve d in this latter experiment, thus suggesting that abalone grazing was deterred significantly by the morphology of L. sinclarii and, to a lesser extent, of M. pyrifera . Polyphenolics extracted from D. californicum reduced abalone grazing rates by 90% when incorporated into agar discs at a concentration of 6 mg·ml −1 . Although abalone were unable to maintain body mass when fed ad libitum on macerated M. pyrifera incorporated into agar discs, polyphenolics from D. californicum further inhibited shell growth when added to the discs at 5 mg·ml −1 . The abalone ate less of the phenol-containing discs than of the discs lacking phenolics. Our results support findings of several prior studies that polyphenolic compounds from brown algae deter grazing by coastal zone herbivores in the northeast Pacific Ocean.

Journal of Experimental Marine Biology and Ecology↗
USGS1987

Origins of seawater intrusion in a coastal aquifer - A case study of the Pajaro Valley, California

Seawater may enter and contaminate stratified coastal aquifers through a number of different pathways. These pathways and their relative contribution are examined in the Pajaro Valley, California, a coastal area with extensive groundwater development. This study considers three pathways of possible intrusion of the primary confined aquifer: (1) onshore leakage from brackish sources, the estuary and sloughs, through the confining layer; (2) near-shore leakage from the ocean through the confining layer; and (3) offshore flow from the ocean through the submarine canyon outcrop of the aquifer. Groundwater flow and seawater intrusion are simulated using an areal, two-dimensional solute-transport computer model. This analysis indicates that leakage through confining layers is the principal mechanism of recharge to the aquifer. Although lateral flow through the offshore outcrop contaminates the aquifer, as a whole, at a higher rate, vertical leakage through the sea floor initially is the main pathway of seawater intrusion to the onshore portion of the aquifer. It is likely that leakage generally is the dominant mechanism of recharge and initial cause of seawater intrusion for poorly-confined, stratified coastal aquifers. This analysis suggests that a significant time interval follows the initial observation of seawater intrusion, during which remedial action can be taken to control lateral flow through the offshore outcrop, which ultimately will be the largest component of future intrusion in these aquifers.

California↗
USGS1980

Sediment waves on the Monterey fan levee: a preliminary physical interpretation.

Sediment waves on the deep ocean floor occur mostly on the lower continental rise on slopes of 1° or less. Previous studies show that their amplitude and wavelength vary greatly, but little is known about their shape in plan. A detailed survey of a 30-km 2 area of abyssal-depth sediment waves associated with the levee of the Monterey fan valley shows a pattern of sinuous crests and troughs with parallel, well-bedded internal structure. Material in the upper 1 m of sediment consists predominantly of bioturbated, muddy coccolith ooze. A single thin, silty horizon can be correlated between adjoining waves. On the basis of measured wave dimensions and an estimate of flow velocity we use a simple two-layer model for water movement to infer approximate flow parameters. The sediment waves are considered to be formed most likely by low-velocity (10 cm/s), low-concentration turbidity flows approximately 100–800 m thick. This interpretation emphasizes the role of low-speed, low-concentration turbidity currents in the downslope movement of fine-grained material. This type of transport—deposition regime explains the formation of sediment waves very well except for certain waves occurring on depositional ridges in the deep ocean.

Marine Geology↗
USGS1981

The terminal Eocene event and the Polish connection

The Eocene/Oligocene boundary in Europe is marked by major discontinuities in all environments: the “Grande Coupure” in continental mammals; the elimination of semitropical elements from high-latitude floras; the virtually complete replacement of the shallow-marine malacofauna; and an extraordinary downslope excursion of carbonate deposition in deep-ocean basins (drop in the CCD). These phenomena collectively represent the “Terminal Eocene Event” (TEE). In the Carpathian Mountains, the TEE is manifested in the thin but regionally persistent Globigerina Marl, a calcareous unit containing abundant cool-water microplankton that occurs within very thick, siliceous, bathyal flysch sequences. In southern Poland, the marl is of very latest Eocene age, within planktonic foraminifera zone P17, calcareous nannoplankton zone NP19/20, and the zone of the dinoflagellate Rhomdodinium perforatum . Zircons from bentonites bracketing the marl are dated by fission-track analysis; at Polany, two underlying bentonites are 41.7 and 39.8 Ma, and at Znamirowice two overlying bentonites are 34.6 and 28.9 Ma, in sequence. This accords with glauconite K/Ar ages in Western Europe by which the Eo/Oligocene boundary age is estimated at 37–38 Ma. Global correlations indicate that the TEE corresponds to a major glacio-eustatic regression with a duration of about 0.5 Ma, in which a large Antarctic ice cap was formed, the ocean circulation was permanently changed to the psychrospheric condition, and world climate shifted irreversibly towards the modern state.

Palaeogeography, Palaeoclimatology, Palaeoecology↗
USGS1986

Paleoceanographic and tectonic controls on deposition of the Monterey formation and related siliceous rocks in California

The timing of paleoceanographic and tectonic events that shaped the deposition of the Monterey Formation of California and related siliceous rocks has been determined by application of a refined biochronology. The base of the Monterey at 17.5 Ma coincides with rising global sea level and a switch in biogenous silica deposition from the Caribbean and low-latitude North Atlantic to the North Pacific. Major polar cooling, which began at 15 Ma, postdates the base of the Monterey by more than 2 Ma and cannot be invoked to cause the deposition of diatomaceous sediments occurring in the lowermost Monterey. Later polar cooling in the early late Miocene, however, apparently caused increased upwelling and deposition of purer diatomites in the upper Monterey. The top of the Monterey at about 6 Ma coincides with a major sea level drop and is commonly marked by an unconformity. Equivalent unconformities are widespread around the rim of the North Pacific and typically separate more pelagic sediments from overlying sediments with a greater terrigenous component. Above the Monterey, diatoms persist in California sediments to 4.5–4.0 m.y., where their decline coincides with increased deposition of diatoms in the Antarctic. Carbon isotope records in the Pacific and Indian Oceans record storage of 12 C in the Monterey Formation and equivalent organic-rich sediments around the rim of the North Pacific. A +1.0‰ excursion in δ 13 C beginning at 17.5 Ma coincides with rising sea level and probably reflects storage of organic material in Monterey-like marginal reservoirs. A reverse −1.0‰ shift at 6.2 Ma closely approximates the top of the Monterey and may represent erosion of these marginal reservoirs and reintroduction of stored organic carbon into the ocean—atmosphere system. Initiation of transform faulting and extension in the California margin in the latest Oligocene and early Miocene caused the subsidence of basins which later received Monterey sediments. A major tectonic event centered at 10–9 Ma, which included rotation of the Santa Barbara Basin and a change in Pacific plate motion, is recorded by an unconformity and/or interval of compressed sediments in many Monterey sections. Another change in plate motion at about 6 Ma may be expressed by the angular discordance observed in many sections across the unconformity at the top of the Monterey.

California↗
USGS1994

Late Pliocene climate change 3.4-2.3 Ma: paleoceanographic record from the Yabuta Formation, Sea of Japan

Late Pliocene paleoceanographic changes in the Sea of Japan between 3.4 and2.3 Ma were investigated through study of molluscs, diatoms, and ostracodes from the Yabuta Formation in Toyama Prefecture. The period 3.4-2.7 Ma was characterized by relatively high sea level and cool water benthic faunas. A progressive paleoceanographic shift towards colder oceanic conditions and lower sea level occurred beginning near 2.7 Ma, intensifying about 2.5 Ma, when important changes in ostracode and molluscan faunas occurred. Between 2.7 and 2.3 Ma, eight glacial events can be inferred based on drops in sea level of 50-60 m and increasing proportions of cold, shallow water ostracode species whose modern ecology and zoogeography indicate colder winter water temperatures (3-4??C). The glacial events between 2.5 and 2.3 Ma were the most intense. Preliminary interpretation of the faunal and oceanographic events of the Yabuta Formation suggests that they correspond to Northern Hemispheric cooling also known from North Atlantic deep-sea oxygen isotope, IRD, and planktic foraminiferal records, North Pacific diatom and radiolarian record, and the Chinese loess sequences. The eight glacial events may record a 41,000-yr obliquity cycle which characterized other late Pliocene climate proxy records. Inferred sea level drops near 2.5-2.3 Ma of about 50-60 m provide direct evidence from an ocean margin setting that supports deep sea oxygen isotopic evidence indicating major changes in global ice volume changes.

Palaeogeography, Palaeoclimatology, Palaeoecology↗
USGS2017

Diatom evidence on Wisconsin and Holocene events in the Bering Sea

Previous work on surface (modern) sediments has defined diatom species which appear to be good indicators of various oceanographic/ecologic conditions in the North Pacific Ocean and marginal seas. Three long cores from the eastern and northern sides of the Aleutian Basin show changes in species assemblage which can be interpreted in terms of changes in the ocean environment during the last glaciation (Wisconsin) and the Holocene. The early and late Wisconsin maxima were times of prolonged annual sea-ice cover and a short cool period of phytoplankton productivity during the ice-free season. The middle Wisconsin interstade, at least in the southern Bering Sea, had greater seasonal contrast than today, with some winter sea-ice cover, an intensified temperature minimum, and high spring productivity. Variations in clastic and reworked fossil material imply varying degrees of transport to the basin by Alaskan rivers. The results of Jouse?? from the central Bering Sea generally correspond with those presented here, although there are problems with direct comparison. ?? 1983.

Quaternary Research↗
USGS1978

Tectonics of the North American Cordillera near the Fortieth Parallel

The North American Cordillera near the Fortieth Parallel consists of the following tectonic units: 1. (A) To the east is a reactivated cratonic area, in the Southern Rocky Mountains and Colorado Plateau, in which the supracrustal rocks (Cambrian to Cretaceous) were broadly deformed during the late Cretaceous-Paleocene Laramide orogeny, and the Precambrian basement was raised in folds of wide amplitude. 2. (B) West of it is a miogeosynclinal belt, in the eastern Great Basin, in which a thick sequence of Paleozoic carbonates and related deposits was thrust eastward along low-angle faults during the middle to late Cretaceous Sevier orogeny. The miogeosyncline is the downwarped western margin of the original North American continent, and its rocks accumulated on Precambrian basement. 3. (C) Beyond is a eugeosynclinal belt, in the western Great Basin, in which Paleozoic graywackes, cherts, and volcanics were thrust easteastward along low-angle faults during several Paleozoic orogenies - the mid-Paleozoic Antler orogeny which produced the Roberts thrust on the east, and the end-Paleozoic Sonoma orogeny which produced the Golconda thrust farther west. The Paleozoic eugeosynclinal rocks accumulated on oceanic basement. They are overlapped from the west by Triassic and Jurassic shelf deposits, which pass westward into eugeosynclinal deposits. 4. (D) A volcanic island-arc belt existed on the sites of the Sierra Nevada in Paleozoic and early Mesozoic time, which produced thick bodies of sediments and volcanics. During the mid-Mesozoic Nevadan orogeny these were steeply deformed and thrust westward over subduction zones, and were intruded by granitic rocks that rose from the upper mantle to form great batholiths. 5. (E) West of the Sierra Nevada, in the Great Valley, is a great sedimentary embankment of later Mesozoic flysch or turbidite, largely younger than the supracrustal rocks of the Sierra Nevada and the Nevadan orogeny. It was formed of the erosional products of the supracrustal and granitic rocks of the Sierra Nevada. 6. (F) This sequence is, in turn, thrust westward over the Mesozoic Franciscan terrane of the Coast Ranges, which forms the westernmost belt of the Cordillera, and which is being treated in other papers in this symposium. The net effect of the prolonged events that produced the Cordillera in this segment has been the addition of successive tectonic belts to the North American continent at the expense of the Pacific Ocean basin during Phanerozoic time.

Tectonophysics↗
USGS1993

The return of sialic material to the mantle indicated by terrigeneous material subducted at convergent margins

At convergent margins where oceanic crust is subducted beneath continental or island-arc crust, sediment on the igneous oceanic crust divides into an accreted and a subducted fraction. Although the subducted fraction is larger, it is obscured in many seismic reflection records because of its depth and the effects of the overlying complex structure. Volumes of accreted and underthrust sediment were quantified at individual margins and global estimates were made of the terrigeneous debris subducted. Also included were debris from subduction erosion. The estimated volume of terrigeneous material subducted beneath continental and island-arc crust is sufficiently large to significantly affect processes along the plate boundary. The possible volume reaching the mantle could have considerable affect on mantle evolution.

Tectonophysics↗
USGS1991

Stratigraphy and paleoceanography of Pliocene deposits of Karaginsky Island, eastern Kamchatka, U.S.S.R.

The lithology and paleontology of Pliocene deposits from Karaginsky Island, off eastern Kamchatka Peninsula, U.S.S.R., are described in order to provide a paleoceanographic reconstruction of this region of the eastern North Pacific Ocean. The stratigraphic sequence is divided into three suites — the Limimtevayamian, the Ust-Limimtevayamian, and the Tusatuvayamian, which correspond to three standard Pacific diatom zones — the Thalassiosira oestrupii, Neodenticula koizumi-N. kamtschatica , and N. koizumi . The entire sequence is further subdivided into six members and 18 distinct beds on the basis of molluscan assemblages and three members and seven beds on the basis of benthic foraminiferal assemblages. Marine ostracodes are described from the Limimtevayamian suite. The marine invertebrate assemblages from Karaginsky Island provide evidence that: (1) ocean water temperatures were warmer than today about 4 Ma and again about 3.5-3.0 Ma; (2) several Arctic-Atlantic species of molluscs and ostracodes migrated to the eastern North Pacific between 4.2−3.0 Ma, presumably through the proto-Bering Strait; (3) many species found in the Karaginsky Island Pliocene represent Pacific taxa which migrated through the Arctic into the North Atlantic during the late Pliocene.

eastern Kamchatka, Karaginsky Island↗
USGS1988

Biological measurements and related chemical features in Soviet and United States regions of the Bering Sea

The U.S. results of a joint U.S.-U.S.S.R. expedition to the Bering Sea in 1984 investigated the chemical and biological interactions in the south, east, north and west regions. The nutrients, phytoplankton biomass and primary productivity were enhanced near the ends of a north-south transect of stations. The southern end of the transect had characteristics of the North Pacific Ocean with high nutrient and low phytoplankton concentrations and an elevated concentration of peridinin indicative of dinoflagellates. The middle station of the transect, near the shelf break, had low nutrients and phytoplankton in the upper euphotic zone, but a submerged chlorophyll b maximum indicated green algae was located on the upper boundary of high ammonium concentration and pycnocline. The north end of the transect over the shelf at mid-depth on the boundary of high nitrate and ammonium concentrations produced the highest primary production. Pigment analysis (chlorophyll a , diadinoxanthin and fucoxanthin) indicated the dominance of diatoms and was coincidental to oxygen saturation values as large as 150%. The highest phaeophorbide a concentrations were also observed in this area, suggesting relatively high grazing stress. Measurements of low molecular weight hydrocarbons also suggest high microbiological degradation rates of organic matter in the sediments in the north region. Overall, this research strongly relates nutrient, oxygen and pigment concentrations to the production, decomposition and recycling processes in the open ocean and shelf areas of the Bering Sea.

Bering Sea↗
USGS1996

The long-term salinity field in San Francisco Bay

Data are presented on long-term salinity behaviour in San Francisco Bay, California. A two-level, width averaged model of the tidally averaged salinity and circulation has been written in order to interpret the long-term (days to decades) salinity variability. The model has been used to simulate daily averaged salinity in the upper and lower levels of a 51 segment discretization of the Bay over the 22-yr period 1967-1988. Monthly averaged surface salinity from observations and monthly-averaged simulated salinity are in reasonable agreement. Good agreement is obtained from comparison with daily averaged salinity measured in the upper reaches of North Bay. The salinity variability is driven primarily by freshwater inflow with relatively minor oceanic influence. All stations exhibit a marked seasonal cycle in accordance with the Mediterranean climate, as well as a rich spectrum of variability due to extreme inflow events and extended periods of drought. Monthly averaged salinity intrusion positions have a pronounced seasonal variability and show an approximately linear response to the logarithm of monthly averaged Delta inflow. Although few observed data are available for studies of long-term salinity stratification, modelled stratification is found to be strongly dependent on freshwater inflow; the nature of that dependence varies throughout the Bay. Near the Golden Gate, stratification tends to increase up to very high inflows. In the central reaches of North Bay, modelled stratification maximizes as a function of inflow and further inflow reduces stratification. Near the head of North Bay, lowest summer inflows are associated with the greatest modelled stratification. Observations from the central reaches of North Bay show marked spring-neap variations in stratification and gravitational circulation, both being stronger at neap tides. This spring-neap variation is simulated by the model. A feature of the modelled stratification is a hysteresis in which, for a given spring-neap tidal range and fairly steady inflows, the stratification is higher progressing from neaps to springs than from springs to neaps. The simulated responses of the Bay to perturbations in coastal sea salinity and Delta inflow have been used to further delineate the time-scales of salinity variability. Simulations have been performed about low inflow, steady-state conditions for both salinity and Delta inflow perturbations. For salinity perturbations a small, sinusoidal salinity signal with a period of 1 yr has been applied at the coastal boundary as well as a pulse of salinity with a duration of one day. For Delta inflow perturbations a small, sinusoidally varying inflow signal with a period of 1 yr has been superimposed on an otherwise constant Delta inflow, as well as a pulse of inflow with a duration of one day. Perturbations is coastal salinity dissipate as they move through the Bay. Seasonal perturbations require about 40-45 days to propagate from the coastal ocean to the Delta and to the head of South Bay. The response times of the model to perturbations in freshwater inflow are faster than this in North Bay and comparable in South Bay. In North Bay, time-scales are consistent with advection due to lower level, up-estuary transport of coastal salinity perturbations; for inflow perturbations, faster response times arise from both upper level, down-estuary advection and much faster, down-estuary migration of isohalines in response to inflow volume continuity. In South Bay, the dominant time-scales are governed by tidal dispersion.

Continental Shelf Research↗
USGS1977

Geochemistry of Precambrian mafic dikes, central Bighorn Mountains, Wyoming, U.S.A.

Precambrian quartz dolerites and metadolerites of the central Bighorn Mountains form dikes that intrude a Precambrian metamorphic and igneous terrane typical of the Laramide uplifts of the middle Rocky Mountains. They have a restricted range of major- and trace-element compositions and are typical of basalts in the middle stages of tholeiitic fractionation. Fractionation in the direction of iron enrichment occurred by removal of plagioclase. Average element concentrations of the two groups are nearly identical to one another, are comparable to those in Archean metabasalts from numerous shield areas, and are intermediate between those of modern oceanic tholeiites and continental tholeiites. These average concentrations suggest a depth of magma generation and thickness of crust intermediate between those for the oceanic and continental environments.

Wyoming↗
USGS1996

Middle Pliocene sea surface temperatures: A global reconstruction

Identification and analyses of Pliocene marine microfossils from 64 globally distributed stratigraphic sequences have been used to produce a middle Pliocene sea surface temperature reconstruction of the Earth. This reconstruction shows little or no change from current conditions in low latitude regions and significant warming of the ocean surface at mid and higher latitudes of both hemispheres. This pattern of warming is consistent with terrestrial records and suggests a combination of enhanced meridional ocean heat transport and enhanced greenhouse effect were responsible for the middle Pliocene warmth.

Marine Micropaleontology↗
USGS1996

Diatom constraints on the position of the Antarctic Polar Front in the middle part of the Pliocene

The relative percentages of diatom taxa in 5 deep-sea cores (DSDP 266, ODP 699A, ODP 747A, ODP 751 A, and Eltanin Core 50-28) from the Southern Ocean are determined for an interval centered on 3.1 to 2.9 Ma in the middle part of the Pliocene. This climatically warm interval, which is being studied by the PRISM Project of the U.S. Geological Survey, coincides with a proposed interval of major deglaciation of East Antarctica. The maximum southerly position of the Antarctic Polar Front between 3.1 and 3.0 Ma is inferred from these diatom studies, the presence of calcareous nannofossils in the sediments, and sedimentologic and micropaleontologic information from the literature. It is suggested that the Antarctic Polar Front may have migrated by as much as 6 ° of latitude further to the south in the southeastern Atlantic and Indian Oceans during this Pliocene warm interval but probably lay close to its present day position in the southwest Atlantic and Drake Passage. Summer sea surface temperatures are inferred to have been no more than 3 °–4 °C warmer than present at latitudes between 55 ° and 60 °S.

Marine Micropaleontology↗
USGS1995

Decadal and annual changes in biogenic opal and carbonate fluxes to the deep Sargasso Sea

Analyses of samples from a 14-year series of sediment-trap deployments in the deep Sargasso Sea reveal a significant trend in the ratio of the sinking fluxes of biogenic calcium carbonate and silica. Although there are pronounced seasonal cycles for both flux components, the overall opal/CaCO 3 ratio changed by 50% from 1978 to 1991 (largely due to a decrease of opal flux), while total flux had no significant trend. These results suggest that plankton communities respond rapidly to subtle climate change, such as is evident in regional variations of wind speed, precipitation, wintertime ventilation and midwater temperatures. If the trends we observe in the makeup of sinking particulate matter occur on a large scale, they may in turn modify climate by modulating ocean-atmosphere CO 2 exchange and albedo over the ocean.

Deep Sea Research Part A, Oceanographic Research P↗
USGS2011

Bioenergetics in ecosystems

A bioenergetics model for a fish can be defined as a quantitative description of the fish’s energy budget. Bioenergetics modeling can be applied to a fish population in a lake, river, or ocean to estimate the annual consumption of food by the fish population; such applications have proved to be useful in managing fisheries. In addition, bioenergetics models have been used to better understand fish growth and consumption in ecosystems, to determine the importance of the role of fish in cycling nutrients within ecosystems, and to identify the important factors regulating contaminant accumulation in fish from lakes, rivers, and oceans.

Book chapter↗