Seasonal fluctuations of plant biomass and photosynthesis are key features of the Earth system because they drive variability of atmospheric CO2, water and nutrient cycling, and food supply to consumers. There is no inventory of phytoplankton seasonal cycles in nearshore coastal ecosystems where forcings from ocean, land and atmosphere intersect. We compiled time series of phytoplankton biomass (chlorophyll a) from 114 estuaries, lagoons, inland seas, bays and shallow coastal waters around the world, and searched for seasonal patterns as common timing and amplitude of monthly variability. The data revealed a broad continuum of seasonal patterns, with large variability across and within ecosystems. This contrasts with annual cycles of terrestrial and oceanic primary producers for which seasonal fluctuations are recurrent and synchronous over large geographic regions. This finding bears on two fundamental ecological questions: (1) how do estuarine and coastal consumers adapt to an irregular and unpredictable food supply, and (2) how can we extract signals of climate change from phytoplankton observations in coastal ecosystems where local‐scale processes can mask responses to changing climate?
Mercury and organic carbon concentrations vary dynamically in streamwater at the Sleepers River Research Watershed in Vermont, USA. Total mercury (THg) concentrations ranged from 0.53 to 93.8 ng/L during a 3-year period of study. The highest mercury (Hg) concentrations occurred slightly before peak flows and were associated with the highest organic carbon (OC) concentrations. Dissolved Hg (DHg) was the dominant form in the upland catchments; particulate Hg (PHg) dominated in the lowland catchments. The concentration of hydrophobic acid (HPOA), the major component of dissolved organic carbon (DOC), explained 41–98% of the variability of DHg concentration while DOC flux explained 68–85% of the variability in DHg flux, indicating both quality and quantity of the DOC substantially influenced the transport and fate of DHg. Particulate organic carbon (POC) concentrations explained 50% of the PHg variability, indicating that POC is an important transport mechanism for PHg. Despite available sources of DHg and wetlands in the upland catchments, dissolved methylmercury (DmeHg) concentrations in streamwaters were below detection limit (0.04 ng/L). PHg and particulate methylmercury (PmeHg) had a strong positive correlation (r 2 = 0.84, p < 0.0001), suggesting a common source; likely in-stream or near-stream POC eroded or re-suspended during spring snowmelt and summer storms. Ratios of PmeHg to THg were low and fairly constant despite an apparent higher methylmercury (meHg) production potential in the summer. Methylmercury production in soils and stream sediments was below detection during snowmelt in April and highest in stream sediments (compared to forest and wetland soils) sampled in July. Using the watershed approach, the correlation of the percent of wetland cover to TmeHg concentrations in streamwater indicates that poorly drained wetland soils are a source of meHg and the relatively high concentrations found in stream surface sediments in July indicate these zones are a meHg sink.
It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been conducted in these environments. We conducted a landscape scale study examining Hg cycling in coastal Louisiana (USA) including four field trips conducted between August 2003 and May 2005. Sites were chosen to represent different ecosystem types, including: a large shallow eutrophic estuarine lake (Lake Pontchartrain), three rivers draining into the lake, a cypress-tupelo dominated freshwater swamp, and six emergent marshes ranging from a freshwater marsh dominated by Panicum hemitomon to a Spartina alterniflora dominated salt marsh close to the Gulf of Mexico. We measured MeHg and total Hg (THg) concentrations, and ancillary chemical characteristics, in whole and filtered surface water, and filtered porewater.
Overall, MeHg concentrations were greatest in surface water of freshwater wetlands and lowest in the profundal (non-vegetated) regions of the lake and river mainstems. Concentrations of THg and MeHg in filtered surface water were positively correlated with the highly reactive, aromatic (hydrophobic organic acid) fraction of dissolved organic carbon (DOC). These results suggest that DOC plays an important role in promoting the mobility, transport and bioavailability of inorganic Hg in these environments. Further, elevated porewater concentrations in marine and brackish wetlands suggest coastal wetlands along the Gulf Coast are key sites for MeHg production and may be a principal source of MeHg to foodwebs in the Gulf of Mexico.
Examining the relationships among MeHg, THg, and DOC across these multiple landscape types is a first step in evaluating possible links between key zones for Hg(II)-methylation and the bioaccumulation of mercury in the biota inhabiting the Gulf of Mexico region
","language":"English","publisher":"Elsevier","doi":"10.1016/j.envpol.2007.12.017","issn":"02697491","usgsCitation":"Hall, B., Aiken, G., Krabbenhoft, D., Marvin-DiPasquale, M., and Swarzenski, C., 2008, Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region: Environmental Pollution, v. 154, no. 1, p. 124-134, https://doi.org/10.1016/j.envpol.2007.12.017.","productDescription":"11 p.","startPage":"124","endPage":"134","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242802,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":215035,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.envpol.2007.12.017"}],"volume":"154","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bd028e4b08c986b32ecd6","contributors":{"authors":[{"text":"Hall, B.D.","contributorId":42408,"corporation":false,"usgs":true,"family":"Hall","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":435035,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Aiken, G. R. 0000-0001-8454-0984","orcid":"https://orcid.org/0000-0001-8454-0984","contributorId":14452,"corporation":false,"usgs":true,"family":"Aiken","given":"G. R.","affiliations":[],"preferred":false,"id":435033,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Krabbenhoft, D. P. 0000-0003-1964-5020","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":90765,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"D. P.","affiliations":[],"preferred":false,"id":435037,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Marvin-DiPasquale, M.","contributorId":28367,"corporation":false,"usgs":true,"family":"Marvin-DiPasquale","given":"M.","affiliations":[],"preferred":false,"id":435034,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Swarzenski, C.M.","contributorId":74856,"corporation":false,"usgs":true,"family":"Swarzenski","given":"C.M.","email":"","affiliations":[],"preferred":false,"id":435036,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032203,"text":"70032203 - 2008 - The effect of variations in relative spectral response on the retrieval of land surface parameters from multiple sources of remotely sensed imagery","interactions":[],"lastModifiedDate":"2022-05-18T14:44:49.389973","indexId":"70032203","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"The effect of variations in relative spectral response on the retrieval of land surface parameters from multiple sources of remotely sensed imagery","docAbstract":"A method has been developed for the simultaneous extraction of chlorothalonil and three of its degradates (4-hydroxy-2,5,6-trichloroisophthalonitrile, 1-carbamoyl-3-cyano-4-hydroxy-2,5,6-trichlorobenzene, and 1,3-dicarbamoyl-2,4,5,6-tetrachlorobenzene) from soils and sediments; the compounds were extracted using sonication with acetone and isolation of the parent compound and matrix interferences from the degradates by solid phase extraction (SPE). The chlorothalonil fraction underwent further coextracted matrix interference removal with Florisil. The degradates were derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) and chlorotrimethylsilane (TMCS). All compounds were analyzed by gas chromatography–mass spectrometry (GC-MS). Recoveries on a spiked (20 and 200 µg kg−1) sediment ranged from 80% to 91% with calculated limits of detection of 1−5 µg kg−1 dry weight sediment. An additional 20 sediment samples were collected in watersheds from the Southeastern United States where chlorothalonil is used widely on peanuts and other crops. None of the target compounds were detected. Laboratory fortified recoveries of chlorothalonil and its degradates in these environmental sediment samples ranged from 75% to 89%.
","language":"English","publisher":"ACS","doi":"10.1021/jf703695s","issn":"00218561","usgsCitation":"Hladik, M., and Kuivila, K., 2008, Analysis of chlorothalonil and three degradates in sediment and soil: Journal of Agricultural and Food Chemistry, v. 56, no. 7, p. 2310-2314, https://doi.org/10.1021/jf703695s.","productDescription":"5 p.","startPage":"2310","endPage":"2314","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242427,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214681,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/jf703695s"}],"volume":"56","issue":"7","noUsgsAuthors":false,"publicationDate":"2008-03-13","publicationStatus":"PW","scienceBaseUri":"5059eb0de4b0c8380cd48ba3","contributors":{"authors":[{"text":"Hladik, M.L. 0000-0002-0891-2712","orcid":"https://orcid.org/0000-0002-0891-2712","contributorId":51111,"corporation":false,"usgs":true,"family":"Hladik","given":"M.L.","affiliations":[],"preferred":false,"id":434149,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kuivila, K.M.","contributorId":34529,"corporation":false,"usgs":true,"family":"Kuivila","given":"K.M.","email":"","affiliations":[],"preferred":false,"id":434148,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70032018,"text":"70032018 - 2008 - Comparison and assessment of aerial and ground estimates of waterbird colonies","interactions":[],"lastModifiedDate":"2012-03-12T17:21:28","indexId":"70032018","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2508,"text":"Journal of Wildlife Management","active":true,"publicationSubtype":{"id":10}},"title":"Comparison and assessment of aerial and ground estimates of waterbird colonies","docAbstract":"Aerial surveys are often used to quantify sizes of waterbird colonies; however, these surveys would benefit from a better understanding of associated biases. We compared estimates of breeding pairs of waterbirds, in colonies across southern Louisiana, USA, made from the ground, fixed-wing aircraft, and a helicopter. We used a marked-subsample method for ground-counting colonies to obtain estimates of error and visibility bias. We made comparisons over 2 sampling periods: 1) surveys conducted on the same colonies using all 3 methods during 3-11 May 2005 and 2) an expanded fixed-wing and ground-survey comparison conducted over 4 periods (May and Jun, 2004-2005). Estimates from fixed-wing aircraft were approximately 65% higher than those from ground counts for overall estimated number of breeding pairs and for both dark and white-plumaged species. The coefficient of determination between estimates based on ground and fixed-wing aircraft was ???0.40 for most species, and based on the assumption that estimates from the ground were closer to the true count, fixed-wing aerial surveys appeared to overestimate numbers of nesting birds of some species; this bias often increased with the size of the colony. Unlike estimates from fixed-wing aircraft, numbers of nesting pairs made from ground and helicopter surveys were very similar for all species we observed. Ground counts by one observer resulted in underestimated number of breeding pairs by 20% on average. The marked-subsample method provided an estimate of the number of missed nests as well as an estimate of precision. These estimates represent a major advantage of marked-subsample ground counts over aerial methods; however, ground counts are difficult in large or remote colonies. Helicopter surveys and ground counts provide less biased, more precise estimates of breeding pairs than do surveys made from fixed-wing aircraft. We recommend managers employ ground counts using double observers for surveying waterbird colonies when feasible. Fixed-wing aerial surveys may be suitable to determine colony activity and composition of common waterbird species. The most appropriate combination of survey approaches will be based on the need for precise and unbiased estimates, balanced with financial and logistical constraints.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Wildlife Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2193/2006-391","issn":"0022541X","usgsCitation":"Green, M., Luent, M., Michot, T., Jeske, C., and Leberg, P., 2008, Comparison and assessment of aerial and ground estimates of waterbird colonies: Journal of Wildlife Management, v. 72, no. 3, p. 697-706, https://doi.org/10.2193/2006-391.","startPage":"697","endPage":"706","numberOfPages":"10","costCenters":[],"links":[{"id":214714,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2193/2006-391"},{"id":242463,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"72","issue":"3","noUsgsAuthors":false,"publicationDate":"2010-12-13","publicationStatus":"PW","scienceBaseUri":"5059f83ce4b0c8380cd4cf74","contributors":{"authors":[{"text":"Green, M.C.","contributorId":37974,"corporation":false,"usgs":true,"family":"Green","given":"M.C.","email":"","affiliations":[],"preferred":false,"id":434161,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Luent, M.C.","contributorId":107953,"corporation":false,"usgs":true,"family":"Luent","given":"M.C.","affiliations":[],"preferred":false,"id":434164,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Michot, T.C. 0000-0002-7044-987X","orcid":"https://orcid.org/0000-0002-7044-987X","contributorId":43426,"corporation":false,"usgs":true,"family":"Michot","given":"T.C.","affiliations":[],"preferred":false,"id":434163,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Jeske, C.W.","contributorId":35557,"corporation":false,"usgs":true,"family":"Jeske","given":"C.W.","email":"","affiliations":[],"preferred":false,"id":434160,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Leberg, P.L.","contributorId":42048,"corporation":false,"usgs":true,"family":"Leberg","given":"P.L.","affiliations":[],"preferred":false,"id":434162,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70031791,"text":"70031791 - 2008 - The role of lecithin cholesterol acyltransferase and organic substances from coal in the etiology of Balkan endemic nephropathy: A new hypothesis","interactions":[],"lastModifiedDate":"2012-03-12T17:21:12","indexId":"70031791","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1685,"text":"Food and Chemical Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"The role of lecithin cholesterol acyltransferase and organic substances from coal in the etiology of Balkan endemic nephropathy: A new hypothesis","docAbstract":"Balkan endemic nephropathy (BEN) occurs in Serbia, Bulgaria, Romania, Bosnia and Herzegovina, and Croatia. BEN has been characterized as a chronic, slowly progressive renal disease of unknown etiology. In this study, we examined the influence of soluble organic compounds in drinking water leached from Pliocene lignite from BEN-endemic areas on plasma lecithin-cholesterol acyltransferase (LCAT) activity. We found that changes for all samples were the most prominent for the dilution category containing 90% plasma and 10% of diluting media. Water samples from BEN villages from Serbia and Romania showed higher LCAT inhibiting activity (p = 0.02) and (p = 0.003), respectively, compared to deionised water and non-endemic water. A secondary LCAT deficiency could result from this inhibitory effect of the organic compounds found in endemic water supplies and provide an ethiopathogenic basis for the development of BEN in the susceptible population. ?? 2007 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Food and Chemical Toxicology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.fct.2007.10.033","issn":"02786915","usgsCitation":"Pavlovic, N., Orem, W., Tatu, C., Lerch, H., Bunnell, J., Feder, G.L., Kostic, E., and Ordodi, V., 2008, The role of lecithin cholesterol acyltransferase and organic substances from coal in the etiology of Balkan endemic nephropathy: A new hypothesis: Food and Chemical Toxicology, v. 46, no. 3, p. 949-954, https://doi.org/10.1016/j.fct.2007.10.033.","startPage":"949","endPage":"954","numberOfPages":"6","costCenters":[],"links":[{"id":239981,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212490,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.fct.2007.10.033"}],"volume":"46","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505baf7ee4b08c986b324835","contributors":{"authors":[{"text":"Pavlovic, N.M.","contributorId":78550,"corporation":false,"usgs":true,"family":"Pavlovic","given":"N.M.","email":"","affiliations":[],"preferred":false,"id":433150,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Orem, W. H. 0000-0003-4990-0539","orcid":"https://orcid.org/0000-0003-4990-0539","contributorId":93084,"corporation":false,"usgs":true,"family":"Orem","given":"W. H.","affiliations":[],"preferred":false,"id":433154,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tatu, C. A.","contributorId":89942,"corporation":false,"usgs":false,"family":"Tatu","given":"C. A.","affiliations":[],"preferred":false,"id":433153,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lerch, H.E.","contributorId":100371,"corporation":false,"usgs":true,"family":"Lerch","given":"H.E.","email":"","affiliations":[],"preferred":false,"id":433155,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bunnell, J.E.","contributorId":63512,"corporation":false,"usgs":true,"family":"Bunnell","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":433149,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Feder, G. L.","contributorId":79508,"corporation":false,"usgs":true,"family":"Feder","given":"G.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":433151,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Kostic, E.N.","contributorId":84981,"corporation":false,"usgs":true,"family":"Kostic","given":"E.N.","email":"","affiliations":[],"preferred":false,"id":433152,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Ordodi, V.L.","contributorId":55210,"corporation":false,"usgs":true,"family":"Ordodi","given":"V.L.","email":"","affiliations":[],"preferred":false,"id":433148,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70031796,"text":"70031796 - 2008 - Climatic and anthropogenic factors affecting river discharge to the global ocean, 1951-2000","interactions":[],"lastModifiedDate":"2012-03-12T17:21:07","indexId":"70031796","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1844,"text":"Global and Planetary Change","active":true,"publicationSubtype":{"id":10}},"title":"Climatic and anthropogenic factors affecting river discharge to the global ocean, 1951-2000","docAbstract":"During the last half of the 20th century, cumulative annual discharge from 137 representative rivers (watershed areas ranging from 0.3 to 6300 ?? 103??km2) to the global ocean remained constant, although annual discharge from about one-third of these rivers changed by more than 30%. Discharge trends for many rivers reflected mostly changes in precipitation, primarily in response to short- and longer-term atmospheric-oceanic signals; with the notable exception of the Parana, Mississippi, Niger and Cunene rivers, few of these \"normal\" rivers experienced significant changes in either discharge or precipitation. Cumulative discharge from many mid-latitude rivers, in contrast, decreased by 60%, reflecting in large part impacts due to damming, irrigation and interbasin water transfers. A number of high-latitude and high-altitude rivers experienced increased discharge despite generally declining precipitation. Poorly constrained meteorological and hydrological data do not seem to explain fully these \"excess\" rivers; changed seasonality in discharge, decreased storage and/or decreased evapotranspiration also may play important roles. ?? 2008 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Global and Planetary Change","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.gloplacha.2008.03.001","issn":"09218181","usgsCitation":"Milliman, J., Farnsworth, K., Jones, P.D., Xu, K., and Smith, L., 2008, Climatic and anthropogenic factors affecting river discharge to the global ocean, 1951-2000: Global and Planetary Change, v. 62, no. 3-4, p. 187-194, https://doi.org/10.1016/j.gloplacha.2008.03.001.","startPage":"187","endPage":"194","numberOfPages":"8","costCenters":[],"links":[{"id":212553,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gloplacha.2008.03.001"},{"id":240054,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f65ae4b0c8380cd4c6f9","contributors":{"authors":[{"text":"Milliman, John D.","contributorId":76735,"corporation":false,"usgs":false,"family":"Milliman","given":"John D.","affiliations":[{"id":6706,"text":"Woods Hole Oceanographic Institution,","active":true,"usgs":false}],"preferred":false,"id":433174,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Farnsworth, K.L.","contributorId":36746,"corporation":false,"usgs":true,"family":"Farnsworth","given":"K.L.","email":"","affiliations":[],"preferred":false,"id":433171,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Jones, P. D.","contributorId":46462,"corporation":false,"usgs":false,"family":"Jones","given":"P.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":433172,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Xu, K.H.","contributorId":63222,"corporation":false,"usgs":true,"family":"Xu","given":"K.H.","email":"","affiliations":[],"preferred":false,"id":433173,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Smith, L.C.","contributorId":88561,"corporation":false,"usgs":true,"family":"Smith","given":"L.C.","email":"","affiliations":[],"preferred":false,"id":433175,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70031955,"text":"70031955 - 2008 - Are we missing a mineralocorticoid in teleost fish? Effects of cortisol, deoxycorticosterone and aldosterone on osmoregulation, gill Na+,K+-ATPase activity and isoform mRNA levels in Atlantic salmon","interactions":[],"lastModifiedDate":"2013-04-09T11:14:38","indexId":"70031955","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1738,"text":"General and Comparative Endocrinology","active":true,"publicationSubtype":{"id":10}},"title":"Are we missing a mineralocorticoid in teleost fish? Effects of cortisol, deoxycorticosterone and aldosterone on osmoregulation, gill Na+,K+-ATPase activity and isoform mRNA levels in Atlantic salmon","docAbstract":"It has long been held that cortisol, acting through a single receptor, carries out both glucocorticoid and mineralocorticoid actions in teleost fish. The recent finding that fish express a gene with high sequence similarity to the mammalian mineralocorticoid receptor (MR) suggests the possibility that a hormone other than cortisol carries out some mineralocorticoid functions in fish. To test for this possibility, we examined the effect of in vivo cortisol, 11-deoxycorticosterone (DOC) and aldosterone on salinity tolerance, gill Na+,K+-ATPase (NKA) activity and mRNA levels of NKA α1a and α1b in Atlantic salmon. Cortisol treatment for 6–14 days resulted in increased, physiological levels of cortisol, increased gill NKA activity and improved salinity tolerance (lower plasma chloride after a 24 h seawater challenge), whereas DOC and aldosterone had no effect on either NKA activity or salinity tolerance. NKA α1a and α1b mRNA levels, which increase in response to fresh water and seawater acclimation, respectively, were both upregulated by cortisol, whereas DOC and aldosterone were without effect. Cortisol, DOC and aldosterone had no effect on gill glucocorticoid receptor GR1, GR2 and MR mRNA levels, although there was some indication of possible upregulation of GR1 by cortisol (p = 0.07). The putative GR blocker RU486 inhibited cortisol-induced increases in salinity tolerance, NKA activity and NKA α1a and α1b transcription, whereas the putative MR blocker spironolactone had no effect. The results provide support that cortisol, and not DOC or aldosterone, is involved in regulating the mineralocorticoid functions of ion uptake and salt secretion in teleost fish.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"General and Comparative Endocrinology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/j.ygcen.2008.03.024","issn":"00166480","usgsCitation":"McCormick, S., Regish, A., O’Dea, M.F., and Shrimpton, J., 2008, Are we missing a mineralocorticoid in teleost fish? Effects of cortisol, deoxycorticosterone and aldosterone on osmoregulation, gill Na+,K+-ATPase activity and isoform mRNA levels in Atlantic salmon: General and Comparative Endocrinology, v. 157, no. 1, p. 35-40, https://doi.org/10.1016/j.ygcen.2008.03.024.","productDescription":"6 p.","startPage":"35","endPage":"40","costCenters":[{"id":197,"text":"Conte Anadromous Fish Research Center","active":false,"usgs":true}],"links":[{"id":214808,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ygcen.2008.03.024"},{"id":242560,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"157","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ed63e4b0c8380cd497ae","contributors":{"authors":[{"text":"McCormick, S. D. 0000-0003-0621-6200","orcid":"https://orcid.org/0000-0003-0621-6200","contributorId":20278,"corporation":false,"usgs":true,"family":"McCormick","given":"S. D.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":433873,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Regish, A. 0000-0003-4747-4265","orcid":"https://orcid.org/0000-0003-4747-4265","contributorId":73837,"corporation":false,"usgs":true,"family":"Regish","given":"A.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":433875,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Dea, M. F.","contributorId":30579,"corporation":false,"usgs":true,"family":"O’Dea","given":"M.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":433874,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Shrimpton, J. M.","contributorId":10362,"corporation":false,"usgs":true,"family":"Shrimpton","given":"J. M.","affiliations":[],"preferred":false,"id":433872,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}