Journal of Foraminiferal Research最新文献

{"title":"Shell Dissolution in Larger Benthic Foraminifers Exposed to Ph and Temperature Extremes: Results from an in Situ Experiment","authors":"Brienne E. Engel, P. Hallock, R. Price, T. Pichler","doi":"10.2113/GSJFR.45.2.190","DOIUrl":"https://doi.org/10.2113/GSJFR.45.2.190","url":null,"abstract":"Areas where CO 2 -enriched gases discharge into shallow-marine environments can serve as natural laboratories to study the effects of elevated p CO 2 (i.e., ocean acidification) on benthic communities. Hydrothermal vents in Tutum Bay, Ambitle Island, Papua New Guinea, occur at depths of ~10 m and are surrounded by a tropical fringing coral reef. Live specimens of seven species of larger benthic foraminifers were collected from a nearby reef location, placed in small mesh bags, and deployed for five days at six different sites along a gradient of temperature (60–29°C) and pH (5.9–8.1). Foraminiferal species that differ in shell structure (porcelaneous vs. hyaline) and composition (high- and intermediate-Mg calcite) were used in the experiment. Approximately 25% of the specimens, representing four of the seven species, retained normal symbiont color and exhibited minimal dissolution when exposed for five days to temperatures up to 60°C and pH as low as 6.2; shells of specimens that lost symbiont color during deployment exhibited extensive corrosion. More than 80% of the specimens, representing at least one of each species, retained normal symbiont color where the temperature was approximately 40°C and pH fluctuated between 5.9 and 7.4. These observations indicate that shells of reef-dwelling foraminifers can substantially resist dissolution, as long as organic matter is largely intact, under pH conditions sufficiently extreme to erase any fossil footprint.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.2.190","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68288264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Living foraminifera in the shallow waters of Admiralty Bay: distributions and environmental factors","authors":"A. R. Rodrigues, E. Braga, B. B. Eichler","doi":"10.2113/GSJFR.45.2.128","DOIUrl":"https://doi.org/10.2113/GSJFR.45.2.128","url":null,"abstract":"The living foraminiferal fauna and associated environmental factors were examined using shallow-water sediment and bottom-water samples collected in the Admiralty Bay (King George Island, Antarctica) during the austral summer of 2004–05. Admiralty Bay has similar environmental characteristics to other Antarctic coastal areas, with bottom water rich in inorganic nutrients and heterogeneous bottom sediments with high concentrations of mud and sand. We found 45 foraminiferal species, including 28 agglutinated and 17 calcareous species. The dominant species were the calcareous Bolivina pseudopunctata and the agglutinated Pseudobolivina antarctica and Portatrochammina antarctica . Only the agglutinated Spiroplectammina biformis was found in all samples. Admiralty Bay contained a typical Antarctic foraminiferal fauna, mainly distinguishable by the type of bottom sediment. We detected two distinct assemblages: (a) from the entrance of the bay area with a main channel, we found an assemblage with relatively high species richness, abundance and diversity, and with abundant Bolivina pseudopunctata and Fursenkoina fusiformis ; and (b) in the inner parts of the three inlets of the bay (Ezcurra, MacKellar, and Martel inlets), mud- and sulfur-rich sediments contained relatively few foraminifers dominated by a few species, mainly of Globocassidulina and Cassidulinoides .","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.2.128","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68288175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of the Miliolid Archaias angulatus to simulated ocean acidification","authors":"P. Knorr, L. Robbins, Peter J. Harries, P. Hallock, J. Wynn","doi":"10.2113/GSJFR.45.2.109","DOIUrl":"https://doi.org/10.2113/GSJFR.45.2.109","url":null,"abstract":"A common, but not universal, effect of ocean acidification on benthic foraminifera is a reduction in the growth rate. The miliolid Archaias angulatus is a high-Mg (>4 mole% MgCO3), symbiont-bearing, soritid benthic foraminifer that contributes to Caribbean reef carbonate sediments. A laboratory culture study assessed the effects of reduced pH on the growth of A. angulatus . We observed a statistically significant 50% reduction in the growth rate (p < 0.01), calculated from changes in maximum diameter, from 160 μm/28 days in the pH 8.0/pCO2 air 480 ppm control group to 80 μm/28 days at a treatment level of pH 7.6/pCO2 air 1328 ppm. Additionally, pseudopore area, δ18O values, and Mg/Ca ratio all increased, albeit slightly in the latter two variables. The reduction in growth rate indicates that under a high-CO2 setting, future A. angulatus populations will consist of smaller adults. A model using the results of this study estimates that at pH 7.6 A. angulatus carbonate production in the South Florida reef tract and Florida Bay decreases by 85%, from 0.27 Mt/yr to 0.04 Mt/yr, over an area of 9,000 km2.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.2.109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68288047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EARLY EVOLUTION AND NEW CLASSIFICATION OF THE ORDER ROBERTINIDA (FORAMINIFERA)","authors":"S. Rigaud, R. Martini, D. Vachard","doi":"10.2113/GSJFR.45.1.3","DOIUrl":"https://doi.org/10.2113/GSJFR.45.1.3","url":null,"abstract":"The discovery of Triassic missing links in the Panthalassan domain (Wallowa terrane, U.S.A.) substantiates a direct lineage between internally simple Triassic multichambered aragonitic foraminifers and internally partitioned Jurassic Robertinida. A new hierarchical subdivision is accordingly proposed for the order Robertinida, which is emended to encompass all known post-Paleozoic aragonitic multicham-bered foraminifers. At the highest taxonomic level, the suborder Robertinina is distinguished from the suborder Duostominina emended to encompass forms without internal structures attached to the aperture, including the planktonic family Favusellidae and the controversial form Pragsoconu-lus. Two new families (Robertonellidae, Trochosiphoniidae), four new subfamilies (Cassianopapillariinae, Praereinholdel-linae, Pragsoconulinae, and Trochosiphoniinae), four new genera (Falsorheinoldella, Praerheinoldella, Robertonella, and Trochosiphonia), and seven new species (Falsorheinol-della ohmi, F. oregonica, Praerheinoldella galei, Robertonella rettorii, R. wallowensis, Trochosiphonia stanleyi, and T. josephi) are introduced. Phylogenetic links between Triassic robertinids, which experienced a rapid diversification during the Triassic, are clarified and their hypothetical long-term relationships with other foraminiferal groups are discussed.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.1.3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68287730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EVOLUTION AND PHYLOGENY OF MID-CRETACEOUS (ALBIAN–CONIACIAN) BISERIAL PLANKTIC FORAMINIFERA","authors":"S. Haynes, B. Huber, K. MacLeod","doi":"10.2113/GSJFR.45.1.42","DOIUrl":"https://doi.org/10.2113/GSJFR.45.1.42","url":null,"abstract":"In this paper we critically examine the biostratigraphy and systematics of late Albian–Coniacian biserial planktic foraminifera using measurements and qualitative observations from SEM and X-radiograph images of exquisitely preserved specimens from hemipelagic sediments of southeast Tanzania, augmented by analogous observations of selected Ocean Drilling Program samples and holotypes and paratypes of nearly all species. We document interspecific differences and intraspecific variability, and propose a revised phylogeny for Cretaceous biserial planktic foraminifera placed within a refined biostratigraphic framework. Taxonomic emendations are proposed for the genera Protoheterohelix Georgescu & Huber, 2009, and Planoheterohelix Georgescu & Huber, 2009, and for the species Pr. washitensis (Tappan, 1940), Pr. obscura Georgescu & Huber, 2009, Pl. moremani (Cushman, 1938), Pl. reussi (Cushman, 1938), and Laeviheterohelix reniformis (Marie, 1941). In addition, a neotype is designated for Pl. globulosa (Ehrenberg, 1840), and Pl. praenuttalli n. sp. is described. Biserial speciation events are recognized in the planktic foraminiferal Rotalipora cushmani Zone (latest Cenomanian), Helvetoglobotruncana helvetica Zone (early Turonian), and at the Helvetoglobotruncana helvetica-Marginotruncana schneegansi zonal boundary (middle Turonian).","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.1.42","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68287904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2014 JOSEPH A. CUSHMAN AWARD TO STEPHEN J. CULVER","authors":"M. Buzas","doi":"10.2113/GSJFR.45.1.1","DOIUrl":"https://doi.org/10.2113/GSJFR.45.1.1","url":null,"abstract":"Stephen J. Culver is the 2014 recipient of the prestigious Joseph A. Cushman Award for Outstanding Achievement in Foraminiferal Research. Stephen is the quintessential foraminiferalogist. His contributions range temporally from Early Cambrian to Recent, environmentally from the intertidal to the abyss and geographically from the Atlantic Coastal Plain of the United States to Malaysia. His contributions (over 150 publications) range from detailed studies on very specific topics to broad insightful reviews to the geology of entire countries (Sierra Le-one). Steve has accumulated knowledge first hand from extensive field work ranging from the Outer Banks of North Carolina to Africa, as well as in the deep-diving submersible, Alvin . The prerequisites for becoming a successful geologist/paleontologist appeared early on when he was a boy. He loved collecting and learning about fossils and was fascinated by maps. After earning his Ph.D. in 1976 at the age of 24 from the University of Wales at Swansea, U.K., he taught for two years at the University of Sierra Leone. As a post-doctoral fellow at the Smithsonian Institution from 1978–81, Stephen undertook and completed one of the most ambitious foraminiferal projects ever attempted. Using all the data (691 papers from 1839–1979) ever published, catalogs on the distribution of Recent foraminifera on the continental margins of North America were compiled on a primitive mainframe computer. The data were transmitted from the Cushman Collection, Todd Library, and card catalogs over a phone line using a teletype machine. At one point, after months of data entry, the entire file went missing. After a few hours of utter anguish, Culver was relieved to find out that the file had …","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.1.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68287960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The foraminiferal signature of recent Gulf of Mexico hurricanes","authors":"Katrina A. Rabien","doi":"10.2113/GSJFR.45.1.82","DOIUrl":"https://doi.org/10.2113/GSJFR.45.1.82","url":null,"abstract":"Down-core activities of ⁷Be ²³⁴Th and ²¹⁰Pb as well as X-radiography have indicated the existence of sediments deposited by hurricanes Ivan (2004) Katrina (2005) and Rita (2005) on the continental margin west of the Mississippi Delta between Southwest Pass and the Mississippi Canyon. These radionuclides have fairly short half-lives on the order of days to decades however and their utility for the identification of hurricane events decreases with progressively older deposits. Foraminifera which can be preserved for geologically significant amounts of time may serve as another proxy for the detection of hurricane event beds. Here I investigate foraminiferal assemblages contained within recent known hurricane units to determine whether they differ significantly from those of non-hurricane units and a unit deposited by a river flood event and whether these differences might give insight into where the hurricane-deposited sediment originated. Cores were collected along the same transect during three different cruises in: 2004 2005 and 2007; the timing of collection reflected periods of hurricane and non-hurricane influenced deposition. The transect runs southwest from Southwest Pass (~30 m water depth) to the head of the Mississippi Canyon (~170 m depth). Surface samples of a unit deposited by the 2011 Mississippi River flood event were also collected to allow comparison with hurricane units. Average relative abundances of foraminifera were analyzed for trends and ANOVA and discriminant analysis were utilized to determine whether the foraminiferal assemblages of hurricane and non-hurricane units were statistically discrete. Hurricane unit foraminifera very close to the mouth of Southwest Pass (9 km; ~30 m water depth) were more abundant per unit volume of sediment than pre-hurricane foraminifera at this location. Hurricane units further out on the shelf (> 80 m water depth) tended to contain less foraminifera per unit volume than did the non-hurricane units. Hurricane units also contained more textulariids and miliolids than the non-hurricane units and sometimes contained rare marsh taxa. ANOVA results show that the abundances of 13 of the 32 most abundant taxa were statistically different between units when comparing all four unit types (hurricane pre- and post-hurricane flood and bioturbated). Ten of these species were statistically different between hurricane and non-hurricane units; relative abundance of coastal taxa increased in the hurricane units. Discriminant analysis indicates that all four unit types are generally discrete. The species that contributed most to the discrimination of unit types were generally rare and some were helpful in the determination of the origin of the hurricane-transported sediment. In contrast the species that were significant in the ANOVA were among the most abundant. Thus both abundant and rare species are useful for identifying hurricane deposited sediment. A portion of hurricane unit sediments was likel","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.1.82","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68287994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"VERTICAL ZONATION OF FORAMINIFERA ASSEMBLAGES IN GALPINS SALT MARSH, SOUTH AFRICA","authors":"K. Strachan, T. Hill, J. Finch, R. Barnett","doi":"10.2113/GSJFR.45.1.29","DOIUrl":"https://doi.org/10.2113/GSJFR.45.1.29","url":null,"abstract":"ABSTRACT Salt-marsh foraminifera are used as precise sea-levelchange indicators as surface assemblages vary in relation totheir position in the tidal frame. Surface-sediment sampleswere collected across an elevation gradient at Galpins saltmarsh, South Africa, to study the vertical distribution offoraminifera and their potential use for sea-level studies. Themarsh is divided into three vertical zones (high marsh, middlemarsh, and mud flats) represented by three assemblagegroups, with agglutinated species restricted to the upperreaches of the marsh and calcareous species more dominanttowards the intertidal channel. The high marsh area isdominated by Jadammina macrescens with a presence ofTrochammina inflata. The middle marsh is characterised byboth T. inflata and Miliammina fusca. Calcareous speciesfound in the mud flats consist of Haynesina germanica,Ammonia batava, and Quinqueloculina sp. This paperdescribes how marsh foraminifera can be used to definesmall-scale vertical zones along modern marsh surfaces andhow these zones correspond to floral zones. We demonstratethat marsh foraminifera have potential to be used as preciseindicators for sea-level reconstructions in South Africa.INTRODUCTIONModern foraminiferal assemblages form discrete verticalzones in salt marshes, strongly correlated with tidal levels(Scott et al., 2001; Gehrels & Newman, 2004). Therelationship between modern foraminiferal distributionand a range of environmental variables, including elevation,vegetation cover, pH, and salinity, can be preciselyquantified (e.g., using multivariate statistics), representinga modern analogue against which to compare fossilassemblages. Salt marshes experience daily and seasonalvariations in salinity and frequency of flooding linked totidal overflow. Several authors suggest that verticalzonation of foraminifera is strongly related to elevation,especially in temperate environments (Scott & Medioli,1980; Scott & Leckie, 1990; Horton & Edwards, 2003, 2006;Leorri et al., 2010).It is well known that a variety of ecological controls exertan influence on the distribution of surface foraminifera(e.g., Murray, 1971; Scott et al., 1998; Horton, 1999),although assemblages are consistently shown to be verti-cally zoned in accordance with tidal frames, either directlyor indirectly (Berkeley et al., 2007). A study conducted inthe Great Marshes of Massachusetts by De Rijk T Horton & Edwards, 2006).Modern analogues of marsh foraminifera are traditionallycollected at the location where a sediment core is extractedfor palaeontological analysis (Gehrels, 1994; Kemp et al.,2009). Where assemblages are identified solely at a singlesite, some fossil samples may lack a modern analogue,thereby compromising the accuracy of the reconstruction(Murray, 2006). This lack of modern analogues could beaddressed by sampling a broader range of contemporaryenvironments (Hayward et al., 2004; Horton & Edwards,2006; Kemp et al., 2009).Researchers have debated the best assemblage mak","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.45.1.29","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68288034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FORAMINIFERAL RESPONSE TO ECOLOGICAL PERTURBATIONS ALONG THE EASTERN MARGIN OF THE CANADIAN WESTERN INTERIOR SEAWAY, CENOMANIAN-TURONIAN INTERVAL","authors":"D. Dionne, C. Schröder-Adams, S. Cumbaa","doi":"10.2113/GSJFR.46.2.124","DOIUrl":"https://doi.org/10.2113/GSJFR.46.2.124","url":null,"abstract":"Ecological perturbations during the Cenomanian-Turonian boundary interval along the eastern margin of the Canadian Western Interior Seaway (WIS) were investigated in a subsurface core from eastern Saskatchewan (distal) and outcrop at the Manitoba Escarpment (proximal). Paleoecological controls on biota included transgressive/regressive cyclicity, the Oceanic Anoxic Event 2, frequent ashfalls, and a stratified water column. Changes in foraminiferal assemblage composition, species richness, and abundance can be correlated between the core and outcrop. The lower Turonian biofacies at both sites is made up exclusively of planktic species, reflecting the persistent bottom water anoxia in the Canadian WIS. The low-diversity assemblage is nearly entirely composed of opportunistic, surface-dwelling species of the genera Muricohedbergella and Heterohelix , responding to water turbidity, reduced salinity, and shallow water depth. Abundances of planktic species are significantly higher in the distal core section. During the early Turonian, diversity slightly increased, with the presence of Whiteinella aprica reflecting periodic improvement of the water column conditions at both sites. The appearance of the clavate species, Clavihedbergella simplex , reflects an expanded oxygen minimum zone, also confirmed by biomarkers, particularly in outcrop. Dwarfing of foraminiferal tests is interpreted as a response to frequent ashfalls that affected the water column. Lowering of sea level during the middle Turonian allowed for seafloor winnowing and caused a brief disappearance of planktic foraminifera. The north-south temperature gradient in the WIS resulted in a lower planktic foraminiferal diversity in what is now Canada compared to the waters that covered what is now the United States and the absence of benthic and deeper-dwelling, keeled planktic species can be attributed to an increasingly well-developed oxygen minimum zone or increasingly stratified water column. The appearance datum of planktic foraminifera is distinctly diachronous along a south to north transect.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.46.2.124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68289517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE INFLUENCE OF AQUACULTURE ON MODERN FORAMINIFERA AND SEDIMENTS IN THE SETIU ESTUARY AND LAGOON, TERENGGANU, MALAYSIA: A TEMPORAL INVESTIGATION","authors":"A. M. Ellis, S. Culver, D. Mallinson, D. Corbett, E. Leorri, M. Buzas, N. Shazili","doi":"10.2113/GSJFR.44.4.365","DOIUrl":"https://doi.org/10.2113/GSJFR.44.4.365","url":null,"abstract":"Foraminifera, grain size, and carbon and nitrogen isotope ratios and abundances were analyzed in surface-sediment samples collected from three floating fish-cage complexes to address how aquaculture has influenced the Setiu estuary and lagoon of northeast peninsular Malaysia. Two currently active floating fish-cage complexes, SET11-S43 and SET11-S40, are located in the semi-enclosed Setiu lagoon, within four km of an inlet connecting to the South China Sea. The sampling areas experience salinities in the 20s, and sediments have mixed agglutinated and calcareous foraminiferal [total] assemblages, generally dominated by Ammonia aff. A. aoteana and Ammobaculites exiguus . The majority of live foraminifera at these sites belong to agglutinated species; percent of live specimens is greater around the SET11-S43 fish-cage complex, likely related to the presence of aquaculture-related organic-rich mud. Percent agglutinated specimens in total assemblages (live + dead) decrease towards the inlet as total assemblage density and diversity increase due to increased salinity. At a recently (1–3 years) abandoned fish-cage complex, SET11-S9A, located in a low salinity (<5) estuarine setting, Miliammina fusca and Am. exiguus dominate total assemblages.\u0000\u0000Surface-sediment grain-size data indicate that fish-cage-related organic-rich mud underlies SET11-S43 and extends tens of meters to the north with a surrounding sandier substrate, typical of most of the Setiu estuary and lagoon system. SET11-S40 is underlain by generally sandy sediment; organic-rich mud characterizes the lagoon immediately to the north of this fish-cage complex. Percent carbon and nitrogen in sediment exhibit distributional patterns that strongly correlate with the distribution of fish-cage mud. Greater amounts of mud, carbon, and nitrogen in sediment are found to the north of the active lagoonal fish-cage complexes. The δ13C and δ13N signatures of the organic matter in this area are attributed to input from the surrounding mangrove forest, whereas their distribution is a result of the interaction of tidal currents with the physical presence of fish-farm complexes. The environmental influence of the active fish cages at lagoonal site SET11-S40 is minimal as a result of the flushing effects of tidal currents from a nearby inlet. Further north at the SET11-S43 lagoonal fish-cage complex, which receives less marine influence (lower salinity and reduced tidal currents), organic-rich mud has accumulated beneath and to the north of the complex. Foraminiferal and sedimentological data from abandoned estuarine fish-farm complex SET11-S9A are indistinguishable from those of adjacent estuarine sites indicating a rapid return to pre-fish-farm conditions following abandonment.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSJFR.44.4.365","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68287361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}