The Japanese longline fishery for tunas and billfishes in the Eastern Pacific Ocean east of 130°W, 1964-1966

ENGLISH: Catch and effort statistics from the Japanese longline fishery operating in the eastern Pacific Ocean east of 130°W, from 1964 through 1966, were examined to study the geographic distribution, trends in apparent abundance, sexual maturity, and size composition of the tunas and billfishes. Yellowfin and bigeye tuna are generally most abundant in the equatorial regions of the high seas between about 10°N and 20°S, but west of 95°W. The marlins are more coastal in distribution, usually occurring to the east, and to the north and south of the heavy concentration of tropical tunas. Sailfish tend to be associated with coastal areas also, whereas shortbill spearfish are more frequently captured on the high seas. Swordfish are found most abundantly in the coastal regions off northern Mexico, and off northern Peru and southern Ecuador. The albacore, a temperate-water species of tuna, is most abundant in the high-seas area of the southeastern Pacific, Trends in apparent abundance were measured by the hook-rate (i.e. catch per 100 hooks). Hook-rates for bigeye tuna have decreased from about 3.5 fish per 100 hooks in 1958 to about 1.1 fish per 100 hooks in 1966. During the same period, effort was increased substantially and total catch has decreased since 1963. It does not appear that increased effort will result in sustained increased catches of bigeye. Hook-rates for yellowfin tuna in recent years have decreased to about one third of their initial levels. The surface fishery for yellowfin in the eastern Pacific apparently affects recruitment to the longline fishery. Assuming that present conditions in the surface fishery do not change appreciably, increased effort in the longline fishery probably would not produce sustained increased catches, but might in fact result in reduced catch rates. Unlike the situation for the other tunas of the eastern Pacific, it appears that the albacore fishery east of 130°W is not having a marked effect on their abundance. Although a high degree of variability was observed in the hookrates for striped marlin, no obvious trends are evident. Catches have decreased slightly from 13,500 tons in 1964 to about 11,000 tons in 1966. Heavy fishing for sailfish began in 1964 with a hook-rate of 10.6 fish per 100 hooks; by 1966 it had dropped to 5.8. Catches of this species in the area of major concentration dropped from 329,900 fish in 1965 to 173,600 fish in 1966. This fishery has operated for too short a period of time to enable one to determine its effect on the sustainable yield. Length-frequency measurements and gonad samples from yellowfin and bigeye tunas collected in the eastern Pacific were analyzed to determine sexual maturity and growth characteristics. The results corroborate the findings of earlier investigators. SPANISH: Las estadísticas de captura y del esfuerzo de la pesca japonesa con palangre que maniobra en el Océano Pacífico oriental al este de los 130°W, desde 1964 hasta 1966, fueron examinadas para estudiar la distribución geográfica, las tendencias de la abundancia aparente, la madurez sexual y la composición de talla de los atunes y de los peces espada. Los atunes aleta amarilla y ojo grande son generalmente más abundantes en las regiones ecuatoriales de alta entre unos 10°N y 20°S, pero al oeste de los 95°W. Los marlines son costaneros en distribución, apareciendo habitualmente hacia el y hacia el norte y sur de la densa concentración de atunes tropicales. pez vela tiende a asociarse también con las áreas costaneras, mientras el pez aguja corta es capturado con más frecuencia en alta mar. Los peces espada se encuentran más abundantemente en las regiones costaneras de México septentrional y frente al norte del Perú y del Ecuador meridional. La albacora, una especie de atún de aguas templadas, es más abundante en el área de alta mar del Pacífico sudoriental. Las tendencias en la abundancia aparente fueron evaluadas por la tasa de captura por anzuelo (i.e., captura por 100 anzuelos). Las tasas de captura por anzuelo del atún ojo grande, disminuyeron en 1958, de unos 3.5 peces por 100 anzuelos a cerca de 1.1 pez por 100 anzuelos en 1966. Durante el mismo período, el esfuerzo fue aumentado substancialmente y, desde 1963, la captura total disminuyó. No parece que el aumento del esfuerzo resultara en un aumento sostenido de las capturas del atún ojo grande. Las tasas de captura por anzuelo de atún aleta amarilla han disminuido en un tercio de los niveles iniciales, en años recientes. La pesca de superficie de esta especie en el Pacífico oriental afectó aparentemente el reclutamiento en la pesca con palangre. Suponiendo que las condiciones actuales de la pesquería no cambien apreciablemente, un aumento del esfuerzo en la pesquería palangrera probablemente no produciría un aumento sostenido de las capturas, pero en realidad podría resultar en tasas de captura reducidas. A diferencia de la situación de otros túnidos del Pacífico oriental, parece que la pesca de la albacora al este de los 130°W no ha tenido un efecto marcado en su abundancia. Aunque se observó un alto grado de variabilidad en las tasas de captura por anzuelo correspondientes al marlin rayado, no fueron evidentes tendencias obvias. Las capturas han mermado ligeramente de 13,500 toneladas en 1964 a unas 11,000 toneladas en 1966. La fuerte pesca por peces vela empezó en 1964 con una tasa por anzuelo de 10.6 peces por 100 anzuelos; en 1966 había mermado a 5.8. Las capturas de esta especie en el área de mayor concentración disminuyeron de 329,000 peces en 1965, a 173,600 peces en 1966. Esta pesquería ha maniobrado por un período demasiado corto de tiempo para que pueda determinarse su efecto en el rendimiento sostenible. Las mediciones frecuencia-longitud, y las muestras de las gónadas de los atunes aleta amarilla y ojo grande, obtenidas en el Pacífico oriental, fueron analizadas para determinar la madurez sexual y las características del crecimiento. Los resultados corroboraron los hallazgos anteriores de investigadores. (PDF contains 144 pages.)

Exploiting the diverse microbial ecology of marine sponges

Marine sponges (phylum Porifera) are the oldest extant metazoan animals on earth and host large populations of symbiotic microbes: Bacteria, Archaea and unicellular Eukaryota. Those microbes play ecological functions which are essential to the health of the host including carbon, nitrogen and sulfur cycling as well as host defence through the production of bioactive secondary metabolites which protect against infection and predation. The diversity of sponge-associated microbes is remarkable with thousands of OTUs reported from individual sponge species. Amongst those populations are sponge-specific microbes which may be specific to sponges or specific to sponge species. While marine natural product discovery concerns many animal phyla, Porifera account for the largest proportion of novel compounds. Evidence suggests that many of these compounds are the products of symbiotic microbes. Descriptions of sponge-associated microbial community structures have been advanced by the development of next-generation sequencing technologies while the discovery and exploitation of sponge derived bioactive compounds has increased due to developments in sequence-based and function-based metagenomics. Here, we use pyrosequencing to describe the bacterial communities associated with two shallow, temperate water sponges (Raspailia ramosa and Stelligera stuposa) from Irish coastal waters and to describe the bacterial and archaeal communities of a single sponge species (Inflatella pellicula) from two different depths in deep waters in the Atlantic Ocean, including at a depth of 2900m, a depth far greater than that of any previous sequence-based sponge-microbe investigation. We identified diverse microbial communities in all sponges and the presence of sponge-specific taxa recruiting to previously described and novel spongespecific clusters. We also identified archaeal communities which dominated sponge-microbe communities. We demonstrate that sponge-associated microbial communities differ from seawater communities indicating host selection processes. We used sequence-based metagenomic techniques to identify genes of potential industrial and pharmacological interest in the metagenomes of various sponge species and functionbased metagenomic screening in an attempt to identify lipolytic and antibacterial activities from metagenomic clones from the metagenome of the marine sponge Stelletta normani. In addition we have cultured diverse bacterial species from sponge tissues, many of which display antimicrobial activities against clinically relevant bacterial and yeast test strains. Other isolates represent novel species in the genus Maribacter and require emendments to the description of that genus.

Effects of temperature, sestonic algae features, and seston mineral content on cladocerans of a tropical lake

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Eocene-Oligocene calcareous nannofossil events of ODP Sites from the Southern Ocean

The evolution of the Southern Ocean climate during the late Eocene-late Oligocene interval is examined through highresolution, quantitative calcareous nannofossil analyses on samples from the Southern Ocean sections on Maud Rise and Kerguelen Plateau. We determined the abundance patterns of the counted species to clarify the biostratigraphy, which we correlated with high-resolution magnetostratigraphy [Roberts, A.P., Bicknell, S.J., Byatt, J., Bohaty, S.M., Florindo, F., Harwood, D.M., 2003a. Magnetostratigraphic calibration of Southern Ocean diatom datums from the Eocene-Oligocene of Kerguelen Plateau (Ocean Drilling Program Sites 744 and 748). In: Florindo, F., Cooper, A.K., O'Brien, P.A. (Eds.), Antarctic Cenozoic Palaeoenvironments: Geologic Record and Models. Palaeogeogr., Palaeoclimatol., Palaeoecol. 198 145-168; Florindo, F., Roberts, A.P., in press. Eocene-Oligocene magnetobiochronology of ODP Sites 689 and 690, Maud Rise, Weddell Sea, Antarctica. Geol. Soc. Am. Bull.], and used this data to interpret paleoceanographic changes through the late Eocene to late Oligocene. Percentage plots of the individual species, compared with R-mode principal component and cluster analysis results, allowed us to divide the assemblages into three groups: temperate-water taxa, cool-water taxa, and no temperature-affinity taxa. We attempt correlations between these paleoecological groups and the major sea-surface temperature (SST) variations with tectonic and paleoceanographic changes in the Southern Ocean. During the late Eocene, the nannofossil assemblage data reveal that there were several minor SST decreases (coolings) from 36 to 34 Ma, before the Eocene/Oligocene (E/O) boundary. A sharp cooling event, dated at 33.54 Ma (earliest Oligocene), occurred about 160 kyr after the E/O boundary, which is dated at 33.7 Ma. Relatively stable, cool conditions are interpreted to persist until the latest Oligocene, when an increase in abundance of temperate-water taxa, which corresponds to an antithetical decrease in abundance of cool-water indicators, is recorded. On the basis of our dating, the opening of the Drake Passage, allowing shallow-water circulation, began by 33.54 Ma at the latest, while the establishment of deep-water connections through the Tasmanian Gateway occurred at 33 Ma, as suggested by Exon et al. [Proc. ODP, Init. Rep. 189 (2001) 1].

Eocene-Oligocene nannofossils from the Labrador Sea

During Ocean Drilling Program (ODP) Leg 105, a thick sequence of lower Eocene to lower Oligocene sediments was recovered from Hole 647A in the southern Labrador Sea. These sediments contain diverse, well-preserved, high-latitude calcareous nannofossil flora. The nannofossil biostratigraphy of the hole indicates the presence of a minor hiatus between Zones NP 16 and NP 17 in the upper middle Eocene and a barren interval separating Zones NP 13 and NP 15. Species abundance is highest within the lower to middle Eocene and starts to decline near the base of the upper Eocene. No major change in the nannoflora was observed across the Eocene/Oligocene boundary, although a slight decrease in species abundance was recorded. The Paleogene calcareous nannofossils of nearby DSDP Site 112 were reexamined and compared with those of Site 647. Several cores were reassigned to different nannofossil zones. The calcareous nannoflora are dominated by high-latitude indicative species and also exhibit a high diversity, which suggests the influence of more temperate water masses in this region during Eocene and Oligocene time. One new subspecies from the middle Eocene, Sphenolithus furcatolithoides labradorensis, is described.

Campanian-Maestrichtian planktonic foraminifera of the southern South Atlantic

Campanian-Maestrichtian planktonic foraminifers were examined from Sites 698 (2128 m water depth) and 700 (3611 m water depth) on the Northeast Georgia Rise (southern South Atlantic, 51°S). Site 698 penetrated 72.5 m of Campanian-Maestrichtian chalk and limestone with only 18.2% recovery, whereas Site 700 recovered 66.8% of a 152.7-m section of Coniacian-Maestrichtian limestone. Preservation of planktonic foraminifers from both sites is moderate in Maestrichtian samples, but worsens with increasing depth in the Campanian. The Northeast Georgia Rise planktonic foraminifers are typical of Late Cretaceous Austral Province faunas described from other southern high-latitude sites; species diversity is low and the assemblages are dominated by species of Heterohelix, Globigerinelloides, Hedbergella, and Archaeoglobigerina. Five species, including Globigerinelloides impensus Sliter, Archaeoglobigerina australis Huber, Archaeoglobigerina mateola Huber, Hedbergella sliteri Huber, and Rugotruncana circumnodifer (Finlay), are considered to be endemic to the Austral Province. Formation of a cool temperate water mass in the circum-Antarctic region, resulting from the final breakup of the Gondwana continents, may have led to increased provincialism of the Austral Province planktonic foraminifers during Campanian-Maestrichtian time. Magnetobiostratigraphic correlation of eight planktonic foraminifer datum events at Hole 700B with ages determined for datums at ODP Leg 113 Holes 689B and 690C (Maud Rise, 65°S) demonstrates regional synchroneity of first and last occurrences within the Austral Province. As was observed at the Maud Rise, several keeled and nonkeeled species previously thought to have been restricted to warmer low-latitude regions first occur later at the Northeast Georgia Rise than at the low-latitude sites. The causes for high-latitude diachroneity among these immigrant species are not clear; neither oxygen and carbon isotope data from the Maud Rise sites nor calcareous nannoplankton distributions for the southern South Atlantic region show conspicuous changes that correlate to the delayed first occurrences.

Calcareous nannofossil stratigraphy and datums of sediments from ODP Leg 198 sites

During Ocean Drilling Program Leg 198, Sites 1207, 1208, 1212, 1213, and 1214 were drilled on Shatsky Rise, coring Lower to mid-Cretaceous successions of nannofossil chalk, porcellanite, and chert. Although recovery was poor, these sites yielded an outstanding record of calcareous nannoplankton, providing valuable data concerning the evolutionary succession and paleobiogeography of the largest Cretaceous marine habitat. Mid-Cretaceous sections (Aptian-Cenomanian) were recovered at all sites, and Site 1213 includes an apparently complete Berriasian-Hauterivian section. Biostratigraphic dating is problematic in places because of the absence or rarity of zonal fossils of both Boreal and Tethyan affinity. The majority of nannofossil assemblages are relatively typical of this age, but there are clear differences that set them apart from coeval epicontinental assemblages: for example, Lithraphidites carniolensis is common to abundant throughout and was most likely an oceanic-adapted taxon; the cold- to temperate-water species Crucibiscutum salebrosum, Repagulum parvidentatum, and Seribiscutum primitivum are entirely absent, indicating the persistence of tropical, warm surface water temperatures; and the warm-water species Hayesites irregularis is common. Most striking, however, is the virtual absence of Nannoconus and Micrantholithus, both taxa that were conspicuous and often common components of many Tethyan and Atlantic nannofloras. These forms were almost certainly neritic adapted and usually absent in deep open-ocean settings away from guyots and platforms. Other Tethyan taxa are also absent or rare and sporadically distributed (e.g., Calcicalathina oblongata, Conusphaera spp., Tubodiscus verenae, and Lithraphidites bollii), and factors related to neritic environments presumably controlled their distribution. Site 1213 also records extended Early Cretaceous ranges for species previously thought to have become extinct during the Late Jurassic (e.g., Axopodorhabdus cylindratus, Hexapodorhabdus cuvillieri, and Biscutum dorsetensis), suggesting these species became Pacific-restricted prior to their extinction. Watznaueria britannica may also have been a species with Pacific affinities before reexpansion of its biogeography in the early Aptian. One new genus (Mattiolia) and thirteen new species (Zeugrhabdotus clarus, Zeugrhabdotus petrizzoae, Helicolithus leckiei, Rhagodiscus amplus, Rhagodiscus robustus, Rhagodiscus sageri, Rhagodiscus adinfinitus, Tubodiscus bellii, Tubodiscus frankiae, Gartnerago ponticula, Haqius peltatus, Mattiolia furva, and Kokia stellata) are described from the Shatsky Rise Lower Cretaceous section.

Middle Eocene to Pleistocene calcareous nannofossils of ODP Leg 113 holes

Long sequences of Upper Cretaceous through Quaternary sediments rich in calcareous and siliceous microfossils were recovered at Ocean Drilling Program Sites 689 and 690 on Maud Rise off East Antarctica. These sites have become the southernmost anchor in the Atlantic Basin for bio-, magneto-, chemostratigraphic, and paleobiogeographic studies. ODP Sites 692 and 693 on the Weddell Sea margin of East Antarctica and Site 696 on the South Orkney microcontinent of West Antarctica yielded calcareous nannofossils within some stratigraphic intervals. Sites 691, 692, 694, 695, and 697 did not recover Cenozoic calcareous nannofossils. Calcareous nannofossil biostratigraphy suggests a major hiatus across the Paleogene/Neogene boundary at Sites 689 and 690, and two additional hiatuses in the middle Eocene-lower Oligocene section at Site 690. Correlation with magnetostratigraphy reveals: the last occurrence (LO) of Reticulofenestra umbilica at Maud Rise is over 1 m.y. younger than that at the middle-latitude sites; the LO of Isthmolithus recurvus is synchronous in the middle-latitude and high-latitude areas (about 34.8 Ma); Reticulofenestra oamaruensis ranges from 38.0 to 36.0 Ma at Maud Rise; Reticulofenestra reticulata has a shorter range at Maud Rise (42.1 to 38.9 Ma) than at the middle-latitude DSDP Site 516; the range of Chiasmolithus oamaruensis is diachronous over different latitudes; and the LO of Chiasmolithus solitus is a good datum at 41.3 Ma from 30°S to 65°S in the South Atlantic Ocean. Comparison of calcareous nannofossil abundances in a latitudinal transect shows: Reticulofenestra bisecta is a temperate-water species and its LO, which crosses below that of Chiasmolithus altus at Maud Rise, is not applicable for the Paleogene/Neogene boundary in high southern latitude areas; Clausicoccus fenestratus is rare or absent at Maud Rise and can not be used as a marker; Coccolithus formosus is a warm-water species which disappeared earlier toward higher latitudes. Calcareous nannofossil assemblages indicate that by at least the middle Eocene, surface water temperatures became considerably lower in the high southern latitudes than in the middle-latitude areas and that there have been more extreme cold events in the high latitudes during the Neogene. Bicolumnus ovatus n. gen., n. sp. is proposed in this paper.

Bolboforma of Eocene and lower Oligocene sediments of Maud Rise, Weddell Sea

Five species of Bolboforma have been found in middle Eocene to lower Oligocene sediments from Maud Rise, Weddel Sea, Antarctica (Leg 113, Holes 689B and 690B), the first reported Bolboforma from the Antarctic Paleogene. The previous oldest known occurrences of Bolboforma in the world's oceans were of late Eocene age and this study extends the known range to the middle middle Eocene (~ 44 Ma). Highest species diversity of Bolboforma in the Weddell Sea region of Antarctica occurred during the late Eocene, after which all but one important species disappeared before the Eocene/Oligocene boundary (36.5 Ma). The remaining species, B. irregularis, disappeared soon after, during the earliest Oligocene. The disappearance of Bolboforma in this region of Antarctica coincided with significant climatic cooling that occurred at the end of the Eocene and during the earliest Oligocene, when subpolar replaced temperate conditions. Bolboforma is not known from younger sediments in the Antarctic except for a brief interval during the late early Miocene, an interval of Neogene climatic warmth. The presence of Bolboforma in Eocene to lower Oligocene sequences in the Weddell Sea region of Antarctica is therefore consistent with this taxon's previously recognized association with temperate water masses. Bolboforma is of limited biostratigraphic value at present, because of relatively long stratigraphic ranges and diachronous extinctions. Previous suggestions that Bolboforma represents an encystment stage of phytoplankton require further critical study because the deposition, in large numbers, at paleodepths up to 2250 m in the open ocean, is an unlikely strategy for an encystment phase of a phytoplanktonic organism. A new species, Bolboforma antarctica, is described, exhibiting a stratigraphic range from middle middle Eocene to the upper Eocene (~ 44 to 39 Ma).

(Table B2) Relative abundances of diatom species used in the Canoco analysis at sediment surface samples from the Chinese inshore waters

Canonical correspondence analysis has been used to analyze and to visualize the relationships between the main species and selected environmental variables in a study of diatoms from surface sediment samples in Chinese inshore waters. The result shows that the diatom distribution in Chinese inshore waters is closely correlated with the environmental variables and that the measured environmental variables account for the major changes of the diatom composition. Winter sea-surface temperature (WST), winter sea-surface salinity (WSS), water depth and summer sea-surface salinity (SSS) play an important role for the diatom distribution. Among the environmental factors, winter sea-surface temperature is the most important, controlling the distribution of diatoms in the surface sediments in Chinese inshore waters, and therefore, it may be potentially reconstructed in palaeoceanographic studies. Three diatom assemblages are distinguished, representing environments with different hydrological characteristics. The temperate-water diatom assemblage may be used as an indicator of the coastal circulation system of Bohai Sea and Yellow Sea. While the warm-temperate water diatom assemblage is closely related to Shanghai-Zhejiang-Fujian coastal currents and Northern Bay coastal currents of South China Sea. The deep water diatom assemblage is a response to that the waters are less controlled by coastal currents, but are more influenced by open sea currents, such as Kuroshio.

A psychrophilic crenarchaeon inhabits a marine sponge: Cenarchaeum symbiosum gen. nov., sp. nov.

Archaea, one of the three major domains of extant life, was thought to comprise predominantly microorganisms that inhabit extreme environments, inhospitable to most Eucarya and Bacteria. However, molecular phylogenetic surveys of native microbial assemblages are beginning to indicate that the evolutionary and physiological diversity of Archaea is far greater than previously supposed. We report here the discovery and preliminary characterization of a marine archaeon that inhabits the tissues of a temperate water sponge. The association was specific, with a single crenarchaeal phylotype inhabiting a single sponge host species. To our knowledge, this partnership represents the first described symbiosis involving Crenarchaeota. The symbiotic archaeon grows well at temperatures of 10 degrees C, over 60 degrees C below the growth temperature optimum of any cultivated species of Crenarchaeota. Archaea have been generally characterized as microorganisms that inhabit relatively circumscribed niches, largely high-temperature anaerobic environments. In contrast, data from molecular phylogenetic surveys, including this report, suggest that some crenarchaeotes have diversified considerably and are found in a wide variety of lifestyles and habitats. We present here the identification and initial description of Cenarchaeum symbiosum gen. nov., sp. nov., a symbiotic archaeon closely related to other nonthermophilic crenarchaeotes that inhabit diverse marine and terrestrial environments.

Stable oxygen and carbon isotope of foraminifera from DSDP Leg 90 sites

High-resolution oxygen and carbon isotope stratigraphy is presented for Miocene to early Pliocene sequences at three DSDP sites from the Lord Howe Rise, southwest Pacific, at water depths ranging from 1,300 to 2,000 m. Site 588 is located in the warm subtropics (~26°S), whereas Sites 590 and 591 are positioned in transitional (northern temperate) water masses (~31°S). Benthic foraminiferal oxygen and carbon isotope analyses were conducted on all sites; planktonic foraminiferal isotope data were generated for Site 590 only. Sample resolution in these sequences is on the order of 50,000 yr. or better. The chronological framework employed in this study is based largely upon ages assigned to Neogene calcareous nannoplankton boundaries. The benthic oxygen isotope record exhibits several major features during the Neogene. During most of the early Miocene, delta18O values were relatively low, reaching minimum values in the late early Miocene (19.5 to 16.5 Ma), and recording the climax of Neogene warmth. This was followed by a major increase in benthic delta18O values between ~16.5 and 13.5 Ma, which is interpreted as representing major, permanent accumulation of the East Antarctic ice sheet and cooling of bottom waters. During the 3 m.y. 18O enrichment, surface waters at these middle latitudes warmed between 16 and 14.5 Ma. During the remainder of the middle and late Miocene, benthic delta18O values exhibit distinct fluctuations, but the average value remained unchanged. The isotopic data show two distinct episodes of climatic cooling close to the middle/late Miocene boundary. The earliest of these events occurred between 12.5 and 11.5 Ma in the latest middle Miocene. The second cooling event occurred from 11 to 9 Ma, and is marked by some of the highest delta18O values of the entire Miocene. This was followed by relative warmth during the middle part of the late Miocene. The latest Miocene and earliest Pliocene (6.2 to 4.5 Ma) were marked by relatively high delta18O values, indicating increased cooling and glaciation. During the middle Pliocene, at about 3.4 Ma, a 0.4 per mil increase in benthic delta18O documents a net increase in average global ice volume and cooling of bottom waters. During this interval of increased glaciation, surface waters warmed by 2-3°C in southern middle-latitude regions. During the late Pliocene, between 2.6 and 2.4 Ma, a further increase in delta18O occurred; this has been interpreted by previous workers as heralding the onset of Northern Hemisphere glaciation. Surface-water warming in the middle latitudes occurred in association with major high-latitude glacial increases in the early middle Miocene (16-14 Ma), middle Pliocene (-3.5 Ma), and late Pliocene (~2.4 Ma). These intervals were also marked by increases in the vertical temperature gradient in the open ocean. Intersite correlation is enhanced by using carbon isotope stratigraphy. The great similarity of the delta13C time-series records within and between ocean basins and with water depth clearly indicates that changes in oceanwide average delta13C of [HCO3]- in seawater dominated the records, rather than local effects. Broad changes in the Neogene delta13C record were caused largely by transfer of organic carbon between continental and oceanic reservoirs. These transfers were caused by marine transgressions and regressions on the continental margins. The dominant feature of Neogene delta13C stratigraphy is a broad late early to early middle Miocene increase of about lâ between ~19 and 14.5 Ma. This trend occurred contemporaneously with a period of maximum coastal onlap (transgression) and maximum Neogene climatic warmth. The delta13C trend terminated during the expansion of the Antarctic ice sheet and associated marine regression. The latest Miocene carbon isotope shift (of up to - 0.75 per mil) at 6.2 Ma is clearly recorded in all sites examined and was followed by relatively low values during the remainder of the Neogene. This shift was caused by a glacioeustatic sealevel lowering that exposed continental margins via regression and ultimately increased the flux of organic carbon to the deep sea. An increase in delta13C values during the early Pliocene (~5 to 4 Ma) resulted from marine transgression during a time of global warmth.