Paleontological Studies of Whale Barnacles in Taiwan Reveal New Cetacean Migration Routes in the Western Pacific Since the Miocene.

John Stewart Buckeridge, Benny K.K. Chan, and Shih-Wei Lee (2018) This paper describes a remarkably prolific accumulation of the whale barnacle Coronula bifida Bronn, 1831 in sediments of late Pliocene to earliest Pleistocene age from central Taiwan. Extant Coronula is host-specific to baleen whales; as such, this accumulation of Coronula fossils represents a site where cetaceans congregated during the Plio-Pleistocene - perhaps for breeding. Although whale bones are found at the site, they are rare and fragmentary; the relatively robust shells of Coronula are thus a useful proxy for establishing ancient cetacean migration routes.

The barnacles included in the superfamily Coronuloidea are epizoic symbionts of various marine vertebrates (including cetaceans, sirenians, and sea turtles) and other crustaceans (crabs and horseshoe crabs). Among Coronuloidea, the so-called turtle barnacles (Chelonibiidae) are known from Paleogene times, whereas the whale barnacles (Coronulidae) likely appeared in the late Pliocene (Piacenzian). Although a derivation from the turtle barnacles (and especially from the genus Chelonibia ) has been proposed, the evolutionary origin of Coronulidae remains to date obscure. In this work we reappraise a fossil record from upper Pliocene (Piacenzian) marine deposits at Casenuove (Empoli municipality, Tuscany, Italy) comprising various shells of Chelonibia testudinaria associated to a partial skeleton of a balaenid mysticete. Based on taphonomic and morpho-functional considerations, we discuss the hypothesis that the barnacles were hosted on the baleen whale, possibly on its callosities, which could have represented an analogous of the horny carapace of marine turtles. This record strongly suggests that the baleen whales can be added to the list of the possible hosts of the barnacles of the genus Chelonibia , thus hinting that the whale barnacles may have evolved from an ancient phase of dispersal of Chelonibia (or a similar ancestor) on mysticete cetaceans.

There was a fauna of baleen whales (Cetacea: Mysticeti) in the Central Paratethys, a Miocene water body which covered the area of present-day Central Europe. Most of the fossil baleen whales from the Central Paratethys have been found in strata assigned to the regional Badenian age and comprise endemic forms, known only from this region. Here a new description is provided for a fragmentary skeleton of a whale found in Belgrade, Serbia, and its age context and biological aspects are discussed. This specimen, consisting of a fragmentary horizontal ramus of the mandible and eight caudal vertebrae, is tentatively identified as ? Parietobalaena sp., a globally known Miocene taxon, with related forms having been recorded earlier from the Eastern Paratethys. An early Sarmatian age (i.e., about 12.7-12.4 Ma) is proposed for the specimen. Based on epiphyseal fusion of caudal vertebrae, the specimen’s age is identified as a subadult, with a body length of around 2.5 m and an estimated adult body length around 3-3.5 m, which is extremely small for baleen whales. This find represents one of the latest records of baleen whales in the Central Paratethys and one of the latest published records of Parietobalaena -like taxa in the world.

There are some localities of residual peridotite xenoliths from western edge arcs of the Circum-Pacific Ocean. Abe (1997) and Abe et al. (1998; 1999) show that the peridotite xenoliths from those arcs underwent wedge mantle metasomatism with some influx from subducted slab. We report the petrological and geochemical characteristics of the ultramafic xenoliths in the Cenozoic alkali-olivine basalts of Oki-Dogo island, another locality reported by Abe (1997) and Abe et al. (1998; 1999) in the Japan Sea. Both Group I and II ultramafic xenoliths (classification by Frey and Prinz (1978), equivalent to Wilshire and Shervais (1975) Cr-diopside and Al-augite series, respectively) come from Oki-Dogo island. Preliminary data on the petrology of the ultramafite, and also mafic xenoliths are in Yamaguchi (1964), Aoki (1977) and Takahashi (1978). We present here their mineral chemistry, especially the abundance of trace-elements in clinopyroxenes of Group I peridotite and the metasomatism by Group II ultramafic xenoliths suite. Oki-Dogo Island is located at the northern end of the Southwest Honshu Arc in the Japan Sea. Extensive alkalic volcanism (mugearite, hawaiite, trachy-andesite, trachyte and alkali rhyolite) took place from late Miocene to early Pliocene in this island. Alkali-olivine basalts with a subordinate amount of basanites were extruded from many vents situated inside of the supposed magma chamber. These basalts were monogenetic in most cases and their extrusion started at least 3.6 Ma and lasted at least until 0.8 Ma (Kaneoka et al., 1977). Most of these alkali basalts are fresh and contain 2 to 15 percent normative nepheline. Ultramafic and mafic inclusions are commonly found in most of the monogenetic lava flows. According to Takahashi (1978), those xenoliths are classified into five groups: spinel lherzolite, banded spinel peridotite, banded plagioclase peridotite, gabbro and granulite groups. The rocks of the banded spinel peridotite group are cumulates formed by fractional crystallization of basic magmas in a pressure range between about 10 and 20 kb, and recrystallized at the same depth. Some of the spinel lherzolite group are cumulates from basic magmas in the upper mantle during the partial melting of the preexisting lherzolite. Group I peridotite, which was classified as spinel lherzolite group by Takahashi (1978), has very low-Cr spinel. The Cr# (=Cr/(Cr+Al) atomic ratio) of chromian spinel is less than 0.3. Their Fo content of olivine varies from 90 to 83, while their NiO content is rather constant (0.25 to 0.40 wt%). Clinopyroxene grains in polished thin sections were analyzed in situ for abundances of REE, Ti, Sr, Y, Zr with the secondary ion mass spectrometer (SIMS; Cameca IMS- 3f) at Tokyo Institute of Technology. The chondrite normalized REE patterns of clinopyroxene in Oki-Dogo Group I xenoliths are flat to U-shaped LREE-depleted. HREE contents, however, almost same level, which suggests that those peridotites have the same degree of melt extraction. The evidence from their REE patterns and trace-element contents suggest that the Group I peridotites underwent Fe-rich mantle metasomatism by the alkaline magma. The continental type mantle metasomatism as well as arc type metasomatism suggested by Abe (1997) occurs in mantle wedge.

Spatial estimation and yearly trends in abundance-index of Japanese jack mackerel (Trachurus japonicus) in the East China Sea and Sea of Japan

Winter climatic anomalies of various time scales in the Japan, Okhotsk seas and Baikal Lake Basin are revealed and compared with anomalies in the Pacific, Indian and Arctic oceans. Time series of ice extent in the Japan and Okhotsk seas, ice thickness and seasonal duration of the ice cover in the Baykal Lake, as well as Hadley SST, surface heat fluxes, wind velocity, atmospheric pressure fields (SLP) and different climatic indices are analyzed. The decadal climate anomalies in the Japan and Okhotsk seas in mid winter, as compared to the Northeast Pacific and South Siberia regions, could have a reversed phase. Alternating cold/warm decadal anomalies in different longitude zones of the North Asian Pacific are accompanied by alternating meridional wind and SLP anomalies at temperate latitudes. Alternating zones of inversed anomalies in temperate latitudes of the Asian Pacific are related to teleconnections with anomalies in both Arctic and Indo-Pacific oceans. Negative SSTA in eastern/central tropical-equatorial Pacific and positive SSTA in El Nino area accompanies rise of northern wind and ice extent in the Okhotsk/Japan Seas in mid-winter. The best predictors of the high cold anomaly in February in the western subarctic Pacific and marginal seas are reduction of the SST and net heat flux from the atmosphere to the ocean in north-eastern and central North Pacific during warm period of a previous year. At the multidecadal time scale the warming/cooling in the Northeast Pacific accompany winter warming/cooling in the Baykal Lake area during all period of observation. At interdecadal time scales the significant link of winter climate oscillations in South Siberia (Baikal Lake Basin) is found with SSTA oscillations in the equatorial region of the Indian Ocean and certain areas of the Pacific Ocean. The linkages of anomalies in the Baikal Lake Basin, Okhotsk, Japan Seas with regional anomalies in some key areas of the Pacific and Indian Oceans, related to the atmospheric centers of action are more stable than that with climatic indices. After climate regime shift in late 70s warm decadal anomaly in both Lake Baykal Basin and Indian Ocean in boreal winter accompany high positive anomaly of the Arctic Oscillation. Scenarios of extreme anomalies in the Baikal Lake Basin and Subarctic Pacific marginal area are also presented.

Trace element analysis of otoliths from core to edge was used to reveal differences in habitats of larvae and early juveniles of Japanese jack mackerel (Trachurus japonicus) caught in the East China Sea (ECS), Pacific Ocean, and Sea of Japan. Multi‐element signatures (Sr:Ca, Mg:Ca, Na:Ca, K:Ca, and Ba:Ca) were analyzed with multivariate statistics to determine whether these element signatures provide insight into regional population structure. The median values of elements: Ca ratios in otolith core region differed significantly among areas, with most elements between the ECS and the Pacific Ocean or Sea of Japan showing significant differences. The Sr:Ca ratios exhibited a V‐shaped trend from the otolith core to the edge, which was likely related to the vertical habitat layer shift of larvae and early juveniles of T. japonicus. Canonical analysis of principal coordinates using the element: Ca ratios and the hatching day were re‐classified according to the sampling area with higher accuracy in the ECS (88–95%) and the Sea of Japan (76–83%) compared to the Pacific Ocean (69–72%). These results indicate that the proportion of eggs, larvae, and early juveniles transported by the Kuroshio Current from the southern ECS—the main spawning ground—to the Pacific Ocean or the Sea of Japan is low and that juveniles distributed in the coastal waters off southwestern Japan may have originated from local spawners. These results suggest that determining the elemental composition of larvae and juveniles of T. japonicus is effective in determining the habitat differences of this species in the three regions. These findings will help to understand population structure and recruitment process of this species around Japan.

Fil: Buono, Monica Romina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Centro Nacional Patagonico. Instituto Patagonico de Geologia y Paleontologia; Argentina

Seasonal variation in the 228Ra/ 226Ra ratio of coastal water within the Sea of Japan: Implications for the origin and circulation patterns of the Tsushima Coastal Branch Current

The oxygen isotopic composition of the winter precipitation was observed in Tohkamachi, central Japan, in 1993/1994 and 1994/1995 winter. Synoptic meteorological conditions of winter precipitation in this area are classified as winter monsoons, cyclones positioned over the Sea of Japan, and cyclones located over the Pacific Ocean near Honshu (main Japanese Island). The oxygen isotopic composition of precipitation does not correlate with surface air temperature (r = 0.012). A close relationship is instead observed between temperature at the cloud top and the oxygen isotopic composition of precipitation (r = 0.662), and the mutual relationships are recognized for each weather condition formed under that winter precipitation (r = 0.772 for winter monsoon, 0.935 for cyclone positioned over the Pacific Ocean near Honshu). Winter precipitation formed during the winter monsoon has a higher value of oxygen isotopic composition than those formed when a cyclone is positioned over the Pacific Ocean near Honshu at the same temperature.

The marine isopod genus Limnoria contains algae-eating species. Previous phylogeographic studies have suggested that Limnoria species feeding on buoyant kelp underwent low genetic differentiation on a large spatial scale because rafting on floating host kelps promotes high levels of gene flow. In this paper, we survey the genetic structure of Limnoria nagatai, which bores into the non-buoyant kelps Eisenia bicyclis and E. arborea. We analyze the mitochondrial DNA (cytochrome oxidase subunit I [COI] gene) and morphological traits of L. nagatai, and the host kelps E. bicyclis and E. arborea from 14 populations along the Japanese archipelago of the Pacific Ocean and the Sea of Japan. Four major lineages are recognized within L. nagatai: three lineages in the Pacific Ocean, and one lineage in the Sea of Japan which might be a cryptic species. For L. nagatai, we show high genetic differentiation between geographically separated habitats in the Pacific Ocean, while low differentiation is found among continuous host kelps habitats in the Pacific Ocean as well as the Sea of Japan. L. nagatai in E. bicyclis in the Pacific Ocean has experienced large population expansion after the Last Glacial Maximum (LGM), whereas the lineage in E. bicyclis in the Sea of Japan has not. We suggest that Limnoria feeding on non-buoyant kelps, may attain low genetic differentiation because they might be able to disperse long distance if the habitat of host kelps is continuous. The historical events affecting Limnoria after the LGM may differ between the coasts of the Pacific Ocean and the Sea of Japan.

Molybdenum and tungsten are redox-sensitive elements, and their stable isotope ratios have attracted attention as paleoceanographic proxies. However, our knowledge of the distribution of stable Mo and W isotopes in the modern hydrosphere remains limited. In this study, we provided the concentrations and isotope ratios of dissolved Mo and W in the oceans (the North Pacific and Indian Oceans), marginal seas (the East China Sea and Sea of Japan), and a river-estuary system in Japan (from the Uji-Yodo rivers to Osaka Bay). In the North Pacific and Indian Oceans, the W concentration was 48.2 ± 6.2 pmol/kg (ave ± 2sd, n = 109), δ186/184W was 0.52 ± 0.06 ‰, the Mo concentration was 105.1 ± 8.0 nmol/kg, and δ98/95Mo was 2.40 ± 0.06 ‰. The results indicate that W has the constant concentration and isotopic composition in the modern ocean as well as Mo. In the East China Sea and the Sea of Japan, the W concentration and δ186/184W in the upper water (< 1000 m depth) were different from those in the ocean (W = 56 ± 18 pmol/kg, δ186/184W = 0.45 ± 0.06 ‰, n = 24). However, the concentrations in deeper water were congruent with those in the oceans (W = 49.9 ± 7.6 pmol/kg, δ186/184W = 0.50 ± 0.02 ‰, n = 7). The Mo concentration was 105.4 ± 3.1 nmol/kg and δ98/95Mo was 2.36 ± 0.03 ‰ (n = 31) throughout the water column, congruent with those in the ocean. In the Uji River-Yodo River-Osaka Bay system, the W concentration reached 1074 pmol/kg and δ186/184W reached 0.20 ‰. We propose that the enrichment of W with a low δ186/184W in the river-estuary system and marginal seas is caused by anthropogenic pollution. Anthropogenic Mo pollution was not detected in marginal seas. However, the Mo concentration and δ98/95Mo showed high anomalies above the mixing line of river water and seawater in the lower Yodo River and Osaka Bay, implying possible anthropogenic pollution of Mo in the metropolitan area.

Seismic waves generated by two explosions of dynamite, 5 tons each, in the Sea of Japan off the coast of northern Honshu were observed at more than 100 temporary and permanent seismological stations in the Hokkaido, Honshu, Sado, and Oki islands. A purpose of these measurements was to extend our investigation of lateral variation in Pn velocity which has been found around northeastern Japan in the previous explosion experiments. In fact, a lateral variation in Pn velocity by about 5% was confirmed in regions of the uppermost mantle below the Sea of Japan and the Honshu island, although the boundary where the velocity change takes place was not determined.The measurements have also revealed an indication that the upper mantle just beneath the Moho interface under the area in the southeastern half of the Sea of Japan is anisotropic with respect to P-wave velocity. The velocity variation in the anisotropy is approximately 0.4km/sec (i.e., 5%) about a mean velocity of 7.94km/sec. The direction of the maximum velocity is 141°E of north which corresponds roughly to a direction perpendicular to the general trend of northern Honshu as well as to magnetic lineations.

Winter climatic anomalies of various time scales in the Japan, Okhotsk seas and Baikal Lake Basin are revealed and compared with anomalies in the Pacific, Indian and Arctic oceans. Time series of ice extent in the Japan and Okhotsk seas, ice thickness and seasonal duration of the ice cover in the Baykal Lake, as well as Hadley SST, surface heat fluxes, wind velocity, atmospheric pressure fields (SLP) and different climatic indices are analyzed. The decadal climate anomalies in the Japan and Okhotsk seas in mid winter, as compared to the Northeast Pacific and South Siberia regions, could have a reversed phase. Alternating cold/warm decadal anomalies in different longitude zones of the North Asian Pacific are accompanied by alternating meridional wind and SLP anomalies at temperate latitudes. Alternating zones of inversed anomalies in temperate latitudes of the Asian Pacific are related to teleconnections with anomalies in both Arctic and Indo-Pacific oceans. Negative SSTA in eastern/central tropical-equatorial Pacific and positive SSTA in El Nino area accompanies rise of northern wind and ice extent in the Okhotsk/Japan Seas in mid-winter. The best predictors of the high cold anomaly in February in the western subarctic Pacific and marginal seas are reduction of the SST and net heat flux from the atmosphere to the ocean in north-eastern and central North Pacific during warm period of a previous year. At the multidecadal time scale the warming/cooling in the Northeast Pacific accompany winter warming/cooling in the Baykal Lake area during all period of observation. At interdecadal time scales the significant link of winter climate oscillations in South Siberia (Baikal Lake Basin) is found with SSTA oscillations in the equatorial region of the Indian Ocean and certain areas of the Pacific Ocean. The linkages of anomalies in the Baikal Lake Basin, Okhotsk, Japan Seas with regional anomalies in some key areas of the Pacific and Indian Oceans, related to the atmospheric centers of action are more stable than that with climatic indices. After climate regime shift in late 70s warm decadal anomaly in both Lake Baykal Basin and Indian Ocean in boreal winter accompany high positive anomaly of the Arctic Oscillation. Scenarios of extreme anomalies in the Baikal Lake Basin and Subarctic Pacific marginal area are also presented.

Validation and use of a HPLC-MS/MS method for the analysis of multiple steroid hormones in humpback whale blubber