Experimental neoichnology of crawling stalked crinoids

Stalked crinoids have long been considered sessile. In the 1980s, however, observations both in the field and of laboratory experiments proved that some of them (isocrinids) can actively relocate by crawling with their arms on the substrate, and dragging the stalk behind them. Although it has been argued that this activity may leave traces on the sediment surface, no photographs or images of the traces produced by crawling crinoids have been available. Herein, we present results of neoichnological experiments using the shallowest species of living stalked crinoid, Metacrinus rotundus, dredged from Suruga Bay (near the town of Numazu, Shizuoka Prefecture, ~ 140 m depth). Our results demonstrate that isocrinids produce characteristic locomotion traces, which have some preservation potential. They are composed of rather deep and wide, sometimes weakly sinuous, central drag marks left by the stalk and cirri, and short, shallow scratch marks made by the arms. Based on the functional morphology and taphonomy, it has been argued that the ability to autotomize the stalk and relocate had already evolved in the oldest stem-group isocrinids (holocrinids), likely in response to increased benthic predation pressure during the so-called Mesozoic marine revolution. Our data show that this hypothesis may be corroborated in the future by ichnological findings, which may provide more direct proof of active locomotion in Triassic holocrinids

In Search of a Sustainable Global Agri-Food System

The potential to meet global food demand fully exists through global development of the high-technology (HT), high-intensity type of agriculture and food processing system prevailing in developed countries. This system unfortunately is also responsible for much natural resource degradation, environmental damage and ecological imbalance. Meantime the Earth's human population continues to grow, placing ever-increasing demand on global natural resources, not only for food but also for living and recreational space. A more sustainable agri-food system must evolve. Sustainability is complex, and ought to be approached from a multidisciplinary perspective and compromise sought in resolving the obvious conflicts amongst biological, environmental, ecological, socio-economic, and other individual disciplines and competing philosophies. These form the basis for comparing three different agricultural production systems: high technology (HT); reduced input (RI), and organic (ORG). The three systems are compared empirically using primary data from farms in each group in southern Ontario, Canada. HT systems prevalent in Canada is highly productive, but its sustainability is questionable. It was concluded that the HT system should not be the model for the future. The ORG system is the least inimical to the environment, ecology, and human operators. It was concluded that the ORG system is sustainable except for its requirement for extensive use of land. The RI system causes minimal environmental and ecological damage. It is most profitable and is supportive of rural farm community viability. It was concluded that the RI system holds the best potential for meeting overall sustainability for the global agri-food system.Farm Management, Land Economics/Use,

Imaging the snorkel effect during submerged germination in rice: Oxygen supply via the coleoptile triggers seminal root emergence underwater

Submergence during germination impedes aerobic metabolisms and limits the growth of most higher plants. However, some wetland plants including rice can germinate under submerged conditions. It has long been hypothesized that the first elongating shoot tissue, the coleoptile, acts as a snorkel to acquire atmospheric oxygen (O2) to initiate the first leaf elongation and seminal root emergence. Here, we obtained direct evidence for this hypothesis by visualizing the spatiotemporal O2 dynamics during submerged germination in rice using a planar O2 optode system. In parallel with the O2 imaging, we tracked the anatomical development of shoot and root tissues in real-time using an automated flatbed scanner. Three hours after the coleoptile tip reached the water surface, O2 levels around the embryo transiently increased. At this time, the activity of alcohol dehydrogenase (ADH), an enzyme critical for anaerobic metabolism, was significantly reduced, and the coleorhiza covering the seminal roots in the embryo was broken. Approximately 10 h after the transient burst in O2, seminal roots emerged. A transient O2 burst around the embryo was shown to be essential for seminal root emergence during submerged rice germination. The parallel application of a planar O2 optode system and automated scanning system can be a powerful tool for examining how environmental conditions affect germination in rice and other plants

Benthic foraminiferal Mn / Ca ratios reflect microhabitat preferences

The Mn / Ca of calcium carbonate tests of living (rose-Bengal-stained) benthic foraminifera (Elphidium batialis, Uvigerina spp., Bolivina spissa, Nonionellina labradorica and Chilostomellina fimbriata) were determined in relation to pore water manganese (Mn) concentrations for the first time along a bottom water oxygen gradient across the continental slope along the NE Japan margin (western Pacific). The local bottom water oxygen (BWO) gradient differs from previous field study sites focusing on foraminiferal Mn / Ca and redox chemistry, therefore allowing further resolution of previously observed trends. The Mn / Ca ratios were analysed using laser ablation inductively coupled plasma-mass spectrometer (ICP-MS), allowing single-chamber determination of Mn / Ca. The incorporation of Mn into the carbonate tests reflects environmental conditions and is not influenced by ontogeny. The inter-species variability in Mn / Ca reflected foraminiferal in-sediment habitat preferences and associated pore water chemistry but also showed large interspecific differences in Mn partitioning. At each station, Mn / Ca ratios were always lower in the shallow infaunal E. batialis, occupying relatively oxygenated sediments, compared to intermediate infaunal species, Uvigerina spp. and B. spissa, which were typically found at greater depth, under more reducing conditions. The highest Mn / Ca was always recorded by the deep infaunal species N. labradorica and C. fimbriata. Our results suggest that although partitioning differs, Mn / Ca ratios in the intermediate infaunal taxa are promising tools for palaeoceanographic reconstructions as their microhabitat exposes them to higher variability in pore water Mn, thereby making them relatively sensitive recorders of redox conditions and/or bottom water oxygenation.Peer reviewe

Sediment accumulation and carbon burial in four hadal trench systems

Hadal trenches are considered to act as depocenters for organic material, although pathways for the material transport and deposition rates are poorly constrained. Here we assess focusing, deposition and accumulation of material and organic carbon in four hadal trench systems underlying different surface ocean productivities; the eutrophic Atacama and Kuril-Kamchatka trenches, the mesotrophic Kermadec trench and the oligotrophic Mariana Trench. The study is based on the distributions of naturally occurring 210Pbex, 137Cs and total organic carbon from recovered sediment cores and by applying previously quantified benthic mineralization rates. Periods of steady deposition and discreet mass-wasting deposits were identified from the profiles and the latter were associated with historic recorded seismic events in the respective regions. During periods without mass wasting, the estimated focusing factors along trench axes were elevated, suggesting more or less continuous downslope focusing of material toward the interior of the trenches. The estimated organic carbon deposition rates during these periods exhibited extensive site-specific variability, but were generally similar to values encountered at much shallower settings such as continental slopes and margins. Organic carbon deposition rates during periods of steady deposition were not mirrored by surface ocean productivity, but appeared confounded by local bathymetry. The inclusion of deposition mediated by mass-wasting events enhanced the sediment and organic carbon accumulations for the past ∼ 150 years by up to a factor of ∼ 4. Thus, due to intensified downslope material focusing and infrequent mass-wasting events, hadal trenches are important sites for deposition and sequestration of organic carbon in the deep sea

Developments of deep-sea light and charge pump circuits fixed with an epoxy resin

海洋観測機器の製作コストやランニングコストを下げるため，プリント基板をエポキシ樹脂に直接固定し，水中や海 底で使用するLED光源とチャージポンプを開発，それぞれ耐圧試験や実海域での作動を確認した．LED光源は水深約 9200 mの海底に5回投入したが，物理的な破損もLEDの故障も生じなかった．この光源を基に製作したものをトンガ海 溝，ホライゾン海淵（水深10800 m）の海底で使用，堆積物直上の様子や底生生物活動のハイビジョン撮影に成功した． チャージポンプには圧力に弱い電解コンデンサが必要なため，樹脂で固定する前にコンデンサをカプセルで覆い，人工 的な気泡の中に配置することで圧力から保護する手法を開発した．この手法で樹脂固定して製作したチャージポンプと 赤色LEDを，伊平屋北熱水フィールド（水深1053 m）内の人工熱水噴出孔における深海電池の発電実験に供した．結 果，LEDの点灯により発電が確認された．エポキシ樹脂は海水，温度，圧力，光などによって劣化することが知られて いるが，深海環境における強度や透明度の変化についての知見はいまだ乏しいため，長期設置と強度試験による寿命の 推定が今後の課題となろう．A high power LED light and a charge pump with a LED indicator fixed with epoxy resin were developed in order to demonstrate reducing the cost of the deep-sea instruments. The LED light was brought at ca. 9200 m depth for five times. The light had no deformation and no crackes, and it worked after the deployents. It was also used to record the bottom at Tonga trench, where the world second deepest site (10800 m), and the video recording was succeeded. The charge pump was applied to confirm the electricity generation at the artificial hydrothermal vent in Iheya North hydrothermal field (1053 m). To protect electrolytic capacitors from pressure, they insulated from the resin with medicine capsules before fixing. The LED indicator was lighted on when the electrode of the fuel cell battery was inserted into the hydrothermal water. However, the degradation process of the epoxy resin under the deep-sea environments attributing high pressure and low temperature environments is still unknown. The guaranteed time of the instruments constructed with epoxy resin should be investigated throughout long term in situ exposure and the strength tests.http://www.godac.jamstec.go.jp/darwin/cruise/yokosuka/yk12-09/

In situ fluorochrome calcein marking of deep-sea molluscs using a new growth chamber

Abstract A new instrument designed for in situ chemical marking experiments was developed and applied to the deep-sea seep clams Calyptogena soyoae and Calyptogena okutanii. Fluorochrome calcein was used for vital staining of four living clams kept in a specially designed in situ growth chamber that was placed on the seafloor at a coldseep site off Hatsushima Island, Sagami Bay, central Japan. The shell margins of both C. soyoae and C. okutanii were clearly stained, forming a thin fluorescent band. This method will be useful for age and growth-rate determinations of many other marine organisms with accretionary growing skeletons

Experimental neoichnology of post-autotomy arm movements of sea lilies and possible evidence of thrashing behaviour in Triassic holocrinids

Echinoderms exhibit remarkable powers of autotomy. For instance, crinoids can shed arm and stalk portions when attacked by predators. In some species, it has been reported that the autotomized arms display vigorous movements, which are thought to divert the attention of predators. This phenomenon, however, has not been well explored. Here we present results of experiments using the shallowest water species of living stalked crinoid (Metacrinus rotundus) collected at 140 m depth. A wide range of movements of detached arms, from sluggish writhing to violent flicks, was observed. Interestingly, autotomized arms produce distinct traces on the sediment surface. They are composed of straight or arched grooves usually arranged in radiating groups and shallow furrows. Similar traces were found associated with detached arms of the oldest (Early Triassic) stem-group isocrinid (Holocrinus). This finding may suggest that the origins of autotomy-related thrashing behaviour in crinoids could be traced back to at least the Early Triassic, underscoring the magnitude of anti-predatory traits that occurred during the Mesozoic Marine Revolution. A new ethological category, autotomichnia, is proposed for the traces produced by thrashing movements of shed appendages

往還型深海TVカメラシステム「江戸っ子1号」開発プロジェクトの概要と実海域（水深7,800m）試験結果

「江戸っ子1号」プロジェクトの始まりは，葛飾区の小企業「杉野ゴム化学工業所」の杉野社長が「深海」を調査することのできる無人探査機（有索ROV）をつくりたいという発案だった。2009年にJAMSTECにアドバイスを求めたが、ROVの開発は、資金的・技術的にも無理であることがわかった。代案として、1978年頃にJAMSTECが研究していた「フリーフォール型ガラス球深海カメラ」の技術を応用し、さらに最新の電子技術を適用すれば、廉価に簡単で確実なシステムが実現できることが示された。このカメラは、海面から海底まで錘の自重で自由落下し、餌によって生物をおびきだし、予め設定しておいた時間撮影した後、錘を捨てて、再び海面に戻ってくる単純なシステムである。大きな特徴は、耐圧容器に市販（米国、ドイツ製）のガラス球を使うことにより、深海における最大の課題である高圧力の問題を回避できることである。そのため、カメラやライトなどは、中小企業の優れた技術力を結集することにより実現できると考えたのである。この提案を受け、新たな参加企業を募り、中小企業各社(杉野ゴム化学工業所、浜野製作所、パール技研、ツクモ電子工業)が参加した。また、コーディネータとして参加した東京東信用金庫が大学に働きかけ、JAMSTECの他に芝浦工業大学、東京海洋大学が参加して、「江戸っ子1号開発プロジェクト委員会」が発足した。その後、2011年に岡本硝子工業やバキュームモールドも参加し、JAMSTECの実用化促進プログラムにも採用され、プロジェクトが一気に動き出した。「江戸っ子1号」の目的は、水深8,000ｍで深海魚の3D動画を撮影するということであり、その実現に向けて各社と大学の作業が始まった。 まず、システムの中核となる耐圧ガラス球は、外国製を凌駕する性能のものが国産化された。さらに、市販の機器（3DカメラやLEDライトなど）を組み合わせ、円滑に動作させるために中小企業各社がその技術力を結集した。最終的に完成したシステムは、左下図のようなものであり、各々のガラス球間を特殊なゴム（大学が担当）により無線LANで繋ぐことで撮影時間などを制御できるようにした。本システムは、小型軽量であるため漁船でも投入でき、撮影終了後、音響コマンドにより錘を切離し、海面に浮上して衛星にGPSによる位置を通報し回収される。実験機は、漁船による相模湾での試験を経て、2013年11月に「かいよう」により日本海溝の水深4,000mと7,800mの海底に投入された。3機の「江戸っ子1号」は、設定されたスケジュールどおり投入から数時間から2日後に無事回収された。機器は完全に作動し、記憶メディアには、無数の世界最深部と思われる魚類（シンカイクサウオの仲間1種）ヨコエビの仲間(3?5種)が流れの方向から集まってくる様子などが、鮮明な3D動画として長時間記録されていた。 なお、本プロジェクトに対し、異業種の中小企業や大学、研究機関が共同で一つの目標を達成したことが評価され「第43回日本産業技術大賞・審査員特別賞」や「産学官連携功労者内閣総理大臣賞」などが授与された。更に2014年後半からは、岡本硝子（株）を中心としてカメラ本体の商品化や耐圧ガラス球の販売などを行うための事業化も始まった。我々は、これらのことから本プロジェクトは、実用化展開促進プログラムの目的を充分に果たしたと考えている。BE15-30講演要旨 / ブルーアース2015（2014年3月19日～20日, 東京海洋大学品川キャンパス）http://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky13-e05/

Researches in Japan on heavy ion inertial fusion

Recent research activities in Japan are presented in this paper in heavy ion inertial fusion (HIF) [1]: shown are particle accelerator developments, beam dynamics researches, interaction between heavy ions and target materials, ion source developments, and illumination schemes of heavy ion beams (HIBs) in HIF..