Le Miocène du Val des Verrières et du Bief des Lavaux(Jura central,Haute-Chaîne): Événements paléobiogéographiques et géodynamiques

The faunas collected in the Miocene of the Centralpart of the Jura High-Range near Pontarlier have allowed to attribute a Burdigalien age at the marine molass and Upper Burdigalien age at the overlying lacustrine deposits. The marine faunas are varied and show very clearly sea-ways from the rhodanoprovencal area. The age of the continental faunas prove that the sea recedes as soon as the end of Lower Miocene, showing the beginning of the emersion of the High-Range is an earliest event than hitherto believed.     

Patterns of benthic mega-invertebrate habitat associations in the Pacific Northwest continental shelf waters: a reassessment

As human impacts and demands for ocean space increase (fisheries, aquaculture, marine reserves, renewable energy), identification of marine habitats hosting sensitive biological assemblages has become a priority. Epifaunal invertebrates, especially the structure-forming species, are an increasing conservation concern as many traditional (bottom-contact fishing) and novel (marine renewable energy) ocean uses have the potential to displace or otherwise impact these slow-growing organisms. The differences in mega-invertebrate species assemblages between high-relief rocks and low-relief sediments are well documented and likely hold for most marine environments. In anticipation of potential development of marine renewable energy faculties off Oregon and Washington (USA), a survey of the benthic invertebrate assemblages and habitats was conducted on three rocky reefs on the continental shelf of the Pacific Northwest, using video footage collected by remotely operated vehicle, to more finely characterize these assemblage–habitat associations. Benthic assemblages appeared to first group by depth (50–80 vs. 100–120 m), then by relief (consolidated rocks vs. unconsolidated rocks and soft sediments). Consolidated rocks were characterized at each site by a combination of various sponges, gorgonians, sea anemones and echinoderms; unconsolidated rocks were characterized at Grays Bank by sea anemones and burrowing brittle stars, and at Bandon-Arago by sponges and echinoderms; soft sediments were characterized at Grays Bank and Siltcoos Reef by sea whips and burrowing brittle stars, as well as pink shrimps and sea stars at Siltcoos Reef, and at Bandon-Arago by sponges, gorgonians and echinoderms. The results of this study will help classify and map the seafloor in a way that represents benthic habitats reflective of biological species assemblage distributions, rather than solely geological features, and support conservation and management planning.     

The lithographic limestones of Cerin (southern Jura Mountains,France). A synthetic approach and environmental interpretation

The lithographic limestones of the Cerin quarry (southern French Jura Mountains), of Late Kimmeridgian age, were famous during the 19th century for their quality and consequently the quarry was intensely exploited. From 1975 to 1994, scientific excavations were carried out in these limestones in order to investigate the depositional environment, the burial of organisms and their taphonomy. A large set of data was collected about various organisms, unusual locomotion tracks, microbial mats and emersion structures. This led to a new interpretation of the environment as a laguna overlying a previously emergent and eroded coral reef. This laguna was episodically connected to the sea by temporary channels, during storms. Lime mud was supplied both from the sea and from the surrounding emergent areas. Most organisms, both marine and terrestrial, were transported, trapped, mixed and buried in the laguna. After death, the preservation of the carcasses was favoured by the presence of microbial mats providing superficial anoxic conditions and protecting them from decaying.     

Patterns of benthic mega-invertebrate habitat associations in the Pacific Northwest continental shelf waters

As human impacts and demands for ocean space increase (fisheries, aquaculture, marine reserves, renewable energy), identification of marine habitats hosting sensitive biological assemblages has become a priority. Epifaunal invertebrates, especially the structure-forming species, are an increasing conservation concern as many traditional (bottom-contact fishing) and novel (marine renewable energy) ocean uses have the potential to displace or otherwise impact these slow-growing organisms. The differences in mega-invertebrate species assemblages between high-relief rocks and low-relief sediments are well documented and likely hold for most marine environments. In anticipation of potential development of marine renewable energy faculties off Oregon and Washington (USA), a survey of the benthic invertebrate assemblages and habitats was conducted on the continental shelf of the Pacific Northwest, using video footage collected by ROV, to more finely characterize these assemblage–habitat associations. Four main associations were found: pure mud/sand dominated by sea whips and burrowing brittle stars; mixed mud–rock (which may be further divided based on size of mixed-in rocks) characterized by various taxa at small densities; consolidated rocks characterized by high diversity and density of sessile or motile mega-invertebrates; and rubble rocks showing less diversity and density than the consolidated rocks, possibly due to the disturbance generated by movement of the unconsolidated rocks. The results of this study will help classify and map the seafloor in a way that represents benthic habitats reflective of biological species assemblage distributions, rather than solely geological features, and support conservation and management planning.     

Lebensspuren von Meersauriern und ihren Beutetieren im mittleren Jura (Callovien) von Liesberg, Schweiz

Summary Numerous gutter-like furrows, up to 60 cm wide and up to 9 m long are preserved at the interface “Macrocephalus Beds”/“Callovian Marl” over a surface of 20 by 200 m. They are interpreted as feeding traces made by large marine vertebrates, most likely plesiosaurs and ichthyosaurs searching for food in the lime mud of the shallow Middle Jurassic sea floor. Possible prey animals were infaunal invertebrates (crustaceans) which produced an intricate meshwork of burrows (mainlyRhizocorallium irregulare andThalassinoides) in the bottom sediments, as well as infaunal bivalves. Evidence from cololites of predatory pelagic reptiles (ichthyosaurs, plesiosaurs) as well as reptile regurgitalites indicate that these animals fed not only on fast-swimming vertebrates and cephalopods but also on epi- and endobenthic invertebrates. In addition, the cololites show that the predators ingested considerable amounts of bottom sediment. Different sizes and shapes of the traces suggest that the gutters were produced by different reptiles or age groups. Candidates for the widest gutters are pliosaurs. Of the marine vertebrates known from Jurassic time, only the snout of adult pliosaurs of the genusLiopleurodon was broad enough to produce gutters more than 40 cm wide. Smaller, less than 15 cm wide gutters, could have been made by plesiosauroids or by the narrow pointed snouts of ichthyosaurs. Almost identical traces described from the Oxfordian of Spain and similar but smaller traces from the Lower Devonian of Prague are equally interpreted as feeding traces on the sea floor. Feeding traces of vertebrates in bottom sediments may give detailed information on the hunting behaviour of the predators. However, the attribution of the traces to definite vertebrate taxa remains uncertain.

     

Origin of mid-cretaceous black shales in the benue through, Nigeria

Black and dark-gray laminated shales with large amounts of both terrestrial and marine organic material are common in upper Cenomanian to lower Santonian rocks of the Benue Trough. These shales were deposited during global mid-Cretaceous marine transgressions when widespread high organic carbon sedimentation took place. The Benue Trough in those times was the site of a shallow, density-stratified, anoxic epeiric sea with estuarine-type circulation. From this reservoir, nutrient-rich oxygen-depleted waters were fed into the northern parts of the South Atlantic Ocean.     

山东海岸木生海洋真菌的研究I.(英文)

为调查中国黄海海域的丝状海洋真菌,从山东威海潮间带海滩收集了沉没木、附着木和沙埋木,并从其上分离到7种高等海洋真菌。Arenariomycestrifurcata,Corollosporamaritima,Alternariamaritima,Trichocladiumachrasporum为中国大陆新记录种,Chaetomiunglobosum,Tetraploaaristata,Torulasp.为中国大陆新生境报道。对每个种作了描述并对分类和形态进行了讨论。     

A recent marine ancestry for diadromous fishes? Sometimes yes,but mostly no!

Synopsis Diadromy in its three forms (anadromy, catadromy and amphidromy) necessarily involves fish spending part of their lives in the sea. It is not uncommon contention that diadromous fish have a recent marine ancestry and that they are in the process of moving from a marine to a freshwater lifestyle. However, analysis of the distribution of diadromy in fishes suggests that, for most species, it is an ancient life history style though, for a few, a recent marine ancestry seems plausible. In general, there is no reason to consider diadromy anything but a stable and successful life history style, and no reason to regard it as transitional between marine and freshwater habitats.Invited Editorial     

Retention of ice-associated amphipods: possible consequences for an ice-free Arctic Ocean

Recent studies predict that the Arctic Ocean will have ice-free summers within the next 30 years. This poses a significant challenge for the marine organisms associated with the Arctic sea ice, such as marine mammals and, not least, the ice-associated crustaceans generally considered to spend their entire life on the underside of the Arctic sea ice. Based upon unique samples collected within the Arctic Ocean during the polar night, we provide a new conceptual understanding of an intimate connection between these under-ice crustaceans and the deep Arctic Ocean currents. We suggest that downwards vertical migrations, followed by polewards transport in deep ocean currents, are an adaptive trait of ice fauna that both increases survival during ice-free periods of the year and enables re-colonization of sea ice when they ascend within the Arctic Ocean. From an evolutionary perspective, this may have been an adaptation allowing success in a seasonally ice-covered Arctic. Our findings may ultimately change the perception of ice fauna as a biota imminently threatened by the predicted disappearance of perennial sea ice.     

Back to the sea: secondary marine organisms from a biogeographical perspective

Secondary marine organisms belong to groups of terrestrial ancestry which have recolonized marine habitats. Some of them are, to various degrees, still dependent on the terrestrial habitat where they originated, which imposes certain limits in the expansion of their distribution range. This makes them an ideal subject for historical reconstruction. Here I perform biogeographical analyses on the global distribution of 12 groups of land-dependent secondary marine plants and animals (mangrove trees, sea turtles, sea snakes, seabirds and seals). When all groups are taken together, species diversity shows a unique bimodal pattern for each hemisphere, with high values in cold-temperate and tropical regions, but low values in mid-latitude regions. None of the individual groups considered reaches its highest species concentration in mid-latitude regions. This is shown to be due to the existence of three different species assemblages, inhabiting the three species-rich latitudinal bands (northern cold-temperate, tropical, and southern cold-temperate), and intermixing to a limited degree in the species-poor mid-latitude bands. This is evidence that secondary marine organisms diversified independently in cold-temperate and tropical regions, and strongly suggests that colonization from terrestrial habitats took place independently in the three species-rich latitudinal bands. Different constraints in the terrestrial habitat of origin are put forward as evolutionary incentives for colonizing the sea: glaciation processes in cold regions and competition in tropical regions.     

Introduction to the symposium "New frontiers from marine snakes to marine ecosystems"

Interest in sea snakes and mythological "sea serpents" dates to ancient times and is represented in the writings of Aristotle, early voyagers, and explorers, and references in the Bible. Since then, awareness of the myriad species of snakes inhabiting the oceans has grown at a gradual pace. Scientific investigations into the biology of marine snakes-especially those in behavior, physiology, and other disciplines requiring living animals or tissues-have been comparatively challenging owing to difficulties in acquiring, transporting, handling, and husbanding these secondarily marine vertebrates. A broadening perspective with increasing interest in these animals peaked during the 1960s and 1970s, and literature from this period contributed to a growing knowledge that marine snakes comprise a very diverse fauna and are a significant part of marine ecosystems. Two persons figured prominently as influential drivers of research on sea snakes during this period, namely William Dunson and Harold Heatwole, and this symposium recognizes the contributions of these two individuals. Following a decline in scientific publications on sea snakes during the 1980s and 1990s, there has been a renaissance of scientific interest in recent years, and a wealth of new research findings has improved the understanding of phylogeny and diversity of marine snakes while simultaneously recognizing threats to marine ecosystems arising from climate change and other anthropogenic causes. The purposes of the symposium are to (1) illustrate the importance and relevance of sea snakes as contributors to better understanding a range of issues in marine biology, (2) establish and promote the use of marine systems as models for investigating conceptual issues related to environment, changing climate, and persistence of biological communities, with focus on marine snakes as novel or useful examples, (3) promote interest in sea snakes as useful organisms for study by scientists in a range of disciplines who might presently work with other organisms or systems, and (4) identify leading-edge topics for which studies of marine snakes might contribute uniquely to the advancement of research.     

“海洋生态系统工程师”及其生态作用

“海洋生态系统工程师”是能够塑造栖息地并使其他海洋生物受益的海洋生物种类。海洋中的植物、动物和微生物中均存在为其他生物种类塑造栖息地的“海洋生态系统工程师”,它们的生态作用是其发挥生态功能的基础。本文基于国内外相关文献,系统阐述了“海洋生态系统工程师”生态作用的相关研究进展,并对今后的主要研究方向和内容提出建议。“海洋生态系统工程师”能够在特定的海洋环境中发挥积极作用,但一旦成为入侵种可能会对入侵海域产生负面影响;有些“海洋生态系统工程师”在发挥积极作用的同时也会在不同程度上带来负面影响。今后,应加强海洋生物床、海洋生物礁、海洋生物膜和复合生态系统工程等研究,有效利用“海洋生态系统工程师”的积极作用并防控其负面影响,实现对海洋的综合开发利用和保护。     

The occurrence of Eubothrium crassum (Cestoda: Pseudophyllidea) in salmon Salmo salar and trout S. trutta of the River Exe

The occurrence, size and maturity changes of Eubothrium crassum (Bloch) have been studied in smolts and adult Salmo salar L. and S. trutta L. of the River Exe and other Devon rivers. Adult parasites are found only in salmon and sea trout migrating up river to spawn, and range in size from small and immature to large and mature, though rarely gravid, worms. It is concluded that they are acquired and only become fully mature in the sea and gravid worms are lost on or before arrival in the rivers. During the upstream migration of salmon there is a selective loss of larger and more mature parasites and the survivors do not increase in length or mature, due to the intestine becoming a progressively more unfavourable habitat as the period of fasting continues. As few salmon return to the sea, most parasites in fresh-water die before breeding. In sea trout, which feed in fresh-water, parasites continue to grow and probably mature on return to the sea. It is suggested that parasites found in adult Atlantic and Pacific salmon in rivers are rarely, if ever, the same worms that are carried to sea by smolts but are of marine origin and are residues of a marine life cycle, and that two biological races of E. crassum exist, a marine and a fresh-water one.     

Dwindling seagrasses: A multi-temporal analysis on Google Earth Engine

Seagrasses, a unique group of marine flowering plants, profoundly influence the marine environment by providing an array of critical ecological functions. They serve as the foundational habitat for several endangered and charismatic species, including sea cows, sea turtles, and sea horses, and are often referred to as coastal canaries. In comparison to boreal and tropical forests, they have an amazing ability for carbon storage. Despite their long evolutionary history, they are threatened by rapid environmental changes caused by climate change and human activity. Long-term monitoring is required to comprehend the changes in this fragile ecosystem. Conventional field survey methods for collecting long-term data are laborious, time-consuming, and expensive. Hence, this work builds a time-series dataset of the seagrass coverage in the Kalpeni lagoon from 2003 to 2020 by analysing Landsat data on Google Earth Engine. We also evaluated the temporal changes in the seagrass coverage of the study area and studied the influence of selected environmental factors on the seagrass coverage. We observed a negative relationship between sea surface temperature and seagrass coverage. The results revealed a decline in more than 99% of seagrass coverage, indicating an alarming threat to this seagrass ecosystem of the region. With such a drastic shrinkage in the seagrass coverage, the hysteresis must be strong, and the recovery of these meadows may require intensive interventions. By establishing a long-term time series database of seagrass coverage, our study also opens up new avenues for future ecological research on the seagrass meadows.     

Void development on carbonate coasts: creation of anchialine habitats

Anchialine caves in coastal locations develop in two ways: by pseudokarst processes that form talus caves, sea caves, tafoni, fissure caves and lava tubes, and by karst dissolutional processes that form stream caves, flank margin caves, and blue holes. Pseudokarst caves are of minor importance in anchialine cave habitat development, with some lava tubes being notable exceptions. Dissolution caves provide the most extensive, variable, and long-term environments for anchialine habitats. The Carbonate Island Karst Model (CIKM) allows dissolutional cave development in carbonate coasts to be understood as the interplay between freshwater and marine water mixing, sea-level change, rock maturity, and interaction with adjacent non-carbonate rocks. Glacioeustatic sea-level changes of the Quaternary have moved all coastal anchialine cave environments repeatedly through a vertical range of over 100 m, and modern anchialine environments could not develop at their current elevations until ~4,000 years ago when sea level reached its present position. Blue holes form by a variety of mechanisms, but the most common is upward stoping and collapse from deep dissolutional voids. As a result, they provide vertical connection between different levels of horizontal cave development produced by a variety of earlier sea-level positions. Blue holes are overprinted by successive sea-level fluctuations; each sea-level event adds complexity to the habitats within blue holes and the cave systems they connect. Blue holes can reach depths below the deepest glacioeustatic sea-level lowstand, and thereby provide a refugia for anchialine species when cave passages above are drained by Quaternary sea-level fall. Blue holes represent the most significant anchialine cave environment in the world, and may provide clues to anchialine cave species colonization and speciation events.     

Biotic interactions of marine algae

Marine algae encompass lineages that diverged about one billion years ago. Recent results suggest that they feature natural immunity traits that are conserved, as well as others that appear to be phylum- or environment-specific. In particular, marine plants resemble terrestrial plants and animals in their basic mechanisms for pathogen recognition and signaling, suggesting that these essential cell functions arose in the sea. Specific traits are based on the synthesis of unique secondary defense metabolites, often making use of the variety of halides found in the sea.     

Effect of sea water concentration on hyphal growth and antimicrobial metabolite production in marine fungi

We studied the effect of sea water concentration in a culture medium on fungal growth and the production of antimicrobial metabolites. Most of the marine fungal isolates were identified as members of the same genera as terrestrial isolates, such asAspergillus andTrichoderma. Many of the marine fungi isolated grew more abundantly as the sea water concentration increased. The production of antimicrobial materials was improved as the sea water concentration increased. Even though the marine fungi were considered to be similar to fungi from terrestrial environments, from a mycological perspective, the two types have different physiological characteristics. The fungi from marine samples are useful microbial resources in the search for new bioactive compounds.     

Low genetic diversity in a marine nature reserve: re-evaluating diversity criteria in reserve design

Little consideration has been given to the genetic composition of populations associated with marine reserves, as reserve designation is generally to protect specific species, communities or habitats. Nevertheless, it is important to conserve genetic diversity since it provides the raw material for the maintenance of species diversity over longer, evolutionary time-scales and may also confer the basis for adaptation to environmental change. Many current marine reserves are small in size and isolated to some degree (e.g. sea loughs and offshore islands). While such features enable easier management, they may have important implications for the genetic structure of protected populations, the ability of populations to recover from local catastrophes and the potential for marine reserves to act as sources of propagules for surrounding areas. Here, we present a case study demonstrating genetic differentiation, isolation, inbreeding and reduced genetic diversity in populations of the dogwhelk Nucella lapillus in Lough Hyne Marine Nature Reserve (an isolated sea lough in southern Ireland), compared with populations on the local adjacent open coast and populations in England, Wales and France. Our study demonstrates that this sea lough is isolated from open coast populations, and highlights that there may be long-term genetic consequences of selecting reserves on the basis of isolation and ease of protection.     

Dehydration and drinking responses in a pelagic sea snake

Recent investigations of water balance in sea snakes demonstrated that amphibious sea kraits (Laticauda spp.) dehydrate in seawater and require fresh water to restore deficits in body water. Here, we report similar findings for Pelamis platurus, a viviparous, pelagic, entirely marine species of hydrophiine ("true") sea snake. We sampled snakes at Golfo de Papagayo, Guanacaste, Costa Rica and demonstrated they do not drink seawater but fresh water at variable deficits of body water incurred by dehydration. The threshold dehydration at which snakes first drink fresh water is -18.3 ± 1.1 % (mean ± SE) loss of body mass, which is roughly twice the magnitude of mass deficit at which sea kraits drink fresh water. Compared to sea kraits, Pelamis drink relatively larger volumes of water and make up a larger percentage of the dehydration deficit. Some dehydrated Pelamis also were shown to drink brackish water up to 50% seawater, but most drank at lower brackish values and 20% of the snakes tested did not drink at all. Like sea kraits, Pelamis dehydrate when kept in seawater in the laboratory. Moreover, some individuals drank fresh water immediately following capture, providing preliminary evidence that Pelamis dehydrate at sea. Thus, this widely distributed pelagic species remains subject to dehydration in marine environments where it retains a capacity to sense and to drink fresh water. In comparison with sea kraits, however, Pelamis represents a more advanced stage in the evolutionary transition to a fully marine life and appears to be less dependent on fresh water.     

溢油事故中渔业资源损失的数值模拟评估模式

海洋溢油污染不仅关系到天然渔业资源、海鸟等生物、海域环境、海岸线生态的破坏,而且对渔业、捕捞业、旅游业都会造成巨大损失,甚至会直接或间接地危害人类的健康。短期来看,一方面石油、燃料油等进入海洋后,对海洋生物资源造成影响;另一方面会危害附近海区的海洋环境,侵害海洋生物以及海鸟赖以生存和栖息的环境。长期来看,持续的海洋污染会导致的生态环境失衡,海洋的生产力也随之下降。溢油事故中的渔业资源损失评估作为追究污染事故责任,尽快恢复海域资源与环境的重要一环需要不断改进创新。为了定量确定海洋溢油事故发生后渔业资源的损失程度,将传统的评估模式与现代科学技术相结合,通过海洋动力学、流体力学、海洋生物学、环境化学等多个学科交叉融合,将流场风场模型、溢油模型、海域调查监测、卫星遥感技术、毒性效应和渔业资源的损失评估方法相结合,形成一种渔业资源损失评估的数值模拟评估模式,以完善溢油事故中渔业资源损失评估体系。在溢油事故现场监测数据的基础上,运用数学计算理论选择相对应的溢油模型,结合具体溢油事故案例的潮流数据和风场数据,模拟海上溢油污染的时空分布情况。采用卫星遥感技术根据不同油品在海水中不同的亮度表现,处理得到溢油油膜信息,与模拟得到的油膜信息进行比对验证,并对模型进行修正,通过模拟得出污染海域油浓度分布与溢油污染范围信息,结合溢油污染对不同海洋生物的毒性效应,得到渔业资源的损失程度,为溢油事故的渔业资源损失评估提供一种思路,为溢油事故发生后的损失评估和事故处理起到一定的参考辅助作用。