Unburnt coal is a widespread and sometimes very abundant contaminant in marine environments. It derives from natural weathering of coal strata and from anthropogenic sources including the processing of mined coal, disposal of mining wastes, erosion of stockpiles by wind and water, and spillage at loading and unloading facilities in ports. Coal is a heterogeneous material and varies widely in texture and content of water, carbon, organic compounds and mineral impu- rities. Among its constituents are such potential toxicants as polycyclic aromatic hydrocarbons (PAHs) and trace metals/metalloids. When present in marine environments in sufficient quantities, coal will have physical effects on organisms similar to those of other suspended or deposited sediments. These include abrasion, smothering, alteration of sediment texture and stability, reduced availability of light, and clogging of respiratory and feeding organs. Such effects are relatively well documented. Toxic effects of contaminants in coal are much less evident, highly dependent on coal composition, and in many situations their bioavailability appears to be low. Nevertheless, the presence of contaminants at high concentrations in some coal leachates and the demonstration of biological uptake of coal-derived contaminants in a small number of studies suggest that this may not always be the case, a situation that might be expected from coal's heterogeneous chemical composition. There are surprisingly few studies in the marine environment focusing on toxic effects of contaminants of coal at the organism, population or assemblage levels, but the limited evidence indicating bioavailability under certain circumstances suggests that more detailed studies would be justified.
{"title":"Biological effects of unburnt coal in the marine environment","authors":"M. Ahrens, D. Morrisey","doi":"10.1201/9781420037449-5","DOIUrl":"https://doi.org/10.1201/9781420037449-5","url":null,"abstract":"Unburnt coal is a widespread and sometimes very abundant contaminant in marine environments. It derives from natural weathering of coal strata and from anthropogenic sources including the processing of mined coal, disposal of mining wastes, erosion of stockpiles by wind and water, and spillage at loading and unloading facilities in ports. Coal is a heterogeneous material and varies widely in texture and content of water, carbon, organic compounds and mineral impu- rities. Among its constituents are such potential toxicants as polycyclic aromatic hydrocarbons (PAHs) and trace metals/metalloids. When present in marine environments in sufficient quantities, coal will have physical effects on organisms similar to those of other suspended or deposited sediments. These include abrasion, smothering, alteration of sediment texture and stability, reduced availability of light, and clogging of respiratory and feeding organs. Such effects are relatively well documented. Toxic effects of contaminants in coal are much less evident, highly dependent on coal composition, and in many situations their bioavailability appears to be low. Nevertheless, the presence of contaminants at high concentrations in some coal leachates and the demonstration of biological uptake of coal-derived contaminants in a small number of studies suggest that this may not always be the case, a situation that might be expected from coal's heterogeneous chemical composition. There are surprisingly few studies in the marine environment focusing on toxic effects of contaminants of coal at the organism, population or assemblage levels, but the limited evidence indicating bioavailability under certain circumstances suggests that more detailed studies would be justified.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86791366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-06-24DOI: 10.1201/9781420037449-10
N. Streftaris, A. Zenetos, E. Papathanassiou
The introduction of non-indigenous species (NIS) across the major European seas is a dynamic non-stop process. Up to September 2004, 851 NIS (the majority being zoobenthic organ- isms) have been reported in European marine and brackish waters, the majority during the 1960s and 1970s. The Mediterranean is by far the major recipient of exotic species with an average of one introduction every 4 wk over the past 5 yr. Of the 25 species recorded in 2004, 23 were reported in the Mediterranean and only two in the Baltic. The most updated patterns and trends in the rate, mode of introduction and establishment success of introductions were examined, revealing a process similar to introductions in other parts of the world, but with the uniqueness of migrants through the Suez Canal into the Mediterranean (Lessepsian or Erythrean migration). Shipping appears to be the major vector of introduction (excluding the Lessepsian migration). Aquaculture is also an important vector with target species outnumbered by those introduced unintentionally. More than half of immigrants have been estab- lished in at least one regional sea. However, for a significant part of the introductions both the establishment success and mode of introduction remain unknown. Finally, comparing trends across taxa and seas is not as accurate as could have been wished because there are differences in the spatial and taxonomic effort in the study of NIS. These differences lead to the conclusion that the number of NIS remains an underestimate, calling for continuous updating and systematic research.
{"title":"Globalisation in marine ecosystems: the story of non-indigenous marine species across European seas","authors":"N. Streftaris, A. Zenetos, E. Papathanassiou","doi":"10.1201/9781420037449-10","DOIUrl":"https://doi.org/10.1201/9781420037449-10","url":null,"abstract":"The introduction of non-indigenous species (NIS) across the major European seas is a dynamic non-stop process. Up to September 2004, 851 NIS (the majority being zoobenthic organ- isms) have been reported in European marine and brackish waters, the majority during the 1960s and 1970s. The Mediterranean is by far the major recipient of exotic species with an average of one introduction every 4 wk over the past 5 yr. Of the 25 species recorded in 2004, 23 were reported in the Mediterranean and only two in the Baltic. The most updated patterns and trends in the rate, mode of introduction and establishment success of introductions were examined, revealing a process similar to introductions in other parts of the world, but with the uniqueness of migrants through the Suez Canal into the Mediterranean (Lessepsian or Erythrean migration). Shipping appears to be the major vector of introduction (excluding the Lessepsian migration). Aquaculture is also an important vector with target species outnumbered by those introduced unintentionally. More than half of immigrants have been estab- lished in at least one regional sea. However, for a significant part of the introductions both the establishment success and mode of introduction remain unknown. Finally, comparing trends across taxa and seas is not as accurate as could have been wished because there are differences in the spatial and taxonomic effort in the study of NIS. These differences lead to the conclusion that the number of NIS remains an underestimate, calling for continuous updating and systematic research.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85007036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-06-24DOI: 10.1201/9781420037449-11
E. Moland, J. V. Eagle, G. Jones
This review examines the literature on mimicry in coral reef fishes and evaluates the prevalence of mimicry in different taxa, its ecological consequences and postulated modes of evolution. Mimicry appears to be a widespread and common phenomenon in coral reef fishes, with approximately 60 reported cases. Although many are largely anecdotal accounts based on colour resemblance, recent quantitative comparisons and experimental manipulations have confirmed that many do represent mimic-model relationships. The distribution of mimics and models among reef fish families appears largely serendipitous. Mimics are most common in the families Blenniidae, Serranidae and Apogonidae and models in the families Pomacentridae, Blenniidae and Labridae. Mimics and model species usually represent less than 10% of species within families, although imperfect forms of mimicry are likely to have been underestimated. Mimicry appears to be particularly important during juvenile stages, with 28% of mimic species losing their mimic colouration when they outgrow their models. All cases of mimicry support predictions that mimics are rare relative to their models. Furthermore, the abundance of mimics in different areas may increase in proportion to model abundance. The spatial distribution of mimics appears to be limited by that of their model species, although some change models in different habitats or in different parts of their range. Many mimics live in close association with their models, and both foraging advantages and predator avoidance have been experimentally demonstrated. Aggressive mimicry appears to be the most prevalent type of mimicry overall in coral reef fishes, constituting 48% of all cases reported to date, followed by Batesian (40%) and social mimicry (12%). Mullerian mimicry seems to be rare, although it may contribute to the mimetic complexes involving members of the blenniid tribe Nemophini. However, these traditional classifications are too simplistic for reef fishes because both foraging advantages and predator avoidance can apply in a single mimetic relationship, and their relative importance has not been evaluated. Preliminary data suggest a high degree of phenotypic plasticity in mimetic colouration and little genetic differentiation among different mimics of the same species. Overall, the review highlights the many significant steps that need to be taken towards a more complete understanding of the ecological and evolutionary significance of mimicry in coral reef fishes.
{"title":"Ecology and evolution of mimicry in coral reef fishes","authors":"E. Moland, J. V. Eagle, G. Jones","doi":"10.1201/9781420037449-11","DOIUrl":"https://doi.org/10.1201/9781420037449-11","url":null,"abstract":"This review examines the literature on mimicry in coral reef fishes and evaluates the prevalence of mimicry in different taxa, its ecological consequences and postulated modes of evolution. Mimicry appears to be a widespread and common phenomenon in coral reef fishes, with approximately 60 reported cases. Although many are largely anecdotal accounts based on colour resemblance, recent quantitative comparisons and experimental manipulations have confirmed that many do represent mimic-model relationships. The distribution of mimics and models among reef fish families appears largely serendipitous. Mimics are most common in the families Blenniidae, Serranidae and Apogonidae and models in the families Pomacentridae, Blenniidae and Labridae. Mimics and model species usually represent less than 10% of species within families, although imperfect forms of mimicry are likely to have been underestimated. Mimicry appears to be particularly important during juvenile stages, with 28% of mimic species losing their mimic colouration when they outgrow their models. All cases of mimicry support predictions that mimics are rare relative to their models. Furthermore, the abundance of mimics in different areas may increase in proportion to model abundance. The spatial distribution of mimics appears to be limited by that of their model species, although some change models in different habitats or in different parts of their range. Many mimics live in close association with their models, and both foraging advantages and predator avoidance have been experimentally demonstrated. Aggressive mimicry appears to be the most prevalent type of mimicry overall in coral reef fishes, constituting 48% of all cases reported to date, followed by Batesian (40%) and social mimicry (12%). Mullerian mimicry seems to be rare, although it may contribute to the mimetic complexes involving members of the blenniid tribe Nemophini. However, these traditional classifications are too simplistic for reef fishes because both foraging advantages and predator avoidance can apply in a single mimetic relationship, and their relative importance has not been evaluated. Preliminary data suggest a high degree of phenotypic plasticity in mimetic colouration and little genetic differentiation among different mimics of the same species. Overall, the review highlights the many significant steps that need to be taken towards a more complete understanding of the ecological and evolutionary significance of mimicry in coral reef fishes.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72572070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pioneering deep-sea surveys established that the fauna of the continental margins is zoned in the sense that individual species and assemblages occupy restricted depth bands. It has been speculated that the causes of this wide-spread pattern might involve cold temperatures, high pressures and limited food availability. Increased sampling over the past two decades has confirmed the global presence of depth zonation. Well-defined zonation in the cold polar oceans and the warm Mediterranean indicate that temperature per se may be of less importance on ecological timescales than originally proposed. Strong alternatives are range restriction by pressure and food availability. Understanding of pressure physiology has advanced greatly, and it is to be expected that all deep organisms possess some form of genetic adaptation for pressure tolerance. Since high pressure and low temperatures affect membrane and enzyme systems similarly, combined piezo-thermal thresholds may limit depth ranges. There is a negative, exponential gradient of food availability caused by the decrease in labile carbon influx to bottom. The TROX model linking carbon influx with interstitial oxygen levels has been successful in explaining deep distributions of benthic Foraminifera and may be more broadly applicable. Current efforts to relate metazoan ranges to food availability are, however, hindered by limited understanding of how organisms recognise and utilise the nutritious content of detritus. Thus, the exact controls of depth zonation remain conjectural. Zonation studies are gaining in importance due to the increasing availability of deep fauna databases and the need to establish regulatory boundaries. Future studies may benefit from a growing body of biogeographic theory, especially the understanding of bounded domains. It is proposed that continental slope fauna may be more effectively studied if viewed as the overlapping of three components: species extending down from the shelf, species extending up from the abyss and species truly restricted to the slope.
{"title":"Zonation of deep biota on continental margins","authors":"R. Carney","doi":"10.1201/9781420037449-8","DOIUrl":"https://doi.org/10.1201/9781420037449-8","url":null,"abstract":"Pioneering deep-sea surveys established that the fauna of the continental margins is zoned in the sense that individual species and assemblages occupy restricted depth bands. It has been speculated that the causes of this wide-spread pattern might involve cold temperatures, high pressures and limited food availability. Increased sampling over the past two decades has confirmed the global presence of depth zonation. Well-defined zonation in the cold polar oceans and the warm Mediterranean indicate that temperature per se may be of less importance on ecological timescales than originally proposed. Strong alternatives are range restriction by pressure and food availability. Understanding of pressure physiology has advanced greatly, and it is to be expected that all deep organisms possess some form of genetic adaptation for pressure tolerance. Since high pressure and low temperatures affect membrane and enzyme systems similarly, combined piezo-thermal thresholds may limit depth ranges. There is a negative, exponential gradient of food availability caused by the decrease in labile carbon influx to bottom. The TROX model linking carbon influx with interstitial oxygen levels has been successful in explaining deep distributions of benthic Foraminifera and may be more broadly applicable. Current efforts to relate metazoan ranges to food availability are, however, hindered by limited understanding of how organisms recognise and utilise the nutritious content of detritus. Thus, the exact controls of depth zonation remain conjectural. Zonation studies are gaining in importance due to the increasing availability of deep fauna databases and the need to establish regulatory boundaries. Future studies may benefit from a growing body of biogeographic theory, especially the understanding of bounded domains. It is proposed that continental slope fauna may be more effectively studied if viewed as the overlapping of three components: species extending down from the shelf, species extending up from the abyss and species truly restricted to the slope.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86320766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review examines a large marine continental shelf ecosystem (the Eastern Scotian Shelf of Canada (ESS)), that has undergone dramatic hysteresis-like changes in the recent past, using a pragmatic approach that combines empirical, reductionist and holistic methods based on the integrated analysis of 55 primary and secondary biotic, abiotic, and human variables over a 43-year period. The integrated analysis reveals that the ESS ecosystem has changed states, i.e., a 'regime shift' from a community dominated by large-bodied demersal fish to one dominated by small demersal and pelagic -fish species and benthic macroinvertebrates. A dynamic interplay between ocean physics, biology and exploitation presents a more realistic casual scenario than any single component hypothesis such as fishing pressure alone. The forces contributing to the stability of the alternate state include both top-down processes involving strong trophic interactions initiated at the apex predator level and bottom-up processes involving energy flow and nutrient cycling that have fundamentally altered the matter and energy flow patterns in the ESS ecosystem. It is suggested that the ESS has been literally 'devolving' when viewed from the perspective of the theory of ecological succession. Further, higher-order variables are identified as early warning indicators, sensitive to the underlying structural and functional changes that occurred on the ESS ecosystem. They have been determined for an adjacent system where systemic changes have not yet been observed and predict a potential collapse within a decade. Integrated assessment of ecosystems is a great challenge and their management requires comprehension of ecological systems. Description alone is not sufficient to allow comprehension, especially if 'information overload' (the disconnect between system description and system comprehension) is to be avoided and meaningful insights and strategies are to emerge. Reductionistic analysis involves the dissection and identification of key processes or feedback mechanisms likely to be operative in an ecological system. However, value cannot be ascertained from variations in processes, as a directionality of time does not exist in such a perspective. In fact, the approach has accelerated the information overload experienced by all stakeholders. Holistic approaches are being increasingly used to aid in the valuation of ecological systems as the directionality of time is made explicit in this perspective. It is suggested that integrated assessment requires not only the integration of descriptive information, but also the integration of our perception of ecological systems as being both a whole and a part.
{"title":"Integrated assessment of a large marine ecosystem : A case study of the devolution of the eastern scotian shelf, Canada","authors":"Jae S. Choi, K. Frank, B. Petrie, W. C. Leggett","doi":"10.1201/9781420037449-4","DOIUrl":"https://doi.org/10.1201/9781420037449-4","url":null,"abstract":"This review examines a large marine continental shelf ecosystem (the Eastern Scotian Shelf of Canada (ESS)), that has undergone dramatic hysteresis-like changes in the recent past, using a pragmatic approach that combines empirical, reductionist and holistic methods based on the integrated analysis of 55 primary and secondary biotic, abiotic, and human variables over a 43-year period. The integrated analysis reveals that the ESS ecosystem has changed states, i.e., a 'regime shift' from a community dominated by large-bodied demersal fish to one dominated by small demersal and pelagic -fish species and benthic macroinvertebrates. A dynamic interplay between ocean physics, biology and exploitation presents a more realistic casual scenario than any single component hypothesis such as fishing pressure alone. The forces contributing to the stability of the alternate state include both top-down processes involving strong trophic interactions initiated at the apex predator level and bottom-up processes involving energy flow and nutrient cycling that have fundamentally altered the matter and energy flow patterns in the ESS ecosystem. It is suggested that the ESS has been literally 'devolving' when viewed from the perspective of the theory of ecological succession. Further, higher-order variables are identified as early warning indicators, sensitive to the underlying structural and functional changes that occurred on the ESS ecosystem. They have been determined for an adjacent system where systemic changes have not yet been observed and predict a potential collapse within a decade. Integrated assessment of ecosystems is a great challenge and their management requires comprehension of ecological systems. Description alone is not sufficient to allow comprehension, especially if 'information overload' (the disconnect between system description and system comprehension) is to be avoided and meaningful insights and strategies are to emerge. Reductionistic analysis involves the dissection and identification of key processes or feedback mechanisms likely to be operative in an ecological system. However, value cannot be ascertained from variations in processes, as a directionality of time does not exist in such a perspective. In fact, the approach has accelerated the information overload experienced by all stakeholders. Holistic approaches are being increasingly used to aid in the valuation of ecological systems as the directionality of time is made explicit in this perspective. It is suggested that integrated assessment requires not only the integration of descriptive information, but also the integration of our perception of ecological systems as being both a whole and a part.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82383788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper examines the burrow environment of thalassinidean shrimps (commonly called mud shrimps), drawing on our experience of a range of U.K. species with differing lifestyles (Calocaris macandreae, Jaxea nocturna, Callianassa subterranea, Upogebia stellata, U. deltaura) and makes comparisons with published work on a diversity of species elsewhere. Information on thalassinidean ecology and burrow structure is used, together with measurements of physicochemical conditions, to illustrate the range of conditions which thalassinideans may experience within their burrows, where conditions may be potentially hostile (hypoxic, hypercapnic, high in sulphide). Behavioural and physiological adaptations to the thalassinidean burrow-dwelling lifestyle are considered, particularly those that relate to survival in hypoxic and sulphidic conditions. Mud shrimps actively irrigate their burrows by pleopod beating, this often being intermittent: burrow irrigation is most intense in suspension-feeding species. Passive irrigation of burrows may also occur, generated by current flow at the plane of the mud surface. Thalassinideans spend progressively more time irrigating their burrows during hypoxia, but such activity is often not pronounced until the oxygen partial pressure of the water has declined to low levels. The shrimps are highly tolerant of hypoxia and are able to maintain aerobic metabolism down to very low oxygen partial pressures. Burrow water is pumped across the gills by the scaphognathites and their activity increases under hypoxia, thus maintaining a supply of oxygen to the gills. Rates of oxygen consumption are lower in thalassinideans than in non-burrowing decapods. The haemocyanins of thalassinideans have high oxygen affinities and have moderate Bohr values that facilitate oxygen uptake during hypoxia. When aerobic respiration can no longer be maintained, thalassinideans resort to anaerobic respiration and show a high tolerance of anoxia, with some species being able to survive anoxic conditions for several days. Thalassinideans may encounter high concentrations of sulphide as a result of their fossorial lifestyle and have a high tolerance to sulphide exposure, oxidising sulphide to thiosulphate. Relationships are explored between mud-shrimp activity, including feeding, burrow structure and burrow physicochemistry. For most mud shrimps the burrow is the feeding environment. Food is extracted either from the burrow water, or the burrow wall, or from macroscopic material accumulated in the burrow lumen. Microorganisms are important in decomposition processes within the burrow, in burrow geochemistry and in mud-shrimp nutrition. Interrelationships between the burrow environment and the wider environment are also considered. The irrigatory activity of mud shrimps not only introduces oxygenated conditions into the sediment column, but also exports nutrients to the overlying water. Burrow walls may act as sinks for trace metals, radionuclides and other
本文研究了海虾目虾(通常称为泥虾)的洞穴环境，借鉴了我们对一系列生活方式不同的英国物种(Calocaris macandreae, Jaxea nocturna, Callianassa subterranea, Upogebia stellata, U. deltaura)的经验，并与其他地方发表的物种多样性研究成果进行了比较。关于海地螺的生态和洞穴结构的信息，以及物理化学条件的测量，被用来说明海地螺在洞穴中可能经历的条件范围，这些条件可能是潜在的敌对条件(缺氧、高碳酸、高硫化物)。考虑了对海腹鱼穴居生活方式的行为和生理适应，特别是那些与缺氧和含硫条件下的生存有关的适应。泥虾通过多足类动物的拍打积极地灌溉它们的洞穴，这通常是间歇性的:在悬浮捕食的物种中，洞穴灌溉最为强烈。也可能发生由泥浆表面平面上的水流产生的洞穴被动灌溉。在缺氧的情况下，thalassinidea花越来越多的时间灌溉它们的洞穴，但这种活动通常在水的氧分压下降到很低的水平时才会出现。虾对缺氧具有高度的耐受性，能够在非常低的氧分压下维持有氧代谢。洞穴里的水被舟石抽过鳃，在缺氧的情况下，它们的活动会增加，从而维持鳃的氧气供应。海鞘动物的耗氧率比非穴居十足动物低。thalassinideans的血青素具有高的氧亲和性和中等的玻尔值，有助于缺氧时的氧吸收。当有氧呼吸不能再维持时，海鞘类动物就会转向无氧呼吸，并表现出对缺氧的高耐受性，有些物种能够在缺氧条件下存活数天。由于其化石生活方式，Thalassinideans可能会遇到高浓度的硫化物，并且对硫化物暴露具有很高的耐受性，将硫化物氧化为硫硫酸盐。探讨了泥虾活动之间的关系，包括取食、洞穴结构和洞穴物理化学。对大多数泥虾来说，洞穴是它们的觅食环境。食物要么从地穴水中提取，要么从地穴壁中提取，要么从地穴腔中积累的宏观物质中提取。微生物在地穴分解过程、地穴地球化学和泥虾营养中起着重要作用。还考虑了洞穴环境和更广阔环境之间的相互关系。泥虾的灌溉活动不仅将含氧条件引入沉积物柱，而且还将营养物质输出到上覆水。地穴壁可作为微量金属、放射性核素和其他化学物质的汇，是成岩过程的重要位点。各种穴居亲缘动物与thalassinideans共享穴居环境，并简要讨论了这些关联的一些含义。在整个过程中，确定了需要进一步研究的各种主题。
{"title":"Aspects of the physiology, biology and ecology of thalassinidean shrimps in relation to their burrow environment","authors":"R. Taylor","doi":"10.1201/9781420037449-7","DOIUrl":"https://doi.org/10.1201/9781420037449-7","url":null,"abstract":"This paper examines the burrow environment of thalassinidean shrimps (commonly called mud shrimps), drawing on our experience of a range of U.K. species with differing lifestyles (Calocaris macandreae, Jaxea nocturna, Callianassa subterranea, Upogebia stellata, U. deltaura) and makes comparisons with published work on a diversity of species elsewhere. Information on thalassinidean ecology and burrow structure is used, together with measurements of physicochemical conditions, to illustrate the range of conditions which thalassinideans may experience within their burrows, where conditions may be potentially hostile (hypoxic, hypercapnic, high in sulphide). Behavioural and physiological adaptations to the thalassinidean burrow-dwelling lifestyle are considered, particularly those that relate to survival in hypoxic and sulphidic conditions. Mud shrimps actively irrigate their burrows by pleopod beating, this often being intermittent: burrow irrigation is most intense in suspension-feeding species. Passive irrigation of burrows may also occur, generated by current flow at the plane of the mud surface. Thalassinideans spend progressively more time irrigating their burrows during hypoxia, but such activity is often not pronounced until the oxygen partial pressure of the water has declined to low levels. The shrimps are highly tolerant of hypoxia and are able to maintain aerobic metabolism down to very low oxygen partial pressures. Burrow water is pumped across the gills by the scaphognathites and their activity increases under hypoxia, thus maintaining a supply of oxygen to the gills. Rates of oxygen consumption are lower in thalassinideans than in non-burrowing decapods. The haemocyanins of thalassinideans have high oxygen affinities and have moderate Bohr values that facilitate oxygen uptake during hypoxia. When aerobic respiration can no longer be maintained, thalassinideans resort to anaerobic respiration and show a high tolerance of anoxia, with some species being able to survive anoxic conditions for several days. Thalassinideans may encounter high concentrations of sulphide as a result of their fossorial lifestyle and have a high tolerance to sulphide exposure, oxidising sulphide to thiosulphate. Relationships are explored between mud-shrimp activity, including feeding, burrow structure and burrow physicochemistry. For most mud shrimps the burrow is the feeding environment. Food is extracted either from the burrow water, or the burrow wall, or from macroscopic material accumulated in the burrow lumen. Microorganisms are important in decomposition processes within the burrow, in burrow geochemistry and in mud-shrimp nutrition. Interrelationships between the burrow environment and the wider environment are also considered. The irrigatory activity of mud shrimps not only introduces oxygenated conditions into the sediment column, but also exports nutrients to the overlying water. Burrow walls may act as sinks for trace metals, radionuclides and other","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82903589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafting of marine and terrestrial organisms has been reported from a variety of substrata and from all major oceans of the world. Herein we present information on common rafting organisms and on ecological interactions during rafting voyages. An extensive literature review revealed a total of 1206 organisms, for which rafting was confirmed or inferred based on distributional or genetic evidence. Rafting organisms comprised cyanobacteria, algae, protists, invertebrates from most marine but also terrestrial phyla, and even a few terrestrial vertebrates. Marine hydrozoans, bryozoans, crustaceans and gastropods were the most common taxa that had been observed rafting. All major feeding types were represented among rafters, being dominated by grazing/boring and suspension-feeding organisms, which occurred on all floating substrata. Besides these principal trophic groups, predators/scavengers and detritus-feeders were also reported. Motility of rafting organisms was highest on macroalgae and lowest on abiotic substrata such as plastics and volcanic pumice. Important trends were revealed for the reproductive biology of rafting organisms. A high proportion of clonal organisms (Cnidaria and Bryozoa) featured asexual reproduction, often in combination with sexual reproduction. Almost all rafting organisms have internal fertilisation, which may be due to the fact that gamete concentrations in the rafting environment are too low for successful fertilisation of external fertilisers. Following fertilisation, many rafting organisms incubate their offspring in/on their body or deposit embryos in egg masses on rafts. Local recruitment, where offspring settle in the immediate vicinity of parents, is considered an important advantage for establishing persistent local populations on a raft, or in new habitats. Some organisms are obligate rafters, spending their entire life cycle on a raft, but the large majority of reported rafters are considered facultative rafters. These organisms typically live in benthic (or terrestrial) habitats, but may become dispersed while being confined to a floating item. Substratum characteristics (complexity, surface, size) have important effects on the composition of the rafting community. While at sea, ecological interactions (facilitation, competition, predation) contribute to the community succession on rafts. Organisms capable to compete for and exploit resources on a raft (space and food) will be able to persist throughout community succession. The duration of rafting voyages is closely related to rafting distances, which may cover various geographical scales. In chronological order, three features of an organism gain in importance during rafting, these being ability to (1) hold onto floating items, (2) establish and compete successfully, and (3) develop persistent local populations during a long voyage. Small organisms that do not feed on their floating substratum and with asexual reproduction or direct development combine all th
{"title":"The Ecology of Rafting in the Marine Environment. II. The Rafting Organisms and Community","authors":"M. Thiel, L. Gutow","doi":"10.1201/9781420037449-9","DOIUrl":"https://doi.org/10.1201/9781420037449-9","url":null,"abstract":"Rafting of marine and terrestrial organisms has been reported from a variety of substrata and from all major oceans of the world. Herein we present information on common rafting organisms and on ecological interactions during rafting voyages. An extensive literature review revealed a total of 1206 organisms, for which rafting was confirmed or inferred based on distributional or genetic evidence. Rafting organisms comprised cyanobacteria, algae, protists, invertebrates from most marine but also terrestrial phyla, and even a few terrestrial vertebrates. Marine hydrozoans, bryozoans, crustaceans and gastropods were the most common taxa that had been observed rafting. All major feeding types were represented among rafters, being dominated by grazing/boring and suspension-feeding organisms, which occurred on all floating substrata. Besides these principal trophic groups, predators/scavengers and detritus-feeders were also reported. Motility of rafting organisms was highest on macroalgae and lowest on abiotic substrata such as plastics and volcanic pumice. Important trends were revealed for the reproductive biology of rafting organisms. A high proportion of clonal organisms (Cnidaria and Bryozoa) featured asexual reproduction, often in combination with sexual reproduction. Almost all rafting organisms have internal fertilisation, which may be due to the fact that gamete concentrations in the rafting environment are too low for successful fertilisation of external fertilisers. Following fertilisation, many rafting organisms incubate their offspring in/on their body or deposit embryos in egg masses on rafts. Local recruitment, where offspring settle in the immediate vicinity of parents, is considered an important advantage for establishing persistent local populations on a raft, or in new habitats. Some organisms are obligate rafters, spending their entire life cycle on a raft, but the large majority of reported rafters are considered facultative rafters. These organisms typically live in benthic (or terrestrial) habitats, but may become dispersed while being confined to a floating item. Substratum characteristics (complexity, surface, size) have important effects on the composition of the rafting community. While at sea, ecological interactions (facilitation, competition, predation) contribute to the community succession on rafts. Organisms capable to compete for and exploit resources on a raft (space and food) will be able to persist throughout community succession. The duration of rafting voyages is closely related to rafting distances, which may cover various geographical scales. In chronological order, three features of an organism gain in importance during rafting, these being ability to (1) hold onto floating items, (2) establish and compete successfully, and (3) develop persistent local populations during a long voyage. Small organisms that do not feed on their floating substratum and with asexual reproduction or direct development combine all th","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90094835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Man-made structures deployed either deliberately or accidentally into the sea are subject to levels of biofouling. The resultant communities are usually dominated by sessile marine invertebrates that tend to utilize suspension-feeding for nutritional gain from the water column. Not all suspension-feeders are filtration-feeders but in general terms a large suspension-feeding community will provide varying scales of water filtration. The potential for utilizing some form of in-water biofiltration in association with localised organic enrichment has long been suggested but with few quantitative estimates of probable efficacy. The major taxa that are likely to be relevant to the process of biofiltration are discussed in relation to the functional classification of suspension-feeders. In order to generate estimates of biofiltration potential, activity rates of the major functional and taxonomic groups of suspension-feeders are derived through a review of the general mode of suspension-feeding, the predominant food sources with the size range of particles retained and individual suspension-feeding rates that are scaled up to the population level. However, any naturally occurring fouling community will consist of a number of species and so estimates of multispecies suspension-feeding, interspecific interactions, rates of biodeposition and nutrient release are derived. The rates and densities of biofouling are dependent of the abiotic and biotic characteristics of the receiving environment and the types of materials used in the provided substrate. The factors affecting biofouling are discussed in relation to existing examples of artificial structures found in European waters or waters of relevance to Europe. In-water outputs from finfish mariculture provide examples of localised point sources of organic enrichment that could benefit from the associated deployments of biological filters. Using estimates of filtration clearance rates combined with the major taxa thought most likely to dominate any filtering community, probable scales of biofiltration required in order to influence the levels of mariculture discharges are calculated. Although, in theory, biofilters in open system finfish mariculture may reduce the levels of organic impact, the scale of intervention required to make a significant effect would probably exceed any form of economic viability.
{"title":"'Biofiltration and biofouling on artificial structures in Europe: the potential for mitigating organic impacts","authors":"D. Hughes, E. Cook, M. Sayer","doi":"10.1201/9781420037449-6","DOIUrl":"https://doi.org/10.1201/9781420037449-6","url":null,"abstract":"Man-made structures deployed either deliberately or accidentally into the sea are subject to levels of biofouling. The resultant communities are usually dominated by sessile marine invertebrates that tend to utilize suspension-feeding for nutritional gain from the water column. Not all suspension-feeders are filtration-feeders but in general terms a large suspension-feeding community will provide varying scales of water filtration. The potential for utilizing some form of in-water biofiltration in association with localised organic enrichment has long been suggested but with few quantitative estimates of probable efficacy. The major taxa that are likely to be relevant to the process of biofiltration are discussed in relation to the functional classification of suspension-feeders. In order to generate estimates of biofiltration potential, activity rates of the major functional and taxonomic groups of suspension-feeders are derived through a review of the general mode of suspension-feeding, the predominant food sources with the size range of particles retained and individual suspension-feeding rates that are scaled up to the population level. However, any naturally occurring fouling community will consist of a number of species and so estimates of multispecies suspension-feeding, interspecific interactions, rates of biodeposition and nutrient release are derived. The rates and densities of biofouling are dependent of the abiotic and biotic characteristics of the receiving environment and the types of materials used in the provided substrate. The factors affecting biofouling are discussed in relation to existing examples of artificial structures found in European waters or waters of relevance to Europe. In-water outputs from finfish mariculture provide examples of localised point sources of organic enrichment that could benefit from the associated deployments of biological filters. Using estimates of filtration clearance rates combined with the major taxa thought most likely to dominate any filtering community, probable scales of biofiltration required in order to influence the levels of mariculture discharges are calculated. Although, in theory, biofilters in open system finfish mariculture may reduce the levels of organic impact, the scale of intervention required to make a significant effect would probably exceed any form of economic viability.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87940518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cold seeps occur in geologically active and passive continental margins, where pore waters enriched in methane are forced upward through the sediments by pressure gradients. The advective supply of methane leads to dense microbial communities with high metabolic rates. Anaerobic methane oxidation presumably coupled to sulphate reduction facilitates formation of carbonates and, in many places, generates extremely high concentrations of hydrogen sulphide in pore waters. Increased food supply, availability of hard substratum and high concentrations of methane and sulphide supplied to free-living and symbiotic bacteria provide the basis for the complex ecosystems found at these sites. This review examines the structures of animal communities in seep sediments and how they are shaped by hydrologic, geochemical and microbial processes. The full size range of biota is addressed but emphasis is on the mid-size sediment-dwelling infauna (foraminiferans, metazoan meiofauna and macrofauna), which have received less attention than megafauna or microbes. Megafaunal biomass at seeps, which far exceeds that of surrounding non-seep sediments, is dominated by bivalves (mytilids, vesicomyids, lucinids and thyasirids) and vestimentiferan tube worms, with pogonophorans, cladorhizid sponges, gastropods and shrimp sometimes abundant. In contrast, seep sediments at shelf and upper slope depths have infaunal densities that often differ very little from those in ambient sediments. At greater depths, seep infauna exhibit enhanced densities, modified composition and reduced diversity relative to background sediments. Dorvilleid, hesionid and ampharetid polychaetes, nematodes, and calcareous foraminiferans are dominant. There is extensive spatial heterogeneity of microbes and higher organisms at seeps. Specialized infaunal communities are associated with different seep habitats (microbial mats, clam beds, mussel beds and tube worms aggregations) and with different vertical zones in the sediment. Whereas fluid flow and associated porewater properties, in particular sulphide concentration, appear to regulate the distribution, physiological adaptations and sometimes behaviour of many seep biota, sometimes the reverse is true. Animal-microbe interactions at seeps are complex and involve symbioses, heterotrophic nutrition, geochemical feedbacks and habitat structure. Nutrition of seep fauna varies, with thiotrophic and methanotrophic symbiotic bacteria fueling most of the megafaunal forms but macrofauna and most meiofauna are mainly heterotrophic. Macrofaunal food sources are largely photosynthesis-based at shallower seeps but reflect carbon fixation by chemosynthesis and considerable incorporation of methane-derived C at deeper seeps. Export of seep carbon appears to be highly localized based on limited studies in the Gulf of Mexico. Seep ecosystems remain one of the ocean's true frontiers. Seep sediments represent some of the most extreme marine conditions and offer unbounded
{"title":"ECOLOGY OF COLD SEEP SEDIMENTS: INTERACTIONS OF FAUNA WITH FLOW, CHEMISTRY AND MICROBES","authors":"L. Levin","doi":"10.1201/9781420037449-3","DOIUrl":"https://doi.org/10.1201/9781420037449-3","url":null,"abstract":"Cold seeps occur in geologically active and passive continental margins, where pore waters enriched in methane are forced upward through the sediments by pressure gradients. The advective supply of methane leads to dense microbial communities with high metabolic rates. Anaerobic methane oxidation presumably coupled to sulphate reduction facilitates formation of carbonates and, in many places, generates extremely high concentrations of hydrogen sulphide in pore waters. Increased food supply, availability of hard substratum and high concentrations of methane and sulphide supplied to free-living and symbiotic bacteria provide the basis for the complex ecosystems found at these sites. This review examines the structures of animal communities in seep sediments and how they are shaped by hydrologic, geochemical and microbial processes. The full size range of biota is addressed but emphasis is on the mid-size sediment-dwelling infauna (foraminiferans, metazoan meiofauna and macrofauna), which have received less attention than megafauna or microbes. Megafaunal biomass at seeps, which far exceeds that of surrounding non-seep sediments, is dominated by bivalves (mytilids, vesicomyids, lucinids and thyasirids) and vestimentiferan tube worms, with pogonophorans, cladorhizid sponges, gastropods and shrimp sometimes abundant. In contrast, seep sediments at shelf and upper slope depths have infaunal densities that often differ very little from those in ambient sediments. At greater depths, seep infauna exhibit enhanced densities, modified composition and reduced diversity relative to background sediments. Dorvilleid, hesionid and ampharetid polychaetes, nematodes, and calcareous foraminiferans are dominant. There is extensive spatial heterogeneity of microbes and higher organisms at seeps. Specialized infaunal communities are associated with different seep habitats (microbial mats, clam beds, mussel beds and tube worms aggregations) and with different vertical zones in the sediment. Whereas fluid flow and associated porewater properties, in particular sulphide concentration, appear to regulate the distribution, physiological adaptations and sometimes behaviour of many seep biota, sometimes the reverse is true. Animal-microbe interactions at seeps are complex and involve symbioses, heterotrophic nutrition, geochemical feedbacks and habitat structure. Nutrition of seep fauna varies, with thiotrophic and methanotrophic symbiotic bacteria fueling most of the megafaunal forms but macrofauna and most meiofauna are mainly heterotrophic. Macrofaunal food sources are largely photosynthesis-based at shallower seeps but reflect carbon fixation by chemosynthesis and considerable incorporation of methane-derived C at deeper seeps. Export of seep carbon appears to be highly localized based on limited studies in the Gulf of Mexico. Seep ecosystems remain one of the ocean's true frontiers. Seep sediments represent some of the most extreme marine conditions and offer unbounded ","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84752478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-01-01DOI: 10.1201/9780203507810.ch3
R. Wotton
Exopolymers (EPS) are exuded by single-celled and multicellular organisms. They consist mainly of carbohydrates that hydrate on contact with water and EPS are absorbent and often thixotropic. These properties result in a large number of uses: for attachments, as an aid to flotation, in locomotion, in feeding, for building structures, as the basis of biofilms, for protection against a number of harsh environmental conditions, as a barrier against attack by pathogens, parasitic organisms and predators, and in communication. In addition, EPS are found free in the water column where they form readily into gels and then into larger aggregates that are foci for biological activity and the breakdown of organic matter to provide nutrients. EPS are truly ubiquitous and are essential to the functioning of all aquatic ecosystems.
{"title":"The essential role of exopolymers (EPS) in aquatic systems","authors":"R. Wotton","doi":"10.1201/9780203507810.ch3","DOIUrl":"https://doi.org/10.1201/9780203507810.ch3","url":null,"abstract":"Exopolymers (EPS) are exuded by single-celled and multicellular organisms. They consist mainly of carbohydrates that hydrate on contact with water and EPS are absorbent and often thixotropic. These properties result in a large number of uses: for attachments, as an aid to flotation, in locomotion, in feeding, for building structures, as the basis of biofilms, for protection against a number of harsh environmental conditions, as a barrier against attack by pathogens, parasitic organisms and predators, and in communication. In addition, EPS are found free in the water column where they form readily into gels and then into larger aggregates that are foci for biological activity and the breakdown of organic matter to provide nutrients. EPS are truly ubiquitous and are essential to the functioning of all aquatic ecosystems.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89602907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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