This review aims to update and extend the synopsis by Tiews (1970) on the biology and fisheries of Crangon crangon (L.). Its wide distributional range along the European coast from the White Sea to Morocco within the Atlantic and throughout the Mediterranean and Black Seas reflects the capability of C. crangon to cope with a wide range of temperature and salinity conditions and is further explained by its migratory capacity. Present knowledge suggests that the limiting factor at the northern cold water edge of its distribution is formed by egg and larval development and at the southern warm water edge by maintenance costs. No information is available about the genetic population structure, but patterns in isoenzymes and in morphometric characters indicate the existence of various subpopulations. Over its distributional range, especially along the north Atlantic coast, clear trends in life-history parameters are observed, most likely reflecting temperature conditions. Due to its generally high abundance, the common shrimp forms a key component in the functioning of coastal shallow ecosystems; however, it is unclear whether the population dynamics of the species is subject to top-down or bottom-up control. On the one hand, C. crangon is an opportunistic feeder with a wide prey spectrum though it remains to be solved whether growth conditions are optimal and only determined by prevailing water temperatures, or whether food limitation is a regulating mechanism. On the other hand, top-down control by predation cannot be excluded since C. crangon is also an important food item for a variety of predators, especially fish species. There are strong indications that predation by C. crangon might regulate some of their prey species. Topics for further research include (1) the analysis of the genetic population structure by means of molecular tools; (2) the study of growth and reproduction in relation to latitude; (3) the application of dynamic energy budgets for the analysis in terms of energy of the various trade-offs, including growth versus reproduction; and (4) the analysis of the mechanisms determining recruitment, especially whether top-down or bottom-up control is occurring.
{"title":"Autecology of crangon crangon (L.) with an emphasis on latitudinal trends","authors":"J. Veer","doi":"10.1201/9781420065756-5","DOIUrl":"https://doi.org/10.1201/9781420065756-5","url":null,"abstract":"This review aims to update and extend the synopsis by Tiews (1970) on the biology and fisheries of Crangon crangon (L.). Its wide distributional range along the European coast from the White Sea to Morocco within the Atlantic and throughout the Mediterranean and Black Seas reflects the capability of C. crangon to cope with a wide range of temperature and salinity conditions and is further explained by its migratory capacity. Present knowledge suggests that the limiting factor at the northern cold water edge of its distribution is formed by egg and larval development and at the southern warm water edge by maintenance costs. No information is available about the genetic population structure, but patterns in isoenzymes and in morphometric characters indicate the existence of various subpopulations. Over its distributional range, especially along the north Atlantic coast, clear trends in life-history parameters are observed, most likely reflecting temperature conditions. Due to its generally high abundance, the common shrimp forms a key component in the functioning of coastal shallow ecosystems; however, it is unclear whether the population dynamics of the species is subject to top-down or bottom-up control. On the one hand, C. crangon is an opportunistic feeder with a wide prey spectrum though it remains to be solved whether growth conditions are optimal and only determined by prevailing water temperatures, or whether food limitation is a regulating mechanism. On the other hand, top-down control by predation cannot be excluded since C. crangon is also an important food item for a variety of predators, especially fish species. There are strong indications that predation by C. crangon might regulate some of their prey species. Topics for further research include (1) the analysis of the genetic population structure by means of molecular tools; (2) the study of growth and reproduction in relation to latitude; (3) the application of dynamic energy budgets for the analysis in terms of energy of the various trade-offs, including growth versus reproduction; and (4) the analysis of the mechanisms determining recruitment, especially whether top-down or bottom-up control is occurring.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89166799","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 : 2008-06-05DOI: 10.1201/9781420065756.CH7
T. Elsdon, B. Wells, S. Campana, B. Gillanders, Cynthia M. Jones, K. Limburg, D. Secor, S. Thorrold, B. Walther
in ever-increasing numbers, researchers wish to extract information based on chemi - cal analyses from otoliths to determine movements and life-history patterns of fish. such analyses make assumptions about chemical incorporation and interpretation that are beyond those that are important for stock discrimination studies, another common application. The authors aim to clarify the methods of determining fish movement based on natural and artificial otolith chemical tags and review current trends in determining movement using otolith chemistry, otolith sampling methods, and what influences otolith chemistry. both spatial and temporal variability in water and otolith chemistries, which underpin the assumptions of several methods, are discussed. Five methods for determining movement and migration of fish are outlined: (1) estimates of movement and life-history traits of a single fish group, (2) assessing connectivity among groups using natural chemical tags in otoliths, (3) transgenerational marks to determine parentage and natal origins, (4) profile analysis to define life-history variation within a population and (5) profile analysis to describe movements through different environments. Within each of these methods, background information, specific hypotheses being tested and assumptions and limitations of each technique are provided. Finally,
{"title":"OTOLITH CHEMISTRY TO DESCRIBE MOVEMENTS AND LIFE-HISTORY PARAMETERS OF FISHES : HYPOTHESES, ASSUMPTIONS, LIMITATIONS AND INFERENCES","authors":"T. Elsdon, B. Wells, S. Campana, B. Gillanders, Cynthia M. Jones, K. Limburg, D. Secor, S. Thorrold, B. Walther","doi":"10.1201/9781420065756.CH7","DOIUrl":"https://doi.org/10.1201/9781420065756.CH7","url":null,"abstract":"in ever-increasing numbers, researchers wish to extract information based on chemi - cal analyses from otoliths to determine movements and life-history patterns of fish. such analyses make assumptions about chemical incorporation and interpretation that are beyond those that are important for stock discrimination studies, another common application. The authors aim to clarify the methods of determining fish movement based on natural and artificial otolith chemical tags and review current trends in determining movement using otolith chemistry, otolith sampling methods, and what influences otolith chemistry. both spatial and temporal variability in water and otolith chemistries, which underpin the assumptions of several methods, are discussed. Five methods for determining movement and migration of fish are outlined: (1) estimates of movement and life-history traits of a single fish group, (2) assessing connectivity among groups using natural chemical tags in otoliths, (3) transgenerational marks to determine parentage and natal origins, (4) profile analysis to define life-history variation within a population and (5) profile analysis to describe movements through different environments. Within each of these methods, background information, specific hypotheses being tested and assumptions and limitations of each technique are provided. Finally,","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86516898","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 : 2008-06-05DOI: 10.1201/9781420065756.CH6
M. Pratchett, P. Munday, S. Wilson, N. Graham, J. Cinner, D. Bellwood, G. Jones, N. Polunin, T. McClanahan
Global climate change is having devastating effects on habitat structure in coral-reef ecosystems owing to extreme environmental sensitivities and consequent bleaching of reef-building scleractinian corals. Coral bleaching frequently causes immediate loss of live coral and may lead to longer-term declines in topographic complexity. This review identifies coral cover and topographic complexity as critical and distinct components of coral-reef habitats that shape communities of coral-reef fishes. Coral loss has the greatest and most immediate effect on fishes that depend on live corals for food or shelter, and many such fishes may face considerable risk of extinction with increasing frequency and severity of bleaching. Coral loss may also have longer-term consequences for fishes that require live corals at settlement, which are compounded by devastating effects of declining topographic complexity. Topographic complexity moderates major biotic factors, such as predation and competition, contributing to the high diversity of fishes on coral reefs. Many coral-reef fishes that do not depend on live coral are nonetheless dependent on the topographic complexity provided by healthy coral growth. Ecological and economic consequences of declining topographic complexity are likely to be substantial compared with selective effects of coral loss but both coral cover and topographic complexity must be recognised as a critical component of habitat structure and managed accordingly. Urgent action on the fundamental causes of climate change and appropriate management of critical elements of habitat structure (coral cover and topographic complexity) are key to ensuring long-term persistence of coral-reef fishes.
{"title":"Effects of climate-induced coral bleaching on coral-reef fishes - ecological and economic consequences","authors":"M. Pratchett, P. Munday, S. Wilson, N. Graham, J. Cinner, D. Bellwood, G. Jones, N. Polunin, T. McClanahan","doi":"10.1201/9781420065756.CH6","DOIUrl":"https://doi.org/10.1201/9781420065756.CH6","url":null,"abstract":"Global climate change is having devastating effects on habitat structure in coral-reef ecosystems owing to extreme environmental sensitivities and consequent bleaching of reef-building scleractinian corals. Coral bleaching frequently causes immediate loss of live coral and may lead to longer-term declines in topographic complexity. This review identifies coral cover and topographic complexity as critical and distinct components of coral-reef habitats that shape communities of coral-reef fishes. Coral loss has the greatest and most immediate effect on fishes that depend on live corals for food or shelter, and many such fishes may face considerable risk of extinction with increasing frequency and severity of bleaching. Coral loss may also have longer-term consequences for fishes that require live corals at settlement, which are compounded by devastating effects of declining topographic complexity. Topographic complexity moderates major biotic factors, such as predation and competition, contributing to the high diversity of fishes on coral reefs. Many coral-reef fishes that do not depend on live coral are nonetheless dependent on the topographic complexity provided by healthy coral growth. Ecological and economic consequences of declining topographic complexity are likely to be substantial compared with selective effects of coral loss but both coral cover and topographic complexity must be recognised as a critical component of habitat structure and managed accordingly. Urgent action on the fundamental causes of climate change and appropriate management of critical elements of habitat structure (coral cover and topographic complexity) are key to ensuring long-term persistence of coral-reef fishes.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79974697","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 : 2008-06-01DOI: 10.1201/9781420065756.CH5
D. Marshall, R. Allen, A. Crean
Maternal effects are non-genetic effects of the maternal phenotype or environment on the phenotype of offspring. Whilst maternal effects are now recognised as fundamentally important in terrestrial systems, they have received less recognition in the marine environment despite being remarkably common. The authors review the maternal effect literature and provide a simple framework for understanding maternal effects that increase offspring fitness (termed anticipatory maternal effects) and maternal effects that increase maternal fitness at the expense of offspring fitness (termed selfish maternal effects). The review then addresses various well-studied (offspring size effects, maternal care, oviposition effects) and poorly studied (manipulating offspring dispersal potential, toxicant resistance, sibling competition, mate choice) examples of maternal effects in the marine environment with a focus on marine invertebrates and fish. Offspring size effects are strong and pervasive in the marine environment but the sources and underlying causes of offspring size variation remain poorly understood. More generally, the authors suspect that changes in offspring phenotype are often adaptive maternal effects in response to environmental change. Maternal effects are of particular importance to marine systems because they not only form a link between the phenotypes of different generations, but the biphasic life cycle of most marine organisms suggests that maternal effects also link the phenotypes of populations.
{"title":"THE ECOLOGICAL AND EVOLUTIONARY IMPORTANCE OF MATERNAL EFFECTS IN THE SEA","authors":"D. Marshall, R. Allen, A. Crean","doi":"10.1201/9781420065756.CH5","DOIUrl":"https://doi.org/10.1201/9781420065756.CH5","url":null,"abstract":"Maternal effects are non-genetic effects of the maternal phenotype or environment on the phenotype of offspring. Whilst maternal effects are now recognised as fundamentally important in terrestrial systems, they have received less recognition in the marine environment despite being remarkably common. The authors review the maternal effect literature and provide a simple framework for understanding maternal effects that increase offspring fitness (termed anticipatory maternal effects) and maternal effects that increase maternal fitness at the expense of offspring fitness (termed selfish maternal effects). The review then addresses various well-studied (offspring size effects, maternal care, oviposition effects) and poorly studied (manipulating offspring dispersal potential, toxicant resistance, sibling competition, mate choice) examples of maternal effects in the marine environment with a focus on marine invertebrates and fish. Offspring size effects are strong and pervasive in the marine environment but the sources and underlying causes of offspring size variation remain poorly understood. More generally, the authors suspect that changes in offspring phenotype are often adaptive maternal effects in response to environmental change. Maternal effects are of particular importance to marine systems because they not only form a link between the phenotypes of different generations, but the biphasic life cycle of most marine organisms suggests that maternal effects also link the phenotypes of populations.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88693916","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 : 2008-01-01DOI: 10.1201/9781420065756.CH1
K. Flynn
The Droop cell quota model is the most cited model of phytoplankton growth, even though many pay scant regard to the original description and to its limitations for the description of the interactions that define phenotypic plasticity. While the mechanistic basis of the concept and most ecosystem applications of quota models are C based, much experimental work is cell based, and most theoretical studies ignore the important differences between cell and C nutrient quotas. The future application of the quota approach would be enhanced by the adoption of a normalised quota ("Quota) description, employing a dimensionless constant (KQ) to define the response curve, rather than using the original fixed-curve form. Establishment of the range of these KQ values for different phytoplankton species would limit the number of free parameters in ecosystem variants of quota models while recognising the importance of curve shape for phenotypic variation. KQ for N is typically >3, while for P it is typically <0.2. In addition, appropriate control linkages are required to regulate nutrient transport to the quotas of limiting and non-limiting nutrients. Together, these would enable the establishment of a more coherent quota-based description of algal growth more fit for the development of plankton functional-type models.
{"title":"Use, abuse, misconceptions and insights from quota models — the Droop cell quota model 40 years on","authors":"K. Flynn","doi":"10.1201/9781420065756.CH1","DOIUrl":"https://doi.org/10.1201/9781420065756.CH1","url":null,"abstract":"The Droop cell quota model is the most cited model of phytoplankton growth, even though many pay scant regard to the original description and to its limitations for the description of the interactions that define phenotypic plasticity. While the mechanistic basis of the concept and most ecosystem applications of quota models are C based, much experimental work is cell based, and most theoretical studies ignore the important differences between cell and C nutrient quotas. The future application of the quota approach would be enhanced by the adoption of a normalised quota (\"Quota) description, employing a dimensionless constant (KQ) to define the response curve, rather than using the original fixed-curve form. Establishment of the range of these KQ values for different phytoplankton species would limit the number of free parameters in ecosystem variants of quota models while recognising the importance of curve shape for phenotypic variation. KQ for N is typically >3, while for P it is typically <0.2. In addition, appropriate control linkages are required to regulate nutrient transport to the quotas of limiting and non-limiting nutrients. Together, these would enable the establishment of a more coherent quota-based description of algal growth more fit for the development of plankton functional-type models.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82478492","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}
The ecological resilience of coral reefs depends critically on the capacity of coral populations to re-establish in habitats dominated by macroalgae. Coral reefs globally are under rapidly increasing pressure from human activities, especially from climate change, with serious environmental, social and economic consequences. Coral mortality is usually followed by colonisation by benthic algae of various forms, so that algae dominate most degraded and disturbed reefs. The capacity of coral populations to re-establish in this algal-dominated environment will depend on direct and indirect impacts of the algae on the supply of coral larvae from remnant adults, on settlement of coral larvae and on the post-settlement survival and growth of juvenile corals. The effects of benthic algae on coral replenishment vary considerably but the thick mats or large seaweeds typical of degraded reefs have predominantly negative impacts. Some algae, mostly calcareous red algae, may enhance coral settlement on healthy reefs. Algal effects on coral replenishment include reduced fecundity and larval survival, pre-emption of space for settlement, abrasion or overgrowth of recruits, sloughing or dislodgement of recruits settled on crustose algae, and changes to habitat conditions. There is a serious lack of information about these effects, which are likely to cause bottlenecks in coral recovery and significantly reduce the resilience of coral reefs.
{"title":"Effects of benthic algae on the replenishment of corals and the implications for the resilience of coral reefs","authors":"C. Birrell, L. McCook, B. Willis, G. Diaz-Pulido","doi":"10.1201/9781420065756-4","DOIUrl":"https://doi.org/10.1201/9781420065756-4","url":null,"abstract":"The ecological resilience of coral reefs depends critically on the capacity of coral populations to re-establish in habitats dominated by macroalgae. Coral reefs globally are under rapidly increasing pressure from human activities, especially from climate change, with serious environmental, social and economic consequences. Coral mortality is usually followed by colonisation by benthic algae of various forms, so that algae dominate most degraded and disturbed reefs. The capacity of coral populations to re-establish in this algal-dominated environment will depend on direct and indirect impacts of the algae on the supply of coral larvae from remnant adults, on settlement of coral larvae and on the post-settlement survival and growth of juvenile corals. The effects of benthic algae on coral replenishment vary considerably but the thick mats or large seaweeds typical of degraded reefs have predominantly negative impacts. Some algae, mostly calcareous red algae, may enhance coral settlement on healthy reefs. Algal effects on coral replenishment include reduced fecundity and larval survival, pre-emption of space for settlement, abrasion or overgrowth of recruits, sloughing or dislodgement of recruits settled on crustose algae, and changes to habitat conditions. There is a serious lack of information about these effects, which are likely to cause bottlenecks in coral recovery and significantly reduce the resilience of coral reefs.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74384169","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}
Mysids often dominate mobile benthic epifaunas of mid-latitude continental shelves. Macquart-Moulin & Ribera Maycas (1995) reported that the six most abundant species on western and southern European shelves are all strong diel migrators. Published daytime epibenthic sledge (sled) data from the surf zone to the shelf edge matched with published behavioural data on the most abundant species were used to test, confirm and extend that relationship to other coastal regions and to identify an association of abundant migrators with species that are important in fish diets. They also reveal another pattern: a correspondence between abundant surf-zone species and species that dominate estuarine faunas seasonally. Population concentrations at estuary mouths, sills of fjords and in the surf zone suggest a lifestyle dependent upon horizontal fluxes. Marine mysids that migrate between habitats are chronically undersampled in the field, however, and are underrepresented in food-web models. Unfortunately, no single methodology samples both pelagic and benthic individuals well and nearly all shelf measurements so far reported must be considered underestimates of local abundance. Mysids are major dietary components for many benthic and pelagic fishes, mammals, cephalopods and decapods, often for key life stages, and often because mysid migrations result in encounters with predators. Mysids can be extraordinarily omnivorous, with demonstrated capabilities to digest cellulose and diets spanning macrophyte detritus, more labile detritus, large microalgae, and smaller animals and heterotrophic protists. They can be sufficiently abundant and active to play roles in sediment transport. Contributing factors to their underappreciation have been the lack of fidelity of mysids to single habitats, coupled with higher fidelity of investigators to the study of single habitats. Sampling with classical methods has been problematic because of effective evasion by mysids, compounded by extreme patchiness associated with mysid schooling. Their frequent absence from coastal and even estuarine food-web models has not been more conspicuous because the combination of their migration and omnivory spreads their feeding impacts and because they are subsidised by horizontally imported plankton and seston and are themselves horizontally exported in the form of predator gut contents and biomass. They clearly link pelagic and benthic food webs in two important and ecosystem-stabilising ways, however, by feeding in both habitats and by succumbing in both habitats to both cruising and sit- and-wait predators. Consideration of resource and predation gradients and limited data implicate horizontal, diel migrations as well, extending these linkages, especially in the onshore-offshore direction. Somewhat paradoxically, the same features that have made them difficult to study by classical means, in particular schooling, diet breadth, ontogenetic change in diet and migration between habitats, suit
{"title":"HABITAT COUPLING BY MID-LATITUDE, SUBTIDAL, MARINE MYSIDS: IMPORT-SUBSIDISED OMNIVORES","authors":"R. Gibson, R. Atkinson, J. Gordon, P. Jumars","doi":"10.1201/9781420050943-5","DOIUrl":"https://doi.org/10.1201/9781420050943-5","url":null,"abstract":"Mysids often dominate mobile benthic epifaunas of mid-latitude continental shelves. Macquart-Moulin & Ribera Maycas (1995) reported that the six most abundant species on western and southern European shelves are all strong diel migrators. Published daytime epibenthic sledge (sled) data from the surf zone to the shelf edge matched with published behavioural data on the most abundant species were used to test, confirm and extend that relationship to other coastal regions and to identify an association of abundant migrators with species that are important in fish diets. They also reveal another pattern: a correspondence between abundant surf-zone species and species that dominate estuarine faunas seasonally. Population concentrations at estuary mouths, sills of fjords and in the surf zone suggest a lifestyle dependent upon horizontal fluxes. Marine mysids that migrate between habitats are chronically undersampled in the field, however, and are underrepresented in food-web models. Unfortunately, no single methodology samples both pelagic and benthic individuals well and nearly all shelf measurements so far reported must be considered underestimates of local abundance. Mysids are major dietary components for many benthic and pelagic fishes, mammals, cephalopods and decapods, often for key life stages, and often because mysid migrations result in encounters with predators. Mysids can be extraordinarily omnivorous, with demonstrated capabilities to digest cellulose and diets spanning macrophyte detritus, more labile detritus, large microalgae, and smaller animals and heterotrophic protists. They can be sufficiently abundant and active to play roles in sediment transport. Contributing factors to their underappreciation have been the lack of fidelity of mysids to single habitats, coupled with higher fidelity of investigators to the study of single habitats. Sampling with classical methods has been problematic because of effective evasion by mysids, compounded by extreme patchiness associated with mysid schooling. Their frequent absence from coastal and even estuarine food-web models has not been more conspicuous because the combination of their migration and omnivory spreads their feeding impacts and because they are subsidised by horizontally imported plankton and seston and are themselves horizontally exported in the form of predator gut contents and biomass. They clearly link pelagic and benthic food webs in two important and ecosystem-stabilising ways, however, by feeding in both habitats and by succumbing in both habitats to both cruising and sit- and-wait predators. Consideration of resource and predation gradients and limited data implicate horizontal, diel migrations as well, extending these linkages, especially in the onshore-offshore direction. Somewhat paradoxically, the same features that have made them difficult to study by classical means, in particular schooling, diet breadth, ontogenetic change in diet and migration between habitats, suit ","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90290579","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}
The giant kelp Macrocystis is the world's largest benthic organism and most widely distributed kelp taxon, serving as the foundation for diverse and energy-rich habitats that are of great ecological and economical importance. Although the basic and applied literature on Macro- cystis is extensive and multinational, studies of large Macrocystis forests in the northeastern Pacific have received the greatest attention. This review synthesises the existing Macrocystis literature into a more global perspective. During the last 20 yr, the primary literature has shifted from descriptive and experimental studies of local Macrocystis distribution, abundance and population and commu- nity structure (e.g., competition and herbivory) to comprehensive investigations of Macrocystis life history, dispersal, recruitment, physiology and broad-scale variability in population and community processes. Ample evidence now suggests that the genus is monospecific. Due to its highly variable physiology and life history, Macrocystis occupies a wide variety of environments (intertidal to 60+ m, boreal to warm temperate) and sporophytes take on a variety of morphological forms. Macrocystis sporophytes are highly responsive to environmental variability, resulting in differential population dynamics and effects of Macrocystis on its local environment. Within the large subtidal giant kelp forests of southern California, Macrocystis sporophytes live long, form extensive surface canopies that shade the substratum and dampen currents, and produce and retain copious amounts of reproductive propagules. The majority of subtidal Macrocystis populations worldwide, however, are small, narrow, fringing forests that are productive and modify environmental resources (e.g., light), yet are more dynamic than their large southern California counterparts with local recruitment probably resulting from remote propagule production. When intertidal, Macrocystis populations exhibit vegetative propagation. Growth of high-latitude Macrocystis sporophytes is seasonal, coin- cident with temporal variability in solar insolation, whereas growth at low latitudes tracks more episodic variability in nutrient delivery. Although Macrocystis habitat and energy provision varies with such ecotypic variability in morphology and productivity, the few available studies indicate that Macrocystis -associated communities are universally diverse and productive. Furthermore, tem- poral and spatial variability in the structure and dynamics of these systems appears to be driven by processes that regulate Macrocystis distribution, abundance and productivity, rather than the consumptive processes that make some other kelp systems vulnerable to overexploitation. This global synthesis suggests that the great plasticity in Macrocystis form and function is a key determinant of the great global ecological success of Macrocystis .
{"title":"GLOBAL ECOLOGY OF THE GIANT KELP MACROCYSTIS : FROM ECOTYPES TO ECOSYSTEMS","authors":"M. Graham, J. Vásquez, A. Buschmann","doi":"10.1201/9781420050943-4","DOIUrl":"https://doi.org/10.1201/9781420050943-4","url":null,"abstract":"The giant kelp Macrocystis is the world's largest benthic organism and most widely distributed kelp taxon, serving as the foundation for diverse and energy-rich habitats that are of great ecological and economical importance. Although the basic and applied literature on Macro- cystis is extensive and multinational, studies of large Macrocystis forests in the northeastern Pacific have received the greatest attention. This review synthesises the existing Macrocystis literature into a more global perspective. During the last 20 yr, the primary literature has shifted from descriptive and experimental studies of local Macrocystis distribution, abundance and population and commu- nity structure (e.g., competition and herbivory) to comprehensive investigations of Macrocystis life history, dispersal, recruitment, physiology and broad-scale variability in population and community processes. Ample evidence now suggests that the genus is monospecific. Due to its highly variable physiology and life history, Macrocystis occupies a wide variety of environments (intertidal to 60+ m, boreal to warm temperate) and sporophytes take on a variety of morphological forms. Macrocystis sporophytes are highly responsive to environmental variability, resulting in differential population dynamics and effects of Macrocystis on its local environment. Within the large subtidal giant kelp forests of southern California, Macrocystis sporophytes live long, form extensive surface canopies that shade the substratum and dampen currents, and produce and retain copious amounts of reproductive propagules. The majority of subtidal Macrocystis populations worldwide, however, are small, narrow, fringing forests that are productive and modify environmental resources (e.g., light), yet are more dynamic than their large southern California counterparts with local recruitment probably resulting from remote propagule production. When intertidal, Macrocystis populations exhibit vegetative propagation. Growth of high-latitude Macrocystis sporophytes is seasonal, coin- cident with temporal variability in solar insolation, whereas growth at low latitudes tracks more episodic variability in nutrient delivery. Although Macrocystis habitat and energy provision varies with such ecotypic variability in morphology and productivity, the few available studies indicate that Macrocystis -associated communities are universally diverse and productive. Furthermore, tem- poral and spatial variability in the structure and dynamics of these systems appears to be driven by processes that regulate Macrocystis distribution, abundance and productivity, rather than the consumptive processes that make some other kelp systems vulnerable to overexploitation. This global synthesis suggests that the great plasticity in Macrocystis form and function is a key determinant of the great global ecological success of Macrocystis .","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90022104","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 : 2007-01-01DOI: 10.1201/9781420050943.ch4
R. Carney
The soft-bottom benthos covers most of the sea floor. Measurement and analysis of the species richness of these habitats are increasingly needed for studies of community regulation and for providing scientific criteria for the conservation of the ocean bottom at all depths. Diversity measures provide an evolving suite of tools that allow benthic ecologists to meet both basic and applied needs. While species diversity is now considered a fundamental aspect of communities and ecosystems, the measurement of benthic diversity did not become commonplace until the late 1960s. Prior to that communities were characterised by representative species with the implicit assumption that minor species components did not warrant detailed analysis. Use of diversity measures in benthic ecology has largely parallelled studies in other ecosystems with an emphasis upon measures that are informative when applied to large amounts of data with high species numbers. Non-parametric indices such as Simpson's and Shannon's are widely used along with simple species richness. Logseries and log-normal distributions have been advocated as general neutral models but receive less use. Current research is especially focused upon extrapolation of unsampled species richness and diversity relationships across spatial scales. Major contributions from benthic ecology include the rarefaction of samples to a uniform size, the development of indices that include phylogenetic relationships in diversity estimation and the extrapolation of full species richness from observed values. In meeting scientific and societal needs, benthic ecologists must apply methods that are insightful yet can be simply explained within the resource-policy arena.
{"title":"Use of diversity estimations in the study of sedimentary benthic communities","authors":"R. Carney","doi":"10.1201/9781420050943.ch4","DOIUrl":"https://doi.org/10.1201/9781420050943.ch4","url":null,"abstract":"The soft-bottom benthos covers most of the sea floor. Measurement and analysis of the species richness of these habitats are increasingly needed for studies of community regulation and for providing scientific criteria for the conservation of the ocean bottom at all depths. Diversity measures provide an evolving suite of tools that allow benthic ecologists to meet both basic and applied needs. While species diversity is now considered a fundamental aspect of communities and ecosystems, the measurement of benthic diversity did not become commonplace until the late 1960s. Prior to that communities were characterised by representative species with the implicit assumption that minor species components did not warrant detailed analysis. Use of diversity measures in benthic ecology has largely parallelled studies in other ecosystems with an emphasis upon measures that are informative when applied to large amounts of data with high species numbers. Non-parametric indices such as Simpson's and Shannon's are widely used along with simple species richness. Logseries and log-normal distributions have been advocated as general neutral models but receive less use. Current research is especially focused upon extrapolation of unsampled species richness and diversity relationships across spatial scales. Major contributions from benthic ecology include the rarefaction of samples to a uniform size, the development of indices that include phylogenetic relationships in diversity estimation and the extrapolation of full species richness from observed values. In meeting scientific and societal needs, benthic ecologists must apply methods that are insightful yet can be simply explained within the resource-policy arena.","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76016131","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 : 2007-01-01DOI: 10.1201/9781420050943.ch6
M. Thiel, E. Macaya, E. Acuña, W. Arntz
The Humboldt Current System (HCS) is one of the most productive marine ecosystems on earth. It extends along the west coast of South America from southern Chile (∼42°S) up to Ecuador and the Galapagos Islands near the equator. The general oceanography of the HCS is characterised by a predominant northward flow of surface waters of subantarctic origin and by strong upwelling of cool nutrient-rich subsurface waters of equatorial origin. Along the coast of northern and central Chile, upwelling is localised and its occurrence changes from being mostly continuous (aseasonal) in northern Chile to a more seasonal pattern in southern-central Chile. Several important upwelling centres along the Chilean coast are interspersed with long stretches of coast without or with sporadic and less intense upwelling. Large-scale climatic phenomena (El Nino Southern Oscillation, ENSO) are superimposed onto this regional pattern, which results in a high spatiotemporal heterogeneity, complicating the prediction of ecological processes along the Chilean coast. This limited predictability becomes particularly critical in light of increasing human activities during the past decades, at present mainly in the form of exploitation of renewable resources (fish, invertebrates and macroalgae). This review examines current knowledge of ecological processes in the HCS of northern and central Chile, with a particular focus on oceanographic factors and the influence of human activities, and further suggests conservation strategies for this high-priority large marine ecosystem. Along the Chilean coast, the injection of nutrients into surface waters through upwelling events results in extremely high primary production. This fuels zooplankton and fish production over extensive areas, which also supports higher trophic levels, including large populations of seabirds and marine mammals. Pelagic fisheries, typically concentrated near main upwelling centres (20-22°S, 32-34°S, 36-38°S), take an important share of the fish production, thereby affecting trophic interactions in the HCS. Interestingly, El Nino (EN) events in northern Chile do not appear to cause a dramatic decline in primary or zooplankton production but rather a shift in species composition, which affects trophic efficiency of and interactions among higher-level consumers. The low oxygen concentrations in subsurface waters of the HCS (oxygen-minimum zone, OMZ) influence predator-prey interactions in the plankton by preventing some species from migrating to deeper waters. The OMZ also has a strong effect on the bathymetric distribution of sublittoral soft-bottom communities along the Chilean coast. The few long-term studies available from sublittoral soft-bottom communities in northern and central Chile suggest that temporal dynamics in abundance and community composition are driven by interannual phenomena (EN and the extent and intensity of the OMZ) rather than by intra-annual (seasonal) patterns. Macrobenthic communities wit
{"title":"The humboldt current system of northern and central chile : Oceanographic processes, ecological interactions and socioeconomic feedback","authors":"M. Thiel, E. Macaya, E. Acuña, W. Arntz","doi":"10.1201/9781420050943.ch6","DOIUrl":"https://doi.org/10.1201/9781420050943.ch6","url":null,"abstract":"The Humboldt Current System (HCS) is one of the most productive marine ecosystems on earth. It extends along the west coast of South America from southern Chile (∼42°S) up to Ecuador and the Galapagos Islands near the equator. The general oceanography of the HCS is characterised by a predominant northward flow of surface waters of subantarctic origin and by strong upwelling of cool nutrient-rich subsurface waters of equatorial origin. Along the coast of northern and central Chile, upwelling is localised and its occurrence changes from being mostly continuous (aseasonal) in northern Chile to a more seasonal pattern in southern-central Chile. Several important upwelling centres along the Chilean coast are interspersed with long stretches of coast without or with sporadic and less intense upwelling. Large-scale climatic phenomena (El Nino Southern Oscillation, ENSO) are superimposed onto this regional pattern, which results in a high spatiotemporal heterogeneity, complicating the prediction of ecological processes along the Chilean coast. This limited predictability becomes particularly critical in light of increasing human activities during the past decades, at present mainly in the form of exploitation of renewable resources (fish, invertebrates and macroalgae). This review examines current knowledge of ecological processes in the HCS of northern and central Chile, with a particular focus on oceanographic factors and the influence of human activities, and further suggests conservation strategies for this high-priority large marine ecosystem. Along the Chilean coast, the injection of nutrients into surface waters through upwelling events results in extremely high primary production. This fuels zooplankton and fish production over extensive areas, which also supports higher trophic levels, including large populations of seabirds and marine mammals. Pelagic fisheries, typically concentrated near main upwelling centres (20-22°S, 32-34°S, 36-38°S), take an important share of the fish production, thereby affecting trophic interactions in the HCS. Interestingly, El Nino (EN) events in northern Chile do not appear to cause a dramatic decline in primary or zooplankton production but rather a shift in species composition, which affects trophic efficiency of and interactions among higher-level consumers. The low oxygen concentrations in subsurface waters of the HCS (oxygen-minimum zone, OMZ) influence predator-prey interactions in the plankton by preventing some species from migrating to deeper waters. The OMZ also has a strong effect on the bathymetric distribution of sublittoral soft-bottom communities along the Chilean coast. The few long-term studies available from sublittoral soft-bottom communities in northern and central Chile suggest that temporal dynamics in abundance and community composition are driven by interannual phenomena (EN and the extent and intensity of the OMZ) rather than by intra-annual (seasonal) patterns. Macrobenthic communities wit","PeriodicalId":54693,"journal":{"name":"Oceanography and Marine Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84328950","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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