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  1. Oceanography and Marine Biology - An Annual Review
  2. Oceanography And Marine Biology--An Annual Review series - otanoxapenyw.ml
  3. 69 editions of this work
  4. 1st Edition

Uv Absorption by Gerrid Cuticles. Limnology and Oceanography. Cheng, L, Lewin RA. Fluidisation as a feeding mechanism in beach flies Cover feature. Cheng, L, Holdway P. Zoological Journal of the Linnean Society. Pacific Insects. Cheng, L, Roussis V. Sex attractant in the marine insect Trochopus plumbeus Heteroptera : Veliidae : a preliminary report. Marine Ecology-Progress Series.

Water Air and Soil Pollution. A bug on the ocean waves Heteroptera, Gerridae, Halobates Eschscholtz. Hug the bug — For love of true bugs. Festschrift zum Geburtstag von Ernst Heiss.. Incorporation of Cadmium into Drosophila. Environmental Pollution Series a-Ecological and Biological. Aquatic insect ecology, Vol. Journal of Experimental Marine Biology and Ecology. Biology of Halobates Heteroptera, Gerridae. Annual Review of Entomology. Guide to the aquatic Heteroptera of Singapore and Peninsular Malaysia.

Gerridae and Hermatobatidae. Abstract Website This is the first guide to the aquatic Heteroptera of Singapore and Peninsular Malaysia to be published as a series in the Raffles Bulletin of Zoology. Cheng, L, Bidleman TF. Chlorinated Hydrocarbons in Marine Insects. Estuarine and Coastal Marine Science. Distribution patterns of individual species of shallow-water sedimentary fauna are determined largely by temperature, salinity, depth, surface productivity, and sediment dynamics over broad scales and by biological interactions, sediment geochemistry, and near-bed flow processes at finer scales.

Particularly over broad scales, geologic history plays a major role in patterns of distribution Jablonski and Sepkowski , although I will focus on ecological rather than evolutionary scales.

This deep-sea mystery is changing our understanding of life - Karen Lloyd

The dependence on temperature, salinity, and depth are easily understood in terms of physiological constraints; many species have specific tolerances to temperature, salinity, and pressure that have to do with osmotic balance and enzyme function. These physiological constraints contribute to the reduced diversity of estuaries and other highly variable, and thus physically challenging, environments.

Given that many organisms derive their nutrition from sediment-associated food particles, higher diversity in sediments of diverse grain size might also be predicted Whitlatch Many species have a complex relationship with the sedimentary environment. Generally speaking, suspension feeders tend to be most abundant in high-energy environments, and deposit feeders are most abundant in depositional areas with fine-grained, muddy sediments. But contrasting these environments in terms of how they determine infau-nal pattern is complex because many important variables vary with flow regime Snelgrove and Butman High-energy environments are typically sandy, with strong bottom flows and horizontal flux of food and perhaps settling larvae.

Sediment grain size is large, and organic content and microbial content tend to be low. High energy produced by waves and strong currents moves sediments and some organisms. Low-energy environments are often muddy, with weak flows and low horizontal but greater vertical flux of food, fine sediments, and potentially larvae. By mechanisms that are not yet fully understood, these flow-, nutrition-, and substrate-related variables contribute to patterns in species distributions that are fairly consistent in time and space.

The challenge is to determine which mechanisms are most important in creating and maintaining pattern. Understanding how patterns in individual species are maintained is a key prerequisite to understanding biodiversity patterns, and some of the advances made in this area are reviewed below. Most of what is known about shallow-water diversity has been learned from experiments designed to determine the impacts of individual species on other species or from observational data.

Among the most relevant of these experiments for understanding regulation of diversity are those that test the impacts of predators on individual species and those that examine the importance of competition in soft-sediment systems. Indeed, experimental approaches in soft-sediment systems have been heavily influenced by studies of rocky intertidal areas, which have demonstrated the critical importance of keystone predators in maintaining diversity and community structure Paine Data from the majority of studies in soft-sediment systems reviewed by Peterson suggest that interspecific competition is probably not a major structuring force in sedimentary communities but that predation can be important.

In reviewing predator exclusion experiments, Peterson found that species richness in sediments tended to increase when predators were excluded. He also found that species richness in seagrass beds exceeded that in ambient sediments, perhaps because of the predator refuge that seagrasses provide.

Numerous studies of changes resulting from foraging predators suggest that foragers have major impacts on densities of dominant taxa but little effect on the relative abundances of species e. But predation effects are not limited to foraging species and their impacts on adult infauna. Indeed, interactions between infaunal adults and settling larvae or recently settled juveniles may be a major structuring force in sedimentary communities.

In reviewing the many studies that have been conducted on adult-juvenile interactions, Olafsson et al. Although suspension feeders can and do filter settling larvae from near-bottom waters, early postsettlement processes may be more important to recruitment success, given the frequency with which deposit feeders have an impact on suspension feeders. Biological disturbances, such as bioturbation, may also enhance diversity Kukert and Smith , although the mechanism is unclear. Bioturbation is also the basis of the trophic group amensalism hypothesis, in which deposit feeders are suggested to constrain distribution patterns in suspension feeders by resuspending sediment that settles and smothers their larvae and clogs their filtering structures Rhoads and Young Although this hypothesis is not accepted as a general hypothesis for benthic pattern Snelgrove and Butman , the interactions that it describes undoubtedly occur in some instances.

Biological structures, such as seagrass blades e. Another factor that may play a major role in establishing pattern is larval supply Figure 1. Many benthic invertebrates produce plank-tonic larvae that, depending on the taxon, spend hours to months in the plankton before taking up a benthic existence. A major question in marine ecology is how these planktonic larvae, which are often poor swimmers, are able to settle in a suitable habitat. Small-scale laboratory experiments that began in the s suggested that larvae have some capacity to choose among sediment types, perhaps based on organic content.

But the scales over which habitat selection behavior may be important are limited, given the relatively weak swimming ability of many larvae. Consequently, these small-scale stillwater experiments may have limited application to nature Butman The challenge of maintaining pattern. Schematic representation of the processes that affect larval settlement of sedimentary invertebrates.

The adult bivalve is shown as a large individual living in mud indicated by solid grey box but unable to live in other sediments indicated by grainy boxes.

Oceanography and Marine Biology - An Annual Review

To maintain populations in an area, the bivalve must complete the cycle indicated by the heavy black circle. Lighter lines indicate sources of mortality. Eggs and sperm are spawned into the water column, where some successful fertilizations will occur but many eggs and sperm will be lost. The successfully fertilized eggs become small swimming larvae that suffer heavy losses as a result of transport away from suitable habitat, predation, starvation from lack of appropriate food, and exposure to temperatures or salinities beyond their physiological tolerance.

As developing larvae settle toward the bottom, they may encounter hypoxic sediments or predation from suspension-feeding bivalves. Even after the larvae settle and metamorphose into small juveniles, heavy loss is incurred shown in boxes because of predators, physical disturbance, low oxygen, insufficient food, unsuitability of sediment, and disturbance by deposit feeders moving through the sediment.

Once they have grown past the juvenile stage, mortality is greatly reduced. One approach to resolving the importance of habitat selection is to study larval settlement in a laboratory flume. A flume is a recirculating seawater channel that is designed to mimic natural bottom flow but that allows confounding variables such as predators and food supply to be controlled. Over the past few years, several studies of larval settlement have found that species with well-defined distributions with respect to sediment type are also capable of choosing one type of sediment over another as they settle, even in moving water Table 2.

The specific sediment cue to which settling larvae respond is unclear, but organic content is a good candidate for at least some species Butman et al. In any case, these results suggest that habitat selection probably plays an important role in shallow-water pattern, although passive transport also regulates delivery of larvae to specific areas see Butman How larval ecology relates to maintenance of assemblages and biodiversity remains to be seen.

Summary of laboratory flume experiments to determine whether settling larvae of different species are capable of habitat selection. In summary, studies from shallow-water environments offer insights into how distributions of individual species are established and maintained, but they have less to say about biodiversity patterns.

Existing data suggest that rocky intertidal paradigms may not be applicable to soft-sediment systems and that additional experimental work will be needed to evaluate critically the factors that regulate biodiversity. Biodiversity in deep-sea ecosystems has generated much interest e. Why the deep sea is so diverse is a subject of some debate. For some areas of the deep sea, overriding environmental variables, such as low oxygen Levin and Gage , hydrothermal fluid emission Dinet et al. The suggestion that the long-term stability of most deep-sea environments has allowed evolution of many specialized species Sanders has been questioned based on the lack of evidence for niche specialization and the parabolic diversity-depth relationship that has been observed in some areas Rex The potential impact of predators cropping populations below levels at which competitive exclusion would take place has been questioned based on population attributes of deep-sea species Grassle and Sanders Indeed, if predation effects in the deep sea are similar to those in shallow water, then reduced predation pressure in the deep sea might actually increase diversity.

It has also been hypothesized that small-scale patches of food and disturbance create microhabitats on which different species may specialize and thus avoid competition in a highly food limited environment Grassle and Sanders Indeed, carbon flux to the deep sea is now known to be patchy in many areas e. To test the potential role of food patches in the deep sea, sediments enriched with different types of organic matter were deployed for varying periods of time at m in depth near St.

Croix in the US Virgin Islands. Different types of organic matter were found to elicit different colonization responses for different species Figure 2 , depending on the type of organic matter Snelgrove et al.

Thus, small-scale patchiness may enhance deep-sea diversity. However, it is important to note that the numbers of species that respond to these types of disturbance are relatively few, and existing data support this mechanism for only a small subset of deep-sea species. It is possible that appropriate patch types have not been identified for other species, but it is also likely that factors such as productivity and evolutionary history come into play in determining biodiversity patterns.

Deep-sea colonization experiments carried out at m depth south of St. Croix, US Virgin Islands. Three polychaete species Capitella spp. The graphs show the responses of total macrofauna upper left and the three polychaete species to different patch types. Two different time periods were compared to test how the species' response to different patch types would change.

All other treatments are densities of animals colonizing 10 cm deep sediment trays with surface areas of cm 2. Trays were unenriched or enriched with Sargassum spp. Artificially aged Sargassum is algae that was aged before deployment to mimic degradation over a longer time period. Bars denote means, and lines denote 1 SE. Data from Snelgrove et al. Conflicting patterns from different data sets must be resolved to establish any comprehensive paradigm explaining the rich diversity of the deep sea.

What is needed is more complete sampling on a global scale, studies that include a broader range of taxa e. Even though marine sedimentary ecosystems are not well understood, there are good reasons to assume that their loss could affect the planet and human populations directly. For example, marine organisms provide a tremendous reservoir of natural products that could prove invaluable and irreplaceable by synthetic equivalents. Ultimately, however, the arguments for preserving marine sedimentary biodiversity that will carry the greatest weight are those of most immediate concern to human populations.

In other words, what have marine sedimentary fauna done for you lately? Although I will focus on marine sedimentary environments, there are considerable parallels with freshwater sediments and terrestrial soils e. Global carbon and geochemical cycling. As a result of the global dominance of marine sedimentary habitats and the importance of sedimentary fauna in local carbon metabolism and burial through their feeding and mixing activities e.

Other important geochemical cycles, such as those of sulfur and nitrogen, can also be affected by the organisms that reside in marine sediments. Marine sedimentary organisms of all sizes play a role in these processes. Bacteria, protozoa, and fungi are important decomposers and are thus important trophic links to larger organisms and nutrient cycling see references in Snelgrove et al. Bacteria are also an important constituent of the diet of deposit feeders, along with the detritus that microbes help to decompose e. Lopez and Levinton Macro- and megafauna, because of their large size, are particularly important in redistributing sediments and organic matter associated with sediments see Gallagher and Keay , thus affecting nutrient availability to different bacterial groups.

Thus, the linkages between different sedimentary organisms are complex and their impacts on global cycling processes may be determined via direct and indirect routes. There are also multiple linkages between marine, terrestrial Wall and Moore , and freshwater Covich et al. Secondary production food. Some sedimentary macrofaunal organisms are commercially fished e. Macrofauna and meiofauna can also be major dietary components for commercial species, such as cod, shrimp, and flounder, that feed on benthos either as juveniles or as adults e.

Thus, benthic organisms are an important part of the food chain and also transfer organic carbon back to the pelagic realm. Pollutant metabolism and burial. Just as pollutants have a tremendous impact on soft-sediment benthos, these fauna also affect pollutant concentration and distribution. By pelletizing sediment as feces or stabilizing them through mucous excretion, organisms within the sediment can increase or decrease the likelihood of sediment-bound pollutants being re-suspended and transported elsewhere. Vertical mixing by sedimentary macrofauna can also increase or decrease the likelihood of burial, depending on whether animals feed at the surface or at depth Gallagher and Keay If pollutants are bound to organic particles, then feeding activity may lead to their removal through incorporation into tissue; as a result, concentrations in the water column are reduced but the likelihood of transfer to higher trophic levels is increased if predators such as fish consume contaminated benthos.

Microbes play a key role in the metabolic breakdown of pollutants and are consequently used in many waste treatment facilities. Because meiofauna play an important role in lower food webs, they also influence the fate of pollutants. Marine sedimentary habitats contribute to water clarity and health in several ways.

Oceanography And Marine Biology--An Annual Review series - otanoxapenyw.ml

Croix in the US Virgin Islands. Different types of organic matter were found to elicit different colonization responses for different species Figure 2 , depending on the type of organic matter Snelgrove et al. Thus, small-scale patchiness may enhance deep-sea diversity. However, it is important to note that the numbers of species that respond to these types of disturbance are relatively few, and existing data support this mechanism for only a small subset of deep-sea species.

It is possible that appropriate patch types have not been identified for other species, but it is also likely that factors such as productivity and evolutionary history come into play in determining biodiversity patterns. Deep-sea colonization experiments carried out at m depth south of St. Croix, US Virgin Islands. Three polychaete species Capitella spp. The graphs show the responses of total macrofauna upper left and the three polychaete species to different patch types.

Two different time periods were compared to test how the species' response to different patch types would change. All other treatments are densities of animals colonizing 10 cm deep sediment trays with surface areas of cm 2. Trays were unenriched or enriched with Sargassum spp. Artificially aged Sargassum is algae that was aged before deployment to mimic degradation over a longer time period. Bars denote means, and lines denote 1 SE. Data from Snelgrove et al. Conflicting patterns from different data sets must be resolved to establish any comprehensive paradigm explaining the rich diversity of the deep sea.


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What is needed is more complete sampling on a global scale, studies that include a broader range of taxa e. Even though marine sedimentary ecosystems are not well understood, there are good reasons to assume that their loss could affect the planet and human populations directly. For example, marine organisms provide a tremendous reservoir of natural products that could prove invaluable and irreplaceable by synthetic equivalents.

Ultimately, however, the arguments for preserving marine sedimentary biodiversity that will carry the greatest weight are those of most immediate concern to human populations. In other words, what have marine sedimentary fauna done for you lately? Although I will focus on marine sedimentary environments, there are considerable parallels with freshwater sediments and terrestrial soils e.

Global carbon and geochemical cycling. As a result of the global dominance of marine sedimentary habitats and the importance of sedimentary fauna in local carbon metabolism and burial through their feeding and mixing activities e. Other important geochemical cycles, such as those of sulfur and nitrogen, can also be affected by the organisms that reside in marine sediments. Marine sedimentary organisms of all sizes play a role in these processes.

Bacteria, protozoa, and fungi are important decomposers and are thus important trophic links to larger organisms and nutrient cycling see references in Snelgrove et al. Bacteria are also an important constituent of the diet of deposit feeders, along with the detritus that microbes help to decompose e. Lopez and Levinton Macro- and megafauna, because of their large size, are particularly important in redistributing sediments and organic matter associated with sediments see Gallagher and Keay , thus affecting nutrient availability to different bacterial groups.

Thus, the linkages between different sedimentary organisms are complex and their impacts on global cycling processes may be determined via direct and indirect routes. There are also multiple linkages between marine, terrestrial Wall and Moore , and freshwater Covich et al. Secondary production food. Some sedimentary macrofaunal organisms are commercially fished e. Macrofauna and meiofauna can also be major dietary components for commercial species, such as cod, shrimp, and flounder, that feed on benthos either as juveniles or as adults e. Thus, benthic organisms are an important part of the food chain and also transfer organic carbon back to the pelagic realm.

Pollutant metabolism and burial. Just as pollutants have a tremendous impact on soft-sediment benthos, these fauna also affect pollutant concentration and distribution. By pelletizing sediment as feces or stabilizing them through mucous excretion, organisms within the sediment can increase or decrease the likelihood of sediment-bound pollutants being re-suspended and transported elsewhere. Vertical mixing by sedimentary macrofauna can also increase or decrease the likelihood of burial, depending on whether animals feed at the surface or at depth Gallagher and Keay If pollutants are bound to organic particles, then feeding activity may lead to their removal through incorporation into tissue; as a result, concentrations in the water column are reduced but the likelihood of transfer to higher trophic levels is increased if predators such as fish consume contaminated benthos.

Microbes play a key role in the metabolic breakdown of pollutants and are consequently used in many waste treatment facilities. Because meiofauna play an important role in lower food webs, they also influence the fate of pollutants. Marine sedimentary habitats contribute to water clarity and health in several ways. Transition zones, such as marshes, seagrass beds, and mangroves act as sediment traps and stabilizers and buffer nutrient loading into the open ocean.

Suspension feeders can have a major effect on water clarity through their filtering activity; the reduction of oysters in Chesapeake Bay through over-fishing, disease, and sedimentation has lowered filtering capacity and reduced water clarity Newell The reverse problem has occurred in San Francisco Bay, where the introduced suspension-feeding Chinese clam, Potamocorbula amurensis , has attained sufficient densities to effectively strip the water of phytoplank-ton and eliminate natural seasonal blooms Alpine and Cloern Thus, sedimentary communities contribute to ecosystem health not only within sediments but also in the water column above.

Sediment stability and transport. Sediment erosion and cohesion depend strongly on resident animals and microbes. Reworking by deposit feeders can substantially increase water content and erodibility Rhoads , and diatom films and mucus excretion can bind sediments and reduce erodibility. Physical structures, such as seagrasses, salt marshes, and mangroves also reduce erosion by trapping sediments. Thus, coastal zone communities can directly affect human environments by influencing coastal erosion implications for land use and deposition implications for dredging of waterways.

An obvious question is whether marine sedimentary ecosystems can sustain loss of biological and genetic diversity and still provide the same sorts of ecosystem services that they have provided historically. The answer is yes and no. There are probably species that can be lost from some ecosystems without substantial alteration of system function. Two species often overlap in the way in which they feed, mix sediments, and decompose material e.

However, they probably do not carry out these activities in exactly the same way, and the functional significance of these differences probably depends on the species and ecosystem in question. In addition, there are some species whose loss will undoubtedly have serious direct or indirect consequences.

Although documented marine extinctions are rare, there is good reason to be concerned that marine biodiversity may be threatened. Because our knowledge of marine systems is so poor, it is likely that species are being lost without our knowing it. Moreover, genetic diversity may be lost as distributions shrink e. Fishing gear that is dragged across the bottom has destructive impacts on sedimentary fauna both directly and indirectly.

The photos from Auster and used with permission of Conservation Biology show an area of the Gulf of Maine ocean bottom before and after a single pass with a scallop dredge. The pretrawled photograph top shows a complex bottom with polychaete tubes, sponges, and other forms of life. Structures of this sort also create habitat for other species. After the trawl has been dragged across the bottom, this complex habitat is obliterated, resulting in loss of habitat for animals that live within the structure e.

These effects will likely influence all of the ecosystem services that benthic organisms provide. Fishing activity affects sedimentary fauna most directly by dragging trawls and dredges across the bottom, physically damaging animals and destroying critical habitat for a variety of species that use the habitat structure created by epifaunal and infaunal presence and activity see box this page; Botsford et al. A second concern is the deliberate, large-scale removal of abundant and large predators the target species , with coincidental bycatch of nontarget species, both of which can alter food chains and related ecological processes Pauly et al.

Fishing activity can also redistribute sediments, cause significant sediment resuspension, and alter sediment stability by disturbing species that influence cohesion and grain size e. Dense human populations living near coastlines discharge large amounts of sewage, agricultural runoff, and toxic compounds, such as heavy metals and PCBs. Areas affected by these sorts of pollutants have high densities and low species diversity Pearson and Rosenberg Genetic effects, such as a reduction in heterozygosity e.

Agricultural runoff and sewage outfalls provide excess nutrients that create both toxic and nontoxic algal blooms, which sink, decompose, and create anoxic conditions similar to those observed in freshwater systems Covich et al. Toxic compounds can be lethal to benthic organisms or may lead to reduced disease resistance or reproductive potential. Benthic organisms that are consumed by humans may also concentrate toxins e. All of these disturbances reduce diversity and create a fauna of a few species that may be aesthetically undesirable and may not carry out ecosystem functioning the way a more diverse community would.

Physical alteration of habitat is a frequent result of agriculture and deforestation because increased sedimentation alters coastal sediment composition and thus the sedimentary biota Smith and Kukert Beach replenishment, harbor dredging, and disposal of dredged sediments all have similar effects. The damming of estuaries can lead to changes in estuarine salinity gradients, sedimentation patterns, and biology. Perhaps the most damaging human alteration of marine sedimentary habitat is the filling of coastal wetlands. Saltmarshes, seagrass beds, and mangroves provide important ecosystem services, yet they have all suffered tremendous areal loss from coastal development.

Although oceans are interconnected, the presence of land masses, deep ocean, and differences in water temperature have created natural dispersal barriers and have thus allowed markedly different faunas to evolve in different areas of the world. Human activity is now wreaking havoc with these patterns. The greatest culprits are ship ballast water and ship hulls, which transport living adults and reproductive propagules to non-native habitats e. Another mechanism of introduction is the accidental release of animals or their parasites after importation for aquaculture or scientific study.

In many cases, exotic species explode in numbers and dominate to the detriment of native species, which may shrink in distribution or disappear from affected areas. Given that temperature is a key delimiter of benthic distribution, it is likely that sedimentary faunal shifts have occurred, or will occur, as a result of global warming. Ultimately, global warming will compress or eliminate habitats as the fauna are shifted.

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A similar effect may be anticipated from rising sea levels as polar icecaps are reduced. Another concern is that global warming may change ocean circulation Manabe et al. Finally, ultraviolet radiation increases associated with ozone depletion could have direct impacts on shallow-water fauna and on the eggs and microplankton of organisms living in deeper water.

Given the present level of knowledge on biodiversity in marine sediments and how it influences ecological processes, what are the next steps that marine scientists should take if biodiversity is to be preserved? Study processes and linkages in marine systems with respect to biodiversity and ecosystem functioning. Although many scientists believe that there is a relationship between biodiversity and how ecosystems operate, the lack of mechanistic detail in the examples cited above illustrates the need for specific and well-documented marine examples.

In particular, studies that make these linkages in economically valuable marine systems are likely to have the greatest impact on legislation and conservation. Recognize and promote taxonomy as an important scientific activity. Trying to document biodiversity pattern and stemming its loss will be impossible if retiring taxonomists are not replaced and more taxonomists are not trained.

Promote the concept of marine reserves, not only for areas deemed to be ecologically unique but also for areas that are representative of broader regions.

These areas could be either partially restricted or completely closed to outside activities, as long as they achieve the critical need of providing natural ecosystem processes and preserving biodiversity. Scientists must provide the best possible information to identify areas that will provide the most important refuges, not only in terms of resident species but also for their capacity to enhance adjacent, nonprotected areas. Scientists who have direct input on fisheries decisions should recommend quotas that are sufficiently conservative to ensure that any uncertainties in the models used to determine catch quotas cannot result in over-fishing in the worst-case scenarios.

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Recommendations on fishing gear should also consider, as a guiding principle, reducing bycatch, and subsidies to an overcapitalized fishing industry should be discouraged. Every effort should be made to communicate to the general public the threats posed to marine sedimentary environments by destructive fishing practices, introduction of exotic species, pollution, destruction of natural coastline, and global climate change.

Because was the United Nations International Year of the Ocean, the timing is perfect for marine scientists to voice opinions and to communicate new findings on biodiversity in marine sediments. That designation for has helped to focus attention on oceans at a time when attention and changed perceptions are needed. Research on ecosystem operation and biodiversity is likely to result in exciting and far-reaching discoveries for sedimentary ecosystems.