Showing papers on "Benthic zone published in 1975"

Limnology: Lake and River Ecosystems

Abstract: Preface 1 Prologue 2 Water as a Substance 3 Rivers and Lakes - Their Distribution, Origins, and Forms 4 Water Economy 5 Light in Inland Waters 6 Fate of Heat 7 Water Movements 8 Structure and Productivity of Aquatic Ecosystems 9 Oxygen 10 Salinity of Inland Waters 11 The Inorganic Carbon Complex 12 The Nitrogen Cycle 13 The Phosphorus Cycle 14 Iron, Sulfer, and Silica Cycles 15 Planktonic Communities: Algae and Cyanobacteria 16 Plantonic Communities: Zooplankton and their Interactions with Fish 17 Bacterioplankton 18 Land-Water Interfaces: Larger Plants 19 Land-Water Interfaces: Attached Microorganisms, Littoral Algae, and Zooplankton 20 Shallow Lakes and Ponds 21 Sediments and Microflora 22 Benthic Animals and Fish Communities 23 Detrirus: Organic Carbon Cycling and Ecosystem Metabolism 24 Past Productivity: Paleolimnology 25 The Ontogeny of Inland Aquatic Ecosystmes 26 Inland waters: Understanding is Essential for the Future References Appendix Index

Benthic nutrient regeneration and its coupling to primary productivity in coastal waters

Abstract: SHALLOW near-shore ocean waters support high primary production because of the availability of inorganic nutrients. The availability is usually attributed to the proximity of fresh-water runoff or to coastal upwelling and deep water advection1,2.

Borings As Trace Fossils, and the Processes of Marine Bioerosion

Abstract: Marine borers are nearly ubiquitous in the modern seabed. Their distinctive excavations provide abundant potential trace fossils, and their general erosional activities (bioerosion) are important factors in marine sedimentation and benthic ecology.

Energy flow through the benthos in a Scottish Sea Loch

Abstract: Analysis of material collected in settlement traps at regular intervals over a period of a year gave an estimate of the annual organic input to the bottom sediment of about 28 gC/m2 year, which is a little less than one third of the primary production in the overlying water column. The aerobic benthic community metabolism, estimated from in situ respiration measurements, was not significantly different from the carbon input. The rate of release of ammonia from the sediment was also measured in situ and would be sufficient to supply the greater part of the required input of inorganic nitrogen for photosynthesis in the water column.

Girvanella and other algae as depth indicators

Abstract: Girvarzella is interpreted to be the calcified sheath of a variety of filamentous blue-green algae. At present there are no clear limits which can be set on its depth of occurrence. The usefulness of benthic calcareous algae as depth indicators in palaeoenvironmental studies is dependent upon the level of identification. At high taxonomic levels it is very limited. Algae are not restricted to the euphotic zone (ka. 150 m). Calcareous green algae are restricted to shallower water (0-ca. 100 m) than are calcareous red algae (0-ca. 400 m) but they are prone to fragmentation and subsequent transportation. Narrower depth limits for lower taxonomic levels have been demonstrated in Recent green and red algae, but have yet to be recognized in ancient environments. In the Palaeozoic, problems of correctly identifying calcareous algae further restrict their use as depth indicators.

Methane Production in Shallow-Water, Tropical Marine Sediments

Abstract: The in situ production of methane was monitored in several types of tropical benthic communities A bed of Thalassia testudinum located in Caesar Creek (Florida Keys) exhibited the highest methanogenic activity (initial rates = 181 to 186 μmol CH4/m2 per h) as compared with another seagrass (Syringodium sp, 015 to 033 μmol/m2 per h) and two coral reef environments (Hydro-Lab, 0016 to 010 μmol/m2 per h; Curacao, 014 to 047 μmol/m2 per h) The results suggest that a wide variety of benthic metabolic processes (eg, photosynthetic oxygen production) influences methane production rates

The benthos of some southern african lakes part v: the recovery of the benthic fauna of st lucia lake following a period of excessively high salinity

Abstract: Summary St Lucia Lakes (Zululand, South Africa) were sampled with a Van Veen grab in January 1972, July 1972, and January 1973. The system had high salinities at the commencement of the programme (70%0-80%0 False Bay, 55%0-60%0 North Lake, 45%0-58%0 South Lake) which quickly dropped to less than sea-water values in the first six months. The January 1972 samples showed that only a few Polypedilum (Chironomidae) survived in False Bay, while a very reduced faunal list was shown for North Lake (9 sp.). Nevertheless South Lake showed a fairly complete faunal list (21 sp.). By July 1972 nine species were recovered in False Bay, 18 in North Lake and 23 in South Lake, indicating reinvasion consequent upon dilution of the salts in the water. No great change was shown by the result of the January 1973 samples. Evidence suggests that most forms would tolerate salinities up to about 55%0 salinity. Beyond this level only Chironomid larvae and Ostracods survived. Most rapid reinvasion of the denuded parts of the system...

Benthic Organisms and the Structure of Marine Ecosystems

Abstract: The contribution of benthic ecology to biological oceanography has been relatively slight, even though the benthos may be crucial in understanding the dynamics of marine ecosystems, as J. H. Steele...

Oregon Continental Shelf Sedimentation: Interrelationships of Facies Distribution and Sedimentary Processes

Abstract: The nature and distribution of sedimentary facies on the Oregon continental shelf are controlled by several factors: (1) river discharge and sediment input, (2) estuarine circulation system, (3) wave dimensions and direction, (4) subsurface and bottom currents, (5) density stratification of the water column, and (6) reworking by benthic organisms. Most of these factors were probably operating during the Holocene transgression of the sea which deposited a basal sand facies over the shelf. As sea level approached its present position, mud (silt and clay) began to accumulate slowly on the mid-and outer-shelf. Through the reworking by benthic organisms, this mud was mixed into the underlying basal sand creating a mixed mud and sand facies. A mud facies developed in the vicinity of the Columbia, Umpqua, and Rogue Rivers where the rate of mud deposition exceeded the reworking activity. The drowned mouths of coastal estuaries produce a sediment trap for fluvial and marine sand and the silts and clays that come i...

Distribution of Fish Species in Great Bear Lake, Northwest Territories, with Reference to Zooplankton, Benthic Invertebrates, and Environmental Conditions

Abstract: Benthic invertebrates in Great Bear Lake are most highly concentrated in the upper 20 m. Densities between 20 and 100 m are low; below 100 m only Mysis relicta and Myoxocephalus quadricornis exist ...

On the influence of sewage pollution on inshore benthic communities in the South of Kiel Bay

Abstract: 1. The influence of organic sewage pollution on the macrobenthic community structure of a shallow inshore region was studied in the South of Kiel Bay (Baltic Sea). 2. The sandy bottom bears three associations within the pollution gradient. They can be characterized by: (a)Capitella capitata and Oligochaeta (50–100 m distance from the sewage outlet), (b)Pygospio elegans (200-ca. 700 m) and (c)Bathyporeia sarsi (>700 m). They have no distinct borders but resemble rather a continuum. 3. In the less affected reaches the influence of biological substrate structure becomes more evident. Distinct associations can be distinguished. 4. The combination of life forms, number of species, diversity and other community features depend on the degree of the substrate's spatial heterogenity in a characteristic way. They are also strongly influenced by the extent of pollution. 5. The inshore benthic macrofauna provides an important contribution to the self purification of the whole ecosystem by transforming particulate organic matter to available fish food. Abundance and biomass are multiplied due to sewage sedimentation. This process creates the danger of accumulation of poisonous substances in addition to the eutrophication problem. 6. More highly diverse systems (e. g. mussel beds) resist better those factors which directly influence the evenness of the community. The ecological buffer consists of many specialized competitors and predators. Systems low in diversity (e. g. sand) react much more strongly to disturbances of this type. 7. Faunal composition, evenness, species richness, population density and biomass of the communities are suitable parameters of an ecological method for the early recognition of environmental stress.

Impact of kraft pulp-mill effluents on estuarine and coastal fishes in Apalachee Bay, Florida, USA

Abstract: A 2-year field study was carried out to determine the impact of kraft pulp-mill effluents on the fish fauna of a shallow-bay system in north Florida (Apalachee Bay, USA). Offshore areas that received kraft-mill effluents (KME) displayed significant increases in color and turbidity and reductions in (benthic) dissolved oxygen compared to a nearby control area. Estuarine and marsh fish assemblages in areas of acute impact were severely reduced in terms of numbers of individuals (N) and species (S). Offshore areas exposed to varying (chronic) levels of KME were characterized by complex interactions that included seasonal variations of impact. A broad offshore area showed reductions in numbers of individuals and species taken per month. However, the cumulative (annual) number of species taken was the same for polluted and unpolluted (control) areas due to a recruitment of relatively rare species in the areas of impact. Such polluted areas showed decreased dominance as well as qualitative differences in species composition compared to control areas. Inshore bay stations that were most severely affected by KME were dominated by the bay anchovy, Anchoa mitchilli. While species richness and species diversity were lower at the highly stressed stations, in other outlying areas of moderate impact (reduced N and S) there were no reductions of such parameters compared to control areas. Thus, species diversity was not an indicator of pollution per se, and was useful only when taken in conjunction with various other parameters. Transition areas (between polluted and unpolluted portions of the bay) showed substantial (although periodic) increases in N, S, and species diversity. Equitability indices were unchanged in polluted portions of the bay. In general, the effects of KME on offshore fish assemblages appeared to be due to a complex combination of habitat alteration, reduced benthic productivity, and individual behavioral reactions. The alterations of fish assemblages were compared to other studies in this area on benthic macrophytes and invertebrates in an effort to assess the usefulness of various indices in studies on the long-term effects of pollution on estuarine and coastal systems. It was found that kraft pulp-mill effluents had a pronounced effect on the benthic standing crop of plants and animals, but that intensive sampling over prolonged periods of time was necessary for an adequate assessment of the problem. Overall, there were some significant changes in the biota such as reduced dominance and productivity in polluted areas that were similar for the various types of organisms sampled.

Anaerobiosis, Meiofauna and Early Metazoan Evolution

Abstract: Boaden, P. J. S. (Queen“s University Marine Biology Station, Portaferry BT22 IPF, Northern Ireland.) Anaerobiosis, meiofauna and early metazoan evolution. Zool. Scr. 4 (1): 21–24, 1975.–Anaerobic marine sands have a fairly diverse fauna and flora consisting mainly of prokaryotes, protists, gnathostomulids, turbellarians, nematodes and gastrotrichs. An increasing body of evidence shows that the Metazoa from this environment are primitive in many respects. This paper suggests that much early evolution occurred in this habitat. Possible supporting evidence for this theory is discussed. It is concluded that the early Metazoa were benthic anaerobes and well established by the Middle Precambrian Era and that, in addition to the Prokaryota and Protista, the Gnathosto-mulida, Platyhelminthes and Aschelminthes originally evolved under anaerobic conditions.

A synoptic study of the limnology of Lake Thonotosassa, Florida

Abstract: Limnological sampling of Lake Thonotosassa was initiated in 1970 to document current conditions following 15 years of artificial enrichment by organic wastes from primary treated sewage and citrus processing plants, and to provide base-level data for a long-term study of the rates of change following the installation of a secondary sewage treatment facility. Results from the first year of study indicated that the lake was in an advanced state of eutrophy. Inorganic nutrient levels were high; oxygen deficits occurred in the hypolimnion and at the mud-water interface; phytoplankton volumes were large and dominated by blue-green algae; primary productivity rates were comparable with those of grossly polluted lakes; small-bodied herbivores dominated the zooplankton; and benthic invertebrate populations were comprised of an overwhelming abundance of oligochaetes and chironomids. Construction of the new sewage treatment plant reduced the organic load and B. O. D. of the incoming waters and benthic diversity in the inlet subsequently increased. However, in the lake itself decreases in coliform bacteria concentrations were the only signs of immediate influence.

Food and Distribution of Underyearling Brook and Rainbow Trout in Castle Lake, California

Abstract: A difference was found in the summer distribution of underyearling brook trout, Salvelinus fontinalis (Mitchill), and planted rainbow trout, Salmo gairdneri Richardson, in Castle Lake, California. Brook trout underyearlings oriented to the bottom and were found primarily in shallow water on the eastern shore of the lake near springs. The rainbow trout underyearlings were more pelagic and were found in the littoral areas along the entire shoreline. Gravimetrically, the food eaten during the summer by brook trout underyearlings was 13% terrestrial, 11% limnetic, and 76% benthic. Rainbow trout ate 15% terrestrial, 15% limnetic, and 70% benthic food. In summer, rainbow trout adults are located in the epilimnion in Castle Lake, whereas adult brook trout are found near the bottom of the lake beyond the littoral zone. Due to this spatial isolation, their diets differ considerably. An earlier study showed that during the summer, adult brook trout ate 20% terrestrial, 31% limnetic, and 49% benthic food (b...

Yellow Perch (Perca flavescens) Biomass Responses to Different Levels of Phytoplankton and Benthic Biomass in Lake Memphremagog, Quebec–Vermont

Abstract: Perch biomass in Lake Memphremagog, Quebec was 2.5 times greater in the more productive south than in the less productive north basins. This difference is on the same order of magnitude as biomass ...

Community patterns on a submerged barrier reef at Barbados, West Indies

Abstract: A quantitative survey of a submerged barrier reef was undertaken in Barbados, West Indies, over a two year period (1971–73). Photo-line transects were employed to obtain coverage data on corals and other benthic organisms. Light, sedimentation, currents, oxygen, temperature and salinity were also monitored. Results indicate corals cover about 30 per cent of the bottom with living colonies; another 7 per cent is contributed by other zoobenthos. The most abundant coral species are Montastrea annularis, M. cavernosa and Siderastrea siderea, each contributing between 4 and 5 per cent of bottom cover. Light is the only physical factor monitored that correlated significantly with biomass; sedimentation may have a secondary effect. Most of the barrier reef is composed of mixed coral associations forming a biologically accommodated community. Comparisons are made between the barrier reef in Barbados and deeper reefs in Jamaica and Curacao. Reefs are, in the main, similar but coral species and community structure differences do occur.

Types of larval development in Littorinidae (Gastropoda: Prosobranchia) of the World Ocean, and ecological patterns of their distribution

Abstract: Relationships between the types of larval development in 4 species of Littorina from British shores and their inhabitancy of different tidal levels were established by Woodward (1909). His data have led to the view that the Littorinidae present a “text-book” example illustrating obligate interrelationships between the distribution of marine bottom invertebrates in certain biotopes and the possession by them of definite types of larval development. Analysis of data describing larval development of 39 species of littorinids from various regions of the World Ocean covering all its climatic zones, from the tropics to the Arctic, accumulated in the literature (Tables 1-5) demonstrates, however, that there exists only a relationship between viviparity and the inhabitancy of supralittoral zones, and between direct development and the inhabitancy of littoral zones. In 34 out of 39 littorinid species studied pelagic development, in various modifications, is present at all tidal levels; it is most common in the supralittoral zone, but not in the sublittoral zone, as has been generally assumed. The data presented in Tables 1-5 confirm the author's opinion (Mileikovsky, 1971, 1973) that the concept of obligate interrelationships between definite types of larvel development in marine benthic invertebrate and their existence in definite biotopes, based on Woodward's scheme, is false and must be rejected.

A community Analysis of the Benthic Insect Fauna of an Abandoned Beaver Pond

Abstract: Over the past decade the importance of allochthonous organic matter as an energy source in aquatic system has received increasing attention. Data are available for streams (Nelson & Scott 1962; Minshall 1967; Kaushik & Hynes 1971), lakes (Wetzel et al. 1972) and rivers (Berrie 1972), but ponds have received little attention. Allochthonous detritus type (Woodall & Wallace 1972), distribution (Egglishaw 1964) and possibly particle size (Cummins & Lauff 1969) have been shown to influence the distribution and hence faunal composition of stream insect communities. Beaver ponds are a characteristic feature of the forested foothill areas of the Rocky Mountains of North America. They are formed by the damming of streams, and at time of formation there is an input of allochthonous material into the pond equal to the standing crop of vegetation plus leaf litter on the flooded area. Furthermore, after being abandoned by beavers, seral succession proceeds and hydrophytes such as Salix sp. colonize the pond margins and ensure a continued input of plant detritus. The objectives of this study were to examine the feeding biology, distribution relative to substrate type and adult phenology of the benthic insect communities associated with a shallow abandoned beaver pond and to assess the importance of allochthonous detritus as a food source for these insects. The insect fauna of such ponds (Appendix 1) differs markedly from that of streams, rivers and lakes (see Hynes 1970), larvae of the Diptera, especially Tipulidae, are the major faunal component: the Chironomidae are poorly represented. Unfortunately, the larval systematics of the Diptera are poorly known and this creates problems.

The Input and Significance of Particulate Terrestrial Organic Carbon in a Subalpine Freshwater Ecosystem

Abstract: In a freshwater ecosystem there are four contributors to the pool of primary produced plant material available for animals, fungi and bacteria: phytoplankton, macrophytes, benthic and epiphytic algae, and allochthonous plant material. Both the relative and absolute amounts of these four components are different in various water bodies.

Quantitative Biological Assessment of the Benthic Fauna in Deep Basins of the Gulf of Maine

Abstract: The abundance, biomass, and diversity of the macro- and mega-fauna in the deep basins of the Gulf of Maine were estimated from 41 quantitative infaunal samples and 19 visual transects made with the...

Quantitative studies on benthic macrofauna of north-eastern Arabian Sea shelf

Abstract: THE orth-eastern Arabian Sea, which is a very pr uctive area in the Indian Ocean1, is not ad uately studied2,s for its benthic fauna. A surve on the benthos of the continental shelf of this regi was undertaken between December 1973 and May 1974. The area covered, is approximately 276000 s . km, lying between latitudes 24° and 16° Nand 1 gitudes 74° and 66°E and extends in the depth ra ge of 20-140 m. Materia s and Methods