bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ bioassays with Chironomus riparius: Laboratory-field comparisons of sediment toxicity and effects during wintering
Authors: den Besten P. J. , Naber A. , Grootelaar E. M. M. , van de	 Guchte C.
Published: October 2003

A field bioassay was developed to study the in situ effects of sediment contamination on Chironomus riparius larvae. The survival, development rate and increase in Chironomus larvae biomass was compared between laboratory bioassays with the field cages. The incidence of mentum deformities was compared not only between laboratory and field bioassays but also with observations on field populations of Chironomus larvae. Survival in the field bioassays was slightly higher than the laboratory, except at locations with known contamination of the surface water. The influence of surface water quality in field bioassays was demonstrated in translocation experiments, in which clean sediment was placed in a polluted site, and vice versa. In a field bioassay carried out in the autumn, an inverse relationship between the rate of development and the initial larval density in the field cages was apparent. In addition, in the field bioassays with C. riparius considerable seasonal variation in the survival and incidence of mentum deformities was found. Field bioassays performed during the winter season indicate that low temperatures can interact with or add to the effects of sediment contamination on chironomid populations.
Quality control of drinking water from the River Rhine with the Multispecies Freshwater Biomonitor
Authors: Gerhardt A. , Janssens de Bisthoven L. , Penders E.
Published: October 2003

The Multispecies Freshwater Biomonitor (MFB) based on quadropole impedance conversion technique is a “biological early warning system” (BEWS) for online water quality biomonitoring. The aim of this study was to test the MFB with two crustaceans (Gammarus pulex and Daphnia magna) in a drinking water processing plant at the River Rhine: 1) Sensitivity of the test species to short-term acid pulses and alarm-responses in the MFB were studied in the laboratory. 2) Long-term monitoring with Gammarus pulex and Daphnia magna in the MFB was performed in situ. A decrease in pH, especially below pH 6.8, resulted in a significant behavioural response of both species according to the Stepwise Stress Model. After a first escape response of D. magna, both species reacted similarly with decreased activity and G. pulex additionally with increased ventilation. G. pulex survived better than D. magna. The behavioural effects remained in the recovery phase. Long-term monitoring showed stable locomotory behaviour and better survival of G. pulex when compared to D. magna. The MFB can be recommended for drinking water control using G. pulex as test species.
A diversity based fuzzy systems approach to ecosystem health assessment
Authors: McGlade Jacqueline M.
Published: October 2003

Ecosystem health assessments generally rely on combining information from variable-oriented surveys and case-studies, which at their extreme represent the ends of an inverse relationship between variables and instances. However, many of the underlying assumptions of both types of analysis, such as homogeneity of systems, simple chains of causality and the representativeness of data, are sufficient to pose fundamental problems in any overall interpretation and analysis. In this paper, an alternative approach is presented which bridges the two extremes and explicitly deals with uncertainty, beliefs and ignorance, complex causality, sufficiency and necessary conditions and diversity amongst classes of attributes and configurations. It adopts a diversity-oriented approach, using fuzzy set theory and logic to construct multiattribute configurations to be able assess different health outcomes. An example of a diversity-based health assessment is presented for the North Sea ecosystem. The results show how sectoral and social benefits over the past 45 years have accrued at the expense of the ecosystem, as evidenced in sets of multiattributes for biodiversity, trophic stability and pollution, despite gains in governance and social cohesion.
Use of rare macroinvertebrate taxa and multiple-year data to detect low-level impacts in rivers
Authors: Turak E. , Koop K.
Published: October 2003

Predictions from AUSRIVAS were used to compare macroinvertebrate data from samples collected over several years from two nearby river sites in the Hunter Valley Region in NSW, Australia. One of the sites was in agricultural land and the other one was in a National Park. Both sites had good water quality and a diverse range of macroinvertebrate habitats.

The AUSRIVAS output most commonly used for assessing river condition is the Observed/Expected (O/E50) value. Only relatively common taxa, ie those that have greater than 50% probability of occurrence are included in the calculation of O/E50 values. T-tests used to test differences between the mean O/E50 values for the individual samples showed no significant differences between the two sites. When similar analyses were performed on outputs calculated using rare taxa, significant differences were found between the two sites for the riffle habitat but not for the edge habitat.

Including the rare taxa in calculating AUSRIVAS outputs and utilising multiple-year outputs for assessing site condition may allow detection of impacts not detected by examining the commonly used outputs.
Phytoplankton responses to nutrient sources in coastal waters off southeastern Australia
Authors: Pritchard T. R. , Lee R. S. , Ajani P. A. , Rendell P. S. , Black K. , Koop K.
Published: October 2003

Reports of visible algal blooms have increased in New South Wales (NSW) coastal waters since 1990. Our three-year, multi-disciplinary study assessed the relative importance of natural and anthropogenic nutrients on the development of phytoplankton blooms in the waters between Port Stephens and Jervis Bay. The hinterland of this region accommodates 85% of the population of the 6.5 million inhabitants of New South Wales, Australia. Three deepwater outfalls represented the principal, continuous, anthropogenic nutrient source with nitrogen mainly in the bioavailable form of ammonia. Sewage effluent typically remained submerged especially during the spring-summer period when algal blooms occur most frequently. On average, coastal catchments contributed relatively small loads of nutrients except during major flood events because extensive estuaries tend to buffer nutrient fluxes to the ocean. Episodic slope water intrusions were the principal source of nitrogen (nitrate) to coastal waters especially during spring and summer. Phytoplankton blooms appeared to occur in response to slope water intrusions irrespective of proximity to other major nutrient sources. A new understanding of mechanisms of slope water intrusion emerged from model simulations and direct observations. A major upwelling event in January 1998, towards the end of the 1997/98 El Niño period, demonstrated the importance of large scale slope water intrusions on the development of algal blooms. Although natural upwelling/uplifting was found to be the principal driver for major algal blooms, it is possible that more subtle impacts of anthropogenic nutrients may be masked by ‘natural’ variability including that due to the El Niño Southern Oscillation.
Long-term changes in functional properties and biodiversity of plankton in Lake Greifensee (Switzerland) in response to phosphorus reduction
Authors: Bürgi H. R. , Bührer H. , Keller B.
Published: October 2003

Lake Greifensee, a dimictic lake situated near Zürich, Switzerland, has been monitored chemically and biologically since 1971, a period during which total phosphorus concentration changed dramatically. Based on analysis of cores of the lake sediment, this lake was oligotrophic 120 years ago. Due to a rapid increase in population in the catchment area to about 100,000 inhabitants, the phosphorus input from sewer systems eventually exceeded the tolerable P-load of 2.3 t y−1. In the early 1970s, this lake was hypertrophic (ca. 600 mg m−3 total phosphorus). Due to P-elimination in sewage treatment plants and a ban of P-containing detergents, phosphorus concentrations declined to less than 50 mg m−3 in spring 2000 (overturn value). Currently we observe growth-limiting phosphorus concentrations in the trophogenic layer from May to November. Therefore, primary productivity dropped from >700 g C m−2 y−1 at the beginning of our investigations (1971) to approximately 400 g C m−2 y−1 in 2000, which is still in the eutrophic range. Ammonia concentrations in the hypolimnion decreased significantly over this period. However, anaerobic conditions still regularly occur in the hypolimnion during May/June.

Although total biomass values of phytoplankton or zooplankton did not show any correlation with the long-term decline of phosphorus concentrations, the composition of different systematic groups showed clear trends. During the period with Ptotal concentrations of >250 mg m−3 phytoplankton biomass was dominated by chlorophytes and cryptomonads, with lesser amounts of diatoms and dinoflagellates. Cyanobacteria and chrysomonads were of minor importance. With declining P load cyanobacteria biomass increased while chlorophytes and dinoflagellates decreased. Chrysomonads and pennate diatoms attained substantial portions, Zooplankton community did not change markedly. Main fraction was contributed by the herbivorous crustaceans, about 20% of total zooplankton biomass was carnivorous.

Functional properties of phytoplankton showed closer relationship with P decline than biomass of systematic groups of algae. Under hypertrophic conditions r-strategists were dominant, especially during spring and early summer. K-strategists were more abundant under moderate eutrophic conditions in the second half of the year. Motility and buoyancy are very important in lakes with thin trophogenic layer (5 m in Lake Greifensee). Nonmotile plankton could survive during overturn (enhanced turbulence) and during clear water periods, whereas motile plankton groups dominated during thermal stratification.

The best criteria for measuring resilience of Lake Greifensee are species richness, biomass-based diversity and evenness indices of phytoplankton and the strength of coupling between different trophic levels. With declining phosphorus content, species richness and diversity indices of phytoplankton increased.
An integrated assessment of the ecosystem health of a protected area: Fathom Five National Marine Park, Lake Huron
Authors: Munawar M. , Munawar I. F. , Dermott R. , Johannssen O. E. , Lynn D. , Munawar S. F. , Niblock H.
Published: October 2003

An assessment of the aquatic ecosystem health of Fathom Five National Marine Park was carried out in an integrated fashion by applying a multi-trophic suite of structural and functional techniques to evaluate the food web (bacteria, heterotrophic nanoflagellates, ciliates, autotrophic picoplankton, phytoplankton, zooplankton and benthos). Extensive biotic assessment revealed the Fathom Five National Marine Park to be an oligotrophic healthy ecosystem similar to Lakes Huron and Superior. The multi-trophic and integrated food web assessment strategy applied previously in the Great Lakes was adopted for the evaluation of a protected area for the first time. Our approach is recommended for ecosystem health monitoring of other protected areas since it is sensitive, rapid, and holistic and includes the entire pelagic food web.
Assessing coastal practitioners' views on environmental indicators: Case studies in U.S. Pacific Northwest estuaries
Authors: Ferriss Bridget E. , Leschine Thomas M.
Published: October 2003

An online survey of coastal practitioners, followed by personal interviews, was conducted to examine the potential of environmental indicators as tools in the management of estuaries along the Washington and Oregon coasts (U.S.A.). Specifically, the perceptions of coastal practitioners regarding current uses of indicators and factors limiting indicator use were explored. Results show that the organizations we surveyed generally do not use indicators to their full potential. Indicator use and factors limiting their use vary across both levels of government (Local, State, Federal) and job functions (Administration, Research, Planning & Development, Management, Education & Outreach). Limiting factors include lack of resources and unfamiliarity with indicators, especially in local management. These results demonstrate that while indicators are potentially beneficial management tools, realizing these benefits likely requires tailoring to the specific needs and limitations of intended users. The scientific community is well aware that a single set of environmental indicators can not be applied across all geographic or ecological scales. This study demonstrates that it is also necessary to recognize the breadth of the spectrum of user groups and management contexts, and how their individual characteristics may affect the applicability of environmental indicators, for them to be truly useful to management.
Imperilled subsurface waters in Australia: Biodiversity, threatening processes and conservation
Authors: Boulton A. J. , Humphreys W. F. , Eberhard S. M.
Published: October 2003

Subsurface waters in Australia span massive aquifers to small cave streams and fluctuating hyporheic zones where stream water exchanges with groundwater. Groundwater resources have been exploited heavily, especially in the arid zone, and usage is predicted to increase. Ironically, preliminary surveys of some groundwater habitats in arid northwestern Australia indicate an extraordinarily diverse subsurface fauna with apparently highly localised distributions. Elsewhere in Australia, changes to river flows, gravel extraction, and poorly managed catchment land uses have altered the extent and ecological integrity of the hyporheic zone in most gravel and sand bed rivers. In many cave streams and karst aquifers, sedimentation, pollution and changes to the water table have caused extinction or reduction of the dependent biodiversity. Most of these subsurface habitats harbour ancient groups absent from surface waters (relictual stygofauna) and are ‘hotspots’ of unexpected aquatic biodiversity.

Unfortunately, our knowledge of the regional extent of this biodiversity and its functional significance is fragmentary. Current threats vary according to the subsurface habitat. For example, lowering of the water table in calcrete aquifers by water abstraction may jeopardise isolated, endemic relictual faunas in Australia's arid zone whereas in many gravel bed rivers, siltation threatens the biodiversity and filtration capacity of the hyporheic zone. Groundwaters in karst, especially cave streams and their dependent fauna, are vulnerable to impacts in their surface catchments but these linkages are seldom obvious. Recognition of the intimate linkages between groundwater and many surface ecosystems has led recently to policies aimed at protecting ‘Groundwater Dependent Ecosystems’ in Australia. However, such protection is hampered by our scant taxonomic and ecological knowledge of these ecosystems. Successful conservation and management of groundwaters and their dependent ecosystems rely on better public understanding of their unique fauna and ‘ecosystem services,’ further research on subsurface processes and taxonomy, and legislative protection of rare and threatened subterranean communities and species.
Australian wetland plants and wetlands in the landscape: Conservation of diversity and future management
Authors: Brock Margaret A.
Published: October 2003

The plant communities that are a feature of Australian shallow wetlands reflect the dynamics of their flooding and drying patterns. Anthropogenic changes to wetlands at individual wetland, catchment and landscape scales can change availability of plant habitats and hence the diversity of wetland plants. Policies for conservation of wetlands and the need for integrating policy, management and science in their implementation are addressed as a way forward for conservation. The natural dynamics of wetland plants and wetlands in the landscape are discussed and their resilience considered as an indicator of response to change. Plant community responses to induced change from alteration of water quantity and delivery (timing, frequency, duration and variability of flooding and drying), water quality, invasions and grazing are demonstrated. The responses of wetland plants, communities and wetlands to different flooding and drying patterns from field observation, experimental testing in glasshouse, outdoor tank trials, field scale experimental wetlands and field manipulations are presented to show how research can form the basis of extrapolation and generalization which can be used for prediction of change. The maintenance of mosaics of wetlands is suggested as a way of conserving biodiversity and enhancing resilience of wetlands in the landscape. The need for collaboration between researchers and conservators to establish principles of precautionary management is proposed.
Ecological impacts and institutional and economic drivers for water resource development—a case study of the Murrumbidgee River, Australia
Authors: Kingsford R. T.
Published: October 2003

Much of the world's water for humans comes from rivers for drinking, generating hydro-electricity, industry and irrigation. Dams and diversions reduce downstream flows, particularly to floodplain wetlands, and their fauna and flora. For many countries, including Australia (75% of water use), the greatest user of water is irrigated agriculture. The Murrumbidgee River in the Murray-Darling Basin is one of the most regulated major rivers in Australia. Water resource development, including the building of 26 storages, over more than 140 years on the Murrumbidgee River in southeastern Australia destroyed or degraded at least 76% of the floodplain that once covered 304,000 ha. Remaining wetland areas are also considerably altered. Water resource development in the catchment with subsequent diversion of water and recent development of the floodplain were the main causes of wetland loss. Establishment of two major irrigation areas in Australia, the Snowy Mountains Hydro-electric Scheme and Australia's capital, Canberra were all drivers for upstream development of water. The major local drivers were community values and expectations of water, reflected in Government decisions and legislation. The water and hydro-electricity agencies were primarily responsible for most of the water resource development before the 1970. After 1980, changing expectations on the Lower Murrumbidgee floodplain and Government investment produced rapid development of the floodplain for irrigation. Likely environmental costs were not adequately considered or made explicit for transparent decision-making. Such case studies need to be used when considering likely impacts of future water resource developments on other river systems.
Conservation of the platypus, Ornithorhynchus anatinus: Threats and challenges
Authors: Grant T. R. , Temple-Smith P. D.
Published: October 2003

The platypus (Ornithorhynchus anatinus) is an Australian icon. It is an integral part of the biodiversity of many eastern Australian freshwater ecosystems and is protected by legislation in all States in which it occurs. Its conservation is of considerable importance not only because of its unique features, status and niche but also because it is the only living representative of a significant lineage of platypus-like animals with a 60 million year fossil history. As a result of its specific habitat requirements it is affected by many of the widely recognised threatening processes operating in Australian limnological systems. In spite of these threatening processes, the species has continued to inhabit and reproduce in considerably degraded environments. The present overall distribution of the platypus appears to be little different from pre-European times. There are, however, now almost certainly no naturally occurring populations in South Australia, where it once occurred, and its distribution has apparently shrunk in the lower reaches of the Murray and Murrumbidgee River systems in Victoria and New South Wales. Despite being considered common throughout its current distribution its abundance is not readily measured and therefore its future conservation status is not easily predicted. Several studies have reported fragmentation of platypus distribution within individual river systems. This has been attributed to poor land management practices associated with stream bank erosion, loss of riparian vegetation and channel sedimentation. There is currently also evidence for adverse effects of river regulation and impoundments, introduced species, poor water quality, fisheries by-catch mortality and disease on platypus populations, but none of these has been well studied. Investigations of these aspects of the species’ biology and interaction with human activities are research priorities, while management priorities include the development and implementation of strategies aimed at reducing the effects of these human activities on the platypus and its habitat.
From mound springs to mighty rivers: The conservation status of freshwater molluscs in Australia
Authors: Ponder Winston F. , Walker Keith F.
Published: October 2003

New morphological, ultrastructural, and molecular techniques have reinvigorated interest in molluscan diversity and phylogeny in Australia. Research in the last two decades has revealed a large fauna of small gastropods, including over 260 species of Hydrobiidae. Many are confined to small areas, including springs associated with the Great Artesian Basin. New members of other snail families, notably the Viviparidae and Bithyniidae, have been found in northern Australia. River regulation has decreased the range and abundance of once common species, particularly in the Murray-Darling Basin. While only four freshwater mollusc taxa are officially recognized as “endangered,” several others would qualify and many warrant protection. Investigations of systematics, ecology and biology are urgently needed to facilitate conservation of freshwater molluscs in Australia.
Ecological position of ‘small barbs’ and their potential for fisheries: An option to reduce fishing pressure on ‘large barbs’ of Lake Tana (Ethiopia)?
Authors: Dejen Eshete , Osse Jan W. M. , Sibbing Ferdinand A.
Published: October 2003

The two barbs, Barbus humilis and Barbus tanapelagius are important pelagic fish in Lake Tana. These ‘small barb’ species (<10 cm fork length) play a key role in the Lake's ecosystem as a link between zooplankton and the top predators, mostly ‘large barbs’. This paper presents an overview on the position of ‘small barbs’ in the food web of Lake Tana as indicated from gut content analysis. Barbus tanapelagius, the most abundant and specialized species, exploited zooplankton. Barbus humilis mostly fed on detritus and zooplankton. Barbus tanapelagius, and to some extent the benthopelagic Barbus humilis, transferred energy from zooplankton to the top level of the food web. Barbus humilis is a vector of energy and biomass from detritus to top predators. Pelagic fisheries are proposed as an option to reduce fishing pressure on the endemic species flock of ‘large barbs’. If, however, a fishery on the ‘small barbs’ is proposed to increase the sustainable yield, implications on the ecosystem balance should be critically assessed. Regulations should be recommended for these fisheries (gear, habitats and season) accounting for the biological constraints.
Shifts in the diets of slimy sculpin (Cottus cognatus) and lake whitefish (Coregonus clupeaformis) in Lake Ontario following the collapse of the burrowing amphipod Diporeia
Authors: Owens Randall W. , Dittman Dawn E.
Published: October 2003

In Lake Ontario, the diets of slimy sculpin Cottus cognatus and lake whitefish Coregonus clupeaformis shifted from a diet dominated by the burrowing amphipod, Diporeia, and to a lesser extent, Mysis, to a more diverse diet, after Diporeia collapsed, to one dominated by Mysis and prey that were formerly less important or uncommon such as Chironomidae, Oligochaeta, and Ostracoda. Additionally, lake whitefish still preyed on native mollusks like Sphaeriidae and Gastropoda, but also preyed on exotic mollusks, Dreissena spp., which are swallowed intact and subsequently crushed in its muscular stomach. Whether Diporeia was abundant (1992) or scarce (1999), selection indices for Diporeia by slimy sculpins was positive, suggesting that Diporeia was a preferred prey. Unlike lake whitefish, slimy sculpins avoided Dreissena; therefore, energy diverted to Dreissena production was a real loss for slimy sculpins. The shifts in the diet of these benthic fishes corresponded with drastic changes in the benthic community between 1992 and 1999. The collapse of Diporeia, formerly the most abundant macroinvertebrate in the benthic community, along with sharp declines in the abundance of Oligochaeta and Sphaeriidae, coincided with the establishment and rapid expansion of Dreissena bugensis, the quagga mussel, and to a lesser degree Dreissena polymorpha, the zebra mussel. It appears that the Diporeia population first collapsed at depths >70 m in southeastern Lake Ontario by autumn 1992, at shallower depths in the eastern Lake Ontario by 1995, and along the entire south shore line at depths <100 m, and perhaps in some areas >100 m by 1999. In response to the disappearance of Diporeia, populations of two native benthivores, slimy sculpin and lake whitefish, collapsed in eastern Lake Ontario, perhaps due in part to starvation, because Diporeia was their principal prey. Presently, alternative food resources do not appear sufficient to sustain these two benthivores at their former levels of abundance. We do not expect slimy sculpin and lake whitefish to recover unless Diporeia returns to earlier levels of abundance.
Effect of wind induced water movements on nutrients, chlorophyll-a, and primary production in Lake Tanganyika
Authors: Langenberg V. T. , Sarvala J. , Roijackers R.
Published: October 2003

We determined the spatial and temporal distribution of major plant nutrients, dissolved oxygen, chlorophyll-a and primary production, at three deep-water locations in Lake Tanganyika to infer patterns of water displacements and to interpret the impact of wind-generated changes in nutrients on the timing and magnitude of phytoplankton production.

In the southern end of the lake, the onset of cooler, windier conditions during May–September caused stratification weakening, tilting of isotherms and upwelling of dissolved inorganic nitrogen and soluble reactive phosphorus from nutrient-rich deeper waters. These factors coincided with an increase in chlorophyll-a concentrations but not with clear evidence of increased primary production. An internal seiche at that time seemed associated with similar but less pronounced events at the other stations after cessation of the winds.

We suggest that internal seiching can spread kinetic energy throughout the lake, triggering upward nutrient fluxes through mixing elsewhere. The response to water displacements in terms of nutrient supply to the epilimnion seems to be governed by differences in the strength of vertical temperature, and by nutrient and dissolved oxygen gradients. At the most northern station, these gradients were strongest and closest to each other and throughout the year primary production rates, phosphorus and chlorophyll-a concentrations in the euphotic zone appeared generally higher than at the other stations, probably also because of increased nutrient input from the Rusizi River.

We emphasise that the intra- and interannual differences between the strength of lake stratification and wind regime are of major importance in determining the extent of upwelling events upwind as well as internal seiching strength and duration. That consequently affects the extent of internal nutrient loading throughout the lake and ultimately plays an important role in the lake trophic status.
Autotrophic picoplankton in Lake Baikal: Abundance, dynamics, and distribution
Authors: Belykh O. I. , Sorokovikova E. G.
Published: October 2003

The autotrophic picoplankton of Lake Baikal was discovered more than 30 years ago; the productivity of the endemic member of the group, Synechocystis limnetica, is of particular interest. In the course of long-term investigations, the abundance of this species was established using the sedimentation technique. Maximum abundance was reached at 104 cells per ml in summer. In addition to estimating the distribution of this species throughout a defined lake area during the spring-summer period, the character of interrelations with large phytoplankton was revealed.

Baikalian autotrophic picoplankton was studied from 1997 to 2000 using epifluorecsence and scanning electron microscopy. The study of seasonal and annual dynamics of picoplankton abundance was conducted monthly at the monitoring station in southern Baikal. The spatial distribution of autotrophic picoplankton was observed in the period when Lake Baikal was free of ice; the lake area was defined by 50 stations. Microscopic examination of planktonic samples revealed that the phycoerythrin-rich cyanobacteria of genus Synechococcus generated the largest biomass of autotrophic picoplankton in Lake Baikal. Morphotype diversity of the representatives of genus Synechecoccus was revealed in the study: Synechococcus spp. of coccoid and ellipsoid forms were dominant by abundance. The coccoid and ellipsoid forms had diameters of 0.9 and 0.7 to 1.3 μm, respectively. The portion of picoplanktonic algae in the Baikalian picoplankton community is not high and does not exceed 10% in the summer time when growth is highest.

The autotrophic picoplankton abundance throughout the year in the 0–50 m layer varies by more than one hundred times. Maximal concentration of picocyanobacteria occurs in late July–August at 10 to 25 m depths where it reached 106 cells ml−1. The minimal concentration (103 cells ml−1) was observed in December at the same depths. A small peak of the picoplankton growth occurred in April of each year when the total numbers of picocyanobacteria increased 2 to 4 times after winter. In 1999 the peak rose to 105 cells ml−1 . During the investigation period the highest indices of autotrophic picoplankton numbers were observed in 1999 and the lowest in 1997. The spatial distribution of this group in the whole Baikal aquatorium was characteristically heterogeneous; its abundance varied by 2 to 10 times in different parts of the lake. The largest fluctuation occurred in August and the least in September. The maximum picoplankton abundance was observed in the epilimnion during the periods of thermal stratification. In the course of homothermy a comparably homogeneous distribution of picocyanobacteria was revealed up to 300 m depth, but the highest numbers were found in the upper 30 m layer.
Improving fishery catch statistics for Lake Victoria
Authors: Cowx I. G. , van der Knaap M. , Muhoozi L. I. , Othina A.
Published: October 2003

The fisheries of Lake Victoria are highly dispersed and catch statistical information is insufficient for supporting management. Catch assessment surveys for the three riparian countries were found to be weak or inadequate and a strategy for improving this source of information is proposed. Considerable illegal fishing, using banned gears and small-meshed nets was prevalent and considered to be detrimental to the sustainability of the fishery. The principal problems underlying the poor fishery assessment were inadequate resources, poorly trained and unmotivated personnel, and externalities, such as poverty and poor employment opportunities, which override the resource monitoring and assessment mechanisms.
Size-fractionated δ15N and δ13C isotope ratios elucidate the role of the microbial food web in the pelagial of Lake Tanganyika
Authors: Sarvala J. , Badende S. , Chitamwebwa D. , Juvonen P. , Mwape L. , Mölsä H. , Mulimbwa N. , Salonen K. , Tarvainen M. , Vuorio K.
Published: October 2003

Food web structure of the pelagic community in Lake Tanganyika was studied using the stable nitrogen and carbon isotopes 15N and 13C. Size-fractionated seston, zooplankton, shrimps, medusae and fish were sampled in the northern part of Lake Tanganyika. Picoplankton fractions as well as cyanobacteria-dominated nano/microplankton fractions had very low nitrogen isotope signatures typical for nitrogen-fixing organisms. Fractions containing mainly dead organic matter (and associated bacteria) or nano/microalgae (chlorophytes and diatoms) had δ15N 2 to 4‰ higher. The low δ15N signatures of small cyclopoids and shrimps suggest they are feeding on nitrogen-fixing cyanobacteria (picoplankton or larger forms), while the higher δ15N signature of larger copepods suggest mixed feeding on large algae and small zooplankton and/or cyanobacteria. Medusae were slightly enriched in δ15N relative to large copepods. Among fish, the signatures of Stolothrissa and small Lates stappersi suggested feeding on large copepods, while Limnothrissa and larger Lates were slightly more enriched, indicating partial piscivory. The enrichment of 13C between the putative trophic levels (2 to 3‰) was higher, while that of 15N (2 to 3‰) was lower, than usual in isotope studies. Our results indicate that picocyanobacteria and possibly also larger cyanobacteria are important producers in the pelagic food web of Tanganyika.
A hypothesis for the assessment of the importance of microbial food web linkages in nearshore and offshore habitats of the Laurentian Great Lakes
Authors: Heath Robert T. , Hwang Soon-Jin , Munawar Mohiuddin
Published: October 2003

Our work in the Laurentian Great Lakes of North America indicates that significant fluxes of carbon and phosphorus can pass through the microbial food webs (MFW) of these lakes. Here we present a synthesis of our recent investigations conducted largely along a trophic axis from the heavily eutrophic coastal Sandusky Bay to offshore communities near the international boundary in the central basin of Lake Erie. We find that the significance of the MFW in transporting C and P to higher trophic levels differs along a trophic gradient. In relatively eutrophic nearshore communities, most C and P are fixed into phytoplankton, transport of materials is largely dependent on grazing by cladocerans, and transport through the MFW is relatively insignificant. In contrast, in relatively oligotrophic offshore communities bacterial biomass often exceeds phytoplankton biomass, the majority of P is fixed into bacteria, bacterivorous grazers (e.g. rotifers and protozoa) dominate, copepods are the dominant microcrustacean, and transport of C and P through the MFW represents a major pathway. We suggest that the management of large-lake ecosystems is largely based on relatively eutrophic “nearshore” views of the base of the food web and needs to be modified to include considerations of the MFW in the more oligotrophic offshore regions of these lakes.
Abundance, biomass and estimated production of planktonic ciliates in Lakes Victoria and Malawi
Authors: Yasindi Andrew W. , Taylor William D.
Published: October 2003

The abundance, biomass and composition of planktonic ciliates were studied in two Great Lakes of Africa, Malawi and Victoria, between June, 1997, and June, 1999, to investigate their role in the food webs of these lakes. Oligotrichs (Strombidium , Strobilidium and Halteria) were the most abundant group of ciliates in both lakes. Other important ciliates in terms of abundance and/or biomass included heterotrichs, peritrichs, haptorids, and peniculids. Mean ciliate abundance was 1.5 ciliates · mL−1 and 20.1 ciliates · mL−1 in Lakes Malawi and Victoria, respectively. Ciliate biomass ranged from 0.03 to 7.82 μg C · L−1 (mean 1.8 ± 0.7 μg C · L−1) in Lake Malawi and ranged from 24.2 to 61.82 μg C · L−1 (mean 36 μg C · L−1) in Lake Victoria. Ciliate abundance and biomass were higher at offshore than inshore stations of both lakes despite that chlorophyll exhibited the opposite trend. Both lakes demonstrated vertical and temporal variation in their ciliate communities as well. Herbivores were an important feeding guild in both lakes, while mixotrophs and bacterivores were also important in Lakes Malawi and Victoria, respectively.
“You Cannae Just Take Cigarettes Away from Somebody and No' Gie Them Something Back”: Can Social Marketing Help Solve the Problem of Low-Income Smoking?
Authors: MacAskill Susan , Stead Martine , MacKintosh Anne Marie , Hastings Gerard
Published: October 2003

Smoking levels have not declined among those living in disadvantaged communities in the UK, presenting a major public health concern. Drawing on qualitative and quantitative data, this article suggests that core concepts of social marketing provide a meaningful framework for identifying appropriate smoking cessation interventions and policy responses. Understanding the consumer reveals that tobacco meets many needs in the struggle to cope with limited income intensified by poorly resourced local infrastructure and limited opportunities. An almost overwhelming range of threats to cessation includes the impact of disadvantage, strong prosmoking norms and environments, and, unsurprisingly, the tobacco industry's reinforcement of continued smoking. Important opportunities include smokers' underlying wish to be nonsmokers, positive responses to new approaches, and gradual amelioration of problems for which smoking provides a coping mechanism. Finally, what is the meaningful exchange that can be offered to smokers in the challenging quitting process? Better health or more money alone are unlikely to be accepted as realistic benefits. Instead, integrated long-term support is required, reflecting the long-term reinforcement strategies of the tobacco industry. At a macro level, policies address hardship. At a community level, increased resources and training give workers tangible products and greater confidence. At a micro level, smokers need tailored “packages” of support, addressing personal barriers to success.
Public Health Social Marketing: The Immunise Australia Program
Authors: Carroll Tom E. , Van Veen Laurie
Published: October 2003

The case study presented here represents the application of social marketing theory and practice to increase the levels of full age-appropriate childhood immunization as part of the Immunise Australia Program. In 1995, an Australian Bureau of Statistics survey found that only 33% of Australian children up to 6 years of age were fully immunized according to the schedule being recommended at the time, and 52% were assessed as being fully immunized according to the previous schedule (ABS, 1996). In response to this situation, the Australian Government formulated the Immunise Australia Program. This program comprised a number of initiatives, including:

▪ improvements to immunization practice and service delivery; ▪ establishment of a National Centre for Immunisation Research and Surveillance; ▪ negotiation with State and Territory Governments to introduce requirements for immunization prior to commencing school; ▪ financial incentives for doctors and parents/guardians; ▪ a national childhood immunization education campaign; and ▪ a specific Measles Control Campaign.

While recognizing the key role played by structural and policy reform within the formulation and implementation of a social marketing strategy, this article focuses primarily on the community education components of this program.
Sponsorship: Impact on Brand Awareness and Brand Attitudes
Authors: Jalleh Geoffrey , Donovan Robert J. , Giles-Corti Billie , Holman C. D'Arcy J.
Published: October 2003

Sponsorship is a rapidly growing tool in both commercial and social marketing areas, in Australia and overseas. Australian health promotion foundations distribute substantial funds to arts, sports, and racing organizations for the opportunity to have these organizations' events sponsored by health promoting organizations. However, in spite of substantial commercial and health expenditures, there has been little published systematic evaluation of sponsorship. Recent years have seen far more attention to this area. This article presents the results of a study designed to evaluate sponsorship effectiveness in terms of its two main communication objectives: brand awareness and brand attitude. Two health and four commercial sponsorships were evaluated at two major sporting events. Overall, the data suggest that sponsorship can influence both brand awareness and brand attitude, and that the health sponsorships had more impact than the commercial sponsors studied. These and other data confirm the potential usefulness for greater use of sponsorship in social marketing campaigns.
Creditsmart© Research: A Study of Consumer Financial Knowledge and Implications for Social Marketing
Authors: Perry Vanessa Gail , Ards Sheila
Published: October 2003

This paper describes a corporate-sponsored research effort whose goal was to help consumers obtain and maintain good credit through consumer education. Freddie Mac in collaboration with five historically Black colleges and universities (HBCUs) and three national nonprofit consumer organizations sponsored this initiative, known as CreditSmart©, which involves research, curriculum development, and outreach. In order to inform the curriculum and outreach, the authors evaluate the effectiveness of learning about finances through formal, informal, and experiential sources. They also examine whether there are ethnic or cultural differences in these effects. The proposed model of consumer financial knowledge was tested using the 1999 Consumer Credit Survey (CCS) data collected from approximately 12,000 consumers. This dataset includes a variety of questions about childhood experiences with money, financial knowledge, attitudes, and experiences, as well as assets, debts, and demographic characteristics.

Findings suggest that formal training and childhood financial experiences are significant predictors of financial knowledge across the sample population as a whole, while informal, word-of-mouth sources have a significant additional impact among African-American consumers. Implications for social marketing and consumer education are discussed.
Branding Behavior: The Strategy behind the TruthSM Campaign
Authors: Evans W. Douglas , Wasserman Jeffrey , Bertolotti Elena , Martino Steven
Published: October 2003

The American Legacy Foundation's truthSM campaign uses a branding strategy to change adolescent and young adults' attitudes and behavior and to encourage them to adopt a nonsmoking lifestyle. This strategy and its execution represent an evolution from previous antismoking social marketing efforts. It offers lessons not only for future antismoking campaigns, but also for social marketing aimed at preventing or controlling many other youth risk behaviors. The persuasive mechanisms by which truth's branding strategy works need to be understood within the context of existing social psychological theories of attitude and belief formation, as well as behavior change.

Brand equity is a central measure of the truth campaign's strategy. We describe a new brand equity scale based on previous work in advertising research and present data from a campaign tracking survey. We conclude that the campaign has high brand equity among its target audience, 12- to 17-year-olds, and has changed important attitudes and beliefs related to smoking. Future research will investigate the relationships among brand equity, relevant intervening variables, and smoking behavior.
Demographic and Psychographic Antecedents of Community Participation: Applying a Social Marketing Model
Authors: Dutta-Bergman Mohan J.
Published: October 2003

Community participation has received a great deal of attention in recent work on political and health communication. Reflective of the extent of collective action in a community, community participation has typically been treated as a macro-level variable. Building on recent research that points out the role of trait-level variables in the production of community participation, this article serves two different purposes. First, based on the notion of a web of congruent activities, interests, and opinions, it proposes a series of psychographic variables in the context of their relationship with community participation. Second, it proposes the use of demographic and psychographic variables to strategically target highly engaged individuals and communities as sites for interventions and social marketing strategies to increase the participation in less involved communities.
Associative Group Analysis: A Tobacco Prevention Case Study
Authors: Peterson Michael , Martin Steven S.
Published: October 2003

This paper seeks to demonstrate the potential utility of the Associative Group Analysis (AGA) process to tobacco-related social marketing by identifying perceptual and cognitive similarities and differences toward “tobacco” and “smoking” between four behaviorally defined groups. AGA-based questions were included in a statewide Random Digit Dial (RDD) household telephone survey using Computer Assisted Telephone Interviewing (CATI) technology. The AGA provided qualitative and quantitative sensitivity of group perceptions and attitudes not available through traditional survey methods. Results provide specific anti-tobacco marketing messages and themes that should be targeted and addressed for each group. This study has the following implications for social marketing: 1) The AGA methodology has the ability to effectively facilitate the development and assessment of anti-tobacco media campaigns; 2) more generally, the technique can be applied to measure the efficacy of social marketing campaigns in other areas; and 3) the application demonstrates the value of adjustments so that communications can adapt and respond to the dynamics of a group's perceptual-representational framework.
A Cross-Cultural Comparison of Consumer Attitudes toward Cause-Related Marketing
Authors: Lavack Anne M. , Kropp Fredric
Published: October 2003

This study examines consumer attitudes toward cause-related marketing (CRM) in four countries: Canada, Australia, Norway, and Korea. It investigates the role of consumer values in shaping these attitudes toward CRM. The study finds that attitudes toward cause-related marketing differ significantly across countries. Attitudes toward CRM appear to be less positive in countries where it is less established (e.g., Korea) and more positive in countries where CRM is well established (e.g., Canada). Differences in attitude toward CRM are also directly correlated with personal values, specifically with internal and external values.
Adaptive Strategies of Tobacco Firms Subsequent to the 1998 Master Settlement Agreement: An Examination of Emergent Tobacco Promotional Mix Efforts
Authors: Czaplewski Andrew J. , Olson Eric M.
Published: October 2003

This article uses the promotional mix framework to examine tobacco promotional efforts in five distinct categories: advertising, sales promotion, direct marketing, personal selling, and public relations. We specifically explore how tobacco companies are adapting their promotional efforts in each category subsequent to the 1998 Master Settlement Agreement (MSA) among the five largest tobacco companies and 46 states. We utilize primarily marketing popular press literature and a comparison between 1998 and 1999 tobacco promotional expenditures to provide a comprehensive picture of emergent tobacco promotional efforts in response to the new restrictions. Numerous adaptations within each category are examined. In particular, substantial new expenditures in the areas of trade-oriented sales promotions, direct marketing, and public relations activities are revealed. Specific tactics being used in each of the five promotional mix categories are discussed.