An historical review of the fish and fisheries investigations of the Freshwater Biological Association, mainly at the Windermere Laboratory

This paper is a review of most of the research work on fish that has been carried out by the Freshwater Biological Association, and includes not only what has been done at Windermere, but also some past work carried out elsewhere. However, current work at the River Laboratory, which is now a separate establishment, has been excluded.
The history of the Association i s traced from its formation in 1929 and its first laboratory at Wray Castle, to its present quarters at the Ferry House. Thc pre-war work of Allen on trout, perch and salmon is described and an account is given of the war time research and fishery for eels and perch, and of how this has led to the experimental removal of perch and pike from Windermere on a large scale. The physiological research, and work on trout fry, on char and other species, as well as many subsidiary investigations, are mentioned. As far as possible brief summaries of the main results are given for most of the 99 papers mentioiicd.     

The effects of pollution and the need for long-term monitoring

The general deterioration of coastal water quality and physical despoilation of habitats along the eastern United States coastline has had a major impact on estuarine and coastal fisheries. To understand the full extent of these effects, and to provide data on the rate at which they are spreading geographically, a new monitoring program called Ocean Pulse has been implemented. Ambient levels of contaminants in waters and sediments of the coastal zone are documented, and biological effects are monitored in habitats over the continental shelf as far seaward as high levels of contaminants can be measured. Samples and experimental measurements are taken at contaminated and uncontaminated sites between the Canadian boundary and Cape Hatteras. The primary aim of the Ocean Pulse program is to use changes in physiological/biochemical responses as indicators of biological change due to contaminant loading. Physiological, behavioral, ecological and other responses are measured so as to relate, ultimately, change in community structure, population responses and pathology to variation in the quality of habitat.     

The potential contribution of vegetation ecology to biodiversity research

The contribution of vegetation ecology to the study of biodiversity depends on better communication between the different research paradigms in ecology. Recent developments in vegetation theory and associated statistical modelling techniques are reviewed for their relevance to biodiversity. Species composition and collective properties such as species richness vary as a continuum in a multi-dimensional environmental space; a concept which needs to be incorporated into biodiversity studies. Different kinds of environmental gradients can be recognised and species responses to them vary. Species response curves of eucalypts to an environmental gradient of mean annual temperature have been shown to exhibit a particular pattern of skewed response curves. Generalised linear modelling (GLM) and generalised additive modelling (GAM) techniques are important tools for biodiversity studies. They have successfully distinguished the contribution of environmental (climatic) and spatial (history and species dispersal ability) variables in determining forest tree composition in New Zealand. Species richness studies are examined at global, regional and local scales. At all scales, direct and resource environmental gradients need to be incorporated into the analysis rather than indirect gradients e.g. latitude which have no direct physiological influence on biota. Evidence indicates that species richness at the regional scale is sensitive to environment, confounding current studies on local/regional species richness relationships. Plant community experiments require designs based on environmental gradients rather than dependent biological properties such as productivity or species richness to avoid confounding the biotic components. Neglect of climatic and other environmental gradients and the concentration on the collective properties of species assemblages has limited recent biodiversity studies. Conservation evaluation could benefit from greater use of the continuum concepts and statistical modelling techniques of vegetation ecology. The future development of ecology will depend on testing the different assumptions of competing research paradigms and a more inclusive synthesis of ecological theory.     

Freshwater fishes of northern South America: a need for field guides

The efficient collection of fishes from structurally complex environments (e.g., coral reefs, kelp forests) is difficult because conventional collecting methods generally cannot be used and many of the fishes are mobile and active. We describe the design, operation, and application of a diver-propelled net for efficiently collecting many species of benthic fish that reside on coral reefs and on kelp-forested rocky reefs. The overall size of the net and mesh size of the netting can be adjusted according to the size and behavior of targeted species to minimize drag and damage to specimens. Altering these dimensions combined with proper use of the net can result in a high rate of capture success. This revised version was published online in July 2006 with corrections to the Cover Date.     

Collaboration in scientific research: a critical need for freshwater ecology

1. Collaboration means actively working together to achieve things which could not be done alone. This article attempts to provide an overall, unified, guiding framework for collaboration in freshwater ecology by discussing aspects of collaboration at individual and organizational levels, and addressing international linkages.
2. The essential elements of collaboration are communication and trust, and effective project management. Barriers to effective collaboration include competition, organizational cultures and organizational instabilities.
3. The success of collaboration can be measured by tangible benefits such as increased numbers of peer-reviewed publications, the production of working models and a number of intangible benefits.
4. Interactions between individuals lie at the heart of an effective collaboration; organizational arrangements should facilitate this interaction. Some governments are encouraging collaboration to increase cost efficiency and allocate accountability. This trend should continue on an international level.
5. Collaboration is a key to future research in freshwater ecology.     

The analysis of planktonic rotifer populations: A plea for long-term investigations

Short-term species succession, and long-term community development, of planktonic rotifer populations of the temperate zone and factors influencing species' abundance (ie., physical and chemical limitations, food and exploitative competition, mechanical interference competition, predation, parasitism) are described and discussed. The long-term development of plankton communities in three European lakes is described and the major events are discussed in relation to ecological interactions. Frequently, the shortcomings of our knowledge about population ecology and ecophysiology of rotifers prevent explanations of short-term and, especially, of long-term developments of these plankton organisms. The need for qualitative and quantitative observations in the field and in the laboratory over long periods becomes obvious.     

Comparative investigations into the feeding ecology of six Mantodea species

Summary Six mantid species (Sphodromantis viridis, Polyspilota aeruginosa, Hierodula unimaculata, Parasphendale agrionia, Mantis religiosa and Empusa pennata) were studied in laboratory feeding experiments. Mantids stalk their prey and pounce on it, grasping it with their forelegs. Only living prey is selected and it is consumed directly after the catch. The predator orients itself optically, and therefore only takes notice of moving prey. The maximum size of prey which mantids can overwhelm is species-specific and depends on the prey type. On average mantids eat crickets of 50% their own body-weight while cockroaches can weigh up to 110%. Feeding experiments with 101 species of potential prey of 21 invertebrate orders showed an average feeding rate of 70% and marked differences among the predators. Polyspilota proved to be the least specialized mantid and Empusa caught the smallest amount of prey. Most of the defence mechanisms which arthropods have developed against their enemies proved to be ineffective against mantids. Neither a hard chitinous exoskeleton nor poisonous substances prevented the mantids from attacking their prey successfully. The protective secretion of the cotton stainer Dysdercus intermedius proved to be effective at least in a few instances. Even though these bugs were killed, the mantids usually refused to eat the abdomen, where the glands that produce the protective secretion are to be found. Thanatosis, as exhibited by the chrysomelid Cassida viridis and by the phasmid Carausius morosus, proved to be the best protection against mantids.     

Predictive Models for Freshwater Biological Assessment: Statistical Approaches,Biological Elements and the Iberian Peninsula Experience: A Review

In the last three decades, predictive models have been developed and applied worldwide for freshwater bioassessment. They consist of statistical tools that follow the concept of the Reference Condition Approach. Composed of several sequential steps, these assessment tools assess the deviation of given site assemblages from the expected biological condition in the absence of human disturbance. The most common approaches (RIVPACS/AUSRIVAS and BEAST) are based on a posteriori classifications that use the biological composition of a community to classify reference sites in groups, and afterwards to establish which environmental features best discriminate the biological groups obtained. Here, we review the predictive modeling procedures used in freshwaters bioassessment (RIVPACS/AUSRIVAS, BEAST, ANNA, Artificial Neural Networks, Bayesian Belief Networks and others) as well as the biological elements to which they have been applied. We also review the Spanish and Portuguese experiences in the development and application of predictive models, with particular attention to regional environmental conditions, the different modeling approaches, and the available implementation tools. Moreover, and considering the natural continuity within the Iberian Peninsula (which include several transnational rivers), we discuss the possibilities of the development of common predictive models across the region, considering all factors that may influence their performance, such as the target scale used to develop the models (regional or peninsular); common reference criteria; sampling and sorting procedures; the taxonomic resolution used in the models; the temporal variability (mainly in the Iberian Mediterranean region); and the biological elements to consider. We concluded that there are good technical conditions for the implementations of a common predictive approach throughout the Iberian Peninsula, which should allow a global biological assessment of streams with different biological elements and seasons that could be used by water managers in the context of the Water Framework Directive. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Nutritional ecology of insect–plant interactions: persistent handicaps and the need for innovative approaches

Quantifying the flow of matter and energy in food webs is indispensable when assessing the effects of increases in atmospheric carbon dioxide, ozone level and temperature as a result of global climate change. In insect nutritional ecology, quantification of digestive and metabolic efficiency is performed using gravimetric methods in all published cases. A few cases combined these methods with calorimetric and respirometric techniques. Since 1986, methodological pitfalls and sources of error inherent to applying gravimetry as the only method to construct nutrient budgets have been addressed in a number of papers without noticeable impact on subsequent research. Especially for insects feeding on living plant tissues, the gravimetric method has inherent handicaps as it can only be used with excised plant tissues and does not allow for the dynamics of plant metabolism. We discuss the major constraints of the gravimetric method as it pertains to the physiological processes of both the insect and plant. We apply a relationship between relative metabolic rate and relative growth rate of the insect for an analysis of the gravimetric literature. The analysis reveals that gravimetry has given rise to physiologically unlikely results for poikilothermic insects. This points to serious constraints on progress in this field. We identify plant respiration as the major source of error in gravimetric studies. We establish that no single study has, thus far, determined the metabolic efficiency of a herbivore feeding on a photosynthetically active plant with its phyllosphere microclimate. We argue that a quantitative understanding of the ecophysiology and nutritional ecology of insect–plant interactions must rely on the adoption of a combination of existing and complementary methods such as the double labelled water method and infrared gas analysis.     

Patterns of Biological Invasions in French Freshwater Systems by Non-Indigenous Macroinvertebrates

Freshwater biodiversity is threatened by several mechanisms, of which the introduction of non-indigenous species and habitat alteration are the two most important. Exotic species act at various levels of organisation of macroinvertebrate communities, and are involved in different processes mediating their impacts on biodiversity, such as habitat modification or negative interactions with autochthonous fauna. The present work gives a list of the 43 French freshwater non-indigenous species, which represent 1.2% of the French freshwater macroinvertebrates. We provide their geographic origins, their distributions among zoological units by comparison with the native fauna and their functional characteristics according to a recent typology based on bio/ecological traits. An exponential trend of the cumulated number of non-indigenous species was evidenced, with a clumping of invaders within crustaceans and molluscs. Donor areas of non-indigenous species are in majority European, and the Ponto-Caspian basin is identified as the principal one. This pattern could be explained by a spread along waterways but its origin lies in a process of recolonisation of defaunated areas following several episodes of glaciation/deglaciation in Western Europe during the last 80,000 years. Finally, from a functional point of view, non-indigenous species exhibit a limited diversity, with two functional groups representing 80% of them.     

城市生态学长期监测的几个关键问题

伴随城市人口快速聚集及人类活动加剧,城市生态环境质量及其对人类社会经济发展的支撑能力正在受到严重挑战,城市生态系统及其变化的研究越来越受到重视,国内外涌现出大量城市生态学长期监测工作,但相关监测方法的讨论还很少。在分析城市生态学长期监测类型和实践经验基础上,从城市面临的环境胁迫和建设管理需求出发,构建了城市生态学长期监测的"胁迫+需求-生态系统响应"总体思路框架;从科学上最基本和社会上最关心的城市生态系统要素、格局和过程着眼,提出城市生态学长期监测的7项内容(土地覆盖与利用、人居环境质量、生物多样性、生物质生产、水文过程、生物地球化学循环和物质代谢);并分析了城市生态学长期监测的4种方法(遥感监测、仪器监测、调查监测、公众科学监测),分析了城市生态学长期监测单元及其空间布局及监测频率。这将为我国城市生态学长期监测工作开展提供方法论基础和实践参考。     

On the use of antibiotics to reduce rhizoplane microbial populations in root physiology and ecology investigations

No straightforward method exists for separating the proportion of ion exchange and respiration due to rhizoplane microbial organisms from that of root ion exchange and respiration. We examined several antibiotics that might be used for the temporary elimination of rhizoplane bacteria from hydroponically grown wheat roots ( Triticum aestivum cv. Veery 10). Each antibiotic was tested for herbicidal activity and plate counts were used to enumerate bacteria and evaluate antibiotic kinetics. Only -lactam antibiotics (penicillins and cephalosporins) did not reduce wheat growth rates. Aminoglycosides, the pyrimidine trimethoprim, colistin and rifampicin reduced growth rates substantially. Antibiotics acted slowly, with maximum reductions in rhizoplane bacteria occurring after more that 48 h of exposure. Combinations of nonphytotoxic antibiotics reduced platable rhizoplane bacteria by as much as 98%; however, this was generally a reduction from about 10⁹ to 10⁶ colony forming units per gram of dry root mass, so that many viable bacteria remained on root surfaces. We present evidence which suggests that insufficient bacterial biomass exists on root surfaces of nonstressed plants grown under well-aerated conditions to quantitatively interfere with root nitrogen absorption measurements.     

Freshwater bryozoans (Bryozoa) of Norway III: distribution and ecology of Plumatella fruticosa

Bryozoans were investigated during field studies of 601 lakes and other surface water bodies throughout Norway from 1960 to 1978. The frequency of occurrence of Plumatella fruticosawas evaluated in relation to 12 environmental variables. Statistically significant deviations from the frequencies expected on the basis of random distribution were described using the categories preference, avoidance, and absence. According to our material P. fruticosais one of the most common bryozoan species in Norwegian fresh water, represented in samples from 251 localities. This species occurred frequently all over the country, north to 71° 06 N (the northernmost record globally). Maximum elevation above sea level was 1179 m (maximum for Northern Europe).In most studies of freshwater bryozoans from the holarctic region, Plumatella fruticosahas been reported as widely distributed, but locally rare. In Norway, however, P. fruticosa is frequently found all over the country, even far to the north. The species apparently finds an optimal climate in the cold temperate and cold regions of Norway. Plumatella fruticosapreferred lakes, avoided slow-flowing rivers and ponds, and was absent in smaller water bodies. The species preferred somewhat higher elevation (400–900 m above sea level), but avoided lakes with the lowest summer temperatures (below 11 °C). P. fruticosa also preferred oligotrophic conditions with poor aquatic vegetation, stony shores, lakes poor in calcium and magnesium (sometimes almost comparable with distilled water), where the water was clear and colourless, and slightly acidic to neutral. The species also preferred lakes surrounded by Sphagnum bogs and was absent when pH was below 5.2. P. fruticosa avoided eutrophic conditions with rich aquatic vegetation, alkaline water (pH above 7.0), lakes with a higher content of calcium and magnesium and those with strongly coloured water (above 100 mg Pt l^–1). In spite of its preference for ion-poor conditions, it was also found in a brackish water lake. For most environmental variables, the species had a wider tolerance range than reported from elsewhere.     

Evidence for the need of long-term antithrombotic therapy in patients with porcine heterograft heart valve

The plasma levels of two platelet specific proteins, namely beta-thromboglobulin (beta TG) and platelet factor 4 (PT4), were investigated in 86 patients with different types of artificial valves, biological and disc, at different times after valve insertion. Significant differences were demonstrated for both proteins with increased age of the disc valve. On the other hand, no significant change in the high average levels was shown for patients with porcine heterograft (Hancock). The general view of anticoagulate or antiaggregate lasting only a few months after bioprosthesis insertion has to be carefully evaluated again.