Integrating monitoring, expert knowledge and habitat management within conservation organisations for the delivery of the water framework directive: A proposed approach

RESUMEN. Existe una creciente necesidad de entender mejor la naturaleza de las relaciones entre los atributos ambientales y las comunidades/especies de agua dulce para poder desarrollar acciones apropiadas que minimicen el impacto del cambio ambiental en los ecosistemas fluviales. Tal entendimiento necesitaría estar basado en investigaciones de relaciones causales más que en estudios de correlaciones estadísticas, como se acostumbra. Otro aspecto es la identificación de la escala a la cual los procesos y las características deben ser medidas para permitir un diseño de programas de monitoreo relevante. En este artículo se presenta una breve revisión de los conocimientos existentes sobre las relaciones especies/hábitat y se discuten los marcos teóricos existentes para la identificación de las características ambientales de importancia para la fauna y la determinación de la escala/s a la que deben evaluarse. Asimismo, proponemos un método para utilizar esas relaciones en el contexto de la supervisión y las prácticas de gestión en las organizaciones de conservación. Mostramos como modelos conceptuales de relaciones entre hábitats y especies pueden ser construidos usando el conocimiento existente y la opinión de expertos y como pueden ser testados utilizando datos recogidos como parte de los programas de monitoreo en las instituciones encargadas de la conservación. Sugerimos que tal marco, si aplicado, podría no sólo ayudar a identificar relaciones causales entre especies, características y procesos actuando a varias escalas, sino también para iniciar un proceso de adquisici´on de conocimiento en las instituciones responsables de la implementación de la Directiva Marco del Agua.ABSTRACT. There is a growing necessity to better understand the nature of the relationships between environmental attributes and freshwater species/communities to enable meaningful action to take place against the impacts of environmental change in river ecosystems. Such understanding would need to be based on the investigations of causal relationships rather than the study of statistical correlations or the use of expert opinion as is generally the case. Another issue is in identifying the scale(s) at which process and features should be recorded and assessed to enable the design of relevant monitoring programs. In this paper, we present a short review of existing knowledge on species/habitat relationships and discuss the importance of adequate theoretical frameworks for identifying environmental features of importance to wildlife and determining the scale/s at which they should be assessed.We further propose an approach for eliciting those relationships within the context of monitoring and management practice in conservation organisations. We show how conceptual models of habitat-species relationships can be built using existing knowledge and expert opinion and tested on data collected as part of existing monitoring programs. We suggest such framework, if applied, could not only help identify causal relationships between species, features and processes acting at various scales, but also initiate a knowledge acquisition process within organisations responsible for the delivery of the Water Framework Directive

Small Water Bodies in Great Britain and Ireland: Ecosystem function, human-generated degradation, and options for restorative action

© 2018 Small, 1st and 2nd-order, headwater streams and ponds play essential roles in providing natural flood control, trapping sediments and contaminants, retaining nutrients, and maintaining biological diversity, which extend into downstream reaches, lakes and estuaries. However, the large geographic extent and high connectivity of these small water bodies with the surrounding terrestrial ecosystem makes them particularly vulnerable to growing land-use pressures and environmental change. The greatest pressure on the physical processes in these waters has been their extension and modification for agricultural and forestry drainage, resulting in highly modified discharge and temperature regimes that have implications for flood and drought control further downstream. The extensive length of the small stream network exposes rivers to a wide range of inputs, including nutrients, pesticides, heavy metals, sediment and emerging contaminants. Small water bodies have also been affected by invasions of non-native species, which along with the physical and chemical pressures, have affected most groups of organisms with consequent implications for the wider biodiversity within the catchment. Reducing the impacts and restoring the natural ecosystem function of these water bodies requires a three-tiered approach based on: restoration of channel hydromorphological dynamics; restoration and management of the riparian zone; and management of activities in the wider catchment that have both point-source and diffuse impacts. Such activities are expensive and so emphasis must be placed on integrated programmes that provide multiple benefits. Practical options need to be promoted through legislative regulation, financial incentives, markets for resource services and voluntary codes and actions

Process-based principles for restoring river ecosystems

Process-based restoration aims to reestablish normative rates and magnitudes of physical, chemical, and biological processes that sustain river and floodplain ecosystems. Ecosystem conditions at any site are governed by hierarchical regional, watershed, and reach-scale processes controlling hydrologic and sediment regimes; floodplain and aquatic habitat dynamics; and riparian and aquatic biota. We outline and illustrate four process-based principles that ensure river restoration will be guided toward sustainable actions: (1) restoration actions should address the root causes of degradation, (2) actions must be consistent with the physical and biological potential of the site, (3) actions should be at a scale commensurate with environmental problems, and (4) actions should have clearly articulated expected outcomes for ecosystem dynamics. Applying these principles will help avoid common pitfalls in river restoration, such as creating habitat types that are outside of a site's natural potential, attempting to build static habitats in dynamic environments, or constructing habitat features that are ultimately overwhelmed by unconsidered system drivers

Interannaul variability in the effects of physical habitat and parentage on Chinook salmon egg-to-fry survival

Mortality during incubation is believed to be a major factor limiting the recovery of many salmon populations though direct field measurements of egg-to-fry survival are rare or small in scale. To determine the effects of physical habitat (river reach, fine sediment intrusion, scour), parentage (mating/source of gametes) on Chinook salmon (Oncorhynchus tshwaytscha) egg-to-fry survival and developmental stage at emergence across a basin, we constructed 324 artificial redds in nine reaches over four years in the Yakima River Basin, Washington, USA. Average egg-to-fry survival ranged from 49% to 69% among reaches from 2009 to 2012 brood years. Survival was significantly different among reaches in 2010, but not 2009, 2011 or 2012, while mating was a significant factor in all years but 2010. In contrast, developmental stage differed significantly among reaches and matings in all four years. Percent of fines, days-in-gravel and median particle size explained only small (The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Assessing ‘modern background sediment delivery to rivers’ across England and Wales and its use for catchment management.

Catchment sediment management across England and Wales continues to require alternative criteria to the existing guideline standard (an annual mean suspended sediment concentration of 25 mg L-1) provided by the European Union Freshwater Fish Directive. In response, a recent collaborative science project has investigated the scope for developing alternative catchment-specific sediment targets using an integrated modelling toolkit coupling sediment pressures from agriculture and impacts on aquatic biota, including fish and macroinvertebrates. Part of this work involved using palaeolimnological reconstruction to quantify “modern background sediment delivery to rivers” (MBSDR) across England and Wales, prior to recent agricultural intensification. It is proposed that the estimates of MBSDR can be used to assess the maximum ceiling of mitigation because no management strategy should aim to control background sediment loss arising from natural physiographic and hydrological drivers, and to correct the gap between past, present or future projected sediment pressures on watercourses and “good ecological status” for sediment

Stratification in Binary Colloidal Polymer Films: Experiment and Simulations

When films are deposited from mixtures of colloidal particles of two different sizes, a diverse range of functional structures can result. One structure of particular interest is a stratified film in which the top surface layer has a composition different than in the interior. Here, we explore the conditions under which a stratified layer of small particles develops spontaneously in a colloidal film that is cast from a binary mixture of small and large polymer particles that are suspended in water. A recent model, which considers the cross-interaction between the large and small particles (Zhou et al., Phys. Rev. Lett. (2017) 118, 108002), predicts that stratification will develop from dilute binary mixtures when the particle size ratio (), initial volume fraction of small particles ( s), and Péclet number are high. In experiments and Langevin dynamics simulations, we systematically vary and s in both dilute and concentrated suspensions. We find that stratified films develop when s is increased, which is in agreement with the model. In dilute suspensions, there is reasonable agreement between the experiments and the Zhou et al. model. In concentrated suspensions, stratification occurs in experiments only for the higher size ratio = 7. Simulations using a high Péclet number, additionally find stratification with = 2, when s is high enough. Our results provide a quantitative understanding of the conditions under which stratified colloidal films assemble. Our research has relevance for the design of coatings with targeted optical and mechanical properties at their surface