1. The European eel population has decreased drastically during recent decades, and new EU-legislation calls for measures to change this negative trend. This decline has been attributed to a number of factors, including habitat fragmentation by structural barriers that prevent eels moving between freshwater and the sea. The success of downstream migrating adult silver eels migrating past a hydroelectric plant (HEP) in Sweden was examined by radio-telemetry, and the results were considered in a historical context by analysing catch data from the river for 1957-2006. 2. The choice of routes and passage success were quantified for three treatment groups and one control group of silver eels. The first treatment, the reservoir group (n = 50), was released into the reservoir upstream of the HEP, and these fish could proceed downstream by passing through the HEP (20 mm rack and turbines) or by entering the spill gates into the former channel, bypassing the HEP. The second treatment group (inside rack, n = 15) was released downstream of the 20-mm rack and had to pass through the turbines to continue migration to the sea. The third treatment group consisted of dead radio-tagged eels (n = 6) that were released into the turbines to study the extent of drifting by dead individuals. Finally, the control group (n = 50) was released downstream of the HEP to test for effects of confounding factors. 3. Most live individuals displayed migratory behaviour and continued to proceed downstream after release. Only 8% of the fish released in the reservoir or downstream of the HEP (control) did not migrate. The probability of reaching the next HEP, 24 km further downstream, was high for the control group (96%) and the reservoir-released individuals that passed the HEP via the spill gates and the former channel (83%). Survival was low and size-dependent for the individuals that passed the turbines (40%) and even lower for the individuals that had to pass through the rack and the turbines (26%). The overall passage success for eels released in the reservoir was 30%, including both routes. 4. Annual catch data from 1957 to 2006 showed that the number of eels in the River Ä tran has decreased. Despite this decrease, escapement biomass has remained unchanged, because of the fact that the mean size of eels has doubled. Passage data from 2007 show that changes in size and abundance have resulted in a reduction of relative escapement to the sea to values that are 21-24% of what they were in 1957-66. However, this low level of 2167 escapement could potentially be rectified if appropriate measures facilitating HEP passage are successfully implemented, since the potential escapement biomass in the river, owing to the large size of the eels, has changed little since the 1950s.
This article is a review of the current understanding of tidal energy resources in the context of the emerging technology of tidal stream power generation. The geographical focus is on the north-west European continental shelf, the scope of a number of published reports on exploitable tidal stream energy resources. These estimates are reviewed as are some analytical models of energy extraction by tidal stream generators.
BackgroundThe efforts and commitments to accelerate progress towards the Millennium Development Goals for maternal and newborn health (MDGs 4 and 5) in low and middle income countries have focused primarily on providing key medical interventions at maternity facilities to save the lives of women at the time of childbirth, as well as their babies. However, in most rural communities in sub-Saharan, access to maternal and newborn care services is still limited and even where services are available they often lack the infrastructural prerequisites to function at the very basic level in providing essential routine health care services, let alone emergency care. Lists of essential interventions for normal and complicated childbirth, do not take into account these prerequisites, thus the needs of most health facilities in rural communities are ignored, although there is enough evidence that maternal and newborn deaths continue to remain unacceptably high in these areas.MethodsThis study uses data gathered through qualitative interviews in Kitonyoni and Mwania sub-locations of Makueni County in Eastern Kenya to understand community and provider perceptions of the obstacles faced in providing and accessing maternal and newborn care at health facilities in their localities.ResultsThe study finds that the community perceives various challenges, most of which are infrastructural, including lack of electricity, water and poor roads that adversely impact the provision and access to essential life-saving maternal and newborn care services in the two sub-locations.ConclusionsThe findings and recommendations from this study are important for the attention of policy makers and programme managers in order to improve the state of lower-tier health facilities serving rural communities and to strengthen infrastructure with the aim of making basic routine and emergency obstetric and newborn care services more accessible.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.