Implementation Of Conservation Measures Research Articles

Tillage Effects on Soil Properties and Spatial Variability in Two Mississippi Delta Watersheds

Abstract This study evaluated changes in soil properties several years after implementation of conservation measures. Two approximately 50-ha fields within two Mississippi Delta oxbow lake watersheds (Deep Hollow and Beasley) were laid out in 60-m grids. Soil from a tilled cotton field in Deep Hollow watershed was sampled at each node in 1996 and again in 2000 after 4 years of reduced tillage cotton (Gossypium hirsutum) and winter wheat (Triticum aestivum L.) cover crops; soil also was collected from conventional tillage cotton in Beasley Lake watershed in 1996 and again in 2006 from the same grid nodes after 4 years of reduced tillage cotton and 5 years of reduced tillage soybeans. Organic matter levels in the soil surface were higher in both watersheds after conservation tillage was implemented, likely caused by increased plant residue accumulation and limited soil mixing. Higher soil P levels in both watersheds under conservation management were attributed to less distribution in soil because of reduced tillage. Lower NO3-N in Deep Hollow in 2000 suggested N immobilization in the soil surface. Nitrogen was not analyzed for Beasley soil samples. Soil pH values were also higher in the later samplings for both watersheds, but because lime was applied in the interim, it is difficult to ascribe an effect from tillage. Potassium, calcium, and magnesium were higher in 2000 after the 4-year reduced tillage practice in the Deep Hollow watershed. However, potassium, calcium, and magnesium were lower in 2006 than in 1996 at the Beasley Lake watershed because no fertilizer was applied to the field since 2001. Regardless of tillage system, relatively high P levels in soils from both watersheds are indicative of high native soil P levels in the Mississippi Delta soils. Similar to other studies, water-soluble P was positively correlated with Mehlich III P. Spatial relationships of P examined using kriging showed that P data were spatially dependent, and their spatial dependence was impacted by tillage practices.

Indicators of the impact of climate change on migratory species

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 7:101-113 (2009) - DOI: https://doi.org/10.3354/esr00162 Indicators of the impact of climate change on migratory species Stuart E. Newson1,*, Sonia Mendes2, Humphrey Q. P. Crick1, Nicholas K. Dulvy3, Jon D. R. Houghton4, Graeme C. Hays4, Anthony M. Hutson5, Colin D. MacLeod2, Graham J. Pierce2, Robert A. Robinson1 1British Trust for Ornithology, The Nunnery, Thetford IP24 2PU, UK 2School of Biological Sciences, Zoology Building, Tillydrone, University of Aberdeen, Aberdeen AB24 2TZ, UK 3The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft NR33 0HT, UK and Simon Fraser University, Biological Sciences, Burnaby, Victoria V5A 1S6, Canada 4Department of Biological Sciences, Swansea University, Swansea SA2 8PP, UK 5Winkfield, Station Road, Plumpton Green BN7 3BU, UK *Email: stuart.newson@bto.org ABSTRACT: The Bonn Convention on the Conservation of Migratory Species of Wild Animals adopted a Resolution in 2005 recognising the impacts of climate change on migratory species. It called on Contracting Parties to undertake more research to improve our understanding of these impacts and to implement adaptation measures to reduce foreseeable adverse effects. Given the large diversity of taxa and species affected by climate change, it is impossible to monitor all species and effects thereof. However, it is likely that many of the key ecological and physical processes through which climate change may impact wildlife could be monitored using a suite of indicators, each comprising parameters of species/populations or groups of species as proxies for wider assemblages, habitats and ecosystems. Herein, we identify a suite of 17 indicators whose attributes could reveal negative impacts of climate change on the global status of migratory species: 4 for birds, 4 for marine mammals, 2 for sea turtles, 1 for fish, 3 for land mammals and 3 for bats. A few of these indicators would be relatively straightforward to develop, but most would require additional data collation, and in many cases methodological development. Choosing and developing indicators of the impacts of climate change on migratory species is a challenge, particularly with endangered species, which are subject to many other pressures. To identify and implement conservation measures for these species, indicators must account for the full ensemble of pressures, and link to a system of alerts and triggers for action. KEY WORDS: Conservation · Management · Birds · Fish · Mammals · Turtles · Bats · Climate change · Migration Full text in pdf format PreviousNextCite this article as: Newson SE, Mendes S, Crick HQP, Dulvy N and others (2009) Indicators of the impact of climate change on migratory species. Endang Species Res 7:101-113. https://doi.org/10.3354/esr00162Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 7, No. 2. Online publication date: May 14, 2009 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2009 Inter-Research.

What explains property‐level variation in avian diversity? An inter‐disciplinary approach

Summary Modern farmed landscapes have witnessed substantial losses in biodiversity principally driven by the ecological changes associated with agricultural intensification. The causes of declines are often well described, but current management practices seem unlikely to deliver the EU‐wide policy objective of halting biodiversity losses. Available evidence suggests that property‐scale factors can be influential in shaping patterns of biodiversity; however, they are rarely included in studies. Using 44 upland farms in the Peak District, northern England, we investigate the roles of ecological, agricultural and socio‐economic factors in determining avian species richness, for the first time incorporating information from all three influences. Although we might expect that habitat quality would be the main factor affecting species richness, these variables had little influence. The landscape context of each property was unimportant in explaining any of the three measures of species richness (Total, Upland and Conservation Concern) used here. Within‐property habitat quality did explain 42% of the variation in richness of upland specialist species, but had no influence on Total or Conservation Concern Richness. Socio‐economic circumstances of farms alone accounted for 24% of the variation in Total Richness, with land tenure and labour inputs important predictors of avian diversity. However, net income, rental value and the level of Agri‐Environment Scheme (AES) payments did not play a role in predicting species richness. Farm management variables, including many of the main prescriptions outlined in AES, accounted for 23% of the variation in the richness of species of Conservation Concern, but less than 10% for Total Richness. However, no farm management variable alone was shown to offer better predictive power of avian species richness than random. Synthesis and applications. The agricultural landscape is managed by a mosaic of landowners, all of whom can influence biodiversity conservation. We demonstrate that variation at the property‐scale in habitat, management and socio‐economics can feed into determining patterns of biodiversity. Currently, farmland conservation policy largely assumes that socio‐economic barriers and financial costs of implementing conservation measures are constant. Incorporating a consideration of the varying circumstances of individual properties into policy design is likely to result in substantial biodiversity gains.

Deep-sea fishes in Canada’s Atlantic: population declines and predicted recovery times

Because of their slow growth rates, late maturity, low fecundity and long potential lifespans, deep-sea fishes are vulnerable to and theoretically slow to recover from overexploitation and bycatch. As industrial fishing moved into the deep sea, population declines were predicted and five species were shown to meet The World Conservation Union (IUCN) criteria for endangered species in Atlantic Canadian waters and two other deep-living species were listed as threatened by the Committee on the Status of Endangered Wildlife in Canada. We used data from scientific surveys to determine population trends in a 17-year time series for an additional 32 deep-sea fishes from the same geographic region. Eight species exhibited significant population declines, five increased, two were data deficient, and 17 showed no significant trends. Thus approximately 38% of the deep-sea bottom-living fishes in that well-investigated region could be at-risk, but definitive assignment to an IUCN category for most species is hampered by a lack of basic biological information, especially species specific generation times. Lack of biological information also limits efforts to determine possible recovery times, especially with respect to calculating intrinsic rates of population growth (r). For two Atlantic grenadiers (where r could be estimated using life-history parameters and standard life table techniques), the time to recovery with no fishing mortality could range from over a decade to over a century. This broad range results from the general uncertainty on life-history characteristics of these deep-sea species. Given the documented declines, the lack of basic data on life-history parameters, and the conservative assumption that recovery rates are likely to be prolonged, we argue that it is imperative to conduct additional studies pertaining to life history characteristics of deep-sea fishes and implement conservation measures in the deep sea immediately.

Using community and population approaches to understand how contemporary and historical factors have shaped species distribution in river ecosystems

ABSTRACTAim To examine how the employment of both community‐ and population‐level approaches can provide a wider view of the importance of contemporary and historical factors on current species distribution. We posit that community ecology should provide more information about contemporary factors, whereas population genetics should provide better information about historical factors.Location Rivers of the western Mediterranean Basin, including four subregions differing in geological history: the Iberian Plate, Transitional, Betic and Rif.Methods For a community‐level approach, Trichoptera richness and community composition were compared between subregions using species accumulation curves and a correspondence analysis. For a population‐level approach, the mtDNA cytochrome C oxidase subunit I (COI) gene of specimens of the Trichoptera midstream‐lowland species Chimarra marginata (L.) was sequenced and analysed using phylogeographical methods.Results The community approach revealed that historical events had more influence on headwater communities than contemporary ecological factors, whereas historical events had negligible influence on midstream‐lowland communities. In midstream‐lowland sites, however, the population approach showed that the genetic structure of C. marginata differed significantly between subregions and revealed patterns of historical gene migration. In terms of species richness, the Rif subregion had the lowest value per basin due to local climatic features and isolation.Main conclusions Both community‐ and population‐level approaches yielded information about the effects of historical factors on species distribution. However, the importance of historical events on current Trichoptera communities depends on the river zonation. Unlike headwater sites, midstream‐lowland sites showed signs of historical events at the population level but not at the community level at the scale used, indicating that both approaches should be employed together in biogeographical studies. Lack of detection of historical events at the community level does not necessarily mean that they are negligible. Most likely, the organizational level used is not appropriate. We also stress the importance of implementing conservation measures for rivers in the western Mediterranean, especially under future scenarios of climate change and human disturbances in the Mediterranean Basin.

Shedding light on the hidden costs of the Habitats Directive: the case of hamster conservation in Germany

The EU Habitats Directive provides in Annexes II and IV a list of species that need to be conserved. In response to this obligation, Member States have implemented a variety of conservation measures. These measures include the rejection, modification or delay of land development plans, payments to landowners for implementing conservation measures and management actions such as breeding programmes. The extent of the cost of these various conservation measures is not always apparent. Particularly when land development plans are modified costs are hidden because there is no visible flow of financial resources. This may lead to an underestimation of conservation costs. In contrast, costs which directly lead to a flow of financial resources, such as expenses for management measures, are visible and may be given more attention. This difference in visibility may result in selecting conservation measures with high but hidden costs, whereas conservation measures with low but visible costs are neglected. The first purpose of this paper is to provide a framework that captures, along with the visible costs, the range of hidden costs relevant to the conservation of species protected by the Habitats Directive. The second purpose is to demonstrate the relevance of the problem of hidden costs by means of a case study. We apply the framework to estimate the costs of protecting the common hamster (Cricetus cricetus, listed in Annex IV of the Habitats Directive) in the region of Mannheim, Germany and find that the hidden costs of changes in development plans are higher than the visible conservation costs by at least an order of magnitude.

Groundwater Demand Management in the Great Lakes Basin—Directions for New Policies

Demand-side management should be used to maximize the efficiency of groundwater use. Implementation of conservation measures would decrease the volume of water use and also exert less pressure on the water distribution system as well as the wastewater treatment system. Allocation of ground water in the Great Lakes basin must conform to priorities established at the community level. Groundwater pricing should reflect the full costs arising from ground water use. A differential pricing structure would help conserve water in the residential and industrial sectors. A user-friendly database on ground water use, quality and quantity for the entire Great Lakes basin is also essential. New policies for sustainable groundwater allocation, regulating water prices for water conservation, conservation education, pollution prevention, recycling and reuse of water as well as effective information management provide new directions for managing the groundwater demand in the Great Lakes basin.

An overlooked threatened species of eagle: Legge's Hawk Eagle Nisaetus kelaarti (Aves: Accipitriformes)

Species delimitation is fundamental to many areas of biology, and in cases where taxonomic status has not been sufficiently clarified the ramifications can be as serious as extinction due to the failure to implement conservation measures. Since 1931, the Mountain Hawk Eagle Nisaetus (Spizaetus) nipalensis Hodgson has included the allopatric Sri Lankan and southern Indian taxon N. kelaarti (Legge) as a subspecies, and its taxonomic status has not been re-evaluated. We found that N. kelaarti differs considerably from N. nipalensis in its relatively much larger bill and claws and short primary projection, and that it also differs consistently in numerous plumage characters and other mensural characters. Its vocalizations differ distinctly, and an earlier study found a moderate degree of genetic differentiation (4.4% in cyt b and 3.1% in CR) from N. nipalensis. The available evidence thus strongly and unambiguously supports the specific distinctness of N. kelaarti.

Effects of forest-dune ecotone management on the endangered heath grasshopper, Chorthippus vagans (Orthoptera: Acrididae)

Dry, oligotrophic ecosystems are highly threatened in Europe due to massive changes in land use and eutrophication. The conservation of these xeric habitats has received much attention, whereas the ecotones between xeric habitats and other habitat types are often disregarded. One species which mainly inhabits the transition zone between pine forests and adjacent xeric habitats is the heath grasshopper, Chorthippus vagans. This species is endangered in large parts of Europe. One of the largest populations in northern Germany is found on a degraded inland dune near Hanover. This population is threatened by dense growth of deciduous trees and litter accumulation. We analyzed changes in the distribution of this population after the implementation of conservation measures (thinning out the forest and removal of leaf litter). Moreover, we examined dispersal distances of the species in order to assess its colonization potential. We also studied the microhabitat preferences of C. vagans to assess key factors influencing its local distribution. Our data show a substantial growth in population size, which might be a consequence of the conservation measures. New patches on the dune were colonized, promoting dispersal between the subpopulations. We propose that restoration of forest-dune ecotones should be considered more often in landscape planning and conservation management.

Characterisation of post-larval to juvenile stages, metamorphosis and recruitment of an amphidromous goby, Sicyopterus lagocephalus (Pallas) (Teleostei : Gobiidae : Sicydiinae)

Sicyopterus lagocephalus post-larvae migrating in Mascarene Archipelago rivers, La Réunion Island, provide an important food source to local populations and fishing activity has a socioeconomic impact. Improved knowledge of the life traits and the characterisation of post-larval stages should enable a better understanding of physiological changes triggering migratory behaviour. It would also help to explain the recruitment processes to managers and to implement conservation measures for stock management. Sicyopterus lagocephalus is an amphidromous fish: adults live in rivers, but larvae are carried to the sea after hatching. The present study characterised the metamorphosis and post-larval stages of Sicyopterus lagocephalus during river recolonisation on La Réunion Island. The results show that cranium reorganisation and pectoral fins transformation are part of the first and major transformations and are completed less than 2 weeks after freshwater colonisation (post-larval stages PL1 and PL2). These transformations, mobilising all the available calcium, seem to be critical for survival in their new environment. Individuals then progressively acquire pigmentation, complete scalation and the fork at the end of the caudal fin disappears (juvenile stages J1 and J2). The end of the recruitment phase takes place 21 to 28 days after entering the river mouth, when territorial behaviour appears.

Has the manatee (<i>Trichechus manatus</i>) dissapeared from the northern coast of the State of Veracruz, Mexico?

Knowledge about the distribution and abundance of the manatee (Trichechus manatus) along the coast of the Mexican state of Veracruz is scarce. Since few studies have been undertaken in this area, boat-based surveys and interviews with local fishermen were carried out to determine if there are remaining herds of manatees in the vicinity of the coastal towns of Tamiahua, Tuxpan, Tecolutla, and Casitas-Nautla. All of the fishermen interviewed noted that they used to see large herds of manatees in the area. Seventy-four percent (371 fishermen) of the survey respondents had not seen a manatee over the last 10 years, and 26% (131 fishermen) responded that the last time they saw large or small groups of manatees was in 1986 and 1995, respectively. However, since 1996, none of the fishermen had observed any manatees in the area. Similarly, no manatees were observed during the boat-based surveys (effort of approximately 1200km). It is almost certain that anthropogenic influences have altered manatee habitat significantly and thus affected the numbers of animals using the area. Also, fishermen speculated that natural phenomena such as cyclones, flooding, and storms caused manatees to move away from the area. More surveys along the coast of Veracruz are needed to determine if manatees still occur in this Mexican state. Also, it is urgent to implement conservation measures in the northern range of the manatee in Mexico to ensure the survival of this species along its original distribution.

The formation of policy for protection of cold-water coral off the coast of Norway

Abstract This paper presents the implementation of conservation measures, especially bottom trawl free areas, for the protection of cold-water coral off the Norwegian coast. The protection measures became effective less than 9 months after the managers were informed and the public became aware of damaged coral on nationwide television. Behind this quick reaction were a number of agents such as the oil industry, fishers, biologists, NGOs as well as policy-makers. The implementation of the protected areas was remarkably free of contention. This work attempts to outline the reasons for this, and determine whether there are lessons to be learned with regard to conservation measures elsewhere.

Conservation of the vaquita Phocoena sinus

ABSTRACT The vaquita Phocoena sinus is a small porpoise that is endemic to the northern Gulf of California, Mexico. It is the most critically endangered marine small cetacean in the world. The most precise estimate of global abundance based on a 1997 survey is 567 (95% CI 177–1073). Vaquitas mainly live north of 30°45′N and west of 114°20′W. Their ‘core area’ consists of about 2235 km2 centred around Rocas Consag, 40 km east of San Felipe, Baja California. Genetic analyses and population simulations suggest that the vaquita has always been rare, and that its extreme loss of genomic variability occurred over evolutionary time rather than being caused by human activities. Gill nets for fish and shrimp cause very high rates of by‐catch (entanglement) of vaquitas. Estimates of bycatch rates are from 1993–94 and refer to one of three main fishing ports: 84 per year (95% CI 14–155) using only data collected by observers and 39 per year (95% CI 14–93) using combined data from observers and interviews with fishermen. Boats from other ports may experience similar rates, and the total is probably well above what would be sustainable. Other less well‐characterized and longer‐term risk factors include the potential for disturbance by trawling to affect vaquita behaviour, and the uncertain effects of dam construction on the Colorado River and the resultant loss of freshwater input to the upper Gulf. However, entanglement is the clearest and most immediate concern. Progress towards reducing entanglement has been slow in spite of efforts to phase out gill nets in the vaquita’s core range, and the development of schemes involving compensation for fishermen. The Biosphere Reserve in the northern Gulf has fallen far short of its potential for vaquita conservation. On 29 December 2005, the Mexican Ministry of Environment declared a Vaquita Refuge that contains within its borders the positions of approximately 80% of verified vaquita sightings. In the same decree, the state governments of Sonora and Baja California were offered $1 million to compensate affected fishermen. The effectiveness of this major initiative remains to be seen. The vaquita’s survival does not depend on more or better science but on improved management. As a funding priority, implementation of conservation measures and evaluation of their effectiveness should come ahead of more surveys or improved estimation of by‐catch.

Farmers' identification of erosion indicators and related erosion damage in the Central Highlands of Kenya

Most soil and water conservation planning approaches rely on empirical assessment methods and hardly consider farmers' knowledge of soil erosion processes. Farmers' knowledge of on-site erosion indicators could be useful in assessing the site-specific erosion risk before planning any conservation measures. The aims of this study were to identify erosion indicators based on the farmers' knowledge and assess relevance of these indicators in estimating soil erosion damage. Household, community and key informant surveys were carried out in an agriculturally high potential smallholder farming system in Central highlands of Kenya. Survey data were assessed based on consensus views, percentage frequency and descriptive statistics. Eleven erosion indicators were identified and described in local language, and their causes outlined, which closely agreed with scientific knowledge. Indicators were not only distinguished between current (splash pedestals, rills, sheetwash, sedimentation, root exposure) and past (stoniness, red soils, gullies, loose soils) but classified into erosion rates of high, moderate and low. Current and past erosion indicators were distinguished by the duration of rainfall event(s). Current indicators were perceived to be reversible in the sense that they were frequently obliterated through seasonal ploughing and weeding. They were therefore assumed to cause less soil damage thus signifying low to moderate soil loss rates. But continuous neglect of current indicators led to formation of past (irreversible) erosion indicators. Soils with such indicators were not easily restored to food crop production instead converted to other enterprises like stone crashing for construction materials and growing of mirraa ( Catha edulis). The spatial distribution of the erosion indicators along the hillslope was described fitting the influence of runoff velocity with increasing gradient and slope length-steepness factors. Steep slopes were more severely damaged than the gentle and flat slopes. Farmers illustrated how relative erosion indicator weights; an index of soil damage, could be used to identify more severely eroded portions of fields or hillslopes that needed conservation attention. This approach did show that severity of erosion risk or extent of soil damage by erosion was dependent on the number and type of erosion indicators, and the total weight index of on-site erosion indicators. Consequently, widescale adoption of farmers' erosion indicators in estimating the rate of soil loss or soil erosion risk might be a rational approach by which land-users would undertake self evaluation of erosion status on their own farms. By this way, they would probably get convinced to implement conservation measures without external enforcement.

Effects of exceptional conservation measures on survival and seasonal hunting mortality in greater snow geese

Summary Large‐scale conservation measures aimed at reducing the abundance of a wild population offer a unique opportunity to study the impacts of human exploitation on demographic parameters. We examined the effects of a spring conservation harvest and liberalized autumn/winter regulations introduced recently to control the rapid population growth of greater snow geese Anser caerulescens atlantica. We predicted that these changes in regulations affected survival and recovery probabilities, as well as kill rates. This was evaluated by analysing data on geese shot by hunters before and after implementation of these measures. Annual survival and recovery probabilities were estimated using likelihood‐based ring recovery models, and we developed a new, flexible seasonal model to determine the specific effects of regulation changes made during different hunting seasons. We used harvest survey data to estimate ring‐reporting rate, and thus to convert recovery rates into kill rates. Adult recovery and kill rates increased considerably with the implementation of the new measures in 1998–99. The addition of the spring harvest in Québec and the liberalized winter regulations in the USA had the largest impacts, whereas autumn regulation changes in Québec apparently had little effect. Juvenile recovery and kill rates also showed a moderate increase, but were highly variable. We observed a decline in mean annual adult survival rate, from 83·0% to 72·5%, although the implementation of conservation measures did not fully explain temporal variation in adult survival; juvenile survival showed no change. Adult survival was negatively related to harvest rate in adults but not in juveniles. Synthesis and applications. We demonstrate that the spring conservation harvest led to a decrease in adult survival and an increase in hunting mortality, and probably contributed to the decline in abundance observed since its implementation. However, regulations during the traditional autumn and winter hunting seasons could also be manipulated for future population control once the spring conservation harvest is discontinued. Our approach for evaluating hunting mortality on a seasonal basis should be useful in the management of other migratory populations that move through several jurisdictions.

Methods and progress in the conservation of elm genetic resources in Europe

The progress made in the conservation of European elm genetic resources since the 1st International Elm Conference is reviewed, and the complementarity of in situ and ex situ methods is discussed. The financial support of the European Union to RESGEN project CT96-78 has permitted to co-ordinate and rationalize the ex situ conservation of elms. The project, which involved 17 partner institutes in nine west European countries, aimed at a better evaluation, conservation and utilisation of the existing collections of native elm clones. Main achievements are: establishing a common database of about 2,000 clones; characterizing over 500 clones through RAPDs and chloroplast DNA PCR-RFLPs molecular markers; completing and rationalizing the existing collections; establishing a long-term core collection of 850 clones; cryo-preserving a subset of 444 clones; and identifying clones of interest for breeding and prudent use in the reconstruction of countryside hedges. The «Noble Hardwoods» network of the pan-European programme EUFORGEN groups members representative of 31 countries, and promotes the dynamic conservation of the genetic resources of several genera of broadleaf forest trees, including Ulmus spp. Strategies for the conservation of the adaptive potential of elm resources were defined and will be disseminated among foresters and conservationists through «Guidelines» leaflets. Some countries have already started implementing conservation measures for U. laevis, associating in situ preservation and the establishment of seed orchards. Others are undertaking inventories, or acquiring genetic knowledge on target populations.

Rates of species loss from Amazonian forest fragments.

In the face of worldwide habitat fragmentation, managers need to devise a time frame for action. We ask how fast do understory bird species disappear from experimentally isolated plots in the Biological Dynamics of Forest Fragments Project, central Amazon, Brazil. Our data consist of mist-net records obtained over a period of 13 years in 11 sites of 1, 10, and 100 hectares. The numbers of captures per species per unit time, analyzed under different simplifying assumptions, reveal a set of species-loss curves. From those declining numbers, we derive a scaling rule for the time it takes to lose half the species in a fragment as a function of its area. A 10-fold decrease in the rate of species loss requires a 1,000-fold increase in area. Fragments of 100 hectares lose one half of their species in <15 years, too short a time for implementing conservation measures.

Issues relating to energy conservation and renewable energy in Bangladesh

Bangladesh is encountering difficulties in supplying energy to maintain its economic growth. The gap between demand and supply is gradually increasing. Although it has some reserves of commercial energy resources (e.g., natural gas and coal), because of economic and technical constraints it is unable to supply sufficient energy. The dependence on imported fuel (oil and coal) is gradually increasing, and the rural population, which uses a fair amount of imported fuel (kerosene and diesel), is largely disadvantaged because of its low purchasing power. Most of the commercial energy used is derived from natural gas and imported oil, while the main consumers are power generation, transport and industry. The major share of the total energy consumption in Bangladesh is from biomass fuels comprising agricultural wastes, animal wastes and fuelwood. The biomass is mainly used in the rural households. Because of shortage of land there are limited prospects of increasing the supply from biomass sources. The emphasis is usually on commercial energy, which plays a decisive role in such aspects of development as industrialization, agricultural mechanization and urbanization. Efficiency of energy production and its utilization in Bangladesh is generally poor. The demand for energy exceeds the available resources and this gap is projected to increase significantly in the near future. There are significant opportunities for increasing energy efficiency and conservation by end-users in all sectors - domestic, industrial, commercial, transport and agriculture. The extent of energy conservation initiatives in the country has been limited. The Energy Monitoring and Conservation Centre of the government has almost no regulation-enforcing authority, and the National Energy Conservation Act is still under consideration by the legislators. Significant and concerted attempts to increase energy efficiency and conservation measures in the various sectors have not been widely applied in the country. Efforts have been made to increase energy efficiency and implement conservation measures in some industries such as sugar mills, spinning mills and fertilizer factories, and also in the rural domestic sector by the expansion of the use of improved cookers. The use of energy-efficient lighting and power-consuming devices can play a role in controlling the increasing demand. Among potential renewable resources solar and biomass have good prospects. Hydropower has already been utilized to a significant extent while the potential of wind energy is limited to coastal zones. In actual practice only a small number of solar photovoltaic devices are currently being used. In the existing scenario energy efficiency and renewable energy can play a more significant role in the energy sector of Bangladesh. This will require a proper and supportive government policy. Action plans to enhance commercialization of energy efficiency and renewable energy technologies have been suggested.

Two hundred years after a commercial marine turtle fishery: the current status of marine turtles nesting in the Cayman Islands

AbstractLarge populations of marine turtles breeding in the Cayman Islands were drastically reduced in the early 1800s. However, marine turtle nesting still occurs in the islands. The present-day status of this nesting population provides insight into the conservation of marine turtles, a long-lived species. In 1998 and 1999, the first systematic survey of marine turtle nesting in the Cayman Islands found 38 nests on 22 beaches scattered through the three islands. Three species were found: the green Chelonia mydas, hawksbill Eretmochelys imbricata and loggerhead Caretta caretta turtles. Comparison with other rookeries suggests that the small number of sexually mature adults surviving Cayman's huge perturbations may be impeding population recovery. This shows the need to implement conservation measures prior to massive reductions in population size.

Economics of Soil Conservation: The Upper Mahaweli Watershed of Sir Lanka

This paper estimates the benefits and costs of soil conservation in the Upper Mahaweli Watershed of Sir Lanka. The costs of soil erosion control include the implementation costs of control measures, while the benefits are reductions in the costs of soil erosion. In contrast to many studies in developed countries, the on‐site benefit of soil erosion control in Sri Lanka is estimated to be greater than the off‐site benefit While a social benefit‐cost analysis demonstrates that it is socially desirable to implement conservation measures, the private financial analyses indicate that it is feasible for individual farmers to adopt the conservation measures. Despite private economic feasibility, programs addressing farmers' reluctance to adopt soil conservation measures may be preferable to public intervention in soil conservation activities when the on‐site benefits are greater than the off‐site benefits.