Damage to marine environments attracts increasing attention and alarm, instilling in many observers a sense of urgency in promoting preventive and restorative measures (see for example Pauly & Maclean 2003; Roberts 2003; RCEP [Royal Commission on Environmental Pollution] 2004; MEA [Millennium Ecosystem Assessment] 2005). Such concerns have had effect. As noted in a recent British policy document, ‘countries all over the world are reviewing the way they manage their marine environment’ (Defra [Department for Environment, Food and Rural Affairs] 2007, p. 1). In much that has been said and written on this subject it is a basic premise that marine ecosystems and biodiversity ought to be protected, at least to some degree. This implies a moral injunction: that it is wrong to allow these systems to be degraded or destroyed, and right to limit human activities that generate harmful impacts. The interesting and fundamental question is why. What Norton (1982, p. 319) calls an ‘intuitive ethic’ for conservation might be invoked, but in a world of conflicting priorities it will often be necessary to support intuition with evidence and argument. Answers to the question, ‘why conserve?’ are important because the reasons offered for defending marine environments have a bearing on the extent to which conservation can be justified, and on the kinds of policies that might ensue. Although different premises will sometimes point to broadly similar actions, there are circumstances in which the underlying rationales for conservation will have divergent policy implications.

Multi-tenure reserve networks (MTRNs) aim to connect areas managed for biodiversity conservation across public and private land (for example biosphere reserves (BRs) and conservation management networks (CMNs)). A key function of MTRNs is facilitating communication, information exchange and management activities between land managers of differing tenures not usually in contact with each other; governance arrangements are therefore crucial. Australian MTRNs vary greatly in their goals and measures of success, criteria for entry, ecosystems targeted, geographic extent and financial arrangements. The successful operation of a MTRN is likely to be influenced by a manager's confidence in the governance model/coordination arrangements (Belcher & Wellman 1991). We analysed the organizational structure of three Australian MTRNs (Fig. 1) including the objectives and role of the coordinating body, entry requirements, goals and measures of success, restrictions placed on the geographic or ecological extent of the network and financial arrangements. We highlight how substantial changes in governance arrangements have occurred for two of three networks studied, suggesting a fluid evolution of MTRN structures is likely.

Bulleri et al. (2007) describe local environmental impacts as ‘assessed by comparing the disturbed site with one or more [unaffected] reference sites . . . [which] can be thought of as a random sample from a population of sites as in design-based approaches (Underwood 1992), or as a set of covariates correlated with the disturbed site as in model-based analyses (Stewart-Oaten & Bence 2001)’ (brackets added). This is misleading. These two approaches are not alternatives. The latter paper shows that reference sites are not essential and that the former paper's use of them is invalid.

We appreciate the effort and thought that Stewart-Oaten (2008) has put into his comment on our paper in Environmental Conservation (Bulleri et al. 2007). Clearly, the philosophical and methodological approaches used in ecological impact assessments (EIAs) warrant much further attention and discussion by ecologists. We would like, however, to clarify that the goals of our comment were far from summarizing available procedures and, even more, from expressing an opinion about which among these should be retained or rejected. This is quite well reflected by the contents of our paper (Bulleri et al. 2007). Our ‘main purpose’ (to quote Stewart-Oaten 2008) was to point out that the degree of naturalness of a site is irrelevant to whether or not some proposed disturbance causes an impact and that all disturbances potentially cause negative impacts.

Ecotourism can capture biodiversity values and provide incentives for conservation, and many integrated conservation and development projects include an ecotourism component. One key assumption behind this strategy is that ecotourism businesses can achieve financial viability. This paper presents a financial case study of the well-known community-based ecotourism lodge ‘Casa Matsiguenka’, owned by an indigenous Matsigenka population in Manu National Park (Peru), only the second such project to be thoroughly analysed in the literature. Built and financed from 1997 to 2003 with German official aid, the lodge's revenues have only just exceeded operating costs and have not covered the costs of infrastructure replacement, thereby failing to secure long-term business sustainability. Wages and income from handicraft sales have covered about a third of individual cash needs in the two participating communities, but communal income from lodge operating profits (for example to pay for community infrastructure, health care or education) has been minimal. The lodge's difficulties are attributed largely to a flawed business plan in which the lodge has sold its services to its own competitors, a group of ecotourism agencies that have used their lobbying power to create a cartel in Manu. In a narrow analysis, the return on investment for this project has been approximately one-third of what could have been achieved to date by merely investing the start-up grant monies in a bank account and paying the interest directly to the Matsigenka communities in exchange for conservation actions. Broader analysis indicates the modest income and slow pace of business so far has permitted gradual social and economic adaptation on the part of culturally conservative indigenous communities. Moreover, the lodge project has generated processes of social and political organization, and sustained positive contact with Peruvian national society, which can be counted among its successes. The lodge has helped produce dialogue between the Park administration and the Matsigenka communities, a process that could ultimately result in co-management agreements that help to resolve people-park conflicts in the Park.

Big-leaf mahogany's listing on CITES Appendix II requires producer nations to certify that exported supplies were obtained in a manner non-detrimental to the species' survival in its role in the ecosystem. Non-detriment findings based on annual export quotas should verify that current harvest rates are sustainable with respect to total commercial stocks. In order to assess this impact, a method for converting export-quality sawnwood volumes to numbers of standing trees is used to estimate the number of mahogany trees and forest area required to produce the original and revised 2007 export quotas set by Peru, correcting for systematic measurement error caused by buttresses and for stem defects caused by heart-rot (hollow bole). Based on large-scale inventory data from three forest sites in nearby south-west Brazil, the average commercial-sized (> 75 cm diameter in Peru) mahogany tree in this region would yield 6.4–8.5 m3 of roundwood (standing volume), which in turn would be processed or milled into 1.7–2.2 m3 of export-grade sawnwood. From this estimate, 6120–8070 commercial-sized trees would have been harvested to supply the original 2007 export quota of 13 477 m3, from a forest area of 407 300–536 750 ha at landscape-scale densities reported by the Peruvian CITES Scientific Authority. To supply the revised export quota of 4983 m3, an estimated 2260–2980 commercial-sized trees will be harvested from a forest area of 150 600–198 450 ha. Both estimates exceed the number of trees the Peruvian Scientific Authority estimates can be sustainably harvested annually (961 ± 144 trees > 75 cm diameter) based on preliminary inventory data. The method estimates that, since 1996, 154 000–203 000 mahogany trees have been logged in Peru from a forest area of 10.2–13.5 million ha to supply the total reported export volume during this period (including the revised 2007 export quota) of 339 114 m3. This area corresponds to 18–25% of mahogany's total natural range in Peru, or 37–49% of mahogany's estimated remaining range in 2001. Without empirical knowledge of density patterns, surviving commercial stocks, and biological and technical issues linking processed lumber (sawnwood) to standing trees (roundwood), it will remain difficult to evaluate the sustainability of export quotas issued at the national level for mahogany or other tropical timber species.

The perceptions of resource users towards any conservation policy can be a major determinant of its success. While co-management policy can enhance the management of fisheries, to date there have been few reports concerning how engagement in co-management regimes may affect fishers' perceptions. This paper assesses the determinants of fishers' environmental perceptions within a co-management regime in Chile. Group meetings and structured questionnaires showed fishers' environmental perceptions were composed of four domains of concern, termed ‘water pollution’, ‘stock conservation’, ‘conservation/profit trade-offs’ and ‘charismatic species’. Fishers' dependence on diving and/or the length of time fishers had engaged with the policy affected their perceptions of each of these domains. Perceptions of the ‘water pollution’ domain were related to length of time fishers had participated in co-management, probably because fishers gained an increased understanding of the market and its need for unpolluted produce. Attitudes towards ‘conservation/profit trade-offs’ tended to become linked to an increasingly conservation-oriented ethic with increasing time of engagement with the policy. Given that the length of time fishers engaged with co-management differentially affected fishers' perceptions of environmental domains of concern, public officials and funding agencies should be careful not to judge co-management prematurely. It takes time to educate participants and overcome distrust. Through co-management processes in Chile, fishers' environmental awareness increased, and sustainable behaviours may consequently increase in the future.

The protected sites defined under the Marine Conservation Corridor of the Tropical Eastern Pacific (MCCTEP) include most of the endemism and a fraction of the areas of high diversity for reef corals and fishes. Although those areas are connected biologically over distances >600 km, lack of large-scale sampling and attention to taxa other than scleractinian corals has limited the protection of shallow coral reef and coral community habitats in some areas of the Tropical Eastern Pacific (TEP) region, particularly non-offshore islands in Ecuador, Panama and Costa Rica. The newly created Las Perlas marine protected area (1688 km2), the second largest archipelago in the TEP, fills a regional conservation gap for the protection of reefs and potentially becomes the second highest coral diversity area in the MCCTEP. This study describes the distribution of live coral cover and species alpha-diversity over 307 ha of shallow coral reefs and coral communities in the Las Perlas Archipelago. Nineteen scleractinian and 38 octocorals were observed, including species previously thought to be uncommon. Although coral communities generally had a greater number of species than coral reefs, species richness did not differ between habitats. However, their coral and octocoral composition and benthic makeup (coral cover, macroalgae, sponge, etc.) differed. The reefs had higher live coral cover (61.2%) and lower algal cover (32.5%) than the coral communities (26.0% and 65.7%, respectively). Octocorals were more common in the communities than on the reefs. There was a negative relationship between live coral cover and species richness, low to moderate cover generally coinciding with coral community sites and higher species richness. Areas are recommended for marine reserve zoning within the new Las Perlas marine protected area to ensure the protection of important habitats and maintenance of diversity in the TEP, both highlighting the importance of the southern islands of the archipelago for coral diversity and the northern islands for their high live coral cover. Review of the representativeness of regional coral diversity would facilitate better design of small-scale reserves across the TEP, following comparable survey methods.

Stakeholder analysis as a specific tool in social science can be used to explain why environmental conflicts arise or persist and identify steps to resolve these. This paper considers the conflict over the great cormorant, a fish-foraging bird with a rapidly growing population, a conflict previously treated only at a local, subnational or national level. The measures taken have sometimes mitigated the conflict, but have not addressed the damage and conflicts owing to the rapid cormorant population expansion. As the population is mobile at the scale of Europe, management of the population needs to be considered at the European level. In the 1990s, the Convention on Migratory Species (CMS) drew up a management plan, which was never endorsed. Interviews with authorities, scientists and other stakeholders revealed they considered the CMS management plan inappropriate because some thought it compromised national autonomy while others thought there was insufficient cormorant protection. A possible step-wise solution to developing a pan-European management plan is proposed, requiring agreement on common objectives and strategies.

Potential impacts of climate change on ecosystems and the environment are generally assessed by summarizing climate change scenarios for broad regions (for example countries), or by specific modelling exercises. This paper presents an alternative approach for summarizing climate change impacts on the European environment, by linking climate change scenarios to recognized environmental divisions. Sixteen climate scenarios from four general circulation models were therefore linked to 84 statistically derived strata sharing common environmental features. In this way, the future distribution of the strata, as defined by their climate characteristics, were quantified and mapped. The results show that Europe is likely to experience major environmental shifts, with pronounced regional variations. As expected, environmental strata shift northwards. In particular the southern Mediterranean strata are projected to expand, whereas Atlantic environments remain much more stable. Alpine and Mediterranean mountain environments decline dramatically. However, the Scandinavian zones show no consistent pattern of change. More detailed analysis of four sample regions shows that the impacts of the projected shifts will largely depend on regional characteristics. Environmental conservation, regional assessments and scenario development could therefore be facilitated by combining relevant regional datasets (for example for vegetation, land cover and species distribution) with the shifting environmental strata.

Since the late 1980s, biodiversity conservation efforts have expanded to incorporate delivering social and economic benefits to communities nearby or within protected areas. Benefits can generate incentives to encourage conservation support; however, such incentive-based programmes (IBPs) have been criticized owing to their inability to provide equal and equitable distribution of benefits. This research examines the distribution of IBPs in the buffer zone of Nepal's Chitwan National Park (CNP). Questionnaire interview data indicate the livelihoods of buffer zone residents remain strained by conservation activities. While benefits under IBPs are recognized by the residents, villages distant from the main tourist entry points to the park where costs associated with conservation are highest recognize few benefits. An individual's level of participation in tourism also affects the benefits received, with those directly employed in tourism receiving the most benefit. Despite the discrepancy in benefit distribution between villages and between levels of involvement in tourism, CNP is making progress in distributing benefits beyond villages where tourism is concentrated. The main IBP flaw in CNP is a limited ability to replicate benefits throughout the buffer zone, providing similar levels of benefit to all villages.