Integration of ecological-biological thresholds in conservation decision making

Identifying thresholds in air exposure, water temperature and fish size that determine reflex impairment in brook trout exposed to catch-and-release angling

Understanding the factors that contribute to fish impairment and survival from angling events is essential to guide best angling practices for catch-and-release (C&R) recreational fisheries. Complex interactions often exist between angler behaviour, environmental conditions, and fish characteristics that ultimately determine biological outcomes for fish. Yet, few studies focus on identifying biologically relevant thresholds. We therefore examined the effects of water temperature, air exposure and fish size on reflex impairment and mortality in brook trout Salvelinus fontinalis exposed to experimental and simulated angling stressors (n = 337). Using conditional inference trees, we identified interactions among these factors as well as threshold values within them that determine brook trout reflex impairment as an indicator of whole animal stress. Specifically, longer air exposure times (>30 sec) and warmer temperatures (>19.5°C) had a synergistic effect leading to higher reflex impairment scores. Further, larger fish (>328 mm) were more sensitive to air exposure durations >10 sec. Of the reflex impairment measures, loss of equilibrium and time to regain equilibrium were strongly and moderately associated with brook trout mortality (18-24 h monitoring), although mortality rates were generally low (6%). These findings support previous research that has established strong links between these reflex impairment measures and fish health outcomes in other species. They also highlight the important interactions among air exposure duration, water temperature and fish size that determine impairment in brook trout, providing specific thresholds to guide best angling practices for C&R fisheries. This approach may be widely applicable to generate similar thresholds that can be encouraged by regulators and adopted by anglers for other common C&R fishes.

"Targets-Plans-Decision": A framework to identify the size of protected areas based on the balance of ecological protection and economic development

A framework called "Targets-Plans-Decision" (TPD) was established for identifying the size of adequate protected areas (PAs) based on the combination of species distribution probability prediction method, systematic conservation planning (SCP) theory, and protection efficiency analysis, to achieve a balance between ecological protection and economic development. The first step of the framework is to determine the protection targets. In this study, the protection targets were defined as important habitats and important ecosystems. The second step is to identify the PAs plans of different sizes. We adopted a SCP method, which takes into account cost-effectiveness while delineating the PAs. The third step is to determine the optimal size of the PAs through ecological protection efficiency analysis. We constructed the protection efficiency index (PEI), which is the protection cost per unit area. Then we used Kaya identity (a structural decomposition method) to decompose PEI. The decomposed PEI included value density (ecological value per unit area) and value cost (cost to realize unit ecological value). By analyzing the changes of the two, the optimal size of the PAs can be determined. We took Nanchang as an example to conduct an empirical study to verify the usability of the TPD framework. The result shows the TPD framework proposed in this study can effectively identify the optimal size of PAs and contribute to forming a cost-effective ecological protection plan. When the size of PAs was set to 70% of the important habitats and important ecosystems, it was most beneficial for ecological protection. Furthermore, the optimal protection efficiency plan recommended by the TPD framework improved the efficiency of ecological protection. The TPD framework can serve as a basis for the size identification of PAs and also support the delineation of PAs worldwide.

Designing a network of green infrastructure to enhance the conservation value of protected areas and maintain ecosystem services

There is a growing demand for holistic landscape planning to enhance sustainable use of ecosystem services (ESS) and maintenance of the biodiversity that supports them. In this context, the EU is developing policy to regulate the maintenance of ESS and enhance connectivity among protected areas (PAs). This is known as the network of Green Infrastructure (GI). However, there is not a working framework defined to plan the spatial design of such network of GI. Here, we use the software Marxan with Zones, to prioritize the spatial distribution of different management zones that accommodate the needs of a network of GI. These zones included a conservation zone, mainly devoted to protecting biodiversity, a GI zone, that aimed at connecting PAs and maintaining regulating and cultural ESS; and a management zone devoted to exploiting provisioning ESS. We performed four planning scenarios that distribute the targets for ESS and biodiversity in different ways across management zones. We also conducted a sensitivity analysis by increasing ESS targets to explore trade-offs that may occur when managing together biodiversity and ESS. We use Catalonia (northeastern Spain) as a case study. We found that the representation of ESS could be achieved for intermediate targets in all scenarios. There was, however, a threshold on these targets over which trade-offs appeared between maintaining regulating and cultural ESS and biodiversity versus getting access to provisioning ESS. These "thresholds values" were displaced towards higher ESS targets when we moved from more strict to more flexible planning scenarios (i.e., scenarios that allowed mixing representation of objectives for biodiversity and ESS within the same zone). This methodological approach could help design a framework to integrate biodiversity and ESS management in holistic plans and decision making and, at the same time, meeting European mandates concerning the design of GI networks, or similar needs elsewhere.

The impact of a public information campaign on preferences for marine environmental protection. The case of plastic waste

This paper evaluates the effectiveness of a public information campaign, which was conducted on a major Greek Island (Syros), aimed at reducing plastic waste - and specifically plastic bags - in the local coastal/marine environment. A choice experiment was conducted to evaluate the effects on individual preferences for reducing plastic waste pollution under different status of environmental awareness, after the information campaign. The evaluation process was quite independent of the information campaign. Two samples of respondents were taken; one consisting of participants in the environmental campaign and the other consisting of non-participants. The results show: (a) significant differences between the preferences of the two samples; (b) variations in the willingness to pay values between the two samples for protection of the coastal/marine environment, but; (c) not significant differences in their commitment to take action (i.e. in their willingness to alter their current plastic bag use behavior).

Hidden collapse is driven by fire and logging in a socioecological forest ecosystem

Increasing numbers of ecosystems globally are at risk of collapse. However, most descriptions of terrestrial ecosystem collapse are post hoc with few empirically based examples of ecosystems in the process of collapse. This limits learning about collapse and impedes development of effective early-warning indicators. Based on multidecadal and multifaceted monitoring, we present evidence that the Australian mainland Mountain Ash ecosystem is collapsing. Collapse is indicated by marked changes in ecosystem condition, particularly the rapid decline in populations of keystone ecosystem structures. There also has been significant decline in biodiversity strongly associated with these structures and disruptions of key ecosystem processes. In documenting the decline of the Mountain Ash ecosystem, we uncovered evidence of hidden collapse. This is where an ecosystem superficially appears to be relatively intact, but a prolonged period of decline coupled with long lag times for recovery of dominant ecosystem components mean that collapse is almost inevitable. In ecosystems susceptible to hidden collapse, management interventions will be required decades earlier than currently perceived by policy makers. Responding to hidden collapse is further complicated by our finding that different drivers produce different pathways to collapse, but these drivers can interact in ways that exacerbate and perpetuate collapse. Management must focus not only on reducing the number of critical stressors influencing an ecosystem but also on breaking feedbacks between stressors. We demonstrate the importance of multidecadal monitoring programs in measuring state variables that can inform quantitative predictions of collapse as well as help identify management responses that can avert system-wide collapse.