Advances in marine conservation: the role of marine protected areas

The world's oceans are now attracting the serious attention of conservationists. Paradoxically, as the value of marine biological diversity is recognized, the ecosystems that harbor this diversity are fast becoming degraded. New thinking about how to conserve coastal areas has resulted in protected-area models that incorporate principles of landscape ecology, adaptive and ecosystem management, and zoning in protected-area plans.     

Mediterranean marine protected areas

A collection of five recent papers assesses the role and effectiveness of marine protected areas (MPAs) in the Mediterranean. The papers provide a broad perspective of MPAs and include social, economic, cultural, biological and statistical components.     

海洋生物多样性保护优先区域的确定

为了有效利用资源和资金,合理保护海洋生物多样性,海洋生物多样性保护优先区域的确定成为目前保护生物学领域的热点之一.本文首先探讨了生物多样性保护优先区域的定义和内涵,认为海洋生物多样性保护优先区域是指生物多样性丰富、物种特有化程度高、珍稀濒危物种分布集中、具有重要生态功能和过程的海洋区域.其次对保护优先区域确定的内容和方法进行了总结,主要包括单元区划、指标体系的构建及保护优先区域评估3个方面.继而根据我国海洋生物多样性现状提出保护优先区域确定的基本思路,即在海洋生物地理分区的基础上,根据物种和生境的生物多样性指标确定保护优先区域.最后针对存在问题提出建议,包括运用生物地理学方法进行单元区划、基于物种和生态系统的方法构建生物学指标以及信息网络数据库的构建等.     

Habitat collapse due to overgrazing threatens turtle conservation in marine protected areas

Marine protected areas (MPAs) are key tools for combatting the global overexploitation of endangered species. The prevailing paradigm is that MPAs are beneficial in helping to restore ecosystems to more ‘natural’ conditions. However, MPAs may have unintended negative effects when increasing densities of protected species exert destructive effects on their habitat. Here, we report on severe seagrass degradation in a decade-old MPA where hyper-abundant green turtles adopted a previously undescribed below-ground foraging strategy. By digging for and consuming rhizomes and roots, turtles create abundant bare gaps, thereby enhancing erosion and reducing seagrass regrowth. A fully parametrized model reveals that the ecosystem is approaching a tipping point, where consumption overwhelms regrowth, which could potentially lead to complete collapse of the seagrass habitat. Seagrass recovery will not ensue unless turtle density is reduced to nearly zero, eliminating the MPA''s value as a turtle reserve. Our results reveal an unrecognized, yet imminent threat to MPAs, as sea turtle densities are increasing at major nesting sites and the decline of seagrass habitat forces turtles to concentrate on the remaining meadows inside reserves. This emphasizes the need for policy and management approaches that consider the interactions of protected species with their habitat.     

基于机会成本法的海洋保护区生态保护补偿标准

建立海洋保护区已被公认为维持海洋生物多样性和防止海洋生态环境恶化的重要途径,而合理实施生态保护补偿是确保海洋保护区建设和管理成效、促进区域经济发展机会公平的关键手段。以土地、海域为载体,从机会成本补偿的角度出发,分别设置了机会成本补偿基数、区域调整系数、分区补偿系数和开发限度补偿系数,构建了海洋保护区生态保护补偿标准测算方法,并选取全国8个省(市)14个国家级海洋自然保护区开展了实证分析。结果表明:2015年案例区的机会成本补偿测算结果介于0.66×10⁴—10.69×10⁴元/km²之间,河北昌黎黄金海岸国家级自然保护区和天津古海岸与湿地国家级自然保护区的补偿金额显著高于其他保护区,分别为10.69×10⁴元/km²和10.47×10⁴元/km²,相比之下,其余12个保护区的平均补偿金额为1.70×10⁴元/km²。     

基于系统保护规划的海河流域湿地保护优先格局与保护空缺识别

以海河流域为研究对象,依托系统保护规划的理论、方法和技术手段,建立气候-地貌-湿地生态地理综合分类单元,并将此单元作为宏观尺度湿地生物多样性的替代单元,同时以湿地水鸟作为物种尺度的指示物种,综合考虑道路、居民点等社会因素,确定了海河流域湿地保护优先格局及保护空缺。研究结果表明：湿地结构上,现有保护体系中仅滨海湿地受保护比例较高,经系统保护规划优后,湿地保护比例可达28.55%,保护面积达36.55 km²;在空间分布上,仅徒骇马颊河水系目前得到较好的保护,建议对滦河及冀东沿海区域及海河流域南北水系通过设立保护小区和建立湿地公园等方式加强保护。研究结果可为海河流域湿地保护体系调整提供参考,为湿地、非湿地生态系统的整合优化提供有益启示。     

Modelling marine protected areas: insights and hurdles

Models provide useful insights into conservation and resource management issues and solutions. Their use to date has highlighted conditions under which no-take marine protected areas (MPAs) may help us to achieve the goals of ecosystem-based management by reducing pressures, and where they might fail to achieve desired goals. For example, static reserve designs are unlikely to achieve desired objectives when applied to mobile species or when compromised by climate-related ecosystem restructuring and range shifts. Modelling tools allow planners to explore a range of options, such as basing MPAs on the presence of dynamic oceanic features, and to evaluate the potential future impacts of alternative interventions compared with ‘no-action’ counterfactuals, under a range of environmental and development scenarios. The modelling environment allows the analyst to test if indicators and management strategies are robust to uncertainties in how the ecosystem (and the broader human–ecosystem combination) operates, including the direct and indirect ecological effects of protection. Moreover, modelling results can be presented at multiple spatial and temporal scales, and relative to ecological, economic and social objectives. This helps to reveal potential ‘surprises'', such as regime shifts, trophic cascades and bottlenecks in human responses. Using illustrative examples, this paper briefly covers the history of the use of simulation models for evaluating MPA options, and discusses their utility and limitations for informing protected area management in the marine realm.     

Conservation biology: beyond marine protected areas

Socioeconomic and ecological analyses of eleven coral reef conservation efforts make clear that marine protected areas are not the answer, and that in fact support of local communities is far more important than some government mandated 'fishing closure'. Apparently there are marine 'paper parks' just as there are terrestrial 'paper parks'.     

Designing marine protected areas for migrating fish stocks

This paper extends an earlier analysis and presents an investigation of how migration rates affect the performance of various types of management regimes with respect to economic yield and conservation benefits. Particular emphasis is placed on evaluating the geometric design of marine protected areas (MPAs). Earlier results have shown that MPAs are only likely to provide significant benefits when they are used in conjunction with direct catch or effort controls, unless they are quite large and cover most of the resource in question. Conversely, catch and effort controls are far more effective when protected areas are included in the management regime as a buffer against uncertainty. Dispersal of reproduction (recruitment) to other areas is an important expected benefit of protected areas, but such dispersal increases the variability of the effects of the area protection. If fishing mortality rates outside of the protected area are not controlled then dispersal can result in nullifying some of the benefits of the protected area. Similarly, adult migration increases the variability in the results when an area is protected and critically depends upon an overall control of fishing mortality outside the area. For both dispersal and migration separately or in combination, however, there are clear benefits to using MPAs in conjunction with catch or effort controls. These benefits are expressed in terms of long-term yield and recovery probabilities. In addition, short-term yield declines relatively slowly with increasing area protected. Design of the protected areas is seen to be important since using contiguous areas provide greater protection against overfishing than protected areas in isolation.     

跨界自然保护区——实现生物多样性保护的新手段

随着区域合作和大尺度景观保护的需求不断增加,跨界资源管理越来越受到人们的关注,作为跨界资源管理的一种典型方式,跨界自然保护区正成为保护区研究中的热点问题。在对跨界自然保护区概念、类型及历史发展进行阐述的基础上,分析了建立跨界自然保护区的效益和代价及影响跨界自然保护区成败的因素,指出建立跨界自然保护区可能是在更大尺度上实现生态系统管理和生物多样性保护的有效途径。同时,分析了我国保护区的跨界现状和存在的问题,并对我国不同行政区间展开跨界合作的必要性进行了探讨。最后对跨界保护的未来研究提出展望。     

自然保护地生物多样性保护研究进展

建立自然保护地是保护生物多样性最为重要的措施之一。总体来看, 自然保护地生物多样性保护研究主要围绕关键生态系统以及珍稀濒危物种等保护对象的状态以及变化两个层面进行, 并重点关注自然保护地数量与面积、保护了多少重要生态系统和物种、能否有效保护生物多样性等一系列科学问题。然而, 在自然保护地生物多样性保护研究方面, 还缺少针对上述研究领域的系统性综述。为此, 本文系统梳理了自然保护地空间布局及其与生物多样性分布的关系、自然保护地生物多样性变化及其保护成效等近20年来相关领域的研究进展。自然保护地的空间布局以及与生物多样性分布的关系主要围绕自然保护地与生物多样性在某一阶段的状态开展研究, 致力于探究自然保护地“保护多少” “代表性如何” “在哪儿保护”等一系列关键科学问题。同时, 自然保护地内的生物多样性会随着气候变化、人类活动以及自身演替等发生时空动态变化, 基于自然保护地生物多样性变化分析, 各国学者在全球尺度、国家尺度和单个自然保护地进行了大量的保护成效评估研究, 并逐渐发展出了自然保护地内外配对分析方法以提升保护成效评估的精度, 进而识别出不同自然保护地的主要影响因素。在此基础上, 本文进一步对自然保护地生物多样性保护研究提出了展望, 主要包括: (1)综合考虑自然保护地生物多样性状态和变化; (2)开展多目标协同的自然保护地空间优化布局; (3)强化自然保护地主要保护对象的识别、调查与监测; (4)提升自然保护地的质量和连通性; (5)探究自然保护地管理措施与保护成效的关联机制。本文可为“2020年后全球生物多样性框架”的制定与实施特别是在自然保护地体系建设与优化方面提供参考与借鉴。     

Key drivers of effectiveness in small marine protected areas

Marine Protected Areas (MPAs) are a key management tool for the conservation of biodiversity and restoration of marine communities. While large, well-designed and enforced MPAs have been found to be effective, results from small MPAs vary. The Hawkesbury Shelf, a coastal bioregion in New South Wales, Australia, has ten small, near-shore MPAs known as Aquatic Reserves with a variety of protection levels from full no-take to partial protection. This study assessed the effectiveness of these MPAs and analysed how MPA age, size, protection level, wave exposure, habitat complexity, and large canopy-forming algal cover affected fish, invertebrate and benthic communities. We found aspect, protection level, complexity and algal canopy to be important predictors of communities in these MPAs. Most MPAs, however, were not effective in meeting their goals. Only full no-take protection (three out of ten MPAs) had a significant impact on fish assemblages. One no-take MPA—Cabbage Tree Bay—which is naturally sheltered from wave action and benefits from an active local community providing informal enforcement, accounted for most of the increased richness of large fish and increased biomass of targeted fish species. Our findings suggest that small MPAs can enhance biodiversity and biomass on a local scale but only if they have full no-take protection, are in sheltered locations with complex habitat, and have positive community involvement to engender support and stewardship. These results provide a baseline for robust assessment of the effectiveness of small MPAs and inform future management decisions and small MPA design in other locations.     

Reconciling conservation and development in protected areas of the Global South

As cornerstones for biodiversity conservation, protected areas (PAs) are critical to safeguard biodiversity. However, PAs are criticized for their limited ecological effectiveness and their negative social impacts. This article seeks to provide an overview on the contested nature of PAs and places PAs in the tension field of conservation and development, which are diverging forces specifically in the Global South. A reconciliation of PAs as parts of a wider landscape of interlinked social-ecological systems may increase the potential of PAs to contribute to the sustainable development goals, including the creation of sustainable human-nature relationships, environmental health and landscape resilience. The environmental justice framework appears useful in the endeavour to improve the social-ecological integrity of current conservation practises and to increase the ability of PA systems to withstand shocks. Considering PAs as systems in which people and nature interact in manifold ways may help increase their integrity, but understanding these interactions requires sustainability researchers and conservation practitioners to recognize the plurality in value towards nature, nature understanding and conceptualisations. Such deep understanding seems pivotal in working towards synergies of sustainable use, biocultural diversity and wilderness. Concludingly, this article emphasizes the need for holistic approaches rather than sectoral specialisations and radicalisations to achieve arrays of sustainability goals.     

Monitoring for management of conservation and recreation in Australian protected areas

Protected areas are key to conservation of biodiversity, and Australia is one of the world’s megadiverse regions. Monitoring programs provide the information to assess the state of conservation resources, the severity of threats and the success of management responses. Here we compare the management priorities, monitoring priorities and actual monitoring practices of protected area management agencies in Australia, using four sets of data at continental scale and five at a more restricted regional scale. We track changes over a period of several years and focus at successively finer levels of detail. At both continental and regional scales, most management plans emphasise fire, invasive species and visitor management; and most monitoring programmes refer to visitor numbers and impacts as well as species and ecosystems. There is only a weak match, however, between reported management priorities and actual monitoring programmes; and the effectiveness of management responses is rarely monitored. The level of detail in visitor monitor programmes varies considerably: most parks count visitors, but few know what those visitors do. Threats from fire and invasive species receive more attention that those from recreation. At regional scale, the proportion of parks with defined monitoring programmes and priorities increased significantly from 2003/2004 to 2006/2007. Whilst only a proportion of protected areas monitor endangered species populations, for those that do this is the parameter reported in most detail, with many parks reporting single records of single individuals. Some parks also maintain anecdotal records of rare species outside routine monitoring programs.     

自然保护地保护成效评估: 进展与展望

自然保护地(protected areas)保护成效是指自然保护地对主要保护对象的保护效果, 及其在维持生物多样性和保障生态系统服务功能等方面的综合成效。近年来自然保护地保护成效评估逐渐成为国内外的研究热点之一。 本文分别从不同空间尺度、评估对象、评估方法以及评估指标等方面综述了相关的研究进展。总体来看, 近年来的研究已基本覆盖了全球、区域、国家和单个自然保护地等不同尺度, 针对森林、湿地、草地和荒漠等代表性生态系统以及野生动植物等主要保护对象进行了评估, 发展了“matching”技术等更为有效的分析方法, 探索了系统的自然保护地保护成效评估指标体系, 并应用一些指标进行了保护成效的案例研究。自然保护区(nature reserve)是我国自然保护地的主体, 近年来我国自然保护区相关管理部门也相继开展了保护成效评估工作, 建议未来进一步加强自然保护区网络尺度和各类型自然保护区的保护成效评估研究, 将自然保护区保护成效评估与管理评估相结合, 研究自然保护区保护成效面临的新问题和潜在影响, 为提升我国自然保护区管理质量提供科学依据。     

Effectiveness of protected areas for bird conservation depends on guild

Aim

Protected areas are key conservation tools intended to increase biodiversity and reduce extinction risks of species and populations. However, the degree to which protected areas achieve their conservation goals is generally unknown for many protected areas worldwide. We assess the effect of protected areas on the abundance of 196 common, resident bird species. If protected areas were beneficial to avian biodiversity, we expect landscapes with a higher proportion of protected areas will have higher densities of species compared to landscapes with no protection.

Location

Greater Gauteng region, South Africa.

Methods

We analysed bird survey data collected over regular grid cells across the study area. We estimated bird abundance in relation to the proportion of a grid cell that was protected with the Royle–Nichols model and fitted the model once for each of the species. We examined variation in estimated abundance as a function of avian guild (defined by the type of food a species preferentially ate and its foraging mode) with a regression tree analysis.

Results

Abundance was significantly positively related to the proportion of protected areas in grid cells for 26% of the species, significantly negatively related in 15%, and not significantly related in 59% species. We found three distinct guild groups which differed in their average abundance, after accounting for associated variance. Group 1 consisted of guilds frugivores, ground‐feeders, hawkers, predators, and vegivores and average abundance was strongly positively related to the proportion of protected areas. Group 2 included granivores, and average abundance was strongly negatively related to proportion of protected areas. Group 3 included gleaners only, and average abundance was not related to proportion of protected areas.

Main conclusion

We conclude that the network of protected areas within the greater Gauteng region sustained relatively higher abundances of common birds and thus perform an important conservation role.

     

Differential movement and movement bias models for marine protected areas

Marine protected areas (MPAs) are promoted as a tool to protect overfished stocks and increase fishery yields. Previous models suggested that adult mobility modified effects of MPAs by reducing densities of fish inside reserves, but increasing yields (i.e., increasing densities outside of MPAs). Empirical studies contradicted this prediction: as mobility increased, the relative density of fishes inside MPAs (relative to outside) increased or stayed constant. We hypothesized that this disparity between theoretical and empirical results was the result of differential movement of fish inside versus outside the MPA. We, therefore, developed a model with unequal and discontinuous diffusion, and analyzed its steady state and stability. We determined the abundance in the fishing grounds, the yield, the total abundance and the log ratio at steady-state and examined their response to adult mobility (while keeping the relative inequity in the diffusion constant). Abundance in the fishing grounds and yield increased, while total abundance and log-ratio decreased, as mobility increased. These results were all qualitatively consistent with the previous models assuming uniform diffusivity. Thus, the mismatch between empirical and theoretical results must result from other processes or other forms of differential movement. Therefore, we modified our original model by assuming that species located on the boundary of the MPA will preferentially move towards the MPA. This localized movement bias model gives rise to steady state profiles that can differ radically from the profiles in the unbiased model, especially when the bias is large. Moreover, for sufficiently large bias values, the monotonicity of the four measures with increased mobility is reversed, when compared with our original model. Thus, the movement bias model reconciles empirical data and theoretical results.     

Prioritizing areas for conservation of Mexican carnivores considering natural protected areas and human population density

In México, 63% of the mammalian carnivore species are considered threatened. Therefore, we performed a prioritization exercise to find sets of areas needed for the conservation of Mexican terrestrial carnivores. Using a grid of half-degree cells, we mapped the distribution of richness, endemic and threaten species. Then, we determine the efficiency of the natural protected areas in México for protecting carnivores. Finally, we define optimal sets of complementary cells needed to represent all species either one or five times, or to represent at least 10% of the geographic distribution range of each carnivore in México. We perform this analysis including or excluding the existing protected areas, or excluding the top 10% cells with highest human population density (HPD). Species richness was higher in south-eastern México, threatened species concentrate in the same region, and also in the Yucatan's Peninsula. The Baja California Peninsula and the central region of the Mexican Plateau is where lower richness and numbers of threatened species are found. There is only one endemic carnivore distributed in the central and southern portion of the Pacific Slope. Complementary analysis showed that sets of three, 16 and 71 cells are required to represent one time, five times or at least 10% of the total distribution range of all species. Sets of 35 cells are needed to complement the natural protected areas to achieve this last representation goal. Finally, if cells with highest HPD are excluded, sets of three, 14 and 71 cells are needed to achieve our three representation goals. Our results provide insight into the ability of different sites to contribute to the representation of carnivore diversity at the national scale, and indicate gaps in the existing protected area network.