Systematic conservation planning is essential in the justification and design of protected areas, especially in an era where every piece of land or water is at a high premium. We used satellite tracking data and regular monitoring of Greater flamingos into the spatial prioritization planning tool Marxan to identify the most important zones for the conservation of the greater flamingo and many other species of waterbirds and marine habitats in one of the economically important areas in the coastal zone of Abu Dhabi. Locations from 11 satellite tracked flamingos and monthly count data since 2009 in the Bul Syayeef area showed a predominant use of a relatively small area which when integrated in Marxan provided optimum boundary with minimum cost. Marxan identified 1, 5, 10 and 15 ha planning units and provided the best solution with 15 ha. The reduced total area of 145 km2 is nearly 40% of the originally proposed area for protection, is more pragmatic and easy to establish, given the high importance of the area for economic development. Using approximately the same boundary, the proposed area was declared a Ramsar site in September 2016 and was subsequently declared a protected area through a government decree in September 2017.
Ecological theory predicts that ecosystems with multiple basins of attraction can get locked in an undesired state, which has profound ecological and management implications. Despite their significance, alternative attractors have proven to be challenging to detect and characterize in natural communities. On coral reefs, it has been hypothesized that persistent coral-to-macroalgae “phase shifts” that can result from overfishing of herbivores and/or nutrient enrichment may reflect a regime shift to an alternate attractor, but, to date, the evidence has been equivocal. Our field experiments in Moorea, French Polynesia, revealed the following: (i) hysteresis existed in the herbivory–macroalgae relationship, creating the potential for coral–macroalgae bistability at some levels of herbivory, and (ii) macroalgae were an alternative attractor under prevailing conditions in the lagoon but not on the fore reef, where ambient herbivory fell outside the experimentally delineated region of hysteresis. These findings help explain the different community responses to disturbances between lagoon and fore reef habitats of Moorea over the past several decades and reinforce the idea that reversing an undesired shift on coral reefs can be difficult. Our experimental framework represents a powerful diagnostic tool to probe for multiple attractors in ecological systems and, as such, can inform management strategies needed to maintain critical ecosystem functions in the face of escalating stresses.
Plastic pollution is prevalent worldwide and affects marine wildlife from urbanized beaches to pristine oceanic islands. However, the ecological basis and mechanisms that result in marine animal ingestion of plastic debris are still relatively unknown, despite recent advances. We investigated the relationship between scavenging behavior and plastic ingestion using green turtles, Chelonia mydas, as a model. Diet analysis of C. mydas showed that sea turtles engaging in scavenging behavior ingested significantly more plastic debris than individuals that did not engage in this foraging strategy. We argue that opportunistic scavenging behavior, an adaptive behavior in most marine ecosystems, may now pose a threat to a variety of marine animals due to the current widespread plastic pollution found in oceans.
The data requirements and resources needed to develop effective indicators of fishing impacts on target stocks may often be great, especially for mangrove fisheries where, for example, tidal cycles sequentially flood and drain the habitat as a result of natural processes. Here, we used underwater video systems to evaluate the impact of small-scale fisheries on mangrove fish assemblages at four levels of fishing pressure (low, medium, high, and no pressure). The lowest values of species richness and abundance were recorded in the areas fished most intensively. Conversely, the highest species richness and the occurrence of larger-bodied fish were recorded in areas of reduced fishing activity, which was surprisingly similar to the “no fishing” areas. The slopes of the community size spectra steepened in response to exploitation, while the relative abundance of medium-sized fish (16–25 cm) declined. Fishing for local or regional markets, rather than subsistence, also led to a decrease in the abundance of larger fish (>41 cm). The marked response of population parameters to fishing pressure reflected the impact of unregulated small-scale fisheries on areas of mangroves. Fishery management practices that ignore contemporary changes in these environments are likely to overestimate long-term yields, leading to overfishing. Thus, size-based approaches to evaluating fishing pressure were suitable for detecting negative responses from the mangrove fish assemblages. A next step will be to integrate size- and species-based ecological approaches that provide mechanisms to address pronounced decreases in specific species as a more profitable indicator of fishing impacts on mangrove fish assemblages. This approach will allow the development of effective conservation and management strategies.
Natural resource policies enacted to protect environmental integrity play an important role in promoting sustainability. However, when resources are shared ecologically, economically, or through a common, global interest, policies implemented to protect resource sustainability in one domain can displace, and in some cases magnify, environmental degradation to other domains. Although such displacement has been recognized as a fundamental challenge to environmental and conservation policy within some resource sectors, there has been little cross‐disciplinary and cross‐sectoral integration to address the problem. This suggests that siloed knowledge may be impeding widespread recognition of the ubiquity of displacement and the need for mitigation. Here, we connect research across multiple disciplines to promote a broader discussion and recognition of the processes and pathways that can lead to displaced impacts that countermand or undermine resource policy and outline a number of approaches that can mitigate displacement.