Restricting human activities through Marine Protected Areas (MPAs) is assumed to create more resilient biological communities with a greater capacity to resist and recover following climate events. Here we review the evidence linking protection from local pressures (e.g., fishing and habitat destruction) with increased resilience. Despite strong theoretical underpinnings, studies have only rarely attributed resilience responses to the recovery of food webs and habitats, and increases in the diversity of communities and populations. When detected, resistance to ocean warming and recovery after extreme events in MPAs have small effect sizes against a backdrop of natural variability. By contrast, large die-offs are well described from MPAs following climate stress events. This may be in part because protection from one set of pressures or drivers (such as fishing) can select for species that are highly sensitive to others (such as warming), creating a ‘Protection Paradox’. Given that climate change is overwhelming the resilience capacity of marine ecosystems, the only primary solution is to reduce carbon emissions. High-quality monitoring data in both space and time can also identify emergent resilience signals that do exist, in combination with adequate reference data to quantify the initial system state. This knowledge will allow networks of diverse protected areas to incorporate spatial refugiaagainst climate change, and identify resilient biological components of natural systems. Sufficient spatial replication further offers insurance against losses in any given MPA, and the possibility for many weak signals of resilience to accumulate.
Coral reefs are among the world’s most endangered ecosystems. Coral mortality can result from ocean warming or other climate-related events such as coral bleaching and intense hurricanes. While resilient coral reefs can recover from these impacts as has been documented in coral reefs throughout the tropical Indo-Pacific, no similar reef-wide recovery has ever been reported for the Caribbean. Climate change-related coral mortality is unavoidable, but local management actions can improve conditions for regrowth and for the establishment of juvenile corals thereby enhancing the recovery resilience of these ecosystems. Previous research has determined that coral reefs with sufficient herbivory limit macroalgae and improve conditions for coral recruitment and regrowth. Management that reduces algal abundance increases the recovery potential for both juvenile and adult corals on reefs. Every other year on the island of Bonaire, Dutch Caribbean, we quantified patterns of distribution and abundance of reef fish, coral, algae, and juvenile corals along replicate fixed transects at 10 m depth at multiple sites from 2003 to 2017. Beginning with our first exploratory study in 2002 until 2007 coral was abundant (45% cover) and macroalgae were rare (6% cover). Consecutive disturbances, beginning with Hurricane Omar in October 2008 and a coral bleaching event in October 2010, resulted in a 22% decline in coral cover and a sharp threefold increase in macroalgal cover to 18%. Juvenile coral densities declined to about half of their previous abundance. Herbivorous parrotfishes had been declining in abundance but stabilized around 2010, the year fish traps were phased out and fishing for parrotfish was banned. The average parrotfish biomass from 2010 to 2017 was more than twice that reported for coral reefs of the Eastern Caribbean. During this same period, macroalgae declined and both juvenile coral density and total adult coral cover returned to pre-hurricane and bleaching levels. To our knowledge, this is the first example of a resilient Caribbean coral reef ecosystem that fully recovered from severe climate-related mortality events.
We used high-resolution fisheries-dependent data and a quantitative modeling approach to examine resilience of a commercial reef fish fleet after the Deepwater Horizon oil spill (DWH) emergency closures in 2010. Our results indicate that the fleet was largely resilient to the closures, although there were spatially-varying differences in attrition, and concomitant management changes and emergency payouts that likely influenced resilience. Five percent of previously active vessels exited the fleet after DWH (compared to the background annual attrition rate of ˜20%). The predicted probability of exiting after DWH was lower for vessels with a pre-closure history of high catch-per-unit-effort, low snapper revenue variability, or low grouper revenue. There was ˜80% overlap in pre- to post-DWH effort distribution, although vessels that exited concentrated effort in the north-central and eastern Gulf of Mexico. The Vessels of Opportunity program and other emergency compensation likely ameliorated some of the negative economic impactsfrom DWH, allowing more vessels to remain in the fleet than may have otherwise. Implementation of gear restrictions and individual fishing quotas leading up to DWH may have also ‘primed’ the fleet for resilience by removing marginal fishers. This work is novel in its use of high-resolution spatial data, coupled with trip logbooks, to construct quantitative models identifying drivers of fisher resilience after significant and sudden perturbations to fishery resources in the Gulf of Mexico. This work also highlights the need to better understand fisher response to disturbance for long-term fishery sustainability and management.
Oxygen restricted conditions were widespread in European shelf seas after the end-Triassic mass extinction event and they are reported to have hindered the recovery of marine benthos. Here we reconstruct the redox history of the Early Jurassic Blue Lias Formation of southwest Britain using pyrite framboid size analysis and compare this with the recovery of bivalves based on field and museum collections. Results suggest widespread dysoxia punctuated by periods of anoxia in the region, with the latter developing frequently in deeper water settings. Despite these harsh conditions, initial benthic recovery occurred rapidly in the British Jurassic, especially in shallowest settings, and shows no relationship with the intensity of dysoxia. A stable diversity was reached by the first recognised ammonite zone after the end-Triassic mass extinction. This contrasts with the deeper-water, more oxygen-poor sections where the diversity increase was still continuing in the earliest Sinemurian Stage, considerably longer than previously reported. Similar recovery rates are seen amongst other groups (brachiopods and ammonites). Oxygen-poor conditions have been suggested to delay recovery after the Permo-Triassic mass extinction, but this is not the case after the end-Triassic crisis. We suggest that this was because the European dysoxia was only a regional phenomenon and there were plenty of well-ventilated regions available to allow an untrammelled bounce back.
The aim of this study was to investigate the key landscape structures of migratory bird habitats that affect abundance of migratory birds to promote resilient coastal green infrastructure planning on the Yellow Sea coast. We classified coastal areas into four watersheds of South Korea and conducted multivariate regression analysis between migratory bird populations and landscape structures including total class area (CA), patch area distribution (MN), patch density (PD), and edge density (ED). At the national level, sandbank MN, sandbank CA, water ED, and grasslands were derived as key landscape structures affecting the abundance of migratory birds. At the watershed level, key landscape structures were determined as follows: Urban area_MN for the Han River watershed, rice paddy MN for the Asan watershed, rice paddy CA for Saemangeum, and grassland MN for the Youngsan River watershed. Considering the multifunctionality, redundancy, and connectivity of the resilience strategy, we provide specific coastal infrastructure planning recommendations at the national and watershed scales.
It is increasingly evident that climate change is having significant impacts on marine ecosystems and dependent fisheries. Yet, translating climate science into management actions and policies is an ongoing challenge. In particular, four aspects have confounded implementation of climate-resilient management: (i) regional management tools may not be well-suited for managing the same systems under climate change, (ii) individual management policies and climate research studies are often implicitly focussed on spatio-temporal scales that are rarely aligned, (iii) management approaches seldom integrate across spatio-temporal scales and are, therefore, maladapted to unidirectional change and extreme events, and (iv) challenges to modelling socio-economic implications of climate change impede projections of cumulative costs to society, disguise adaptive limits, and ultimately impact climate risk and management trade-off assessments. We suggest that addressing environmental change favours adaptive and dynamic management approaches, while addressing shifting socio-economic and political conditions favours fixed long-term measures; considering both jointly requires a combination of dynamic-adaptive-fixed approaches. We outline a framework to integrate climate-responsive tools into a unified climate-resilient management approach using nested dynamic-adaptive-fixed management portfolios that improve management effectiveness and efficiency. This approach may help reduce future conflict between marine resource extractive and conservation goals through more explicit characterization of management trade-offs and identification of social and ecological tipping points.
The emerging threat to the coastal urban ecosystems from increased intensity and frequency of weather events is a compelling reason for improving our understanding of the integrity of the existing ecosystem. Resilience of an ecosystem is a critical property that aids recovery and adaptation when subject to intense stress. Quantifying the resilience of an ecological system requires a detailed understanding of the vulnerabilities and interactions within a complex web of interconnected social, technological and economic networks. Through an ecological network analysis of ascendency and redundancy of the flux of energy and material flows, the causal relationships are established through structural equations modeling (SEM) techniques. A model based-on the five factors of driving force (D), pressure (P), state (S), impact (I), and response (R) (DPSIR), recognizes the different roles these factors play in the coastal urban ecological security system of China. Energy and material flows transmission equations of the ecological security network are developed to evaluate the resilience of the ecological security network. The results show that the ecological security network of Chinese coastal cities has a relatively high network occupation rate (A/C = 0.6898), indicating a relatively mature state of the ecological security network of coastal cities with sufficient metabolic capacity and steady status. The low vacancy rate (R/C = 0.3102) shows that the coastal ecological security network lacks flexibility of surplus space. The energy and material flows conversion and dissipation ability in the network are strong: the five factors of DPSIR are highly interdependent, and the ecological security network framework is both steady and mature. However, the resilience of the coastal urban ecosystem against external impacts is weak. It is critical for coastal cities to broaden their planning protocols to introduce more flexible space to increase resilience and guarantee a robust pathway for sustainable development. This study contributes to a rational method for testing the internal causal relationships among DPSIR linkages toward quantifying our understanding of the resilience of a security ecosystem.
Climate change constitutes a new threat to the sustainability of coral ecosystems. The vulnerability of a coral ecosystem to climate-related hazards can greatly increase when it suffers from chronic anthropogenic disturbances (wastewater discharges, eutrophication). These indeed reduce the ability of coral reefs to withstand these hazards (resistance) and their potential to recover their initial condition (resilience) in case of very impacting hazards. Therefore, there is a risk of an amplifier feedback loop snapping in place with an endpoint of a crippling loss of resilience of coral formations and eventually the disappearance of most of them. Reducing such an amplifier feedback loop should be one of the main objectives of the coral coastal management in order to build new human/coral reef societies coviability to face climate change. Reconsidering the strategies of the creation of marine protected areas fits into this framework. This requires a focus on reef connectivity, resistance and resilience of species and species assemblages.
The resilience and recovery dynamics of deep-sea habitats impacted by bottom trawling are poorly known. This paper reports on a fishing impact recovery comparison based on four towed camera surveys over a 15-year period (2001–2015) on a group of small seamounts on the Chatham Rise, east of New Zealand, on which pre-disturbance benthic communities are dominated by thicket-forming scleractinian corals. The six seamounts studied encompass a range of trawl histories, including one with high and persistent levels of trawling throughout the survey period, two with intermittent and intermediate levels of trawling, two which were low/untrawled, and one, ‘Morgue’, which was closed to trawling in 2001, having been heavily trawled up to that point. Still photographs from all surveys were analyzed for the identification and abundance of all visible benthic fauna with effort made to ensure consistency of data among surveys. Because increases in image resolution and quality over time resulted in a persistent trend of increasing abundances, analyses were concentrated on comparisons among seamounts within surveys and how these relationships changed with time. The abundance, species richness, and diversity of benthic communities were higher on low/untrawled seamounts than on those that had been trawled. Multivariate community structure showed similar patterns at each survey point, the low/untrawled seamounts being strongly dissimilar to the persistently trawled seamount, with the others ranged between these extremes, broadly in accordance with their cumulative trawl histories. Community structure on the persistently trawled seamount was less variable than on the other seamounts throughout the study period, possibly because of regular ‘re-setting’ of the community by disturbance from trawling. Although there was some variability in results between whole seamount and summit sector analyses, in general communities on Morgue remained similar to those on the persistently trawled seamount, showing little indication of steps toward recovery to its pre-disturbance state following its closure. These results indicate low resilience of benthic communities on the seamounts to the effects of bottom trawling.
Coral reef managers currently face the challenge of mitigating global stressors by enhancing local ecological resilience in a changing climate. Effective herbivore management is one tool that managers can use in order to maintain resilience in the midst of severe and frequent bleaching events. One recommended approach is to establish networks of herbivore management areas (HMAs), which prohibit the take of herbivorous reef fishes. However, there is a need to develop design principles to guide planning and implementation of these HMAs as a resilience-building tool. We refine available guidance from fully protected marine protected area (MPA) networks and developed a set of 11 biophysical design principles specifically for HMAs. We then provide a case study of how to apply these principles using the main Hawaiian Islands. We address site-specific considerations in terms of protecting habitats, including ecologically critical areas, incorporating connectivity, and addressing climate and local threats. This synthesis integrates core marine spatial planning concepts with resilience-based management and provides actionable guidance on the design of HMAs. When combined with social considerations, these principles will support spatial planning in Hawai‘i and could guide the future design of HMA networks globally.