Marine monitoring in the northeast Atlantic is delivered within identifiable monitoring themes, established through time and defined by the geographical area and policy drivers they serve, the sampling methodologies they use, their assessment methodologies, their funding and governance structures and the people or organisations involved in their implementation. Within a monitoring theme, essential components for effective monitoring are governance, strategy and work plan, sampling protocols, quality assurance, and data and assessment structures. This simple framework is used to analyse two monitoring theme case studies; national ecosystem health monitoring, and regional fish stock monitoring. Such essential component analyses, within marine monitoring themes, can help improve monitoring implementation by identifying gaps and overlaps. Once monitoring themes are recognised, explicitly defined and streamlined, travel towards integrated monitoring may be made easier as the current lack of clarity in thematic marine monitoring implementation is one barrier to integration at both national and regional scales.
The declining health of the Great Barrier Reef (GBR) from poor water quality has increased the urgency for pollutant reductions at the same time that available financial resources and knowledge regarding the most appropriate interventions are limited. Prioritisation of water quality interventions in the Great Barrier Reef catchments is the process of identifying which land based actions can achieve the largest environmental benefits at the lowest cost. For prioritisation to be effective a focus is required on the outcomes of pollution reduction activities as compared to the inputs. In this paper we set out a framework for prioritising actions to improve water quality into the Great Barrier Reef, as well as providing a case study analysis using 47 individual river basins across the six large scale catchments, three pollutants and two industries. The results identify the most cost-effective options for water quality improvements aligning to locations of medium risk to reef health. The outcomes of the analysis highlight the importance of seeking pollutant reductions where the most effective outcome can be achieved rather than simply targeting an industry or a catchment.
It is proposed that emissions of volatile sulfur compounds by coral reefs contribute to the formation of a biologically-derived feedback on sea surface temperature (SST) through the formation of marine biogenic aerosol (MBA). The direction and strength of this feedback remains uncertain and constitutes a fundamental constraint on predicting the ability of corals to cope with future ocean warming. We investigate the effects of elevated SST and irradiance on satellite-derived fine-mode aerosol optical depth (AOD) throughout the Great Barrier Reef, Australia (GBR) over an 18-year time period. AOD is positively correlated with SST and irradiance and increases two-fold during spring and summer with high frequency variability. As the influence of non-biogenic and distant aerosol sources are found to be negligible, the results support recent findings that the 2,300 km stretch of coral reefs can be a substantial source of biogenic aerosol and thus, influence local ocean albedo. Importantly however, a tipping point in the coral stress response is identified, whereby thermal stress reaches a point that exceeds the capacity of corals to influence local atmospheric properties. Beyond this point, corals may become more susceptible to permanent damage with increasing stress, with potential implications for mass coral bleaching events.
The study of recent past trajectories of vulnerability to climate-related hazards allows for highlighting the prevailing environmental and anthropogenic drivers that operated over the last fifty to sixty years and given latency phenomena in social systems, therefore have the potential to continue driving a system’s vulnerability in the coming decades. Stop or even reverse these trends represents as much unavoidable solutions for enhancing concrete long-term adaptation to climate change, whatever the end-century warming scenario.
Using the case study of Reunion Island (Indian Ocean), we emphasize four major drivers of the recent coastal trajectory of vulnerability, i.e. changes in human-built assets, shoreline position, natural buffers’ characteristics, and the extent of coastal protection structures. Together, these drivers highlight the need for controlling the urbanisation process to reduce the anthropogenic pressures exerted on morphological-ecological systems, restoring the buffering function of the latter, and moving towards a less hard structure-dependent coastal defence strategy. Such a shift in coastal management however supposes some radical changes in the way coastal development strategies consider environmental issues (hazards, resources and services). Here we bring empirical material showing that neither Reunion Island decision-makers are keen to drive such radical changes, nor the population is ready to accept potentially constraining policies that will have benefits only in the future. We conclude on the need for further advancing the design of adaptation pathways that build on the implementation of context-specific unavoidable solutions, and thus that seriously consider limiting the risk of maladaptation as a baseline strategy.
In the last 15 years, conservation has shifted increasingly towards perspectives based on the instrumental value of nature, where what counts is what provides benefits to humans. The ecosystem services framework embraces this vision of nature through monetary valuation of the environment to correct market failures and government distortions that hinder efficient allocation of public goods, including goods and services provided by biodiversity and ecosystems. The popularity of this approach is reflected in different countries legislation; for instance, US, EU and UK have introduced economic criteria for comparing costs and benefits of environmental policies in protecting ecosystem services.
From an operational perspective, the ecosystem services framework requires ecologists to estimate how the supply of services is affected by changes in the functionality and/or the extent of ecosystems; and economists to identify how changes in the supply affect the flow of direct and indirect benefits to people. However, this approach may be simplistic when faced with the complexity of social-ecological systems. We investigated this for three different marine services: assimilative capacity of waste, coastal defense and renewable energy. We find that economic valuation could provide efficient and fair allocations in the case of assimilative capacity, but leads to social clashes between outputs generated by cost benefit analysis and citizens' expectation in the case of coastal defense. In the case of renewable energy, controversies can be generated by regulatory mechanisms that are not necessarily aligned with the interests of industry or important social groups. We conclude that there is a need to integrate perspectives arising from utilitarian allocation of resources with those involving legislation and communal values in order to reconcile conflicting interests and better sustain marine social-ecological systems.
Hazards resulting from asteroid ocean impacts were modelled using hydrocode simulations to examine the near-field effects including the initial formation and subsequent long range propagation of tsunami waves that can transport potentially damaging energy far from the impact site.
Three-dimensional simulations of oblique impacts into deep water, with trajectory angles ranging from 27° to 60° above the horizontal, were performed with the Los Alamos Rage hydrocode. The simulations include atmospheric effects such as ablation and airbursts. These oblique impact simulations are performed in order to help determine whether there are additional dangers due to the obliquity of impact not covered by previous studies. The energy transferred to both the air blast wave and the water are calculated as well as the amount of sea water lofted into the upper atmosphere. Water crater sizes and subsequent surface elevation profiles, surface pressures, and depth-averaged mass fluxes within the water are prepared for use in far-field propagation studies. Like previous three-dimensional simulations, these simulations show that except at exceedingly shallow entry angles below those simulated here the resulting waves are roughly circular and that the initial waves and central jet oscillation are highly turbulent and dissipate a lot of the energy.
Two-dimensional axisymmetric simulations of long range propagation of impact tsunami were performed using the Lawrence Livermore ALE3D hydrocode on the NASA Pleiades supercomputer. These simulations showed that impacts under 1 gigaton TNT equivalent into the deep ocean basins will create deep-water waves that undergo dispersion, whereas impacts onto continental shelves will create shallow-water waves that do not suffer dispersion. The simulations also showed that on the order of 1% of the kinetic energy of the impact is converted into the tsunami wave. This is an order of magnitude less than previous semi-empirical estimates of ∼15% based on explosion test data and laboratory scale impacts.
Marine Protected Areas are rapidly becoming a central method for conservation of aquatic resources, but quantifying the success of these reserves in restricting fishing remains a challenge. Monitoriang fishing has long been difficult - there are many types of fishers accessing resources in remote places from a diverse set of platforms (e.g., boat types). We used aerial surveys in conjunction with a novel application of species distribution modeling to develop a method for monitoring the change in fisher distributions following the implementation of MPAs. Aerial survey transects were conducted for 3.5 years before and after the implementation of 25 MPAs along the mainland southern California coast in 2012 and resulted in 13,558 vessel observations representing 19 different boat types. We compared actively fishing commercial and recreational vessels with non-fishing vessels to evaluate the use of MPA areas. There was a statistically significant decrease in proportion of vessels observed within MPAs from 17.5% before to 11.4% after MPA implementation, with MPA-implementation, fishing type, and the interaction all predicting the probability of a vessel being observed within MPA boundaries. Distribution models showed both an overall shift in distributions across all boat types and a decrease in predicted probability of habitat suitability of fishing within MPA boundaries after MPA implementation, although results differed among boat types. We illustrate the utility of distribution modeling for evaluating spatial patterns in human activities, providing a powerful tool for conservation biologists and demonstrate the importance of monitoring programs for establishing both baseline and response data needed for adaptive management of marine ecosystems.
Protected areas are the primary management tool for conserving ecosystems, yet their intended outcomes may often be compromised by poaching. Consequently, many protected areas are ineffective ‘paper parks’ that contribute little towards conserving ecosystems. Poaching can be prevented through enforcement and engaging with community members so they support protected areas. It is not clear how much needs to be spent on enforcement and engagement to ensure they are frequent enough to be effective at conserving biodiversity. We develop models of enforcement against illegal fishing in marine protected areas. We apply the models to data on fishing rates and fish biomass from a marine protected area in Raja Ampat, Indonesia and explore how frequent enforcement patrols need to be to achieve targets for coral reef fish biomass. Achieving pristine levels of reef fish biomass required almost year-round enforcement of the protected area. Surveillance of the protected area may also be enhanced if local fishers who support the reserve report on poaching. The opportunity for local fishing boats to participate in surveillance was too small for it to have much benefit for total reef fish biomass, which increases slowly. However, specific functional groups of fish have much higher population growth rates and their biomass was predicted to increase markedly with community surveillance. We conclude that budgets for park management must balance the cost of conducting frequent patrols against supporting alternative activities, like education to build community support. Optimized budgets will be much more likely to achieve ecological targets for recovering fish biomasses and will contribute to fiscal sustainability of protected areas.
Fishery ecosystems are complex and influenced by various drivers that operate and interact at different levels and over multiple scales. Here, we propose a holistic methodology to determine the key mechanisms of fisheries, trophodynamics, and environmental drivers of marine ecosystems, using a multilevel model fitted to data on global catch, effort, trophic level, primary production, and temperature for 130 ecosystems from 1950 to 2012. The model describes the spatial‐temporal dynamics of world fisheries very well with a pseudo R2 = 0.75 and estimates the effects of key drivers of fishery production. The results demonstrate the integrative operation of bottom‐up and top‐down regulated trophic interactions at the global level and great variations in their relative importance among different types of ecosystem. The estimation of key drivers’ effects on marine ecosystems provides practical mechanisms for informed ecosystem‐based fisheries management to achieve the sustainable objectives that are consistent with the needs of specific fisheries.
During their migrations, marine predators experience varying levels of protection and face many threats as they travel through multiple countries’ jurisdictions and across ocean basins. Some populations are declining rapidly. Contributing to such declines is a failure of some international agreements to ensure effective cooperation by the stakeholders responsible for managing species throughout their ranges, including in the high seas, a global commons. Here we use biologging data from marine predators to provide quantitative measures with great potential to inform local, national and international management efforts in the Pacific Ocean. We synthesized a large tracking data set to show how the movements and migratory phenology of 1,648 individuals representing 14 species—from leatherback turtles to white sharks—relate to the geopolitical boundaries of the Pacific Ocean throughout species’ annual cycles. Cumulatively, these species visited 86% of Pacific Ocean countries and some spent three-quarters of their annual cycles in the high seas. With our results, we offer answers to questions posed when designing international strategies for managing migratory species.