Coastal and ocean acidification has the potential to cause significant environmental and societal impacts. Monitoring carbonate chemistry parameters over spatial and temporal scales is challenging, especially with limited resources. A lack of monitoring data can lead to a limited understanding of real-world conditions. Without such data, robust experimental and model design is challenging, and the identification and understanding of episodic acidification events is nearly impossible. We present considerations for resource managers, academia, and industry professionals who are currently developing acidification monitoring programs in the Mid-Atlantic region. We highlight the following considerations for deliberation: 1) leverage existing infrastructure to include multiple carbonate chemistry parameters as well as other water quality measurements, 2) direct monitoring efforts in subsurface waters rather than limiting monitoring to surface waters, 3) identify the best available sensor technology for long-term, in-situ monitoring, 4) monitor across a salinity gradient to account for the complexity of estuarine, coastal, and ocean environments, and identify potential areas of enhanced vulnerability, 5) increase sampling frequency to capture variability, 6) consider other drivers (e.g., freshwater discharge, nutrients, physiochemical parameters) that may affect acidification, and 7) conduct or continue monitoring in specific ecological and general regions that may have enhanced vulnerability. Through the incorporation of these considerations, individual monitoring programs can more efficiently and effectively leverage resources and build partnerships for a more comprehensive data collection in the region. While these considerations focus on the Mid-Atlantic region), similar strategies can be used to leverage resources in other locations.
Equatorial corals were previously thought not to spawn synchronously at the assemblage level. However, recent studies have reported multi-specific coral spawning events in equatorial regions. Here, we report the reproductive activity of 21 Acroporaspecies in the Karimunjawa Archipelago over five consecutive years (2008–2012). We also infer the month of spawning for Acropora humilis, Acropora gomezi, and Acropora muricata from the presence of mature oocytes. We found that Acroporaassemblages exhibit a high degree of inter-specific reproductive seasonality. The highest proportion of colonies with mature oocytes was observed in March 2011 (65%, n = 80). Oocytes likely developed during June–March, 6 to 10 months before spermatogenesis. Spermatocytes were observed in samples collected during March; however, the onset of spermatogenesis could not be precisely determined as samples were not collected in January and February. This was because of weather constraints and difficulty in detecting the early stages of spermatogenesis. Multi-specific spawning events were observed during the first transition period (March–April) and the second transition period (September–October) between monsoons. The number of species containing mature oocytes was higher during March–April (12 species) and September–October (8 species). Spawning patterns likely follow the lunar cycle. However, two distinct spawning events coincided with two periods of higher temperature (March–April and September–October). Daily temperature records indicate that spawning occurred on days where temperature dropped before the expected spawning time during the warming period. During the period of rising temperature, wind speeds were lower, which might serve as a signal leading to the multi-specific spawning of corals in the tropics, at least in the Karimunjawa Archipelago of Indonesia.
Coasts are dynamic socio-ecological systems, subject to increasing anthropogenic pressures that present complex challenges for the design of effective coastal and marine governance systems. There are many contributing factors to the unsustainability of the marine environment, including weak governance arrangements. Typically, the management of coastal and marine ecosystems is undertaken in a fragmented way, with responsibilities dispersed across a number of bodies. ‘Integrated management’ is often proposed in normative approaches to marine management as a mechanism for securing more sustainable outcomes. The implementation of integrated management, however, tends to occur within existing governance structures and fails to address deep-rooted issues such as path dependency, institutional inertia, and policy layering. These barriers to transformative marine governance are re-framed in this paper as ‘persistent problems’ which inhibit more holistic approaches to achieve effective integrated management. Using insights from two Irish case studies to show how the implementation of innovative local initiatives for sustainable coastal and marine management are constrained by persistent institutional problems, it is concluded that an alternative management paradigm is required to understand and address the complexities involved in the design and delivery of an integrated management regime.
Corals in the Persian/Arabian Gulf are the most thermally tolerant in the world, but live very near the thresholds of their thermal tolerance. Warming sea temperatures associated with climate change have resulted in numerous coral bleaching events regionally since the mid-1990s, but it has been unclear why unusually warm sea temperatures occur some years but not others. Using a combination of 5 years of observed sea-bottom temperatures at three reef sites and a meteorologically linked hydrodynamic model that extends through the past decade, we show that summer sea-bottom temperatures are tightly linked to regional wind regimes, and that strong ‘shamal’ wind events control the occurrence and severity of bleaching. Sea bottom temperatures were primarily controlled by latent heat flux from wind-driven surface evaporation which exceeded 300 W m-2 during shamal winds, double that of typical breeze conditions. Daily temperature change was highly correlated with wind speed, with breeze winds (<4 m s-1) resulting in increased warming, while faster winds caused cooling, with the magnitude of temperature decline increasing with wind speed. Using observed and simulated data from 2012 to 2017, we show that years with reported bleaching events (2012, 2017) were characterized by low winds speeds that resulted in temperatures persisting above coral bleaching threshold temperatures for >5 weeks, while the cooler intervening years (2013–2016) had summers with more frequent and/or strong shamal events which repeatedly cooled temperatures below bleaching thresholds for days to weeks, providing corals temporary respite from thermal stress. Using observed data from 2012 onward and simulated data from 2008 to 2011, we show that the severity of bleaching events over the past decade was linked to both the number of cumulative days above bleaching thresholds (rather than total days, which obfuscates the cooling effects of occasional brief shamal events), as well as to maxima. We show that winds of 4 m s-1 represents a critical threshold for whether or not corals cross bleaching threshold temperatures, and provide simulations to forecast sea-bottom temperature change and recovery times under a range of wind conditions. The role that wind-driven cooling may play on coral reefs globally is discussed.
The vast developmental opportunities offered by the world’s coasts and oceans have attracted the attention of governments, private enterprises, philanthropic organizations, and international conservation organizations. High-profile dialogue and policy decisions on the future of the ocean are informed largely by economic and ecological research. Key insights from the social sciences raise concerns for food and nutrition security, livelihoods and social justice, but these have yet to gain traction with investors and the policy discourse on transforming ocean governance. The largest group of ocean-users – women and men who service, fish and trade from small-scale fisheries (SSF) – argue that they have been marginalized from the dialogue between international environmental and economic actors that is determining strategies for the future of the ocean. Blue Economy or Blue Growth initiatives see the ocean as the new economic frontier and imply an alignment with social objectives and SSF concerns. Deeper analysis reveals fundamental differences in ideologies, priorities and approaches. We argue that SSF are being subtly and overtly squeezed for geographic, political and economic space by larger scale economic and environmental conservation interests, jeopardizing the substantial benefits SSF provide through the livelihoods of millions of women and men, for the food security of around four billion consumers globally, and in the developing world, as a key source of micro-nutrients and protein for over a billion low-income consumers. Here, we bring insights from social science and SSF to explore how ocean governance might better account for social dimensions of fisheries.
Microplastics are widespread contaminants, virtually present in all environmental compartments. However, knowledge on sources, fate and environmental concentration over time and space still is limited due to the laborious and varied analytical procedures currently used. In this work we critically review the methods currently used for sampling and detection of microplastics, identifying flaws in study design and suggesting promising alternatives. This work provides insights on bulk sample collection, separation, digestion, identification and quantification, and mitigation of cross-contamination. The sampling of microplastics will improve in representativeness and reproducibility through the determination of bulk sample volume, filter's pore size, density separation and digestion solutions, but also through use of novel methods, such as the enhancement of visual identification by staining dyes, and the generalized use of chemical characterization.
Indo-Pacific coral reefs face an unprecedented level of anthropogenic pressure. Cyanide fishing is a highly destructive method employed to capture live fish from Indo-Pacific coral reefs and supply the live fish food trade in Asia and the global marine aquarium trade. To allow the development and implementation of an effective and reliable testing platform to screen live reef fish for cyanide poisoning, without their sacrifice, and thus contribute to the ban of this practice from Indo-Pacific coral reefs, the following research topics must be urgently addressed: 1) selection of a suitable model species; 2) standardization of experimental methodologies; 3) exclude the possibility that the target compound(s) being monitored to detect live reef fish illegally collected using cyanide originate from other sources than cyanide poisoning; 4) clarification of the excretion physiology and cyanide pharmacokinetics in marine fish; and 5) evaluate interspecific differences in excretion physiology and cyanide pharmacokinetics in marine fish.
Coral reefs are subject to multiple stressors. Global stressors include climate changeand ocean acidification, while local stressors include overfishing and eutrophication. Some stressors stem from land-based activities, like intensive agriculture or sewage production, while others are sea-based, like fishing or diving. Processes that aim to tackle coral degradation are transpiring on different levels. These include the UNDP's Sustainable Development Goal 14, and the Coral TriangleInitiative, which foresees the installation of marine protected areas and conservation planning. This paper uses Evolutionary Governance Theory (EGT) to understand the current processes of changes in governance influencing coral reef health. EGT sees the change of governance as an evolutionary process. It emphasises that discourses play a crucial role in understanding governance evolution. Power, in particular power-knowledge in the Foucaultian sense, plays a crucial role as a driving factor. Governance does not change in a vacuum, but according to EGT is shaped by path, inter- and goal dependencies. Of late, the role of materiality - ecological and technological conditions - has been stressed as an important driver of governance change. The paper considers the main threats to corals identified in the literature and analyses how those factors mentioned by EGT help us to understand the observed governance changes. The case of coral reefs was chosen as it represents an example of extremely diverse processes of institutional changes. Therefore, it is well suited to learn if EGT helps in understanding governance changes observed in the marine sector.
Cultural ecosystem services (CES) are defined as the non-material benefits that arise from human-ecosystem relationships. Such benefits contribute to quality of life and positive sentiment towards protected areas but are difficult to quantify, especially at large spatial scales. Building on recent studies, we assess CES in Brazil's largest marine protected area (MPA) using user-contributed georeferenced photographs from a popular image- and video-hosting website. In total, we assessed 1,984 photographs taken by 207 users between 2010 and 2016. The most represented CES categories were landscape appreciation and social recreation, clearly reflecting the obvious attractions of this tropical beach location. Artistic/cultural expressions and appreciation, and nature appreciation where also highly represented, though no photographs depicting educational engagements or scientific research were identified. Engagements with CES had clear spatial and temporal patterns relating to user behaviour and reflecting the biophysical and infrastructural characteristics of different sites within this MPA. The broad spatial coverage and high spatio-temporal resolution of the data makes this approach ideal for identifying CES hotspots/coldspots and, despite limitations, holds great potential to monitor the impact of management interventions on CES provision. Our study highlights how the analysis of high volumes of digital photographs extends the methodological tool-box available to researchers and provides a powerful new means to quantify and map CES at broad spatial scales.
Time series now have sufficient duration to determine harmful algal bloom (HAB) responses to changing climate conditions, including warming, stratification intensity, freshwater inputs and natural patterns of climate variability, such as the El Niño Southern Oscillation and Pacific Decadal Oscillation. Against the context of time series, such as those available from phytoplankton monitoring, dinoflagellate cyst records, the Continuous Plankton Recorder surveys, and shellfish toxin records, it is possible to identify extreme events that are significant departures from long-term means. Extreme weather events can mimic future climate conditions and provide a “dress rehearsal” for understanding future frequency, intensity and geographic extent of HABs. Three case studies of extreme HAB events are described in detail to explore the drivers and impacts of these oceanic outliers that may become more common in the future. One example is the chain-forming diatom of the genus Pseudo-nitzschia in the U.S. Pacific Northwest and its response to the 2014-16 northeast Pacific marine heat wave. The other two case studies are pelagic flagellates. Highly potent Alexandrium catenella group 1 dinoflagellate blooms (up to 150 mg/kg PST in mussels; 4 human poisonings) during 2012-17 created havoc for the seafood industry in Tasmania, south-eastern Australia, in a poorly monitored area where such problems were previously unknown. Early evidence suggests that changes in water column stratification during the cold winter-spring season are driving new blooms caused by a previously cryptic species. An expansion of Pseudochattonella cf. verruculosa to the south and A. catenella to the north over the past several years resulted in the convergence of both species to cause the most catastrophic event in the history of the Chilean aquaculture in the austral summer of 2016. Together, these two massive blooms were colloquially known as the “Godzilla-Red tide event”, resulting in the largest fish farm mortality ever recorded worldwide, equivalent to an export loss of USD$800 million which when combined with shellfish toxicity, resulted in major social unrest and rioting. Both blooms were linked to the strong El Niño event and the positive phase of the Southern Annular Mode, the latter an indicator of anthropogenic climate change in the southeastern Pacific region. For each of these three examples, representing recent catastrophic events in geographically distinct regions, additional targeted monitoring was employed to improve the understanding of the climate drivers and mechanisms that gave rise to the event and to document the societal response. Scientists must be poised to study future extreme HAB events as these natural experiments provide unique opportunities to define and test multifactorial drivers of blooms.