Our global oceans are threatened by climate change, overfishing, pollution and a growing list of other impacts that demonstrate an urgent global need for sustainable ocean management. Whilst marine conservation initiatives and protected ocean spaces have increased over recent years, ocean management still lags behind the terrestrial sectors in incorporating and involving communities in its development. ‘Social licence to operate’ is used broadly across the terrestrial literature, but its understanding and application within the marine has been limited to date. This review sought to collate and synthesise instances of social licence in the marine realm as documented in the literature, aiming to create an understanding that may inform future research and development of social licence. Its results determine that social licence is yet an emergent concept in the marine sector but there may be great potential for its application in the marine context. Social licence has become an important theme for development in marine industry and resource use, particularly towards exploring communication and stakeholder engagement. This paper identifies future themes and areas requiring investigation and application in this domain.
The irregular appearance of planktonic algae blooms off the coast of southern California has been a source of wonder for over a century. Although large algal blooms can have significant negative impacts on ecosystems and human health, a predictive understanding of these events has eluded science, and many have come to regard them as ultimately random phenomena. However, the highly nonlinear nature of ecological dynamics can give the appearance of randomness and stress traditional methods—such as model fitting or analysis of variance—to the point of breaking. The intractability of this problem from a classical linear standpoint can thus give the impression that algal blooms are fundamentally unpredictable. Here, we use an exceptional time series study of coastal phytoplankton dynamics at La Jolla, CA, with an equation-free modeling approach, to show that these phenomena are not random, but can be understood as nonlinear population dynamics forced by external stochastic drivers (so-called “stochastic chaos”). The combination of this modeling approach with an extensive dataset allows us to not only describe historical behavior and clarify existing hypotheses about the mechanisms, but also make out-of-sample predictions of recent algal blooms at La Jolla that were not included in the model development.
The advent of social media and microblogging platforms has radically changed the way we consume information and form opinions. In this paper, we explore the anatomy of the information space on Facebook by characterizing on a global scale the news consumption patterns of 376 million users over a time span of 6 y (January 2010 to December 2015). We find that users tend to focus on a limited set of pages, producing a sharp community structure among news outlets. We also find that the preferences of users and news providers differ. By tracking how Facebook pages “like” each other and examining their geolocation, we find that news providers are more geographically confined than users. We devise a simple model of selective exposure that reproduces the observed connectivity patterns.
Earth’s energy imbalance (EEI) drives the ongoing global warming and can best be assessed across the historical record (that is, since 1960) from ocean heat content (OHC) changes. An accurate assessment of OHC is a challenge, mainly because of insufficient and irregular data coverage. We provide updated OHC estimates with the goal of minimizing associated sampling error. We performed a subsample test, in which subsets of data during the data-rich Argo era are colocated with locations of earlier ocean observations, to quantify this error. Our results provide a new OHC estimate with an unbiased mean sampling error and with variability on decadal and multidecadal time scales (signal) that can be reliably distinguished from sampling error (noise) with signal-to-noise ratios higher than 3. The inferred integrated EEI is greater than that reported in previous assessments and is consistent with a reconstruction of the radiative imbalance at the top of atmosphere starting in 1985. We found that changes in OHC are relatively small before about 1980; since then, OHC has increased fairly steadily and, since 1990, has increasingly involved deeper layers of the ocean. In addition, OHC changes in six major oceans are reliable on decadal time scales. All ocean basins examined have experienced significant warming since 1998, with the greatest warming in the southern oceans, the tropical/subtropical Pacific Ocean, and the tropical/subtropical Atlantic Ocean. This new look at OHC and EEI changes over time provides greater confidence than previously possible, and the data sets produced are a valuable resource for further study.
Despite rapid growth in the marine tourism sector, the impacts of recreation on the marine environment are generally not well understood. Most existing studies of marine recreation ecology have focused on behavioural changes resulting from direct interactions between humans and wildlife including provisioning. However, non-consumptive, non-provisioning human impacts may also result in persistent behavioural impacts to shark populations. In this study, we examined differences in residency, abundance, and behaviour of reef sharks at Palmyra Atoll in response to long-term SCUBA diving activity, using a combination of survey techniques including baited remote underwater video systems and multi-year passive acoustic monitoring. In most locations with recreational diving operations, some level of human impact is pervasive, but on Palmyra, extractive fishing is prohibited, and scientific diving activities are concentrated on just a few sites that house long-term monitoring projects. These sites experience relatively intensive diving, while the majority of the island is entirely undived. Evidence from elsewhere has shown that sharks behaviourally respond to people in the water over short time scales, but our results indicate that this response may not persist. We did not detect differences in reef shark abundance or behaviour between heavily dived and undived locations, nor were there differences in shark residency patterns at dived and undived sites in a year with substantial diving activity and a year without any diving. Our results suggest that humans can interact with reef sharks without persistent behavioural impacts, and that well-regulated shark diving tourism can be accomplished without undermining conservation goals.
Governments and regional agencies of the Pacific Islands are strengthening their commitment to sustainable oceans management through proactive policies and programs. The Blue Economy concept is increasingly being invoked, yet clarity on definitions and implementation steps remain vague. This paper reviews reports, academic literature and regional speeches to develop a Blue Economy conceptual framework which is then applied to three case studies from the fisheries sector – small scale fisheries, urban fish markets and onshore tuna processing. The cases illustrate an imbalance in attention paid to key components of the Blue Economy and missed opportunities for integration across scales, time and stakeholders with a few noteworthy exceptions. Issues of power, agency and gender remain weakly addressed even in the most recent initiatives. While clearly defining components of the Blue Economy provides a valuable tool for assessing coverage of key elements of sustainable ocean management, it is less obvious that the new label, Blue Economy, significantly advances practice beyond existing sustainable development frameworks. A proliferation in terms adds more complexity to an already challenging management space. Nevertheless, the conceptual framework is useful for structuring evaluations of practice, and helping to reveal missing ingredients necessary for the sustainable development of oceans.
The Arctic has seen rapid sea-ice decline in the past three decades, whilst warming at about twice the global average rate. Yet the relationship between Arctic warming and sea-ice loss is not well understood. Here, we present evidence that trends in summertime atmospheric circulation may have contributed as much as 60% to the September sea-ice extent decline since 1979. A tendency towards a stronger anticyclonic circulation over Greenland and the Arctic Ocean with a barotropic structure in the troposphere increased the downwelling longwave radiation above the ice by warming and moistening the lower troposphere. Model experiments, with reanalysis data constraining atmospheric circulation, replicate the observed thermodynamic response and indicate that the near-surface changes are dominated by circulation changes rather than feedbacks from the changing sea-ice cover. Internal variability dominates the Arctic summer circulation trend and may be responsible for about 30–50% of the overall decline in September sea ice since 1979.
The population of Pacific cod inhabiting off northeastern Honshu Japan has remarkably increased in the 3 yr after the Great East Japan Earthquake in 2011. We examined the processes and factors leading to this increase based on the results of estimations of commercial catch and fishing activities, and trawl surveys. Pacific cod was highly exploited from 1 yr old before 2011. However, fishing pressure has markedly decreased after 2011 in the area around Fukushima waters. Fish abundance in 2013 and 2014 was estimated to be more than four-fold of the maximum amount before 2011. The cohort structure of the population in 2013 and 2014 was primarily composed of 2–4-yr-old fish (2010–2011 yr classes) whereas the population in pre-2011 was primarily of 1-yr-old fish. The 2010–2011 yr classes had almost the same population sizes until 1.3 yr old to the pre-2009 yr classes, but became much higher more than 2.8 yr old. Pacific cod from 1.3 to 2.8 yr old were concentrated in the area off Fukushima Prefecture. These results suggest that Pacific cod increased post-2011 not because of the occurrence of strong year classes followed by good recruitments but because of the lower mortality after recruitment owing to reduced fishing mortality. Waters off Fukushima, the primary nursery of Pacific cod, are effectively serving as a marine protected area after the tsunami events. A close coincidence between the nursery area of young fish and the protected area strongly altered the age composition of the population and enhanced fish abundance.
In this era of fiscal constraint following the global financial crisis, marine protected areas (MPAs) occupy a remarkable position in the economic landscape. Few government authorities seem concerned about the prevalence of white elephants – illusionary MPAs that carry a financial cost. Whereas no government minister would consider developing a health system based solely on number of hospital beds (irrespective of whether all hospitals are concentrated within a single city, or occupants of beds have access to medical staff, or patients are living or dying), MPAs are largely assessed on a single numerical target (total area). Inconsistent self-identification adds an extra level of opaqueness. The net consequence is an unaccountable and under-performing system, an outcome that is both tragic and economically wasteful.
Plastic pollution is a growing global concern. In the present study, we investigated plastic pollution in 21 species of sea fish and 6 species of freshwater fish from China. All of the species were found to ingest micro- or mesoplastics. The average abundance of microplastics varied from 1.1 to 7.2 items by individual and 0.2–17.2 items by gram. The average abundance of mesoplastics varied from 0.2 to 3.0 items by individual and 0.1–3.9 items by gram. Microplastics were abundant in 26 species, accounting for 55.9–92.3% of the total number of plastics items in each species. Thamnaconus septentrionalis contained the highest abundance of microplastics (7.2 items/individual). The average abundance of plastics in sea benthopelagic fishes was significantly higher than in freshwater benthopelagic fishes by items/individual. The plastics were dominanted by fiber in shape, transparent in color and cellophane in composition. The proportion of plastics in the stomach to the intestines showed great variation in different species, ranging from 0.5 to 1.9 by items/individual. The stomach of Harpodon nehereus and intestines of Pampus cinereus contained the highest number of plastics, (3.3) and (2.7), respectively, by items/individual. Our results suggested that plastic pollution was widespread in the investigated fish species and showed higher abundance in comparison with worldwide studies. The ingestion of plastics in fish was closely related to the habitat and gastrointestinal tract structure. We highly recommend that the entire gastrointestinal tract and digestion process be used in future investigations of plastic pollution in fish.