PNAS – Proceedings of the National Academy of Sciences of the United States of America
http://www.pnas.org/content/early/
(Accessed 23 April 2016)

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Commentary: Averting a global fisheries disaster
Boris Worm
PNAS 2016 ; published ahead of print April 19, 2016, doi:10.1073/pnas.1604008113
Oceans cover 71% of Earth’s surface and support an estimated 3 billion people with food and vital micronutrients (1). Consequently, the fate of the ocean and its living resources is a first-order question in ecology and environmental science (2). In this context, a 2006 panel of ecologists and fisheries scientists empirically charted the consequences of an ongoing depletion of marine biodiversity, such as declining fisheries, reduced water quality, loss of habitat, and less resilient ecosystems (3). The paper became widely known, however, for a scenario of global fisheries collapse derived from extrapolating catch trends to the year 2048. This projection served as a flash point in the ongoing discussion about the sustainability of global fisheries, or lack thereof (4). A polarized debate ensued, which was productively addressed by a subsequent panel that highlighted solutions for rebuilding depleted fisheries, where appropriate governance structures exist (5). That work, however, along with several follow-up papers (6⇓–8), did not revisit the original projections. A new paper in PNAS (9) now uses updated methodology and an innovative combination of available data on catch trends, life history, and stock assessments to revisit the prospect of a global fisheries disaster, and what may be required to avert it.

The analysis of Costello et al. (9) confirms that the average state of global fish stocks is poor and declining. Of 4,714 fisheries assessed in the year 2012, only 32% remained at or above the biomass target that supports maximum sustainable yield (BMSY), whereas 68% have slipped below that critical threshold. This compares to 63% of assessed stocks tracking below BMSY in 2006 (5). Even more concerning is the finding that only 35% of stocks are currently fished at …

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Biological Sciences – Ecology:
Predicting the spread of marine species introduced by global shipping
Hanno Seebens, Nicole Schwartz, Peter J. Schupp, and Bernd Blasius
PNAS 2016 ; published ahead of print April 18, 2016, doi:10.1073/pnas.152442711
Significance
Predicting the arrival of alien species remains a big challenge, which is assumed to be a consequence of the complexity of the invasion process. Here, we demonstrate that spreading of alien marine species can be predicted by a simple model using only global shipping intensities, environmental variables, and species occurrence data. We provide species lists of the next potentially invading species in a local habitat or species causing harmful algal blooms with their associated probability of invasion. This will help to improve mitigation strategies to reduce the further introduction of alien species. Although this study focuses on marine algae, the model approach can be easily adopted to other taxonomic groups and their respective drivers of invasion.
Abstract
The human-mediated translocation of species poses a distinct threat to nature, human health, and economy. Although existing models calculate the invasion probability of any species, frameworks for species-specific forecasts are still missing. Here, we developed a model approach using global ship movements and environmental conditions to simulate the successive global spread of marine alien species that allows predicting the identity of those species likely to arrive next in a given habitat. In a first step, we simulated the historical stepping-stone spreading dynamics of 40 marine alien species and compared predicted and observed alien species ranges. With an accuracy of 77%, the model correctly predicted the presence/absence of an alien species in an ecoregion. Spreading dynamics followed a common pattern with an initial invasion of most suitable habitats worldwide and a subsequent spread into neighboring habitats. In a second step, we used the reported distribution of 97 marine algal species with a known invasion history, and six species causing harmful algal blooms, to determine the ecoregions most likely to be invaded next under climate warming. Cluster analysis revealed that species can be classified according to three characteristic spreading profiles: emerging species, high-risk species, and widespread species. For the North Sea, the model predictions could be confirmed because two of the predicted high-risk species have

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Knowledge Systems for Sustainable Development Special Feature Sackler Colloquium –
Perspective: Crafting usable knowledge for sustainable development
William C. Clark, Lorrae van Kerkhoff, Louis Lebel, and Gilberto C. Gallopin
PNAS 2016 ; published ahead of print April 18, 2016, doi:10.1073/pnas.1601266113
Abstract
This paper distills core lessons about how researchers (scientists, engineers, planners, etc.) interested in promoting sustainable development can increase the likelihood of producing usable knowledge. We draw the lessons from both practical experience in diverse contexts around the world and from scholarly advances in understanding the relationships between science and society. Many of these lessons will be familiar to those with experience in crafting knowledge to support action for sustainable development. However, few are included in the formal training of researchers. As a result, when scientists and engineers first venture out of the laboratory or library with the goal of linking their knowledge with action, the outcome has often been ineffectiveness and disillusionment. We therefore articulate here a core set of lessons that we believe should become part of the basic training for researchers interested in crafting usable knowledge for sustainable development. These lessons entail at least four things researchers should know, and four things they should do. The knowing lessons involve understanding the coproduction relationships through which knowledge making and decision making shape one another in social–environmental systems. We highlight the lessons that emerge from examining those coproduction relationships through the ICAP lens, viewing them from the perspectives of Innovation systems, Complex systems, Adaptive systems, and Political systems. The doing lessons involve improving the capacity of the research community to put its understanding of coproduction into practice. We highlight steps through which researchers can help build capacities for stakeholder collaboration, social learning, knowledge governance, and researcher training.