William W. L. Cheung

A mid-term analysis of progress toward international biodiversity targets

In 2010, the international community, under the auspices of the Convention on Biological Diversity, agreed on 20 biodiversity-related “Aichi Targets” to be achieved within a decade. We provide a comprehensive mid-term assessment of progress toward these global targets using 55 indicator data sets. We projected indicator trends to 2020 using an adaptive statistical framework that incorporated the specific properties of individual time series. On current trajectories, results suggest that despite accelerating policy and management responses to the biodiversity crisis, the impacts of these efforts are unlikely to be reflected in improved trends in the state of biodiversity by 2020. We highlight areas of societal endeavor requiring additional efforts to achieve the Aichi Targets, and provide a baseline against which to assess future progress. Although conservation efforts are accelerating, their impact is unlikely to improve the global state of biodiversity by 2020. Indicators of progress and decline The targets set by the Convention on Biological Diversity in 2010 focused international efforts to alleviate global biodiversity decline. However, many of the consequences of these efforts will not be evident by the 2020 deadline agreed to by governments of 150 countries. Tittensor et al. analyzed data on 55 different biodiversity indicators to predict progress toward the 2020 targets—indicators such as protected area coverage, land-use trends, and endangered species status. The analysis pinpoints the problems and areas that will need the most attention in the next few years. Science, this issue p. 241

Signature of ocean warming in global fisheries catch

Marine fishes and invertebrates respond to ocean warming through distribution shifts, generally to higher latitudes and deeper waters. Consequently, fisheries should be affected by ‘tropicalization’ of catch (increasing dominance of warm-water species). However, a signature of such climate-change effects on global fisheries catch has so far not been detected. Here we report such an index, the mean temperature of the catch (MTC), that is calculated from the average inferred temperature preference of exploited species weighted by their annual catch. Our results show that, after accounting for the effects of fishing and large-scale oceanographic variability, global MTC increased at a rate of 0.19 degrees Celsius per decade between 1970 and 2006, and non-tropical MTC increased at a rate of 0.23 degrees Celsius per decade. In tropical areas, MTC increased initially because of the reduction in the proportion of subtropical species catches, but subsequently stabilized as scope for further tropicalization of communities became limited. Changes in MTC in 52 large marine ecosystems, covering the majority of the world’s coastal and shelf areas, are significantly and positively related to regional changes in sea surface temperature. This study shows that ocean warming has already affected global fisheries in the past four decades, highlighting the immediate need to develop adaptation plans to minimize the effect of such warming on the economy and food security of coastal communities, particularly in tropical regions.

Increasing jellyfish populations: trends in Large Marine Ecosystems

Although there are various indications and claims that jellyfish (i.e., scyphozoans, cubozoans, most hydrozoans, ctenophores, and salps) have been increasing at a global scale in recent decades, a rigorous demonstration of this has never been presented. Because this is mainly due to scarcity of quantitative time series of jellyfish abundance from scientific surveys, we attempt to complement such data with non-conventional information from other sources. This was accomplished using the analytical framework of fuzzy logic, which allows the combination of information with variable degrees of cardinality, reliability, and temporal and spatial coverage. Data were aggregated and analyzed at the scale of Large Marine Ecosystem (LME). Of the 66 LMEs defined thus far that cover the world’s coastal waters and seas, trends of jellyfish abundance after 1950 (increasing, decreasing, or stable/variable) were identified for 45, with variable degrees of confidence. Of those 45 LMEs, the majority (28 or 62%) showed increasing trends. These changes are discussed in the context of possible sources of bias and uncertainty, along with previously proposed hypotheses to explain increases in jellyfish.

Benefits of rebuilding global marine fisheries outweigh costs.

Global marine fisheries are currently underperforming, largely due to overfishing. An analysis of global databases finds that resource rent net of subsidies from rebuilt world fisheries could increase from the current negative US

Nutrition: Fall in fish catch threatens human health

13 billion to positive US

Evaluating taboo trade-offs in ecosystems services and human well-being.

54 billion per year, resulting in a net gain of US

Scaling up experimental ocean acidification and warming research: from individuals to the ecosystem

600 to US

Fisheries: Hope or despair?

1,400 billion in present value over fifty years after rebuilding. To realize this gain, governments need to implement a rebuilding program at a cost of about US

Predicting the Impact of Climate Change on Threatened Species in UK Waters

203 (US

Climate-change induced tropicalisation of marine communities in Western Australia

130–US