Overexploitation—the unsustainable use of natural resources—is one of the greatest pressures that human populations force upon ecosystems worldwide. Overfishing, a type of overexploitation based on “catching too much fish,” contributes to the well-established decline of fish stocks.
According to the Food and Agriculture Organization of the United Nations (FAO), globally, the fraction of fish stocks that are within biologically sustainable levels has exhibited a decreasing trend, from 90.0 percent in 1974 to 66.9 percent in 2015. Further compounding this, the percentage of stocks fished at biologically unsustainable levels increased from 10 percent in 1974 to 33.1 percent in 2015, with the largest increases in the late 1970s and 1980s, and a slight decline in 1996. However, a study published in 2016 shows that we catch much more fish than estimated by the FAO. Daniel Pauly, lead author of the study, told The Guardian: “Our results differ very strongly from those of the FAO. Our results indicate that the decline is very strong and is not due to countries fishing less. It is due to countries having fished too much and having exhausted one fishery after another.” Continue reading →
What’s in soil? Water, air, sand, silt, clay, and organic matter. What’s in organic matter? Humus, earthworms, insects, bacteria and, we just learned, giant viruses. As their name implies, these viruses are big—their dimensions and genome sizes are comparable to those of bacteria. Continue reading →
Can you imagine our beautiful planet becoming a “plastic planet”? In the BBC documentary film Blue Planet II, members of the producing team noted that plastic waste is ubiquitously floating in the sea, including fishing lines, plastic packages, and plastic bottles. Marine organisms can be trapped by plastic waste that is everywhere in the oceans, even in the deepest and most remote parts. So it is essential to carry out intensive studies of plastic waste. Large plastics can either be physically or chemically broken into fragments after having been in the water a long time, traveling long distances. Such fragments, coupled with ones that were released into seas as fine plastic particles (smaller than 5 mm), are collectively called microplastics.
Surface water trawling for floating microplastic collection on the Pearl River estuary in China. Inset pictures are pieces of microplastic (fragments, pellets, and lines) from the trawl. Credit: Lei Mai.
The following post is one of a series previewing the research that will be presented at the SETAC Europe Annual Meeting in Rome, Italy (13-17 May 2018).
A guest post by Gemma Giménez Papiol
How do toxic natural compounds such as microalgae toxins or plant secondary metabolites affect water quality, ecosystem functioning, and human health? For the majority of natural toxins—of which there are at least 25,000 different compounds—we do not know! Natural toxins include some of the worlds’ most toxic substances. Continue reading →
Air pollution is defined by the World Health Organization as the “the world’s largest single environmental health risk” and causes millions of premature deaths annually. Exposure to air pollution is associated with respiratory diseases (including asthma and changes in lung function), cardiovascular diseases, adverse pregnancy outcomes (such as preterm birth), and even death. In 2013, the World Health Organization concluded that outdoor air pollution is carcinogen to humans. In other words, air pollution is an invisible killer—may not always be visible, but it can be deadly. Continue reading →
The 23rd conference of the United Nations Framework Convention on Climate Change was in full swing recently (6–17 November 2017). There, the countries that signed the 2015 Paris agreement discussed steps to keep the threat of climate change under control and—according to the Paris Agreement’s central aim—hold the rise in global temperatures to “well below” 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels by curbing industrial emissions of carbon dioxide. At the same time, scientists involved in the Global Carbon Project reported that total carbon dioxide emissions held stable from 2014 to 2016, at about 36 billion tons per year. They went on to clarify that this was a temporary hiatus that will end in 2017, and that economic projections suggest the likelihood of further emissions growth in 2018. Continue reading →
Many advocates of environmental policy see the Trump administration’s view of the environment and the U.S. Environmental Protection Agency as a setback that dims the prospects for new and stronger environmental laws. Consequently, some state and local governments are picking up the slack. For example, California recently expanded its cap-and-trade program for greenhouse gases, and the mayor of Atlanta vowed to meet his city’s commitments to lower carbon dioxide emissions, despite the President’s decision to withdraw from the Paris climate accord. In this current complex landscape, economic theory can contribute valuable insight when designing climate and environmental policies at the federal, state, or local level. In particular, economic theory suggests that market-based environmental policies may provide clear advantages when compared to command-and-control policies. Let me explain why.