Earth & Space

Number of breaks: 9

The silent battle of young corals against ocean acidification

Coral reefs are ecosystems of extraordinary diversity. Considered "the rainforests of the sea", they contain ~35% of described marine species despite only occupying 0.2% of the world's ocean. Although they are extremely important habitat providers and form large living structures (some reefs can be seen from space!) the coral animals themselves are small and very sensitive to changes in their environmental conditions. A stressed coral can indicate changes in the physical and chemical properties of the seawater and pressures on the whole ecosystem. Coral reefs are currently faced with an unprecedented mix of human-induced stressors, ranging from overfishing of herbivorous fish (which allows turf algae to overgrow the coral), to changes in the water quality from coastal development, dredging and (...)

· Taryn Foster | Postdoctoral Research Fellow at School of Earth and Environment, The University of Western Australia, Australia

Published on October 19, 2016 Reading time: 4 min

Nitrogen pollution from lowlands reaches distant mountain lakes

Nitrogen is required by all living things, but too much of it can be a problem for aquatic ecosystems. Excess reactive nitrogen (nitrate and ammonium, forms that can be used directly by plants and algae) can cause lakeeutrophication which can include harmful algal blooms, declining water quality, loss of biodiversity and other changes in lake ecosystems. Humans have more than doubled the amount of reactive nitrogen in the natural system.1 The main sources of reactive nitrogen are agricultural and industrial runoff, sewage, fossil fuels, and legume crop production. These sources are found in populated areas, but evidence is mounting that reactive nitrogen pollution is more widespread. For example, several researchers have suggested that the amount of reactive nitrogen is increasing in (...)

· Fred Longstaffe | Distinguished Professor at Department of Earth Science, Western University, London, Canada

· Katrina Moser | Associate Professor at Department of Geography at Western University, London, Canada

· Beth Hundey | Adjunct Research Professor & eLearning specialist at Teaching Support Centre, Western University, London, Canada

Published on September 21, 2016 Reading time: 3 min

Resetting nature’s clock: shifting seasons and species relationships

Every year, many of us gaze in fascination at the movement of nature's clock, looking forward to seeing wild plants coming into bloom or the arrival of the first migrant birds. Less obvious, but just as dramatic, populations of phytoplankton bloom below the surface of lakes and oceans, while fish migrate to their spawning grounds. Over time, the dedicated observer may even come to anticipate the dates that their favourite natural events will occur on. However, the timing of these seasonal events is changing. Many familiar "signs of spring" are occurring earlier in the year than they used to. Often these changes have come about because seasonal biological events are sensitive to climatic conditions. For this very reason, they continue (...)

· Stephen Thackeray | Freshwater Ecologist at Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK

· Sarah Burthe | Animal Population Ecologist at Coastal Seas Ecology Group, Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK

Published on September 14, 2016 Reading time: 3.5 min

Ocean acidification and its effects on coral reef growth

Aptly named "Rainforests of the Sea", tropical coral reefs are one of the most biodiverse ecosystems on the planet. Much like how trees of a forest provide shelter for plants and animals living within, corals reefs provide food and shelter for millions of species ranging from microscopic bacteria to predatory sharks. Not only do coral reefs harbor vast ecological wealth, but they also provide us with ecosystem services valued at over $300 billion each year by supporting tourism, fishing, and protecting our coastlines by absorbing wave energy. Unfortunately, coral reef health is in decline worldwide (read also the Break: The silent battle of young corals against ocean acidification). Reefs are currently challenged by a variety of threats ranging from local factors (...)

· Rebecca Albright | Postdoctoral Research Scientist at Department of Global Ecology, Carnegie Institution for Science, Stanford University, CA, USA

Published on July 8, 2016 Reading time: 3.5 min

The use of neonicotinoid pesticides affects wild bee populations

Bees are more than honey-makers. They pollinate crops and hence are key elements in our food production. Honeybees, wild bee species such as bumblebees and solitary bees, butterflies, wasps, and flies, all provide an invaluable work of pollination. In fact, a third of the food that we eat depends on them! Nowadays beekeepers around the world continue to observe the mysterious disappearance of bees as well as declines in honeybee colony sizes. The use of insecticides in agriculture could be one of the main factors responsible for it. Neonicotinoids are pesticides widely used to coat the seed and make it resistant to attack from insects in the soil. However, these pesticides may represent a consistent risk to bees because, after seed (...)

· Maria Sentandreu | Postdoctoral Research Fellow at Department of Botany and Plant Biology, University of Geneva, Switzerland

Published on June 10, 2016 Reading time: 4 min

A dangerous habit: bees prefer pesticide-contaminated nectar

The impact of pesticides on pollinators is an important factor for the future of world food security, as well as a hotly debated and controversial topic. Pollinating insects like bees help to increase the yields of many food crops but, in doing so, are inadvertently exposed to pesticides in floral nectar and pollen. Neonicotinoids represent a class of neuro-active insecticides with a chemical structure similar to that of nicotine, and are widely used to protect crops from insect pests. They have been introduced in the early 1990s as a seed treatment for crops such as oilseed rape or sunflowers that are pollinated by bees. As the plant grows, it absorbs some of the insecticide from the seed treatment and the substance (...)

· Sébastien Kessler | Research Associate at Institute of Neuroscience, University of Newcastle, Newcastle upon Tyne, England

Published on February 12, 2016 Reading time: 3 min

An exoplanet surrounded by an atmosphere larger than its star

In the past 20 years, scientists have discovered many planets around other stars than the Sun. Nearly half of these so-called exoplanets orbit extremely close to their star (more than ten times closer than Mercury revolves around the Sun in our Solar System), raising many questions about the state of their atmosphere: theoretical studies show that the huge amount of energy that the planets receive from their stars can swell the atmosphere, up to the point where some of its gas is far enough from the planet to escape its gravity and drift away. This phenomenon is called ‘evaporation’. Because it is light and very abundant, neutral hydrogen escapes more easily from the atmosphere of an exoplanet than any other (...)

· Vincent Bourrier | Postdoctoral Research Fellow at Department of Astronomy, Geneva Observatory, University of Geneva, Geneva, Switzerland

Published on November 26, 2015 Reading time: 4 min

Tara Oceans Expedition sequences the ocean

The Tara Oceans consortium recently published five scientific papers in the journal Science presenting the initial wave of scientific results from the first six years of the project.1-5 The findings show the extraordinary diversity of plankton in the world’s oceans, uncover many of the interactions between them, and reveal how plankton impact and are influenced by the environment. One of the papers1 describes an ocean microbial reference gene catalog containing 40 million genes from marine microbes (bacteria, viruses, Archaea and picoeukaryotes). Derived from samples of seawater collected from all over the world and at depths down to 1,000 metres the authors show that this publicly available DNA sequence dataset is more than 1,000 times larger than what was previously (...)

· Chris Bowler | CNRS Director of Research at Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Paris, France

Published on November 24, 2015 Reading time: 4 min

Why some forests burn better than others

Forest fires are dramatic ecological events as they can wipe out most of the plants and animals within several kilometers in only a few hours and often also pose a major threat to human settlements. They have a positive ecological impact when occurring naturally because they clear the organic matter residues and favor new plant growth. However, exceptionally frequent or devastating fires - caused by climate change or, more frequently, human negligence - can lead to the extinction of some species in a certain area and completely reshape the landscape. They can also directly impact on human communities located nearby and/or whose economy depends on forest goods, especially wood and paper. Thus, a better understanding of how fires spread and (...)

· Elisa Dell'Aglio | Postdoctoral Research Fellow at Department of Botany and Plant Biology, University of Geneva, Switzerland

Published on May 19, 2015 Reading time: 4 min