Articles on oceans and the effects of climate change on marine ecosystems like coral reefs and blue carbon mangroves. Plus how warming affects deep water currents, sea level rise, ocean acidification & deoxygenation, the marine food web, and much more.
We examine the causes, categories and effects of severe ocean heat on shellfish, the marine food web, corals, mangrove forests and other coastal ecosystems. We explain what drives this type of extreme weather event and examine its connection to climate change. We ask: how bad will marine heatwaves get?
We look at the causes and effects on marine life of ocean oxygen deprivation (hypoxia), a process which is spreading across the open sea. We look at ‘dead zones’ – hypoxic areas of oceans and large lakes – and ask: will we run out of breathable air? As usual the solution to lack of oxygen in the hydrosphere is simple: stop burning fossil fuels.
We explain all about the acidification of seawater caused by the burning of fossil fuels. We take a brief look at the ocean chemistry involved, and the pH forecasts. We also explain the effects of an acidic ocean on tropical coral reefs and other marine creatures, including the problems of chemical communication and hypercapnia.
All you need to know about Krill, the most important shrimp-like crustacean in the marine food web. We examine its life cycle, diurnal migration, and the threats posed to it by global warming to sea temperature and stocks of phytoplankton, its favorite prey.
Learn all about the fascinating microorganisms that drive the marine food web. They play a huge role in the recycling of carbon and other nutrients, and are crucial to the Microbial Loop and the Viral Shunt. Marine microbes are also vital providers of energy and oxygen to the entire biosphere. Without them, no human life is possible. But climate change is now beginning to pose major threats.
Zooplankton form a critical link in the ocean food web between phytoplankton and other marine species, and are essential to all life on Earth. We explain the different types of zooplankton, like krill, copepods and dinoflagellates. We look at their predator and prey relationships, as well as the wider risks they face. The latter include loss of habitat (under polar ice) ocean warming, acidification, deoxygenation – all caused by global warming – and pollution.
All you need to know about “who eats who” in the water. We explain the basic predator/prey relationships in the marine food chain, the different trophic levels, from primary producers to apex predators. We look at how humans are damaging the marine food web by polluting the ocean with heavy metals and other toxic chemicals, and by burning fossil fuels.
Tropical coral reefs are fragile but diverse habitats that teem with biological diversity. We take a close look at how corals form, grow, and reproduce. We examine the different types of coral reef and the main threats to their survival. These include mass bleaching events triggered by marine heatwaves and ocean acidification, caused by the effects of climate change. We also explain why the impact of dissolved sunscreen products is another concern.
All you need to know about the mangrove forest biome. We explain why mangroves are important, how they survive in salty water, how they cope with oxygen shortages, and how they anchor themselves in water. We also look at biodiversity in the saline mangal swamps and woodlands. As well as providing critical protection from storms, mangroves are regarded as a critical carbon sink due to their storage of ‘blue carbon’. They sequester more carbon per hectare than tropical rainforests.
The ocean has a massive influence on global warming. We explain how it acts as a sponge, soaking up more than 90 percent of the heat produced by global warming. We also look at the three carbon cycle pathways in the ocean that help to mitigate climate change: the solubility pump, the biological pump and the ocean-atmosphere exchange of carbon dioxide (CO2).
Phytoplankton are arguably the most critical species on Planet Earth. A microscopic type of marine algae, they are similar to land plants in that they contain chlorophyll and need sunlight in order to live and grow. Hence they live in the sunlit upper ocean. They were instrumental in helping life to take hold on the planet around 3.8 billion years ago, and they continue to create the oxygen and energy that all species need to survive. We explain all you need to know.
Straddling the world’s oceans is a serpentine network of important ocean currents. Their purpose is to distribute cold water from the polar regions towards the equator, and warm water from equatorial regions to the poles. As well as wind-driven surface currents, this network includes a number of massive deep-water currents known as the thermohaline circulation. We explain how these currents work, how they exert a critical influence on global climate and the marine biome, and why climate change is threatening to destabilize them.
We look at seven of the most serious effects of global warming on the oceans. They include: rising sea levels, marine heatwaves, ocean acidification and loss of coral reefs, ocean deoxygenation (hypoxia), weakening of the deep-water thermohaline circulation, damage to blue carbon ecosystems, and more. It’s worth remembering that we on land have experienced less than 10 percent of global warming. The other 90 percent has been absorbed by the ocean.
• Our oceans absorb 93 percent of the heat of global warming and around 25 percent of all man-made carbon dioxide emissions. • To put this heat absorption into context, if five Hiroshima atomic bombs were dropped into the ocean every second, it would be roughly equivalent to the amount of heat being absorbed by the oceans as a result of global warming. • The IPCC's Fifth Assessment Report (2014) estimates that since 1975 the upper ocean (down to 750m/ 2,500 ft deep) has warmed by about half a degree Celsius. Imagine the amount of heat that is needed to raise the temperature of our seas and oceans by this amount. • Ocean acidification is happening faster than at any time in the past 300 million years. It is caused by the excess absorption of CO2 from the atmosphere, which is triggering a change in the ocean’s chemistry. • Marine animals need oxygen to breathe, just as animals on land do. However, scientists calculate that between 1960 and 2010, oxygen levels in the ocean have declined by about 2 percent due to climate change. In some tropical locations the loss is 50 percent. • Areas of the ocean that have little or no oxygen are known as ‘dead zones’, because they cannot support fish or marine life. There is a large dead zone in the Gulf of Mexico which spans on average 9,000 square kms (5,000 sq. miles). • The deepest point on Earth is the crescent-shaped Mariana Trench, an ocean valley some 2,550 km (1,580 mi) in length, in the western Pacific, east of Guam. Its maximum confirmed depth is 10.9 kilometers (6.8 miles).