Climate change: Why whales matter
Between 1900 and 2015, a staggering 3,000,000 whales were caught by the whaling industry, causing great whale populations to plummet by around 66 to 90 per cent. Little did we know the importance of these great whales in climate change mitigation and fisheries management, or we may have acted differently. WHALES ARE ECOSYSTEM ENGINEERS Whales are truly ecosystem engineers; able to modify the environment around them, maintaining the health of the oceans and providing services to humans. READ MORE: * My generation has failed young Kiwis, but the student climate strike gives me hope * Scientists set 30 per cent target for the protection of open ocean by 2030 * Climate change will even change the colour of oceans, research finds These impressive animals influence: * Global carbon storage * The health of commercial fisheries * The functioning of the oceans, buffering marine ecosystems from stresses such as climate change. HEALTHY FISHERIES NEED WHALES Whales were once thought to be the bane of fishermen, taking their catch, but are now known to increase the productivity of oceans and fisheries through their faecal cycle. Whale faeces are deposited wherever whales routinely congregate, fertilising the waters and encouraging the growth of phytoplankton. These microscopic plants form the base of marine food chains and allow other more complex life to grow ensuring there are plenty of fish in the ocean and supporting the fisheries we rely upon. Without this fertiliser input from whales, such ecosystems would likely collapse as phytoplankton no longer bloomed. WHALES MINIMISE THE EFFECTS OF CLIMATE CHANGE Blooms of phytoplankton are also the basis of the ocean's ability to absorb greenhouse gases and store them away permanently protecting us from the impacts of climate change. As much as a third of the carbon dioxide produced by burning fossil fuels is absorbed by the ocean but this may be declining. As whales migrate from their productive feeding areas to calving areas, they move nutrients thousands of miles and defecate in new areas such as the Pacific Islands; increasing the area's productivity and carbon absorption. This input of nutrients not only supports local fish stocks but ensures healthy and resilient areas where ecotourism and local communities can thrive. In remote places such as Antarctica where iron is limited, marine life is reliant upon whales to bring iron and nitrogen-rich faeces to the area, so that life can grow and flourish. The iron-limited Southern Ocean plays an important role in regulating the planet's atmospheric carbon dioxide levels, with the 12,000 sperm whales found there permanently remove 200,000 tonnes of carbon from the atmosphere each year. WHEN WHALES DIE, THEY TAKE CARBON WITH THEM When whales die, their huge bodies sink to the bottom of the ocean and perform another surprising climate management service. Their carcasses store a vast amount of carbon, which sinks to the deep ocean; providing food and habitat for other species. Dozens, if not hundreds, of species rely upon these whales. This deep ocean carbon storage removes carbon from the atmosphere produced by humans and further helps prevent the impacts of climate change. Added to this, the great whales bring nutrients up from the ocean floor during their lifetime when they dive and surface, which helps even more phytoplankton to grow and absorb carbon dioxide from our atmosphere. THREATS TO WHALES AND HOW YOU CAN HELP Whilst whaling has ended in most countries, whales are still threatened by human activities such as: * Entanglement in fishing gear * Changes in sea temperature * Chemicals and metals in food chains * Plastic pollution You can find out more about the threats to whales and discover how to protect them in this new ocean superhero infographic. SWIMMING WITH WHALES For the experience of a lifetime, you can dive or swim with whales at a variety of destinations around the world. Popular choices locally include swimming with humpback whales at Ningaloo Reef in Western Australia, dwarf minke safaris at the Great Barrier Reef and humpback whale swimming at Tonga. This article and infographic was provided by writers at LiveAboard.com