Happy Earth Day! – April 22, 2020
Happy Earth Day! In honor of the 50th anniversary of Earth Day, we are celebrating our planet this week! The COVID-19 pandemic is showing us just how fragile and beautiful life is and that we cannot take our health or the health of our planet for granted. Take a look at posts from this whole week over at the Science in the Wild FB page.
The Earth system is a wonderfully complex network of physical, chemical and biological processes that interact to shape the world in which we live. This week, we’ll take a look at all these “spheres” and how they are interconnected. Today’s focus? The biosphere – the sphere of life.
Our biosphere is made up of biomes (biophysical zones like forest, grassland and desert), home to many ecosystems. Each ecosystem, in turn, is made up of a set of species adapted to their specific conditions: from the oceans, to the forests, to the mountains. Lifeforms range in size from microscopic bacteria to the 25-meter long blue whale! While the biosphere has been around for billions of years, it has been hit by 5 mass extinctions in our geologic past due to massive and sustained volcanic eruptions and asteroid impacts. Now species face existential threats due to human activity, related to land use change. This results in species being forced into environments for which they are ill-suited to survive. Humans encroaching on natural habitats also leads to diseases (e.g., coronaviruses) spreading more easily from other mammals to us. Hopefully, someday soon, we will learn to live in better harmony with the other species of our planet.
Given today is Science Wednesday, we have a special post related to the theme of the biosphere and human impacts by guest, Dr. John Dudeney. John has spent his entire career involved in work in the Antarctic, first as a field atmospheric physicist and base commander, spending two years there in the 1960s, and then as a career scientist and administrator with the British Antarctic Survey. Following his retirement in 2006, John has developed a new interest in the human and political history of Antarctica and as a historian/guide for Antarctic tourism. Here is an excerpt from a book he is writing on whaling and how you, as a citizen scientist, can help scientists gather data:
“Whaling in the Southern Ocean began in December 1904 when Carl Larsen established a whaling station at Grytviken in Cumberland Bay on the Island of South Georgia. To start with, whales were so abundant his ships didn’t need to leave the bay to catch them. Whaling quickly spread to other sites in South Georgia and then further into the Scotia Sea to Deception Island in the South Shetlands, and also to the South Orkney Islands and down the western coast of the Antarctic Peninsula. As Britain claimed all these places as Dependencies of the Falkland Islands it was able to manage the industry pretty well exclusively up to the mid-1920s because the Whalers needed either safe anchorages with an abundant water supply for their floating factories, or a land site on which to build a factory. During this time, Britain made a determined attempt to create legislation to protect the whale stocks while also earning an income for the Falklands from licensing and taxing the whalers. However, technology raced ahead of legislation in the 1920s with the emergence of the fully autonomous whale factory ships, each with their own fleet of catchers, which could operate on the high seas, out of the reach of the authorities. From that time on the slaughter of the whales was inevitable.
Could there have been a sustainable industry before WW1? At the time the total annual catch of whales from the waters around South Georgia was circa 6,000 animals, an order of magnitude smaller than it reached in the late 1920’s. So, in principle, it could have been possible. But although the British were studying hard whether the whales needed protection and if so how that should be protected, almost nothing was known about stock size, distribution, population structure, life cycle parameters, feeding habits, distribution of food or migratory behaviour of the whales. Much of the evidence presented to government by “experts” was based on hearsay, speculation and special pleading with most originating from the whalers themselves. It is therefore not surprising that what “evidence” that did exist was contradictory, with even individual experts seeming to contradict themselves. The most common belief was that the Southern Ocean was a huge region uniformly populated with whales, so that the chance that whaling from a few isolated locations could put the whole population under threat was just not tenable. But most important as far as the Humpback was concerned was that for the first few years almost all the whales killed were Humpbacks. In just the four years leading up to the war around 16,000 succumbed, and suddenly to the whalers’ surprise there were none left to catch. The prevailing view at the time was that they had been frightened away, not that they had been wiped out.
After the war the British established a very comprehensive multi-year oceanographic research programme known as the Discovery Investigations to try to provide the scientific underpinning for regulating the industry. It was funded entirely from the licenses and taxes paid by the whalers, but for the Humpback whales it was already too late. We now know that Humpback whales are migratory, feeding in the polar waters in the summer and retreating to warmer waters in the winter to breed. Also, crucially they are divided into sub-populations that have distinct migratory paths. The South Georgia population feeds on the abundant krill off the Island in summer and breeds off the coast of Brazil in winter. It is now estimated that this group numbered around 25,000 animals at the turn of the last century and that the whalers effectively wiped it out in less than a decade. Whaling effectively ceased in the 1980s, but it has taken the long period from then until now for the population to finally recover to something like its original size. Citizen science has played a very important part in the current understanding of Humpback population and particularly migratory habits. The underside of the fluke (tail) of a Humpback has unique patterning which makes it easy to identify individual animals from photographs taken of them, no matter where they are in the world. There is an international database (https://happywhale.com/home) where anybody can submit a photograph with location and date information to add to the growing body of knowledge. So, for keen whale watchers, submit your photos and help science!”
Further reading:
Zerbini AN, Adams G, Best J, Clapham PJ, Jackson JA, Punt AE. 2019 Assessing the recovery of an Antarctic predator from historical exploitation. R. Soc. open sci. 6: 190368. http://dx.doi.org/10.1098/rsos.190368
Dudeney J. R., and J Sheail, 2019, Claiming the Ice Britain and the Antarctic 1900-1950, Cambridge Scholars Publishing, 390p, ISBN 978-1-5275-3048-5
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