Marine Biology: A Very Short Introduction (Very Short Introductions)
Philip V. Mladenov
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The marine environment is the largest, most important, and yet most mysterious habitat on our planet. It contains more than 99% of the world's living space, produces half of its oxygen, plays a critical role in regulating its climate, and supports a remarkably diverse and exquisitely adapted array of life forms, from microscopic viruses, bacteria, and plankton to the largest existing animals. In this unique Very Short Introduction, biologist Philip Mladenov provides a comprehensive overview of marine biology, offering a tour of marine life and marine processes that ranges from the polar oceans to tropical coral reefs, and from shoreline mollusks to deep-sea hydrothermal vents. Mladenov also looks at a number of factors that pose a significant threat to the marine environment and to many of its life forms-threats such as overfishing, coastal development, plastic pollution, oil spills, nutrient pollution, the spread of exotic species, and the emission of climate changing greenhouse gases. Throughout the book he successfully weaves around the principles of marine biology a discussion of the human impacts on the oceans and the threats these pose to our welfare.
About the Series:
Oxford's Very Short Introductions series offers concise and original introductions to a wide range of subjects--from Islam to Sociology, Politics to Classics, Literary Theory to History, and Archaeology to the Bible. Not simply a textbook of definitions, each volume in this series provides trenchant and provocative--yet always balanced and complete--discussions of the central issues in a given discipline or field. Every Very Short Introduction gives a readable evolution of the subject in question, demonstrating how the subject has developed and how it has influenced society. Eventually, the series will encompass every major academic discipline, offering all students an accessible and abundant reference library. Whatever the area of study that one deems important or appealing, whatever the topic that fascinates the general reader, the Very Short Introductions series has a handy and affordable guide that will likely prove indispensable.
Antarctic krill Uwe Kils/Wikimedia Commons 19 The central place of Antarctic krill in the Southern Ocean food web 20 Aerial view of coral reefs of Heron Island, Great Barrier Reef, Australia Ove Hoegh-Guldberg, Global Change Institute, University of Queensland 21 Distribution of coral reefs Source: http://www.iyor.org/reefs/ 22 Anatomy of a coral polyp 23 Stages in the formation of an atoll reef 24 Crown-of-thorns sea star feeding on coral colonies David
food for sperm whales, killer whales, Weddell seals, and large squid, so their removal will potentially impact on these dependent species. Even the krill in the Southern Ocean are subject to human exploitation. Antarctic krill fishing began in the 1970s and by the early 1980s about half a million tonnes were being harvested annually. Catches then declined to around 100,000 tonnes per year as most nations abandoned the fishery because of the high cost of operating in the Southern Ocean. However,
for prolonged periods during most tide cycles. This zone is densely covered by a variety of marine plants and animals. The low intertidal zone is the area between the average low tide level and lowest spring tides. Thus it stays completely submerged during most tide cycles and is the least physically stressed part of the intertidal region. 31. The division of the rocky intertidal into four ‘universal’ zones On rocky intertidal shores in temperate regions the splash zone is colonized by
brown seaweeds are also competing for space in the mid intertidal and, if they become well established, they can maintain their foothold by preventing mussel and barnacle larvae from settling there. This appears to be a result of the blades of the seaweeds being swept back and forth across the rocky surface by wave action and preventing mussel and barnacle larvae from securing an attachment. On the other hand, grazing on seaweeds by limpets and snails can reduce seaweed cover, allowing mussels
organisms for shell-forming purposes. It thus becomes more difficult for these organisms to secrete their calcium carbonate structures and grow. The oceans in motion On a planetary scale, the surface of the Global Ocean is moving in a series of enormous, roughly circular, wind-driven current systems, or gyres, each thousands of kilometres in diameter (see Figure 4). The northern hemisphere gyres in the North Pacific and North Atlantic Oceans flow clockwise; the southern hemisphere gyres in