Planet Earth

A STUDYGUIDE bY Andrew Fildes

www.metromagazine.com.au www.theeducationshop.com.au Overview

Planet Earth is a BBC production with five episodes in the first series (episodes one through five) and six episodes in the second series (episodes six through eleven). Each episode examines a specific environment, focussing on key species or relationships in each habitat; the challenges they face; the behaviours they exhibit and the adaptations that enable them to survive. Recent advances in photography are used to achieve some spectacular ‘first sights’ – in particular, stabilised aerial photography gives us remarkable views of migrating animals and the techniques used by their predators to hunt them. As the series examines pristine environments where possible, they are often extreme. These are the parts of the world where few humans have chosen to live as the climate and landscape is too challenging, too difficult and dangerous. The plants and animals that do survive here have made some spectacular adaptations in forms and behaviour to live in these far reaches of the planet. The series is suitable for middle secondary students studying Science and SOSE, and for senior secondary students of Biology, Environmental Science and Geography. SCREEN EDUCATION

1 Episode Eleven: Ocean and crustaceans that huddle around gered more by the threats to its food Deep volcanic fissures on the ocean floor, source than hunting, as in the past. outpourings of superheated water in so The deep oceans, the pelagic zone cov- called ‘black smokers’. The plumes of Resources ers more than half our planet’s surface mineral rich hot water form huge chim- and is one of the least explored areas. neys and whole, unique ecosystems http://www.pbs.org/saf/1207/ Much of it is simply an empty blackness tread a fine line between that water features/113.htm (Black Smoker but the upper reaches are a vital part of venting at hundreds of degrees and the Discovery) the earth’s habitat and climatic systems freezing deeps around them. These are 3D IMAX movie – Aliens of the Deep and even the deepest, darkest zones contrasted with the great seamounts, hold some remarkable surprises. undersea volcanoes that rise kilometres Species List from the abyss to provide a platform for We begin with the largest fish of all, the life. Some like Ascension Island in the Whale Shark – Rhinocodon typus harmless whale shark that was almost Atlantic break the surface and create Yellowfin Tuna – Thunnus albacares unknown a few years ago but has now a special habitat for frigate birds and Oceanic White Tip Shark – Carcharhi- become a tourist spectacle in many turtles. Finally we return to the ocean gi- nus longimanus places. It cruises the warm waters of ants, creatures that could only live here Pilot Fish – Naucrates ductor the sub-tropical reefs, swallowing huge with the limitless space and the support Rainbow Runners – Elagatis bipin- quantities of plankton and small fish, as of the water. But this time it is the great nulata does the manta ray, master of underwa- blue whale, the largest animal ever to Dolphin – Tursiops spp., Delphinus ter flight. These are the great grazers of have lived on earth and now endan- spp. the ocean, scooping up the microscop- Blue Jack Mackerel – Trachurus pic- ic plants and some small animals too. turatus True predators like the white tip shark Episode 11: Ocean Deep Time Log Cory’s Shearwater – Calonectris di- are long distance hunters, cruising the omedea borealis vast reaches of the open ocean in the Intro 00:00 - 01:25 Mobula Ray – Mobula spp. constant hunt for scarce food while Whale Shark 01:25 - 05:00 Indo-Pacific Sailfish istiophorus– large tribes of dolphins take a more platypterus proactive approach, herding their prey White Tip Shark 05:00 - 07:20 Manta Ray – Manta birostris into tight bunches before they strike Pteropod (Sea Butterfly) –Theco - Dolphin and Shearwater 07:20 - 11:10 mercilessly. somata Plankton Night Grazers 11:10 - 13:53 Sea Cucumber – Holothuroidea But beneath the warm and sunlit waters Sea Spider – Muneurycope spp. of the surface lie unimaginable depths Submarine Descent 13;53 - 17:30 Sawtooth Eel – Serrivomer spp. of dark, cold water. Some animals may Vampire Squid 17:30 - 18:57 Dumbo Octopus – Grimpoteuthis spp. dive down there hunting food but most Vampire Squid – Vampyroteuthis of it is a high pressure desert, inhabited Deep Ocean Floor 18:57 - 23:55 infernalis by strange beasts that live on what- Atlantic Smokers 23:55 - 25:26 Sea Urchin – Phormosoma placenta ever falls, dead, from the upper levels. Monkfish –Lophius piscatorious These are highly specialized creatures, Dragon Chimneys 25:26 - 27:03 Giant Isopod – Bathynomus giganteus adapted to filter their food blindly from Death of a Vent 27:03 - 28:56 Sperm Whale – Physeter macrocepha- the downward drifting ‘snow’ or to hunt lus each other in the total dark above the Sea Mounts 28:56 - 31:10 Spider Crabs – Hyas spp. great plains of sand and ooze. Like Squat Lobster – Shinkaia crosnieri Nautilus 31:10 - 33:24 the vampire squid which can light up Giant Tubeworm – Riftia pachyptila to confuse its predators or prey and Dolphin and Squid 33:24 - 36:00 Whip Corals – Iridgorgia spp. the scavengers of the plains sifting out Chambered Nautilus – Nautilus pom- Sunfish 36:00 - 37:00 any organic particles from the ocean pilius

floor. Eventually even the giants die and Frigate Birds on Ascen- 37:00 - 41:56 Pacific Spotted dolphin –Stenella SCREEN EDUCATION the carcass of a huge sperm whale is sion attenuata slowly consumed by the scavengers of Ocean Sunfish –Mola mola Green Turtle Hatching 38:50 - 41:32 the abyss. Ascension Frigate Bird – Fregata Sailfish 41:56 - 44:50 aquila There are odd communities down Green Turtle – Chelonia mydas here, discovered only in the last few Blue Whale 44:50 - 48:09 Atlantic Sailfish –Istiophorus albicans years. Communities of strange worms (Timings are approximate) Blue Whale – Balaenoptera musculus 1

Blackline Master | Planet Earth | Episode 11: Ocean Deep Viewing Questions SCREEN EDUCATION

1 How much of the planet is covered by deep ocean? ��

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�� 6 When does the deep water plankton rise?

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2 What is the biggest fish in the ocean? ��

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�� 7 Name the two big grazing fish that eat the plankton

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3 What area does the white tip shark patrol for food? ��

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�� 8 What is the ‘marine snow’ of the deep levels?

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4 What do the dolphins use to detect prey? ��

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�� 9 What is the unique defence of the vampire squid?

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5 How deep can the shearwaters dive? �� SCREEN EDUCATION ��

�� 10 At two miles down (just over 3.2km) what is the water

�� pressure? �� 1b

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�� 15 What kind of coral can live in deep water?

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11 What do most sea floor animals eat? ��

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�� 16 What do the dolphin prefer to eat?

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12 What energy source can start an ecosystem down ��

here? 17 What does the sunfish (mola mola) eat in the deeps?

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�� 18 What is the biggest animal that has ever existed?

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13 What is the fastest growing marine invertebrate? ��

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�� 19 What do they eat?

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14 How many undersea volcanoes are there? ��

�� 20 What was their original population and how many are SCREEN EDUCATION �� now left?

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Blackline Master | Planet Earth | Episode 11: Ocean Deep Ocean Deep Ecosystems SCREEN EDUCATION

2a The open ocean zone beyond the several centimetres in diameter in the continental shelf is called the pelagic weeks before they sink to the abyssal zone. It is then divided into sub-zones plains. based on depth. The first thing to consider is whether light can penetrate This snow is the producer of the deep – if any light from the surface at all sea ecosystem where no light pene- can be detected, it is called the photic trates and what is not eaten during its zone. Below that it is totally dark and descent, becomes part of the layer of referred to as aphotic. organic waste on the sea floor which is scavenged and filtered by small The pelagic area is further divided animals. Without it, nothing could live into depth zones, each with its own permanently in the deep waters. ecosystem. This is often a function of depth, temperature and pressure at Pelagic Ecosystems the increasing depths, as well as what – Discussion Questions light can penetrate. 1. The largest predators on earth live Epipelagic (Surface down to 200m). on the some of the smallest organ- Epi – surface. This is the surface zone isms. How does this work? where enough light penetrates to al- wandering across the abyssal plains 2. Whale sharks have become an low photosynthesis. Most plants and filtering out small organic particles or important ecotourism resource. animals live in this thin zone and the scavenging dead animals that sink to Why? large fish that cruise long distances, the floor. 3. The dolphins and shearwaters like sharks and sailfish are usually seem to work together to catch found here. Hadopelagic (Deep ocean trench- small fish. Are they competing or es in the sea floor). co-operating? Mesopelagic (200m to 1,000m Hades – hell, the ancient Greek un- 4. Deep water animals often seem to deep). derworld. Mostly unexplored and with have bizarre and outrageously ugly Meso – middle. This is the zone where little life. shapes and adaptations. How can the light gets increasingly dim and we explain this? plant growth – photosynthesis is im- The bottom three zones are very 5. Photoluminescence is a strange possible. Phytoplankton – microscopic similar and are almost lifeless except adaptation and is used by terres- plants cannot grow so the ecosystem around any source of energy like a trial and marine animals. How does has to live on other materials such as hydrothermal vent – black smoker. it work? detritus – sinking debris and rubbish. Marine Snow Extension Tasks Bathypelagic (1,000 to 4,000m deep). Deep sea organisms rely mostly on • Draw up a visual presentation Bathys – deep. Totally dark apart so-called ‘marine snow’ which falls (poster) that compares the ecosys- from those animals that can produce constantly from the upper levels. It tems of the pelagic zones – com- their own light, using photolumines- is mostly organic ‘detritus’ (waste) pare the photic and aphotic zones. cent bacteria – they have symbiotic and those animals that rely on it are • Prepare a visual presentation or bacteria in their tissues that can glow referred to as detritivores – waste report on the unique ecosystem and can be used as lures or decoys, feeders. It may include dead or dy- of the hydrothermal vents of the rather than headlights! As there are no ing microscopic animals and plants deeps (black smokers), explaining plants, small animals live on the falling (plankton), protists (diatoms), fe- how these systems can survive marine ‘snow’ and larger animals are cal matter and inorganic particles without any photosynthesis to predators. Giant squid live here and (sand and dust). The ‘snowflakes’ produce energy.

sperm whales dive to catch them. are clumps or strings of material held • Research and report on the explo- SCREEN EDUCATION together by strings of sugary mucus, ration of the abyssal depths – what Abyssopelagic (4,000m to ocean the wastes of bacteria that are feeding research equipment and tech- floor). on the contents of the wastes. Those niques have been used and what Abyssos – bottomless. No light bacteria become an important part has been discovered in recent whatsoever and huge pressure. Most of the food resource in the material. years? animals are blind and colourless, They continue to grow and may reach 3

Case Study | Planet Earth | Episode 11: Ocean Deep ‘Black Smokers’ SCREEN EDUCATION

Not Photosynthesis If sunlight is unavailable and Chemosynthesis is the biological – Chemosynthesis! photosynthesis impossible, how conversion of carbon molecules can the organisms make use of (usually carbon dioxide or methane) We are used to thinking of ecosystems the heat energy from the vent to and nutrients into organic matter as being based on producer organisms establish a habitat? There is one using the oxidation of inorganic – green plants that can convert inorgan- case of a bacterium that can use molecules (e.g. hydrogen gas, ic materials into organic energy through the faint glow from the volcanic hydrogen sulfide) or methane as photosynthesis. Even systems that exist activity for photosynthesis, the only a source of energy, rather than in total darkness still rely on it – cave organism known to use any other sunlight, as in photosynthesis. systems live on material brought in from light but sunlight, but this is a unique Large populations of animals can the outside, such as bat droppings exception. be supported by chemosynthetic (guano) and even the creatures of the primary production at hydrothermal black abyssal plains kilometres down Usually microscopic organisms, vents. Chemoautotrophs, organisms beneath the ocean rely on the ‘snow’, archaea, convert heat and sulphides that obtain carbon through the constant rain of decaying material directly into organic material by chemosynthesis, are responsible for that slowly settles down through the an alternative process called the primary production in oxygen- water and feeds the detritivores, the chemosynthesis – then the higher deficient environments and generally rubbish feeders. organisms such as worms and clams fall into four groups: methanogens, can feed on those, so creating the halophiles, sulphur reducers, and However, there is one class of systems two base layers of the food chain. thermoacidophiles. that seems to defy this absolute rule Like bacteria, archaea are single- – the so-called ‘smokers’ or volcanic celled organisms lacking nuclei Many microorganisms in dark regions vents on the ocean floors. These have and so are prokaryotes, classified of the oceans use chemosynthesis only been explored in the last twenty as monera. They were originally to produce biomass from 1-carbon to thirty years, since their discovery in described in extreme environments, molecules. There are two categories. 1977 and represent the most ex- but have since been found in all types In the rare sites at which hydrogen

treme environments on earth in terms of habitats. Many are referred to as molecules (H2) are available such as of temperature, pressure and toxic ‘extremophiles’ – organisms that love smokers, the energy available from the

chemistry. We may be surprised to find extreme environments. reaction between CO2 and H2 (leading

blue-green algae surviving in the near to production of methane, CH4) can be boiling waters of hot springs up here Archaea are usually placed into large enough to drive the production in the sunshine but they are delicate in three groups based on preferred of biomass. comparison to the organisms that cling habitat. These are the halophiles, to life in these odd zones. methanogens, and thermophiles. Alternatively, in most oceanic Halophiles live in extremely saline environments beyond the They are hydrothermal vents, where environments. Methanogens live volcanic environments, energy superheated water bubbles up through in anaerobic environments and for chemosynthesis derives from

the earth’s crust at its thinnest points produce methane. Many archaeans reactions between O2 and substances – volcanically active ocean floor zones. are thermophiles. They can survive such as hydrogen sulfide or Because they are at an average depth and thrive at even relatively high ammonia. In this second case, the of over 2,000 metres deep, the water temperatures, often above 100°C, as chemosynthetic microorganisms are does not boil even though it can be at found in geysers and black smokers. dependent on photosynthesis which 400 degrees due to pressure. The vent Other extremophiles are found in occurs elsewhere and which produces

water is a soup of dissolved minerals, very cold habitats or in highly acidic, the O2 that they require. often rich in sulphides which crystallise or alkaline water. However, other as they hit the cold ocean water, form- archaeans are mesophiles, and have Because it makes life possible in ing chimney structures, sometimes at been found in environments like such extreme environments and

up to 300mm per day . Smokers occur marshland, sewage, sea water and habitats, it has been suggested that SCREEN EDUCATION in groups but each one tends to have a soil. Many methanogenic archaea are chemosynthesis may support life unique ecosystem because, although found in the digestive tracts of animals below the surface of Mars, on Jupiter’s some species can migrate from one such as ruminants, termites, and moon Europa, and on other planets. to another, many cannot and can only humans. Archaea are usually harmless survive in a narrow temperature zone to other organisms and none are Hydrogen sulphide chemosynthesis – around each vent. known to cause disease. CO +O +4{H S}‡CH O+4{S}+3{H O} 2 2 2 2 2 10 3ANSWER SHEET

Viewing Questions Discussion Questions tal co-operation if anything. 4 It is totally dark so they don’t 1 Over half of the planet is deep 1 The big whales, manta rays and need to be pretty or worry about ocean the whale shark live on plankton camouflage or speed. Some of 2 The whale shark and krill. This food resource is the adaptations that allow them to 3 The top 100m of open water huge and only very large animals survive look very strange but they 4 SONAR (SOund Navigation And with special adaptations to their are working blind – huge mouths Ranging) – sound echo location mouths can scoop up the huge with massive hooked teeth may 5 Twenty metres quantities that are needed to sup- help them latch on to prey with just 6 The plankton rises every night port their massive bodies. It is only a touch!. 7 Sailfish and manta ray possible if there are large algal 5 Organisms like glow worms, 8 The rubbish (detritus) sinking from ‘blooms’ and huge swarms of krill fireflies, and deep sea creatures the surface animals – anything that threatens those are in a symbiotic relationship with 9 Lights from bioluminescent bacte- swarms will threaten the large photoluminescent bacteria. These ria in its arms to confuse predators marine animals. bacteria have the ability to emit 10 300 atmospheres (300x surface 2 They migrate on a regular pattern light energy and live in the tissues pressure) and are easy to approach – they of other animals when there is an 11 They scavenge dead animals or are very docile, quite harmless. It advantage for both species. The filter particles is possible to swim with them in bacterium is fed and protected 12 Hot volcanic vents areas like the Ningaloo Reef off with the tissues while the host may 13 Giant tubeworms north-western Australia and a local use them as a sexual lure (fireflies), 14 Up to thirty thousand industry has grown up around their predatory lure (angler fish) or a 15 Soft corals migration. defence (vampire squid). 16 Squid 3 Neither really. The shearwaters 17 Jellyfish are taking the opportunity as the BBC and Planet Earth are trade marks 18 The blue whale fish are driven to the surface and of the British Broadcasting Corpo- 19 Krill the dolphin are advantaged as the ration and are used under licence. 20 300,000. Now three per cent of fish are confused and driven back Planet Earth logo © BBC 2006. BBC that – 9,000 down by the birds. It is an acciden- logo © BBC 1996.

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