S180 Life In The Oceans: Exploring Our Blue Planet
I've decided to try out some short science courses over the winter, and as I was fascinated by the Blue Planet TV series, I've decided on S180 Life In The Oceans: Exploring Our Blue Planet.
I registered for this course on the 17th September. This course is linked to the Blue Planet BBC TV series. The course material arrived on 12th November, and consists of three video's, a S180 Life In The Oceans: Exploring Our Blue Planet book, Discovering the Deep Oceans booklet (taken from OU course S280), a cdrom and the End of Course Assignment(ECA).
Depending on previous experience and other commitments, the course can be studied over 8 or 12 weeks, each option has a separate end of course assignment(ECA). I've chosen to take this course over eight weeks, and submit the ECA by 31st January 2003.
The course has various learning outcomes which I intend to keep in sight as I study this course:
• Understand some of the underlying scientific concepts associated with the study of life in the oceans and the oceans themselves
• Understand some of the terminology and nomenclature appropriate to the introductory study of marine biology
• Demonstrate knowledge and understanding of essential facts and concepts relating to life in the oceans
•Understand the contribution that science can make to informed debate on environmental issues.
This section uses module one of the CDROM on biodiversity:
• An overview of the main events in the evolution of life in the oceans over geological time.
• An introduction to the classification of marine organisms.
• A summary of the main groups of marine animals.
Some of the geological time scale and taxonomic hierarchy seemed complicated, but I treated this as an introduction, and hopefully it will fall into place as the course progresses. Plants and bacteria were discussed, and the idea of photosynthesis and respiration was introduced.
Photosynthesis =
carbon dioxide + water + light energy -> carbohydrate + oxygen
Respiration =
carbohydrate + oxygen -> energy + carbon dioxide + water
Note: respiration is the reverse of photosynthesis
The first question of the ECA is associated with chapter one of the 'Life in the Oceans' book, and the biodiversity CDROM module - I intend to complete the ECA as I come to each section rather than leave it until the end.
This section gave a general introduction to the marine environment by discussing the properties of seawater, how plants and animals survive in seawater, and the topography of the ocean floor. The oceans contain 97% of the water on Earth.
Properties of sea water:
• Salinity (concentration of dissolved salts) = 35g/lt.
• Density greater than freshwater (1030kg per M3 compared to 1000kg per M3 for freshwater).
• Contains dissolved gases such as nitrogen (N2), oxygen (O2), argon (Ar), and carbon dixoide (CO2), but in different proportions to the atmosphere. The most abundant gas in seawater is (CO2), in contrast to the atmosphere which is (N2).
• Freezing temperature of seawater = -1.9°C.
• Temperature range = -1.9°C to 32°C (compared to -68°C to 58°C on land).
• Transparent to visible light, to a certain extent.
• Sound can travel through sea water further than light.
The shape of the ocean basins and the topography of the ocean floor influence how much living space is available to marine life. The ocean floor (ocean lithosphere) is continually being formed or constructed at the mid ocean ridges (constructive margins) e.g Mid Atlantic Ridge, and destroyed at the trenches (destructive margins).
'Living in the Oceans CD module'. A introductory look at five contrasting organisms:
• baleen whale;
• planktonic algae;
• copepod;
• squid;
• angler fish.
Introductory video
• Marine mammals;
• marine reptiles;
• shorebirds and seabirds.
Phytoplankton are often called the 'grass of the sea'. They are primary produces that use photosynthesis to convert carbon dioxide, water and light energy into carbohydrate and oxygen. Satellite imagery shows that the most productive regions on Earth are coastal areas, particularly river mouths where fertilizer and sewage run off enhance growth of plant material.
Photic, or euphotic zone the depth where there is enough light to support plant growth and reproduction (about 100m in open ocean).
Aphotic zone - Insuffcient light to support plant growth and therefore no primary production.
Some deep sea fish can perceive daylight at a depth of 1000m (sometimes known as the twilight zone).
Thermocline - transition zone between warmer surface waters above and cold dense water below. (little variation in temperature in the deep ocean.)
Coriolis effect - tendency for any moving body on or above the earth's surface, e.g., an ocean current, to drift sideways from its course because of the earth's rotation.
Intertropical transvergence zone (ITCZ) - where the wind systems of the two hemispheres meet.
Anticyclonic - winds that blow around high pressure areas regardless of hemisphere.
Cyclonic - winds that blow around high pressure areas regardless of hemisphere.
Upwelling - in coastal waters winds cause nutrient-rich water to upwell from below the thermocline.
The vast majority of fish are bony fish or teleosts, other classes are jawless fish, and cartilaginous fish, also known as elasmobranchs.
Neutral buoyancy is achieved by either a gas filled swim bladder (teleosts) or by deposits of low density fat or oil (elasmobranchs).
Two types of muscle - white muscle for short bursts of speed and red muscle for normal cruising.
Large tuna and some sharks have a higher body temperature than other fish because of how their blood vessels are arranged - this allows them to swim fast for long periods.
Schooling is likely to be a defense mechanism against predators - those in the centre of the bait ball as more protected than those on the outside. The schooling fish spending only a short time on the outside.
I've decided to try out some short science courses over the winter, and as I was fascinated by the Blue Planet TV series, I've decided on S180 Life In The Oceans: Exploring Our Blue Planet.
I
This section uses module one of the CDROM on biodiversity:
This section gave a general introduction to the marine environment by discussing the properties of seawater, how plants and animals survive in seawater, and the topography of the ocean floor. The oceans contain 97% of the water on Earth.
This section focuses on tides - what causes them, how they influence marine life and tides and weather.
Phytoplankton are often called the 'grass of the sea'. They are primary produces that use photosynthesis to convert carbon dioxide, water and light energy into carbohydrate and oxygen. Satellite imagery shows that the most productive regions on Earth are coastal areas, particularly river mouths where fertilizer and sewage run off enhance growth of plant material.
Coriolis effect - tendency for any moving body on or above the earth's surface, e.g., an ocean current, to drift sideways from its course because of the earth's rotation.
The vast majority of fish are bony fish or teleosts, other classes are jawless fish, and cartilaginous fish, also known as elasmobranchs.
