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ocean biology - Coggle Diagram
ocean biology
marine organisms
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Tourism - particularly coral reefs, whales and dolphins
Regulation of CO2 and climate - CO2 can be directly altered by biological activity in the ocean over small timescales
Carbon Sequestration - on geological timescales (1000+ years), atmosphere co2 regulation is effectively infinite. Production and burial in sediment carbon and calcium carbonate shells and skeletons is the primary removal pathway for volcanic co2. The burial of marine organic matter is the source of current oil and gas reserves.
Each step in the food chain is a tropic level and energy is transferred - without the first tropic level e.g. phytoplankton , all fish wouldn’t exist
Ocean food chain - primary producers are phytoplankton, then secondary produces are species such as krill and shrimp, then third producers = squids, dolphins etc and the top is killer whale
Phytoplankton – constitute primary producers- they are photosynthesising algae suspended in water - ocean phytoplankton produces the same amount of primary production as the land
The light is obtained from chlorophyll , a green pigment found in most algae
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In spring, phytoplankton blooms in English Channel – we use satellite imagery to detect phytoplankton from chlorophyll
Coccolithophores – large phytoplankton forming calcium carbonate shell - there are up to around 300 different species of 5-100 micro metres – the shell protects against grazing by zooplankton or photo inhibition – once coccolithophores die, their shell sinks to the bottom of the ocean and after a really long time produce chalk sediments e.g. white cliffs of dover
• Diatoms – they form a silica shell – single cell or come in colonies - 2 to 200 micro meters - diatoms are found in high latitude southern hemisphere in January
Prochoorococcus—0.5-0.7 micrometres and synechococcus– 0.8-1.5 micrometres – found more in low latitude regions in January – smallest phytoplankton in ocean – contribute to half of primary production – no shell
nutrient regulation
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The composition of phytoplankton is N:P – 16:1 if the ration is bigger than 16 then the env is phosphorous limited and if smaller than it is nitrous limiting
Some species of phytoplankton can also assimilate nitrogen fas dissolved in the water . These organisms are called nitrogen fixers – they grow in nitrogen limited water
Iron is essential for life but only in trace amount (~1:200 of phosphate). Iron is considered a micronutrient
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Iron – hard to measure iron in ocean – model estimates are more reliable - they show that there is a lot of iron in north atlantic, north Arabian sea and by the equator. Very little iron in south – this has consequences to phytoplankton.
High nitrate , low chlorophyll regions , HNLC describe areas of ocean where phytoplankton is low on spite of high nutrient concentrations, three of them . These regions are in the North Pacific, the equatorial Ear pacific and the Southern ocean – HNLC are thought to be caused by the scarcity of dissolved iron
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