<P> In land ecosystems, the waste products of plants and animals collect mainly on the ground (or on the surfaces of trees), and as decomposition proceeds, plants are supplied with fertiliser in the form of inorganic salts . In water ecosystems, relatively little waste collects on the water bed, and so the progress of decomposition in water takes a more important role . Investigating the level of inorganic salts in sea ecosystems shows that unless there is an especially large supply, the quantity increases from winter to spring--but is normally extremely low in summer . As such, the quantity of seaweed present reaches a peak in early summer and then decreases . The thinking is that organisms like plants grow quickly in warm periods and thus the quantity of inorganic salts is not enough to keep up with the demand . In other words, during winter, plant - like organisms are inactive and collect fertiliser, but if the temperature rises to some extent they will use this up in a very short period . </P> <P> It is not entirely true that their productivity falls during the warmest periods . Organisms such as dinoflagellate have mobility, the ability to take in solid food, and the ability to photosynthesise . This type of micro-organism can take in substances such as detritus to grow, without waiting for it to be broken down into fertiliser . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2012) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2012) (Learn how and when to remove this template message) </Td> </Tr>

Which of the following is an example of a detritus food chain