Filter feeders (suspension feeders) definition: animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, ... Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers.

Role of filter feeders in the biosphere: new facts, new ideas.
http://5bio5.blogspot.com/2013/05/filter-feeders-sub-group-of-suspension.html
Filter feeders (suspension feeders) are animals that feed by straining suspended matter and food particles from water,
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Filter feeders (suspension feeders) are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, ... Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers.
[from Wikipedia, with some changes].

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see the paper:

Biological Filters Are an Important Part of the Biosphere. Published in: Science in Russia (the journal is being published by Praesidium of Russian Academy of Sciences ) 2009 2-30-36; Eng Abstract; Site of Full Text Of the English Editition:

http://www.scribd.com/doc/104805842/56828623-Ostroumov-S-a-Biological-Filters-Are-an-Important-Part-of-the-Biosphere-Science-in-Russia-2009

Biological filters are an important part of the biosphere: http://sites.google.com/site/ostroumovsa/ostroumov-sa-biological-filters-are-animportant-part-of-the-biosphere--science-in-russia-2009--2-p-30-36;

Ostroumov S.A. Biological filters are an important part of the biosphere // Science in Russia. 2009. No. 2, p. 30-36

published in: Science in Russia, 2009
Reference: Ostroumov S.A. Biological filters are an important part of the biosphere // Science in Russia. 2009. No. 2. P. 30-36