Meiofauna in impact assessment (EIA) and monitoring work

What is meiofauna?

Small (less than 1 mm), benthic, multicellular animals.  There are meiofaunal representatives of the major animal groups (e.g. polychaetes, crustaceans, bryozoans and molluscs) but some major zoological categories (phyla) are exclusively meiofaunal (e.g. Gastrotricha, Loricifera, Kinorhyncha)

 

What are the advantages of using these animals in ecological studies?

· They are widespread and can be found in intertidal/estuarine, shelf and deep-sea sediments, saltmarshes, river beds, lake floors and among aquatic vegetation (seaweeds, freshwater macrophytes, bryophytes etc.)

· They are often highly abundant

· Meiofauna communities are usually species rich.  This enhances their sensitivity as pollution indicators and is especially useful where the macrofauna has low diversity or is absent

· They are sedentary.  Dispersal is relatively slow.  Responses reflect local effects

· Larvae are benthic, unlike most macrofaunal animals whose planktonic dispersal stages complicate the interpretation of adult distribution patterns

· Life cycles (and hence response times to disturbance events) are short, enabling effects to be detected rapidly

· Cultivation can be straightforward making rapid and cost effective laboratory bioassays possible

· Samples require less storage space (useful in large ship based studies) and are easier (cheaper) to transport.  Sampling is often less destructive than in macrofauna work

· Specialist laboratory equipment is not required.  Meiofaunal work may be undertaken using a high power binocular microscope and a compound microscope with oil immersion lens.

 

And the disadvantages?

· Specialized sampling equipment may be required

· Identification is not easy, especially for the non-specialist.  For the experienced technician, however, determination to genus level is rapid.

· Extraction from the sediment is tedious, but staining followed by flotation can achieve high efficiency.  This is non-specialist work.

 

For more information...

· Giere, O. (1993) Meiobenthology.  The microscopic fauna in aquatic sediments.  Springer Verlag, Berlin

· Somerfield, P. J. & Warwick, R. M. (1996) Meiofauna in marine pollution monitoring programmes.  A laboratory manual.  Ministry of Agriculture, Fisheries and Food Directorate of Fisheries Research, Lowestoft

 

Contact details:

Marine Invertebrate Ecological Services

Marine Invertebrate Ecological Services

Dr Stephen Jarvis

30 Mill Road

Mutford, Beccles

Suffolk

NR34 7UR

UNITED KINGDOM

 

Harpacticoid copepod