MEPS 210:85-91 (2001)  -  doi:10.3354/meps210085

A growth cline in encrusting benthos along a latitudinal gradient within Antarctic waters

David K. A. Barnes1,*, Rodney Arnold2

1Department of Zoology and Animal Ecology, University College Cork, Lee Maltings, Cork, Ireland
2British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, England
*E-mail:

ABSTRACT: Growth and mortality of 3 species (Inversiula nutrix, Celleporella bougainvillei, Fenestrulina rugula) of encrusting bryozoans were examined from 5 Antarctic localities, along a latitudinal gradient. Typically, growth in marine invertebrates is, for ecological equivalents, slower or much slower in cold seas than warm waters. Contrary to the general trend, growth rates of 3 bryozoans were found to accelerate with increasing latitude in Antarctic waters. Population age structure also showed a dramatic change across the 5 study sites (from 54 to 68°S) through hugely increased mortality with increasing latitude. Reduction in inter-specific competition is theorised as explaining higher growth rates. Increased levels of ice scour are probably responsible for the differential mortality.


KEY WORDS: Benthos · Antarctic · Growth · Mortality · Disturbance · Cline


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