Estimation of Oxygen Consumption of a Deposit-feeding Polychaete Capitella sp. I

Abstract

Attempts to re-establish dense colonies of a deposit-feeding polychaete, Capitella sp. I for promoting the organic decomposition of organically polluted marine sediment below fish net pen culture need more information on the oxygen consumption characteristics of the worms. In this study, the oxygen consumption characteristics of Capitella colonies have been examined in laboratory conditions by using a method consisting of measuring the depletions of dissolved oxygen concentrations ([O2]; mg O2/l) over the reconstituted sediment cores containing a given number of active adult Capitella. Oxygen uptake rate (OUR) of the worms (ca. 20,000 individuals/m2) was calculated and expressed as an oxygen flux (mgO2/m2-h). Worm OUR was found to be a function of [O2] and can be characterized by OUR = 14.45+ 36.75 log[O2], under an constant temperature of 21 + 1 °C. Compared to other benthic oxygen consumption data, respiratory activities of Capitella colonies were slightly low. During oxygen depletion periods, the worms have revealed an ability to adapt well. Moreover, they still survived for several days although ambient [O2] was beneath 0.3-0.5mgO2/l. These results demonstrated that Capitella has appropriate abilities to be utilized as an effective biological treatment for poorly oxygenated sediment below fish net pen culture areas. © 1994, The Japanese Society of Fisheries Science. All rights reserved.