Individual growth rates of salps in three populations

One of the fastest growing planktonic species, the salp Thaliademocratica, was analysed for growth rate in three differentoceanic blooms in winter, summer and spring. Each bloom wasmarked by a pair of drogues, and sequentially sampled to obtaina sesies of length frequencies in each population through time.The length frequencies were analysed by an improved method ofmodal analysis. Length-specific growth rate was calculated fromthe progression through time of the resulting series of modes.The blooms showed average growth per individual of 10.4, 14.7and 19.8% in length per hour in winter, summer and spring respectively.These growth rates in the field are compared with growth ratesobtained previously in the laboratory, and the reasons for thevarying estimates of growth rate in the literature are examined.