In order to understand the recruitment dynamics of early blue crabs, it is necessary to sample quantitatively across early stages and habitats at appropriate spatio-temporal scales. Few studies of early blue crab recruitment have considered the potential role of soft-sediment habitat or directly related megalopal supply to local densities of early stages. During a 7-wk peak recruitment period, fluctuations in early stages of blue crabs from settlement collectors were significantly cross-correlated between two sites separated by 7.5 km, showing connectivity on this large spatial scale. Moreover, numbers of megalopae from settlement collectors were directly correlated with densities of early juveniles from nearby soft-sediment, showing that settlement collectors may reflect local recruitment intensity. Significant habitat variables included depth and salinity (i.e., water mass) for small post-settlement juveniles (CW), and substrate type for large juveniles ( greater than or equal to6 mm CW). Early juveniles from soft-sediment habitat were spatially aggregated at relatively low densities; although initial rates of loss may not be as high there as in structured habitats. Thus, soft-sediment habitat may subsidize the supply of early juvenile stages to structured habitats.
Bulletin of Marine Science
Rakocinski, C. F.,
Perry, H. M.,
Abney, M. A.,
Larsen, K. M.
(2003). Soft-Sediment Recruitment Dynamics of Early Blue Crab Stages in Mississippi Sound. Bulletin of Marine Science, 72(2), 393-408.
Available at: http://aquila.usm.edu/fac_pubs/4381