|Considerations in estimating larval dispersal distances from oceanographic data|
Largier, J.L. (2003). Considerations in estimating larval dispersal distances from oceanographic data. Ecol. Appl. 13(1, Suppl.): S71-S89
In: Ecological Applications. Ecological Society of America: Tempe, AZ. ISSN 1051-0761, more
Determination of larval dispersal distances and larval origins is a centralchallenge in contemporary marine ecology. In this work, the larval dispersal problem isdiscussed from the perspective of oceanography. Following formulation of the advection-diffusion model, the importance of scale is argued. When considering dispersion parametersat the appropriate population scales, advection is usually weaker than initially anticipated(and often used), and diffusion is stronger than typically used in model studies. Focusingattention on coastal populations, the importance of retention zones is described, and themore general existence of a coastal boundary layer is discussed. The coupling of crossshoreand alongshore dispersion results in a nonlinear relation between alongshore dispersaldistance and larval planktonic period for dispersion in a sheared flow. Thus, small changesin cross-shore dispersal, whether due to environmental differences or larval behavior resultin significant differences in alongshore dispersal. Finally, the interplay between advectionand diffusion is explored, showing the importance of adequately representing the diffusiveeffects that mitigate alongshore advection. In most cases, diffusion acts to prevent ‘‘washout’’of a population and allows for more flexibility in the size and spacing of effectivemarine reserves. Future challenges must bring oceanographers and ecologists togetheraround specific dispersal problems if there is to be a significant improvement in the notableabsence of hard data in this field of enquiry.