Dispersal of an introduced larval cohort in a coastal lagoon

Abstract

Patterns of larval dispersal influence the structure of marine biological communities, but many aspects of larval dispersal remain poorly understood. For example, much of our present understanding of larval dispersal is based on models that integrate aspects of physical oceanography and larval biology, but the predictions of those models are generally not tested because we lack the methodology for real-time larval tracking. In the present study, we used both modeled and measured data to track an introduced larval cohort essentially from fertilization to presumed settlement. Larvae of the hard clam Mercenaria were released into a labeled water parcel in the Banana River Lagoon, Florida, within 8.5 h of nursery production and then were tracked for the duration of their estimated 8-d pelagic life span. Comparisons of modeled versus measured larval distribution indicate that the fate of the larvae as predicted by a tracer model and by the concentration of coincidentally released sulfur hexafluoride (SF 6 ) did not agree with the fate of the larvae as predicted by the path of subsurface drifters and by a particle trajectory model. Thus, modeled predictions of larval dispersal must be interpreted with care. Additionally, one component of larval dispersal that was observed in the study but that was not accounted for in the model was the spread of larvae along the path of advection. That trail of larvae may have important consequences for patterns of recruitment and resultant community structure, but it is not considered in most treatments of larval dispersal.The life history and dispersal of marine invertebrate larvae has long been a focal point for marine ecologists (Young 1990) because of the essential role that larvae play in the maintenance of many marine invertebrate populations (Grosberg and Levitan 1992). Larval dispersal influences the structure and connectivity of marine benthic communities Acknowledgments

Stage-specific distribution of barnacle larvae in nearshore waters: potential for limited dispersal and high mortality rates

“…More direct approaches based on in situ tracking and intensive sampling of planktonic aggregations have been attempted for larval crustaceans (e.g. Natunewicz et al 2001), bivalves (Arnold et al 2005), and echinoderms (Lamare & Barker 1999), and provided valuable information on the scales and processes that may shape the distribution of larvae relative to their parental populations.…”

“…Therefore, in order to assess the dispersal of crustacean larvae over periods of days to weeks we must either find natural tags that are conserved throughout planktonic development or resort to a high frequency characterization of nearshore plankton distribution and circulation patterns (e.g. Natunewicz et al 2001, Arnold et al 2005.…”

In situ hybridization on whole larvae: a novel method for monitoring bivalve larvae

“…In situ hybridization on whole larvae could be used in multidisciplinary studies, providing new insights into population connectivity over a range of scales (e.g. Gilg & Hilbish 2003, Arnold et al 2005. The method can be easily implemented in any biological laboratory; it does not need costly equipment or consumables and does not require staff to go through advanced specific training.…”

The Lobster Node of the CFRN: co-constructed and collaborative research on productivity, stock structure, and connectivity in the American lobster (Homarus americanus)

“…First, the quality of the settlement predictions made by the biophysical model of larval dispersal should be evaluated to assess the model's usefulness and guide research for its improvement. Whereas similar models have been used to study larval dispersal in numerous species of invertebrates (Arnold et al 2005;White et al 2010;Jolly et al 2014;Jorde et al 2015) and fishes (Koeck et al 2015), the spatiotemporal settlement patterns they predict have been rigorously validated in only a few studies (Bolle et al 2009;Kough et al 2013;Koeck et al 2015). Second, research should be done to assess the usefulness of further parameterizing the dispersal model on the basis of vertical and horizontal larval swimming behaviour (e.g., Stanley et al 2016) and settlement decisions (e.g., substrate and thermal effects).…”