Project: Spawning During Storms and the Subsequent Dispersal and Settlement of Coastal Invertebrate Larvae

The study will address four questions concerning invertebrate spawning on the US West Coast: 1) Which nearshore benthic invertebrates spawn during winter? 2) What conditions are associated with spawning events? (Preliminary data lead the PIs to predict that most spawning will occur during periods of large waves and coastal downwelling.) 3) What is the pattern of dispersal of these winter-spawned larvae in the coastal ocean? 4) How do variations in ocean conditions during pelagic development affect delivery of larvae to the shore?

Water will be sampled daily from the seawater intake for the Oregon Institute of Marine Biology marine laboratory in Coos Bay, OR. Water is pumped at high tide when the intake samples coastal ocean water. Early larval stages will be identified by genetic barcoding and a visual ID key will be developed from individuals raised in the lab. Time series analysis will be used to test for the effects of oceanographic parameters (e.g., temperature, salinity, Chl-a, wind stress, and wave data) on spawning events indicated by the sudden appearance of zygotes or embryos. Following a spawning event, oceanographic cruises in the coastal ocean will follow the dispersal and pelagic development of the larvae and relate their distribution to coastal hydrodynamics. Using daily samples from the seawater system and settlement collectors at intertidal sample sites, the PIs will monitor the abundance of late stage larvae in the near-shore and settlement in the intertidal zone. These time series will be compared to hydrographic parameters to identify conditions favoring the maintenance of larvae in the waters adjacent to the coast and the delivery of larvae to the shore.