Ichthyoplankton Sampling After All Bankwide Stations Are Occupied

  1. After all bankwide stations have been occupied, estimate the numbers of hours remaining until the ship returns to port. Subtract from this the time required to return to a station of high or, preferably, highest abundance and running time from there to port.
  2. If 12 or more hours of work time remain after these subtractions, then return to the high abundance station and make a bongo tow, following previously described protocol. Immediately examine the net's contents to determine weather the patch of larvae has again been located; if not see items #6- 9.
  3. If larvae of the targeted species are abundant(>3), continue immediately with a CTD cast and MOC-1 tow following previously described CTD and MOC-1 ichthyoplankton protocols.
  4. Run the computer program LATLONG for coordinates of additional stations to occupy, their priority and gear to set. Occupy as many of the stations as time allows.
  5. If larvae of the target species are not abundant, at the first revisited station, consult with a physical oceanographer to evaluate lapsed time, weather conditions and larval drift since the initial encounter. On the basis of this evaluation, determine where to locate the next station. Continue the search until the patch of larvae is relocated.
  6. When relocated, follow steps 1 through 5 above.
  7. If a concentration (e.g..>10) of the targeted larvae is not encountered at any of the bankwide stations on cruises in peak occurrence months of March, April or May, consult with NEFSC ichthyoplankton personnel to determine search area. These search areas are based on historical MARMAP data plotted on a navigational chart.
  8. Select the appropriate area based on month of ongoing survey. If larvae are found, conduct sampling operations as described in 1 through 5 above.
Feb. 2, 1995