Download Oyster Hatchery Manual

7) When the sieve begins to fill up and flow rate through it slows down, the sieve can be sharply
smacked with a short piece of PVC pipe and it will “unclog”. As clogging becomes more
frequent (usually only a problem for smaller sieve sizes) exchange with the alternate sieve.
8) Wash the larvae on the sieve using a gentle stream of filtered sea water from the supply hose
or use a spray bottle. While washing them direct the larvae toward one side of the sieve.
9) Move the sieve over the graduated harvest bucket and invert. Backwash the larvae from the
sieve into the harvest bucket. Put an air stone into the harvest bucket to keep collected larvae
suspended and aerated.
10) Repeat steps 5-7 until the tank is completely drained.
11) Unless larvae are close to setting do not wash contents from the tank bottom into the sieve.
The bottom sediments contain accumulated waste and dead larvae, which can be discarded.
12) After harvesting larvae, count them and enter on tank record sheet.
13) When a new tank is ready follow the protocol for restocking larvae.
Note: Larvae in early stages appear pink in color and collect in one area of the sieve, algal
particles and other debris appear brown or green and stay suspended in the sieve while larvae
generally sink.