9420.pdf

4.4 Herring Processing
4.4.1 General
The main product of herring processing in the B.C. Lower Mainland is cured herring roe.
However some processing of herring caught in the fall does occur. Due to the relatively
short fishing season and the necessity for freezing herring to preserve fish shape and
quality of the roe, herring processing is divided into two distinct phases:
● Vessel unloading and freezing, and,
. Thawing, roe “popping”, and roe processing.
These phases take place at different times. The fish processing operations that occur
during the individual phases are described in detail in the following sections.
4.4.2 Freezing
Herring are delivered to the fish
of fishing boats and fish packer
processors suspended in chilled seawater in the holds
vessels. Vessel unloading is done with wet pumps, as
described in Section 4.1. Intermediate storage of the herring may be required, as the
capacity of the vessel unloading pumps may exceed the throughput of subsequent
handling steps.
Freezing generally takes place in brine freezing channels which contain a saturated
sodium chloride solution at -180 C followed by tunnel” freezing to rapidly freeze the
individual fish.
Herring sex sorters are available to separate male from female herring. The use of such
sorters results in reduced water consumption and wastewater contaminant loadings, and
reduces Iabour requirements for subsequent handling steps, as all male fish would be
sent to a reduction plant rather than
belly slitting - see Section 4.4.3).
immediately after vessel unloading.
undergo additional handling (washing, freezing, and
Ideally, sex sorting of herring should take place
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