- Animals: Oysters
- Animal Production: animal protection and health, aquaculture, genetics
- Farm Business Management: risk management
The Ostreid Herpesvirus is a highly lethal virus and is the most imminent threat to the survival of the U.S.
Shellfish industry. One variant (OsHV-1µVar) of this virus has devastated Pacific Oyster culture
industries in Australia, Europe and New Zealand. Other commercial species of bivalves are vulnerable in
varying degrees. The U.S. variant OSHV-1 is so far only present in Tomales Bay (CA) and adjacent areas
but is only slightly less damaging. Up to 90% of juvenile oysters can be lost each year and cumulative
losses can be up to 35%. Although research is being conducted to develop OsHV-1 resistant strains, this
research is slow and takes at least 2-3 generations to develop partial resistance and potentially millions of
dollars. The three oyster companies involved in this proposal (Goosepoint Oyster Co., Hog Island Oyster
Co. and the Willapa Bay Fish and Oyster Co.) propose to test a more rapid screening method to determine
whether individual oyster broodstock possess some degree of resistance and thus can begin to form the
basis of broodstock pools to be used in an emergency situation if the virus spreads outside of Tomales
Bay. The Hog Island Oyster Co. can make immediate use of this since they have considerable losses
annually due to this disease. This method is based on using individual pair spawns, cryopreservation of
sperm and the warm Hawai`i conditions to reduce generation time. Progeny oysters will be out planted in
Tomales Bay to expose them to the virus. Oysters retained at the Hawaii hatcheries from cohorts which
have better survival in the field can then be used to begin breeding to reinforce the resistant traits. Thus,
developing resistant Pacific Oysters for commercial production can be jump started ahead of an
emergency, rather than waiting 8-10 for more traditional approaches to succeed.
Project objectives from proposal:
The overall of objective is to test a new, rapid and less costly screening method to assess the
degree of disease resistance in individual broodstock oysters. These individual oysters will form
the core of a new breeding population which could essentially save the industry if a disease
outbreak occurs. We view this as an urgent and emergency measure.
Objective 1: Use individual pair spawns to produce a limited number of families to be screened
for disease resistance to OsHV-1 at Tomales Bay, CA. The parents (F0) of progeny (F1) that
show any degree of resistance will then be used in a variety of crosses to reinforce resistance.
Objective 2: Continue to develop cryogenic methods as an additional and valuable tool for
selective breeding and other uses, both practical and for research