Currently the size of the Foveaux Strait oyster population is influenced more by disease mortality (specifically, the parasite Bonamia exitiosa) than by fishing.

 

Here we update the previous oyster stock assessment from 2017, by adding the most recent data from the catch history, catch-per-unit-effort, commercial catch sampling, and estimates of population sizes for three difference sizes of oysters.

 

The first innovation we introduce is to model disease in more detail, by keeping track of the numbers of diseased oysters, newly deceased oysters and older deceased oysters.

 

The second innovation is to simulate disease mortality five years into the future, based on the disease events seen in the past.

 

It is estimated that the current (2023) population size for the base case is approximately 940 million oysters, which is 32.6% of the virgin biomass (maximum population size).

 

It appears from the data that we entered another disease mortality event in 2023.

 

The abundance in 2028 is predicted to be around 31% of the virgin biomass for the base case, with the alternative models giving similar abundances.

Document date
Thursday, 27 June 2024

Document type
V 1.3

File format
Adobe PDF

File size
10.7 MB

Reference number
2024/27

Sort order

FAR: 2024/27;
AUTHOR: Doonan, I.J.; Datta, S.; Michael, K.P.;
ISSN: 1179-5352;
ISBN: 978-1-991285-88-1;

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