I am currently conducting researches on the flyingfish roe fishery in Taiwan. This is a very unique fishery as it targets on the egg instead of the adult fish (i.e., essentially, no fishery for the adults). Fishers collected eggs using straw mats deployed on the sea surface. We could calculate CPUE based on the catch (in terms of weight) and effort (in terms of vessel number, or no. of straw mat deployed) data of the fishery. After several years of data collection, we could now understand the resource trend based on a standarized CPUE series calculated from fishery operational (such as vessel size, targeting vs. non-targeting ..etc) and environmental data (such as SST, rainfall..etc). However, we also wish to know the possible sustainable yield of the fishery. Thus, we tried to use the CPUE and the data to estimate the MSY for the fishery, but such an approach may violate assumptions of the model as “egg” does not grow, and have a surplus production. An alternative way is to convert egg caught (in terms of weight) to the biomass of the spawner (as the reproductive biology and the sex ratio of the species are available), and then estimate the MSY of the stock.

I wondering whether such an alternative approach is appropriate and valid for this purpose, and/or whether there are any other better approaches can be used to estimate the possible sustainable yield of the fishery?

Any of your suggestions will be greatly appreciated.