Calibrating Video Survey Data in an Era of Evolving Technology

The rapid pace at which camera technology changes presents a unique challenge when utilizing video to assess changes in fish distribution and abundance over time and space (e.g., in fishery-independent surveys). While traditional survey gears (e.g., trawls, hooks, traps) often change minimally over multiple decades, it is not uncommon for specific camera models to be improved or be discontinued within a few years after becoming commercially available. Given the importance of maintaining a continuous time series to the utility of survey data for stock assessment purposes, it is critical that fisheries scientists are able to generate a coherent data set while navigating frequent changes in survey equipment. The authors conducted two video gear comparison experiments focusing on reef fish populations in the southeastern US Atlantic, with the goal of calibrating video index data across multiple changes in camera gear. The results of these experiments are presented as a case study in how to approach the issue of data continuity.