Project Kingfish uses a range of state-of-the-art approaches including biochemical analyses, satellite tracking technology and computer modelling, to produce novel scientific information that will help inform the status of the ‘Eastern Australia’ biological population.
Tracking technology has been successfully used on a plethora of marine animals to gain a deeper understanding of their natural behaviours and effectively inform management and conservation strategies. The small satellite transmitters (weighing only 57 grams in air) are deployed on spawning-sized kingfish for a pre-programmed amount of time (up to ~12months), collecting data on their location, swimming depth, ambient sea temperature and overall activity every second.
When the tag releases from the fish, it floats to the surface and begins transmitting the stored information to satellites. The light-level data stored by the tag are then used to estimate the daily position of the fish and generate movement tracks, whilst the temperature and depth profile summaries generated each day provide crucial insights into its habitat preferences.
In addition, the research team uses other approaches such as otolith biochemistry to gain insights into optimal spawning sea temperatures for east Australian kingfish. Otoliths, the ear bones of fish, grow incrementally as fish get older. As they grow, they store a record of the environmental conditions for each year of the fish’s life.
Using oxygen stable isotopes, we can ‘zap’ the core of the otolith to determine at which sea temperature a fish was spawned. This information will help us refine our models to identify suitable spawning habitats for kingfish off east Australia, and predict subsequent larval recruitment to the coast.
As the effects of climate change and ocean warming keep driving marine species to move south, including kingfish, projects such as Project Kingfish will help produce a new baseline upon which future changes can be identified, and will help gain the insights required to predict future changes in the availability of this species along Australian shores.