I am delighted to announce that my seven(!) year research study on the migratory behaviours of deep-sea demersal fishes has been published this week with the Journal of Animal Ecology. This study has been 10 years in the making, and represents the efforts of an international collaboration between multiple research institutes, BP, BP Angola and Sonangol.
This study was the original topic for my PhD, and developed into a really interesting piece of work, in which we were able to identify seasonally-recurring patterns in the abundance of fishes living at the seafloor at 1400 m depth on the Angolan continental slope, which are significantly correlated with seasonal patterns of primary productivity in the overlying surface ocean.
It's well known that fish living in the water column conduct daily migrations from deep waters to the surface ocean to feed and reproduce, but this is the first time that anyone has demonstrated recurrent, seasonal patterns like this in the fishes living at the seafloor, and we believe that these migrations could be really important in stabilising deep-sea ecosystems. It also highlights just how connected the deep oceans are to the surface ocean - essentially, what happens at the surface (e.g., impacts from climate change) will propagate down into the deep sea. The effects of this aren't well understood yet, and definitely represents an area where we need to do more work. We're also not sure where the fish are moving to and from on this seasonal cycle, but we do know that it must represent a behavioural choice, because the changes occur too quickly for them to be related to population processes (e.g., recruitment or death). We definitely have a lot more work to do to to understand the ecology of deep-living fishes, and we're excited to keep studying them in the Seascape Ecology lab at NSU!
The paper is open-access, and you read it here: https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2656.13215