During
the DEEP ROVER submersible dives from KAHAROA my job as a fisheries biologist
is to help identify the species we see filmed on the video screen. My specialty
area is research on deepwater fish species and so I'm particularly interested
in identifying and observing fish from 600-900 meters.
While the main aim of the survey is to try to locate and film the giant squid, I am really excited to have the opportunity to view the species we film during the search. I have been working in this field for several years, and to be able to see the fish in their natural habitat and not as lifeless forms on the deck will be fantastic. Normally, by the time some deepwater species have been caught in the net and hauled up onto the deck, their eyes are very bulbous, their stomachs often everted, and with their swim bladder over inflated, their bodies can be unnatural looking. Colours too are different between the surface and at 800 meters.
What
will be particularly interesting will be seeing the deepwater fish orange roughy
- my specialist species. This species is bright orange coloured, but camouflaged
and hard to see in the dark deep ocean. Also, to see the lantern fish with their
illuminated photophores and other fish with luminescent lures, to observe species
in their own environment with fins and tail functioning and their bodies oriented
as we can only guess, and the benefits to observe feeding behavior and prey
items, will be fantastic. The
other aspects of the project provide an interesting experience. Seeing how the
submersible operates and how the filming is carried out both from the submersible
and on board KAHAROA with the BBC team, has made the days spent at sea this
week very worthwhile.
Most
of my work has been on deepsea fishing trawlers and on our NIWA research vessel
TANGAROA.
We carry out trawl and acoustic surveys to measure the size of the fish stocks,
and we make biological measurements on the fish - length, sex, reproductive
state, and feeding. This new area of science that I am experiencing with international
teams is quite a different opportunity.
Di Tracey
National Institute
of Atmospheric and Water Research (NIWA)