Tuna, Tuna, Tuna, Everywhere! Nina Pruzinsky

Hi everyone!

My name is Nina Pruzinsky. I am a graduate research assistant in Dr. Tracey Sutton’s Oceanic Ecology Lab at Nova Southeastern University. I defended my master’s thesis on the “Identification and spatiotemporal dynamics of tuna (Family: Scombridae; Tribe: Thunnini) early life stages in the oceanic Gulf of Mexico” in May and will continue working in Dr. Sutton’s lab post-graduation. In my thesis, I determined characteristics that differentiate juvenile tuna species, which have been previously poorly described, and then mapped the distributions of the most abundant species (little tunny, blackfin tuna, frigate tuna, and skipjack tuna) collected in the Gulf of Mexico from 2010-2011 and 2015-2017.

Photo:  Nina with a juvenile little tunny

With that being said, this is my first DEEPEND cruise! I am ecstatic to be a part of the team that is out surveying the Gulf’s deep pelagic ecosystem. I have worked with these specimens in the lab for the past two and a half years, and it is incredible to see the specimens when they first come up in the nets! The different coloration patterns and photophores of these deep-sea fish are amazing to see!  On this DEEPEND cruise, I am working as the database manager and work alongside Natalie Slayden. Our job is to back process the fish specimens identified by taxonomists Drs. Tracey Sutton and Jon Moore. Check out Natalie’s blog below to learn more about our jobs at sea.

In regards to my research, I am continuing to sample the larval and juvenile tuna in the Gulf of Mexico. Scombrid counts on this cruise exceed all other DEEPEND cruises thus far! On this cruise, we have collected various scombrid species and life stages.  The majority of our catch has consisted of larval and juvenile little tunny. Due to the collaboration with C-Image III, we have also fished/caught adult tunas as well. As Heather mentioned, we are collected tissue samples of these adults for C-Image III and for stable isotope analyses conducted by Travis Richards.

Photo:  Mixed larval tuna species (mostly little tunny)

We have collected larval and juvenile frigate and bullet tuna. At the juvenile stage, these two species cannot be differentiated; thus, we are running genetic analyses to determine which species this specimen is (see picture below).  Additionally, we found a skipjack tuna in the stomach of one of the adult little tunny that Max Weber caught on the cruise! The MOCNESS also collected a larval skipjack as well. We also caught an adult bonito, and Gray Lawson, our MOCNESS operator, caught an adult yellowfin tuna. It is exciting to see the diversity of tuna species collected this trip!

  Photos:  Max and Nina with a little tunny; Bottom photo:  Gray with a yellowfin tuna

As I spent the majority of my thesis surveying larval and juvenile tunas, this cruise was the first time I saw adult tunas. We had several schools circling the boat, which was very exciting!! Hoping for more tuna sightings and catches as the cruise continues! J