Greetings, fellow deep-sea enthusiasts! I'm Pedro A. Peres, a postdoc at Florida International University, and I'm back with my second post on the blog. Today, I want to talk about an exciting new technique that is revolutionizing the way we study deep-sea environments: environmental DNA (eDNA).

Traditionally, to analyze the DNA of marine animals, we would collect and extract tissue samples directly from the animal. But what if we could get DNA samples without even seeing or sampling the animal? This is where eDNA comes in. Every living creature in nature releases DNA molecules in the environment through various means like skin, mucus, feces, and more. Scientists have discovered that we can extract and sequence these DNA fragments to detect specific species or assess community composition, all without ever having to interact with the animals directly.

In DEEPEND|RESTORE, Dr. Bracken-Grissom and I are working with Jonah Ventures (ww.jonahventures.com) to use this amazing technique focusing on deep-sea environments. The main challenge is that eDNA is a relatively new method but even newer for deep-sea environments. Many of the references available investigate freshwater or shallow waters, which have different features than the deep sea. This means that replicating their sampling method might not be ideal for the deep sea. For instance, animals in the deep sea are more spread out than in other environments, so should we filter more water to have a fair representation of the community we are investigating? Can we use acoustics to guide where to fire the CTD to collect water? And many other questions that we are thrilled to investigate!

On this cruise, PhD candidate Stormie Collins is in charge of filtering the water, preserving the filters, and logging the CTD data so we can analyze everything later. She and I assembled a cool eDNA setup provided by Jonah Ventures, and Dr. Kevin Boswell and PhD student Haley Glasmann are helping with the CTD. Teamwork! I’m excited to see our findings and what eDNA can reveal to us about deep waters.

Hi everyone!  DEEPEND science is so exciting that even the whales are following us!  Just wanted to share that some of our team were lucky enough to catch a glimpse of an Orca today!  Even though it was a bit far from the vessel, a few pictures and video were captured.

As rare as they are to see out here, it is thought that there are some resident Orcas that live here in the Gulf of Mexico.  

We will be keeping our eyes open when we are out on deck as the sea state is perfect for more whale sightings!

               Hi! My name is Stormie Collins, and I am a PhD candidate at Florida International University. I have been involved in processing samples collected from DEEPEND|RESTORE cruises since 2019, however, this is my first time getting to go to sea with the group! I am largely interested in the way that organisms perceive the world around them, and the associated adaptations they have evolved to survive within their environment. In the deep-sea, many organisms utilize bioluminescence; a process through which a chemical reaction produces light. My dissertation focuses on vision and bioluminescence in deep-sea shrimps. Being able to see the animals freshly collected allows me to observe color as they are in life and provides a better opportunity to consider bioluminescence across species as many light organs become invisible after animals are placed in preservative. 

               Shrimps can be bioluminescent through dermal light organs called photophores, internal photophores that arise as a modification of the hepatopancreas, or through a luminous secretion, which may also be referred to as “spew”. Among decapod shrimps, luminous secretions are most common, and many species use this as a defense mechanism to evade approaching predators. Dermal photophores are embedded within the cuticle and are obvious. Internal photophores are obvious in sergestid shrimp (see below), however, they are also present in other shrimps, where they are much easier to overlook, particularly in red pigmented shrimps. The caridean shrimp Plesionika richardi is documented to have internal photophores, however, they have never been previously observed in this species by our team. Upon collection of 2 P. richardi, observation of internal photophores were indeed confirmed (see below), and when looking for them, are obvious. It is likely that this has been overlooked as the red pigmentation sort of masks the internal organs and they are no longer visible in preserved material.

               The most up-to-date count of bioluminescence depicts 94 independent origins across the tree of life, making this perhaps the most common form of communication on the planet. Though our current understanding of bioluminescence in shrimps with both dermal and internal photophores suggest they are used for counterillumination camouflage, I believe that the functional role of bioluminescence should be considered separately for each species. The presence of internal photophores in P. richardi provide an excellent example of how underestimated and overlooked bioluminescence may be in decapod shrimps, as well as many other marine organisms.

P.s.- the view from the ship is NOT too shabby ?

Hi everyone! My name is Natalie Howard and I’m a master’s student in Dr. Jon Moore’s lab at Florida Atlantic University’s Harbor Branch Oceanographic Institute. This is my first time participating in one of the DEEPEND/RESTORE cruises and I am very excited to be here! I was introduced to the project while pursuing my undergraduate degree at the University of South Florida. While I was there, I helped Dr. Heather Judkins with pteropod data, and she introduced me to Dr. Jon Moore, where I now work with fish collected from the cruises.

This is an image of Melamphaes suborbitalis. It’s one of the larger Melamphaes, with an average standard length that’s over 90 mm! It also has a small spine on the top of its head, which is a distinguishing trait of this species.

My thesis project is focused on vertical migration and diversity of Melamphaes (Melamphaidae). The Melamphaes fish we find in the Gulf of Mexico are relatively small, averaging between 20- and 30-mm standard length and are dark brown in color. These fish reside in the meso- and bathypelagic zones during the day but will migrate into shallower waters at night to feed and avoid predation. This behavior is referred to as diel vertical migration, which I will be investigating as part of my research project. There have also been many recent taxonomic revisions of the family Melamphaidae, so I’m hoping that we find one of the newly identified species on DP09! 

Yes, you guessed it!  It’s time for another DEEPEND cruise in the Gulf of Mexico!  Vans are loaded and being driven to Gulfport, MS, gear is packed. scientists are scrambling to make sure we have everything we need, and everyone is traveling in the next day or two to arrive in Gulfport for another successful adventure.

Our current plan includes loading all the gear onto the R/V Point Sur on Monday and depart from Gulfport, MS at midnight.  We will be heading to our usual stations for collecting samples from 0-1500 m deep using the MOC10 net system once again.  This will be our 9^th DEEPEND cruise and the 3^rd as part of the NOAA RESTORE program which concludes next year.  We are very excited to keep this long-term survey going as we still know so very little about the deep ocean we are exploring.

We will be posting blogs along our journey once we get underway so stay tuned!