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Hello! My name is Richard Hartland, I am currently working on a Master’s degree in marine environmental science at Nova Southeastern University. I am a part of Dr. Tammy Frank’s Deep-Sea Biology laboratory. My thesis is focused on performing a taxonomic and distributional appraisal of the deep-pelagic shrimp genera Sergia and Sergestes of the northern Gulf of Mexico, in the area where the Deepwater Horizon oil spill occurred in 2010. The shrimp I study are important members of the oceanic community, both as consumers of zooplankton and as prey for higher trophic levels (e.g., tunas, mackerel, oceanic dolphins).
Left: Sergestes corniculum. Right: Sergia splendens. Images courtesy of T. Frank.
I will be examining the abundance (how many) and biomass (how much they weigh) of the shrimps in the Gulf, and whether or not these values have changed over the years, starting in 2011 (six months after the oil spill) and continuing from 2015, through 2016, and into 2017. The boxplot below shows changes in the patterns of abundance for the most abundant species, Sergia splendens. These data seem to show a sharp decrease in abundance between 2011 and 2015, while slowly increasing in the years to follow.
Boxplot of Sergia splendens abundance from 2011 through 2017.
What we are seeing is a reduction in the number of individuals caught from 2011 and 2015, then we see an apparent increase from 2015 to 2016 and into 2017. Although there appears to be a dramatic drop in the abundance from 2011 to 2015, we cannot state that this is due only to the oil spill in 2010, as there are many other reasons the numbers could be different. What we should do is continue to sample in the same areas and monitor how the population changes over time. I am also looking into how these shrimp move up and down the water column during daylight and nighttime hours. This daily vertical migration is one of the many ways that deep-sea organisms are important components of oceanic ecosystems – this movement takes carbon from the near surface (in the form of their food) and transports it deep into the ocean, thus helping mitigate the increases in atmospheric carbon due to the burning of fossil fuels.
Hello Everyone! My name is Devan Nichols, and I am a master’s student at Nova Southeastern University working in Dr. Tamara Frank’s deep-sea biology laboratory. Our lab specializes in deep-sea crustaceans (aka shrimp!) and my thesis focuses on a particular family of deep sea shrimp known as Oplophoridae. As we all know, shrimp are fairly small organisms in the grand scheme of creatures that live in the deep sea, so why is it important that we study them? Great question! The deep-sea shrimp that I study range in size from 2-20 cm in length. Organisms this small, are perfect prey for larger animals such as deep-sea fish, squid and marine mammals. This means that Oplophoridae make up the base of the food chain, and act as primary producers for many organisms that are higher in the food chain. When the base of the food chain is impacted, even in a small way, it can throw off the balance of an entire ecosystem. These little guys are important!
Two species of Oplophoridae; Systellaspis debils (left) and Notostomus gibbosus (right). Images courtesy of DEEPEND/Dante Fenolio 2016.
Very little is known about the effects of oil spills on the deep sea. When people think of oil spills what usually comes to mind are the impacts it has on the ocean surface. When these disasters occur, the deep sea is not often thought of. It is kind of an out of sight out of mind situation. The Deepwater Horizon oil Spill (DWHOS) occurred in the Gulf of Mexico on April 20th 2010 releasing an estimated 1,000 barrels of oil per day for a total of 87 days into the Gulf. This oil was released from a wellhead located approximately 1,500 m deep.
My thesis is unique in that I have the opportunity to examine data collected one year after the oil spill (2011) and compare it to data collected five, (2015) six (2016) and seven (2017) years after the Deepwater Horizon oil spill. I am looking particularly at oplophorid assemblages. This means that I am looking at how the numbers of shrimp may have changed (abundance) and how the weight of shrimp may have changed (biomass) over these sampling years. The boxplot shown below, shows the patterns that I am seeing so far in oplophorid abundance as time goes by. These data seem to show a sharp decrease in abundance in 2011 to subsequent years.
Boxplot of oplophorid abundances during the four sampling years.
Although we cannot attribute any of these changes to the oil spill directly because we do not have a baseline (data from the area collected before the spill), we can still monitor how this oplophorid assemblage has changed over time, and use this information as a baseline to monitor future changes in the Gulf of Mexico. Along with assemblage changes, my thesis will also provide information on whether or not certain species are seasonal reproducers, and if the presence of the Loop Current has any significant effect on oplophorid ecology. The deep sea is a mysterious place, and scientists still have a lot to learn about its complexity and the organisms found there. The picture below shows the net we use to catch these deep sea shrimp, and some of the equipment we use to lower the net into the deep sea!
A 10-m2 MOCNESS net being towed behind the RV Point Sur during a DEEPEND cruise.
Another day at sea – one of our last for this cruise.
My name is Laura Timm and I am a PhD student at Florida International University. This is my fourth DEEPEND cruise and the data we collect from it will contribute to the last chapter of my dissertation.
I work on crustacean genetics. Specifically, I use the DNA of a few shrimp species to describe diversity and characterize how (or if) it is moving within the Gulf. These two things, diversity and gene flow, provide a lot of insight into the health and resilience of these target species. Most of my work with DEEPEND has focused on three shrimp: Acanthephyra purpurea is a bright red color and produces a bioluminescent spew to scare off predators.
Systellaspis debilis is also red (though younger ones can look orange), but with tiny light-producing organs called photophores polka-dotting its body.
Sergia robusta can be dark red or even purple and has photophores around its mouth and tail.
To me, all three are uniquely beautiful.
My research focuses on questions related to genetic diversity, which is a good metric for species health. Where is the most diversity found? Has this changed since 2011? How is diversity distributed? Is some genetic diversity unique to certain places? Answers to these questions provide unprecedented insight into how the Gulf copes with disturbances.
Now, a little perspective.
We trawl with a MOC10 net. It is very large. Every person on the ship could go stand in the frame of the net. However, when compared to the size of the ocean, it is tiny – it has been described as the equivalent of investigating terrestrial diversity using just a butterfly net. Yet, we still catch thousands of shrimp. Of these thousands of shrimp, a few hundred are targeted (A. purpurea, S. debilis, S. robusta). Of these hundreds, 96 are sequenced (this is due to the sequencing process; I can only sequence 96 at a time). The genomes of these species have not been sequenced, so I target a few thousand base pairs of DNA. A few thousand base pairs out of billions of base pairs. About 100 shrimp out of hundreds, hundreds out of thousands, thousands out of every shrimp in the Gulf. This tiny amount of data (which, in the history of science, is unprecedentedly large) can tell us so much about the animals living in the Gulf and how they came to be there and whether they are likely to survive whatever comes next.
The Sargassum Triggerfish (Xanthichthys ringens)
A larval flatfish (Bothus sp.)
I Love me some squid (Abralia redfieldi)
Female anglerfish, larvae (Linophrynidae). Still has her jelly coat.
Leptocephalus (eel larvae)..and a cool species at that - the False Moray(Kaupichthys hyoproroides).
Happiness is shooting anglerfishes day in and day out. This is an odd one (Oneirodes carlsbergi). A close up of the esca (lure) is in the upper corner. The lure glows and attracts prey items. Only females grow to this size and have lures.
Another (Centrophryne spinulosa). Close op of the esca to the upper left....
Crazy weather this morning....this right next to the ship.
The life and death of a waterspout.
Although the weather was crazy it didn't' stop us from pulling up some really cool animals like this larval shrimp.
And this Dragonfish (Photostomias guernei).
And this Joubin's squid (Joubiniteuthis portieri)
A fish I have wanted to see for years (Inops murrayi). This deep water species is usually found between 1,460m and 3,500m. This is a juvenile we caught in the water column. Instead of functional eyes, what remains of photoreceptive tissue lies beneath bone in this species. The "eyes" have no lenses but can detect light.
We also captured a beautiful shrimp today. She is "in berry" or brooding eggs beneath her tail. The inset to the top left depicts the eggs beneath her tail. I am holding her to show size.