Last night, I headed down to the beautiful Bell House, in the Gowanus section of Brooklyn, for this month's Secret Science Club lecture featuring Dr Mercer Brugler of CUNY's City Tech and the American Museum of Natural History. Dr Brugler is a marine biologist, deep-sea adventurer, and activist helping to get women and minority students involved in the sciences.
Dr Brugler opened his talk with a couple of photographs- beginning with a nice shot of a newly discovered genus and species of low-light coral, following this up with a photograph of a whale turd which had attracted the attention of some hungry sea cucumbers. The bottom of the food pyramid of the sea consists of light-dependent phytoplankton, many of the denizens of the deep sea rely on biological material 'raining down' from the upper levels of the ocean.
The focus of the talk then quickly shifted to coral, which are Cnidarians. The Cnidaria are approximately six-hundred million years old. A coral colony can be likened to a ton of 'mouths' (polyps) that secrete a skeleton and clone themselves. A coral colony is composed of genetically identical individuals. Each individual polyp can be likened to an 'upside-down jellyfish (the technical term for a jellyfish is medusa)'. Cnidarians are two cell layers thick, with a goo called mesoglea filling the space between the layers, and have a two-way digestive system, spitting out undigested material from their 'mouths'. Coral polyps reproduce asexually and the colony secretes a calcium carbonate skeleton over which the polyps can grow. The polyps are connected by a layer of tissue known as a coenosarc. Coral colonies can reach an age of four thousand years. Like all Cnidarians, corals have stinging structures known as nematocysts, which have barbed 'harpoons' which inject venom- Dr Brugler quipped that the venoms are of various toxicity levels- this determines whether or not one has to go to the hospital. Coral colonies shed mucus, which is being studied to determine if it has cancer-fighting or antibiotic properties. Corals that dwell in shallow regions have photosynthetic dinoflagellate symbionts called zooxanthellae. When coral bleaching occurs, the beneficial zooxanthellae die off, stressing the coral.
Corals are divided into subclasses- the 8-tentacled octocorallia, the 6-tentacled hexacorallia, and the tube-dwelling ceriantharia. Among the octocorallia is Corallium rubrum- Dr Brugler ruefully noted that his mother likes coral jewelry, made out of the skeletons of dead animals. Also among the octocorallia is the blue coral. The hexacorralia includes the reef-building stony corals (Scleractinia) and the sea anemones.
Certain corals thrive in extreme environments, such as the vicinity of hydrothermal vents and cold seeps and under polar ice. The black or thorny corals are deep-dwelling hexacorallia with protein based skeletons. Among the black corals are the wire corals, which through convergent evolution resemble the octocorallia sea whips. Dr Brugler displayed a succession of slides which beautifully illustrated the variety of coral forms- branches, fronds, feathers, bushes, spines... He recounted the DNA sequencing of the genus Bathypathes and noted that DNA plus environment equals morphology.
The topic then slightly shifted to Australia's Great Barrier Reef, the largest structure of biological origin on Earth. As large as it is, the Great Barrier Reef is succumbing to bleaching.
Dr Brugler then completely changed direction, turning his attention to the deep sea. Sunlight can penetrate seawater to a depth of 200 meters (this sunlit area is the photic zone). Below 200 meters, photosynthesis cannot occur, the water is cold (typically -2 to 4 degrees Celsius), and the pressure is extreme- for every ten meters one submerges, the pressure increases one atmosphere. There is little food in the deeps- the dead bodies of phytoplankton rain down from the shallow waters to the bottom- this detritus is known as 'marine snow'. Among the pictures Dr Brugler displayed of deep-sea life was a time-lapse sequence of amphipods Hirondellea gigas swarming over a feast of dead fish. Despite Edward Forbes' belief in an Azoic region of barren sea beds, there is life in the deep sea. Dr Brugler jokingly described the deep seas as 'Dr Seuss Land'- the sort of biome which houses ten foot-tall corkscrews.
The next topic of the lecture was the means by which humans explore the depths. Dr Brugler began with a question, "Should we phase out human occupied vehicles like Alvin?" Human-occupied vehicles cost about $45,000 per day to operate, while remote-operated vehicles cost $4,000-$11,000 per day to operate. ROVs can stay down longer and collect more specimens. The deepest region of the ocean, the Marianas Trench reaches a depth of perhaps eleven-thousand meters at its deepest area, the Challenger Deep. Seventy-percent of the Earth's surface is covered by the oceans, sixty-five percent by the deep seas- the deep ocean is Earth's largest environment. Dr Brugler gave us a quick overview of the bottom topography of the oceans- the continental shelves border the continents, then the continental slope reaches a depth of about two-hundred meters. Beyond the continental slope, the seabed abounds in trenches, canyons, seamounts, and spreading areas.
In 1934, William Beebe and Otis Barton descended to a depth of more than 900 meters in a bathysphere until the water pressure caused the airhose to collapse, necessitating a hasty retreat to the surface. In 1960, the crew of the bathyscaphe Trieste descended to a depth of about nine-thousand meters when their plexiglass window cracked, necessitating a hasty retreat to the surface (I sense a trend here).
Dr Brugler then described shipping out on the icebreaker Nathaniel B. Palmer to the Drake Passage between southern South America and Antarctica in order to obtain deep sea specimens- only one sample had been obtained in the region by Russian scientists. Dr Brugler described the area, with its strong currents and multiple seamounts as the 'washing machine of the ocean'. He noted that if one were to fall overboard into the cold waters of the 'Passage, one would die in five minutes, which basically translates into 'you die'. The seas are high, with rogue waves of ten meters in height. Ice chunks in the water can snap chains meant to secure equipment on deck. Deckhands have to work in rotating teams, because frostbite can set in in five minutes. The water freezes into pancake ice, then can form small icebergs. Dr Brugler recounted tales of cetaceans following the icebreaker while 'pterodactyl-like' wandering albatrosses fly overhead. On the pack ice, clueless chinstrap penguins try to flee the unfamiliar humans, and are set into a panic by two stupid individuals which attempt to 'toboggan' on their bellies... uphill.
Despite the difficulties, there are rewards- the team obtained some deep sea glass sponges- Euplectella aspergillum, known as the Venus' flower basket because each sponge houses a mated pair of shrimp.
In the depths of the ocean, hydrothermal vents provide homes for such creatures as the newly-discovered Relicanthus daphneae, a hexacorallian which, through convergent evolution, appears like a giant (meter wide polyp, three meter tentacles) sea anemone... DNA sequencing indicated that this organism doesn't place with other anemones. Other hydrothermal vents seem to be monospecific environments, housing only crabs, only anemones, or only basket sponges.
Dr Brugler then introduced the audience to Alvin, a famed submersible paired with the research vessel Atlantis. He gave us a stem-to-stern description of the submersible- the outside houses electrical equipment, batteries, cameras; the crew compartment is a six-foot diameter sphere which is designed to accommodate three persons (the good doctor is 6'4", so he's a bit cramped)- one driver and two observers. Also inside the sphere are twelve oxygen tanks and two carbon dioxide scrubbers. There's no heater, and the sphere gets cold, so the crew members need to pack a bag of extra clothes. Crew members cannot wear metal accoutrements- while titanium is strong, it is soft, and scratches are a no-no. The Alvin was recently overhauled, and now has five cameras to replace the original three cameras. Additional portholes were added to the sphere, and it is more ergonomically friendly. Often paired with Alvin is the Autonomous Underwater Vehicle Sentry- Dr Brugler joked that Sentry 'mows the lawn', taking photos and scouting out the scene before Alvin goes down. Dr Brugler treated us to lovely images of the New England and Corner Rise Seamounts (PDF), chains of seamounts characterized by numerous canyons. A ferromanganese(Fe-Mn) crust overlays a basalt substrate, and corals thrive on it. Dr Brugler cited the work of the University of Rhode Island's Inner Space Center in deep sea exploration.
We were then given a quick 'tour' of the seabed- seamounts are undersea mountains of volcanic origin, the mid-ocean ridges are areas of increased water flow beneficial to life, methane seeps give off plumes of methane which feed communities of micro-organisms, deep sea brine pools are hypersaline pools on the seabed which are denser that surrounding waters- they even have their own 'waves' as they interact with surrounding waters. In 1977, hydrothermal vents were discovered along the Galápagos Rift, home to giant tube worms with bright-red hemoglobin-rich plumes (most worms use copper-based hemocyanin for oxygen transport). Also found near the vents were large mussels and snot-like bacterial mats. Certain bacteria are methane-fixing. Among the chordates thriving in the deep are the sharklike chimaerae.
Dr Brugler then introduced us to a dazzling array of Remote Operated Vehicles- the Pisces IV and V, the Herculesand Argus. Dr Brugler noted that if any audience members liked playing on the XBOX, they should become ROV operators so they could explore the Manning Seamount. Dr Brugler then noted that deep sea exploration is hit-or-miss. Sometimes, hours are spent looking for something, but nothing is found... at a cost of $45,000. Conversely, sometimes a crew will discover a wealth of information.
All the while, Dr Brugler was showing slides of the gorgeous organisms found in the depths, such as the 'bubblegum coral', Paragorgia arborea, which can attain lengths of six meters, and the black coral Leiopathes, which grows micrometers per year, but which can attain 4,265 years of age. While deep sea corals do not form large reefs, the coral Lophelia pertusa forms deep-water reefs off the coast of Ireland and Florida. The big reefs are in the shallows, Dr Brugler noted, but there are singletons in the deep sea. Sea spiders, pycnogonids, feed on corals with a proboscis. Seastars often feed on fallen coral, but avoid the upright corals. Taller corals provide access to greater water flow for worms, crabs, and brittle stars. Some of the larger polychaete worms can attain lengths in excess of a meter. Other organisms lay egg masses on corals- recently, eggs of the Dumbo octopus were found on a coral- one egg hatched in captivity, but the low-pressure conditions led to the death of the octopus shortly after hatching.
Dr Brugler stressed the importance of public outreach- black corals are harvested for jewelry and illegally traded. It is difficult to identify black corals... the Department of Justice collaborates with the Smithsonian and the U.S. Fish and Wildlife Sevices, confiscating suspected corals and having them identify biological materials. Dr Brugler recounted having a couple of Feds oversee him while he was attempting to identify a coral item. He displayed a picture of a gaudy bauble made of gold, red coral, and black pearl. One a more hopeful note, deep sea bamboo corals can possibly be used as living bone implants. The Revlon cosmetics company uses an extract from the 'sea whip' Pseudopterogorgia elisabethae in makeup for its anti-inflammatory properties.
Dr Brugler then discussed the effects of global warming and ocean acidification on corals- certain corals, exposed to conditions of high acidity, can stop forming skeletons and take on the appearance of sea anemones (a topic also addressed in Dr David Gruber's July 2014 SSC lecture). Will our kids have coral reefs? When the pH is moved by a factor of .3, the corals adapt to take on their anemone-like forms, the current shift in pH is .1. When acidification ceases, the corals resume forming skeletons.
Dr Brugler then touched on the topic of genome sequencing. He noted that the genetics of leeches are being studied in order to determine medicinal uses for leech anticoagulants (one cannot work in the Department of Invertebrate Biology at AMNH without dealing with the Leech Guy). The DNA sequence of bedbugs is being determined in order to develop better pesticides. DNA sequencing is becoming faster and cheaper, DNA sequencing equipment is getting smaller, and sequencing can be done in real time in the field.
Dr Brugler left off the lecture with a quote from author C.P. Idyll: "It was once considered absurd to expect life to exist in the deep sea- cold, perpetually dark, and subject to crushing pressures."
The lecture was followed with a Q&A session, as always. One individual in the audience asked about the evolution of deep sea corals- it is generally thought that shallow corals invaded the deep sea, rather than vice-versa. Another individual asked about the mechanisms by which animals survive when the pickings are so slim in the deeps- Dr Brugler suggested lipid storage as the best mechanism for long-term survival. Some bastard in the audience asked if different hydrothermal vent communities were compared genetically with each other- how much connectivity is there in the deep sea. Dr Brugler likened hydrothermal vents to evolutionary stepping stones- rich oases of life, but noted that corals evolve very slowly, their changes in DNA tend to occur one-hundred times slower than typical invertebrates (chalk a lot of that up to asexual reproduction). Asked what he wants most to know, Dr Brugler stated that he wants to know what is in the deep trenches (some bastard in the audience, perhaps fed up with this year's presidential election, joked that maybe Cthulhu could be found). When asked about the Hudson Canyon, Dr Brugler expressed a hope that there would be a DIY ROV movement, with hobbyists building there own submersibles to explore the waters around NYC- he noted that this would be a great way to monitor invasive species. When asked what the greatest threat to the oceans was, Dr Brugler stated unequivocally that it was carbon dioxide emissions.
After the Q&A session, Dr Brugler gave a coda to his lecture, describing his roundabout route to his doctorate. As a child in Texas, he was introduced to SCUBA diving by his father, but his diving was limited to lakes with low visibility. He attended University of Miami, Florida as an undergrad and applied to a masters program at the University of Charleston, where he was accepted by mistake. After an initial confusion about his status, he was told to sequence the DNA of black coral, and things smoothed out for him... because of this unorthodox start, he decided that his life goal (which is totally awesome) would be to ensure that no high school or college student who want for experience to pursue the goal of studying what they want to.
This particular lecture hit what I've come to call the 'Secret Science Sweet Spot'- it was a great blend of hard science, adventure narrative, gorgeous visuals, and advocacy. Put succinctly, Dr Brugler hit it out of the park. Kudos to Dr Brugler, Margaret and Dorian, and the staff of the beautiful Bell House. High fives all around.
After the lecture, I had the pleasure of meeting Dr Brugler and two of his grad students, both young women of Latin heritage. The good doctor takes his goal of STEM diversity seriously. Also in the audience was SSC lecturer Dr Simon Garnier, who has been a regular audience member. One of the other regulars outed me as a blogger... it's kinda odd to come out and tell people you're a blogger, and I'm not big on self-promotion. He read my recap of his lecture and didn't hit me with a shoe afterward. Sorry, Monsieur Docteur, I should have told you earlier... Dr Frans De Waal sussed me out on his own. Dr Garnier was accompanied by a couple of his grad students- as a big nerd, I have to say that it's a lot of fun to be able to geek out on Atta in a bar, and to hear anecdotes about one's homework being eaten by army ants. Good times! This is what the Secret Science Club is all about.