Deep Sea Biology

HMS Challenger

Beginning of modern oceanography(Institutional, collaborative, multidisciplinary) C. WyvilleThomson - Expedition leader+ 4 naturalists (Murray, Buchanan, von Willimoes-Suhm, Moseley) + 1 artist (Wild)•3.5 years•68,890 nautical miles •362 stations•40% time spent in ports Departed Portsmouth - 21 Dec. 1872South to Madeira, St. Thomas, Bermuda, Halifax, Azores, Cape Town, Kerguelen to Antarctic pack ice, Melbourne, Fiji, Hong Kong. Philippines, Japan, Hawaii, Tahiti, Valparaiso, Falkland Islands.Arrived Portsmouth - 24 May 1876 "A corvette" •Dredging equipment•Winch•Dredging platform•Accumulators (safety springs)•Beam trawl

Bias

distance of an estimated parameter or value from the actual value or true parameter (skewed data)

Plankton (GENERAL)

pelagic organisms that don't have the swimming power to fight the direction of currents, but may have some swimming capabilities within their local space - microbes, small zooplankton invertebrates & fishes, larger gelatinous animals like jellyfishes

Deep Sea Biology

•Eric Mills - Problems in Deep-Sea Biology: an historical perspective (In: The Sea, Vo. 8 - the deep -sea edited by G. Rowe - 1983) - book on reserve •To n y K o s l o w - Chapter 1 in The Silent Deep. "The rise of deep-sea Exploration: Early paradigms" pp 8-22 Chapter 2. "On the shoulders of giants: The Challenger Expedition"pp. 23-39.

Primordial Ooze

•Ernst Haeckel had proposed that life came from a primordial slime he called Urschliem•In 1868 Huxley had found gelatinous matter -which he called Bathybiushaeckelii- proposed it formed a living sheet over much of the ocean and provided food source for higher organisms•Huxley thought he had found the missing link between inorganic matter and life•What he actually found was a chemical precipitation of a gypsum jelly formed when seawater is mixed with alcohol (as a preservative for the sample)•This error was corrected in 1876

Paradox of the plankton

•First proposed in 1961 by ecologist G. Evelyn Hutchinson•Extraordinarily high diversity of phytoplankton and zooplankton•Ecological theory would suggest few dominant species in a uniform environment•Why is plankton so diverse?•Hutchinson thought gradients in light, constantly changing environment, & selective predation night be answer •Recent papers suggest chaotic ever-changing environment prevents any particular species from dominating•Fluid flow, selective grazing/predation, patchiness of resources in both space and time, and environmental fluctuations

WW1-WW2

•From 1910 until after WWII - de-emphasis of deep-sea research•More emphasis on coastal fisheries problems and plankton dynamics•Woods Hole Oceanographic Institute (WHOI) started in 1930•Initially did a lot of exploration with sailing vessel Atlantis Iin Atlantic, Caribbean and East Pacific coast of Mexico and US•Worked for US Navy in WWII•Discovered Deep Scattering Layer (DSL) that obscured sonar from finding submarines

Wavelength use of light

•Function of latitude, season and time of day•When sun is high (45-90°), only 2-3% reflected and lost•When sun is low (<20°) or seas are rough, 13-100% reflected•In tropics, angle is good year round•In temperate zones, angle low in winter•Near poles, angle so low nearly dark all winter•Ice also drops penetration of light

Valdivia Expedition

•German national Deep-Sea Expedition•Carl Chun expedition leader•European and African coasts to Antarctica, Indian Ocean, Red Sea, Suez Canal, Mediterranean Sea to Hamburg•Opening/closing nets revealed extensive deepwaterpelagic fauna to 2000 m depth, below which fauna became sparse

Symbiodiniaceae

•These dinoflagellates usually live as symbionts in corals, foraminifera, giant clams, etc.•Can be expelled into the water when those host animals are undergoing bleaching•Also can be partially expelled during spawning to provide symbionts to fertilized eggs and young

Cyanobacteria

•Too small for nets, collected in water samples and filtered or centrifuged out•Known as blue-green algae because have blue accessory pigment - phycocyanin•Some also have red accessory pigment -phycoerythrin•Abundant in tropics•Red Sea gets its name from blooms of species with red accessory pigment•Ancient prokaryote group - stromatolites from 3.5 BYA

ROV System

•Typically a two-vehicle system•Camera sled attached to ship by hard wire with open core for electronics cables•Flexible cable attaching camera sled to ROV•Flexible cable length determines the radius of movement for ROV•Drifting of ship above can pull ROV off site, best if ship has dynamic positioning thrusters that can keep ship on station

Coccolithophores

•Unicellular eukaryotes•Covered with series of calcium carbonate plates•These plates have accumulated to form chalk deposits•Usually spherical, some with flagellum•Complex life cycle with several stages•Most abundant in warm waters

Biases in Data

- all data collecting methods will selectively sample a particular portion of a community or species or segment of the population -no one method catches all life stages of all species in numbers proportional to the actual population in the wild- susceptibility to capture can be affected by size, sex, behavior, season, etc.- can be good if that is our target (don't get many non-target organisms); can be bad if we want to sample those organisms that are being missed In any sampling program, it is good to know what potential biases you are facing in data collection given the: 1. Timeframe of your data collection period (what season, day vs. night, etc.)2. Type of gear used (wide mesh nets do not generally capture small baby animals, baited hooks rarely catch herbivorous fishes or detritus feeders, etc.)3. Location of sampling (adult areas vs. nursery grounds, etc.)If we know the approximate biases in our sampling methods, we can adjust for it, but unknown biases may lead to incorrect interpretation of study results

Earth/Ocean percentage

-71% covered in Ocean -99% of living volume of space on planet -5% of ocean explored by humans -85% is dark cold deep sea -63% of the surface area for life and ~90% of the volume of the biosphere

Scanning comparisons: Moon/Mars/Ocean

-Mars: 100 m (330 ft) over 60% of Mars in certain areas 20 m (66 ft) -Moon: 7 m (23f ft) -Ocean: 5000 m (16404 ftor 3.1 miles)

A magazine once said

..we know more about the moon's behind than the ocean's bottom..."

Theories solved by Challenger

1. Azoic Theory disproved. Animals present throughout the deep sea to 5500 m, one sample at 7000 m Japan Trench2. Huxley's Bathybius- (artifact of preservation) addition of alcohol to seawater caused precipitation of gypsum 3. No living fossils - no trilobites or belemnites [extinct cephalopods] Rather deep fauna evolved from continental shelf and slope forms relatively recently - with onset of glaciation in Cenozoic4. No large, cosmopolitan deep-sea species, but genera widely distributed (5-7% at high and low latitudes, 3-4% had bipolar distributions). 1 species in common between Pacific and Atlantic at mid equatorial latitudes

Primary Production

1. Production-- the amount of carbon fixed into biomass per time 2. Primary productivity- rate of formation of organic compounds from inorganic materials; carbon fixed per unit area (or volume) per time 3. Gross production-- total amount of fixed carbon4. Net production-- gross production minus respiration by the phytoplankton themselves -- amount of fixed carbon available to other trophic levels (used to make biomass) 5. Photic zone -surface region where light is sufficient for photosynthesis

Production

1. Production-- the amount of carbon fixed into biomass per time 2. Primary productivity- rate of formation of organic compounds from inorganic materials; carbon fixed per unit area (or volume) per time 3. Gross production-- total amount of fixed carbon4. Net production-- gross production minus respiration by the phytoplankton themselves -- amount of fixed carbon available to other trophic levels (used to make biomass) 5. Photic zone -surface region where light is sufficient for photosynthesis

Post WW2

1. Swedish Deep-Sea Expedition(1947-1948)•Circumnavigation in Albatross Expedition•Seismic studies, piston coring, bottom water sampling•Only last 3 months devoted to deep-sea benthic trawling •Benthic trawling in Puerto Rican Trench - to 7900 m - deepest trawl in N. Atlantic

Challenger exoedition pt 2

1.Animals collected throughout the ocean to 5500 m depth2.Many deep-sea species of many taxa, high proportion of rare species, many with direct development3.Decreasing abundance and diversity with depth - generated paradigm of the Depauperate Deep. 4.Different taxa in deep than shallow water (zonation)5.Stability of deep-sea environment (temperature, chemical composition, lack of seasonal changes)6.Constant seawater constituent ratios7.Deep-sea sediments (calcareous, siliceous oozes) of pelagic origin (foraminifera, radiolarians, coccolithophores, pteropods, diatoms, etc.)8.Red clay of terrestrial origin in central oceans, manganese nodules rich in metals9.Description of water masses based on T and S10.Description of shelf, continental slope and rise

Beginning of Deep Sea exploration

1.John Ross- (1818 - 1819) Baffin Bay, Canada - deep sea 'clamm' - 4 samples from 850 to 2000 m [crustaceans, corals, shellfish, worms, basket star from 1600 m)In searching the NW Passage 2. James Clark Ross(1841-1847)Tasman Sea/Antarctic - fauna to 750 mNoted similarity with high latitude fauna and concluded uniform cold temperature at seafloor.3. Harry Goodsir- (1845)Davis Strait (between Canada and Greenland) -fauna dredged to 550 m

French Expeditions

1.Travailleur- (1880) -Bay of Biscay 2.Talisman - (1888-1927) - E. Atlantic, Mediterranean•Distinctive deep-water ichthyofauna, withvertical migrators•Distinctive abyssal molluscan fauna originating at high latitudes•Homogeneity of deepwaterfauna across the Atlantic•Ancient annelids are widespread, modern ones are not

Modern Dives

1949: there were less than 100 oceanographers in the USA1959: Oceanography budget 21 million1969: Oceanography budget 221 million. In those 10 years: 20 new vessels and 8 new laboratoriesAmerican non-expedition studies (1960's)- Strong financial support from U.S. government- Establishment of Gay Head Bermuda transect (55 to 5000 m depth) - Howard Sanders and Bob Hesslerin 1965- Anchor dredge, epibenthic sled, finer sieves- Higher abundance, greater species diversity- Alvin sub launched in 1964 for WHOI and Navy to do deep dives

Danish Expedition

Anton Bruun- expedition leader•1st thorough study of abyss & hadal zones•1st microbiology in the deep sea•1st quantitative abyssal samples (grab)•Trawled to 10,190 m in Philippine Trench (sea anemones, amphipods, isopods, bivalves, holothurians) •Trawled in five trenches recovering 115 species > 6000m depth - found a distinct hadal fauna•Isolation of barophilic bacteria from deep-sea (Zobelland Morita, 1959)•First use of 14C to estimate primary productivity (SteemanNielsen 1952)

False Hypothesis

Azoic Hypothesis(Forbes 1859)•Because of his work in Aegean Sea, the thought life absent > 550 m (300 fathoms)•Deep sea is •Dark•Cold•High Pressure•Stagnant and anoxic

HMS Lightening, HMS Porcupine

Carpenter and Thomson

PlanktonGroups

Common NameBlue -green algae (cyanobacteria & prochlorophytes)Green algaeCoccolithophoridsDinoflagellatesDiatoms

Galithea Expedition (2006-2007)

Danish

Thalassophobia

Fear of the Ocean: People have feared the ocean for thousands of years Deep sea myths A lot of our phrases for deteriorating mental health are described as "being down", "hitting rock bottom", or our "deepest, darkest fears"

HMS Porcupine

First ship specifically equipped for oceanographic studies in deep water (first fully organized oceanographic expedition)Carpenter and Thomson - chief scientistsWest of Ireland - dredged to 2700 mSouth of England/France - to 4450 mMediterranean Sea w of SpainRecovered all major groups (mollusks, crustaceans, echinoderms, sponges, stalked crinoids, banks of Lopheliapertusa, primitive urchins - Living fossils1st use of protected thermometerLed to hypothesis of density-driven, deep-water circulation

Pre WW1

Michael Sars cruise (1910) •a European collaboration •John Murray (Great Britain) and Johan Hjort(Norway) -worked in N.E. Atlantic•Extensive pelagic trawling, minimal benthic trawling (5160 m)•Further speculation on sources of nutrition for deep sea-phytoplankton - zooplankton - detritus-dissolved organic matter•Influential text on oceanography (Murray and Hjort, 1912 -The Depths of the Ocean)

Challenger Expedition

Objectives - To map:1. Global patterns of deep-water circulation2. Chemistry of world's oceans3. Geology of the deep-sea floor4. Distribution/abundance/origin of deep -sea organismsDetermine: chemical composition of seawater, physical conditions of the deep sea, characteristics of sediment deposits, distribution of organic life

Who question Azoic Theory

Otto Torell (1861 -1865)•Benthic fauna at 2560m off Spitzbergen Michael Sars and G.O. Sars (1864 -1868)•Dredging to 550 m in Norwegian fjords•427 species of invertebrates including asteroids and crinoids (connections to fossil record)Led to the idea of deep sea a refuge for extinct faunas. L.F. de Portales & L. Agassiz (1867-1868)Dredged fauna off Grand Bahama Bank to 1555 m depth W.B. Carpenter & C. WyvilleThomsonH.M.S. Lightning (1868)Dredged fauna to 1189 m N.E. AtlanticDeep water temperatures low (0 - 8.5oC)

Cold War Era

Russian deep-sea expeditions in 1950s and early 1960sVityaz- extensive grab sampling to determine benthic biomass in deep basins and trenches of Atlantic, Pacific and Indian Oceans (Zenkevitch, 1963; Belyaev, 1972)Emphasis on feeding ecology and biotic surveys

Challenger Results

Scientific results published in 50 volumes with final summary by John Murray in 1895- 13 years after WyvilleThomson's death29,500 pages 3,000 platesSamples were distributed to experts globallya. high species diversity in deep-seab. common taxa in high latitudesc. greater depth ranges for deeper species, sharper zonation in shallow waterd. endemism common in deep watere. first proof of deepwaterplankton (between 915 and 1830 m depth)f. Discovery of mid Atlantic Ridge

Before Exploration

Socrates (600 BC):The beginning of wisdom is to know that one knows nothingAristotle (300 BC):The ocean (deep sea) is a frontier to be explored [lists 180 spp. recorded from the Aegean Sea]Pliny (50 BC): The deep sea is an inferior world. All we know of it is all there is to be known.Posidonius(1 BC)Mediterranean Sea is 2000 m deep.

Nekton

free-swimming pelagic animals that can move against currents - marine mammals, fishes, squid, some larger crustaceans

Benthopelagic

organisms generally associated with the bottom, but also known to swim in the water column up to 100 m over the bottom (sometimes more)

Pelagic

organisms living in the open water, generally away from the bottom, for either a portion of their lives or for their entire lives

Benthic

organisms living on or in the ocean bottom

Plankton

organisms with limited locomotion that are at the mercy of the prevailing water movement (e.g., currents, waves, wind)

Environmental Conditions

•Temperature - it's cold •Pressure - increases with depth •Light - decreases with depth •Oxygen - decreases at mesopelagic depths •Substrate - mostly mud, limited rock •Currents - generally slow •Food supply - comes from above

Food

• Almost all the primary production is up in the epipelagic• Food in the form of detritus, dead bodies, fecal pellets, marine snow, exoskeleton molts, etc. all rain down• Variable in time and space (e.g., more abundant during plankton blooms)• Seasonal variation•Seasonality in productivity, migration patterns, storms, etc.•May produce seasonal patterns in biological processes (e.g., behavior, feeding, metabolism, reproduction, recruitment)• Episodic large inputs may introduce variability on other time and space scales - big food falls could persist for years

Light

• Decreases with depth• Epipelagic, a.k.aphotic zone, enough light for photosynthesis • Mesopelagic, a.k.a. dysphoticzone, dim light, only a few low -light adapted photosynthesizersin the upper mesopelagic depths (red and green algae on mesophotic reefs at 200-350 m) • Bathypelagic and deeper, a.k.a. aphotic zone, no light from sun and surface, but some light from bioluminescent organisms • Affects development of eyes and increased reliance on other sensory systems in many deep species below 1500 m

Large Scale Currents

• Driven by thermohaline circulation• Sea ice formation makes very salty, very cold water that flows along the bottom to deeper abyssal areas• That becomes deep water masses that are the lowest layer in the ocean (e.g., Antarctic Bottom Water, North Atlantic Deep Water)• Slightly less saltier and less cold water becomes intermediate water masses (e.g., Antarctic Intermediate Water, North Atlantic Intermediate Water)• Mediterranean Intermediate Water is extra salty and dense because of evaporation, but it is not as cold as the other intermediate waters• Generally really slow -Mean speeds typically <5 cm/s (0.1 mph) with peaks less than 20 cm/s (0.4 mph) in most areas

Temperature exceptions

• Exceptions •Deep Mediterranean is ~13 oC •Red Sea can be 21.5 oC @ 2000 m depth •Weddell Sea can be -1.9 oC (this is the freezing point of full salinity seawater) •Hydrothermal vent effluent can approach 400 oC with a rapid decline in temps away from the vent

Substrate

• Most of deep sea floor covered by sediments•Margins - Coarser terrigenous sediments (pebbles, sands, silts, and mud)•Basins - Biogenic oozes (>30% biogenic skeletal material) and/or terrigenous clays (below CCD at ~4000 m)•Biogenic oozes - made of plankton skeletons•Siliceous oozes - diatoms (high latitudes) or radiolarians (tropics)•Calcareous oozes - foraminiferans, cocolithophores, pteropod shells (below productive areas)• Low organic content (typically <1%)• Exposed hard substrate is uncommon•Rocks (glacial dropstones, lava flows, seamount volcanoes, canyon walls), polymetallic nodules, biogenic material (coral skeletons, clam shells, worm reefs, old calcareous algal reefs), shipwrecks, trash

Smaller Scale currents

• Obstructions like ridges and seamounts or even large rocks can generate swifter currents > 90 cm/s (2 mph)• Can see scour marks downstream of rocks and ridges• Filter feeders concentrate in places where swift currents bring food faster• Periodically, certain areas experience benthic storms• They disturb the sediment & redistribute both it & small burrowing animals• Bigger storms typically last days to weeks• Smaller storms may act like dust devils and dissipate in minutes• All these currents are source of temporal and spatial variability in sediments and biota

Temperature of deep sea

• Thermocline is transition from warmer surface waters to colder deep-sea waters • Deep sea is cold -typically -1 to 4 oC (so from the temperature of the inside of your fridge to just below freezing)

Proof against false hypothesis

•Attacked by G.C. Wallich•1860 - 13 starfish recovered from a sounding line at 1260 fathoms (2300 m) in the N. Atlantic off Greenland•1861 - Allman and Milne Edwards -15 species recovered from a broken telegraph cable in the Mediterranean between Sardinia and N. Africa at 2300 m including stony coralYet the azoic paradigm persisted John Jeffreys (1861 - 1868)Shetland Island dredging to 311 m found 204 species

Deepwater Horizon(BP Oil Spill)

•BP oil well blowout in Gulf of Mexico in 2010•210 million gallons of crude oil spilled, possibly more•Spurred huge cleanup and research response to study the impacts•Wellhead was at 1500 m depth, so it was a deep-sea event•Impacts of oil at surface was widely distributed in deepResearch sub Alvinat a deep coral site near the BP wel

Benthic Traps

•Baited traps and pots•Biases: only animals attracted to bait, able to enter trap, and contained within mesh size of trap•Good for: capturing mobile fauna that may be attracted to bait

Benthic Infauna

•Box cores, multicorers, grabs, suction sampler•Biases: only capture animals small enough to fit inside grab or core, some species may escape before sample is taken, patchiness of species means some species could be missed in sample, lack of replicates (except with multicorer)•Good for quantitative analysis of faunal diversity in the patch sampled

ROV or SUB collecting

•Can collect samples using manipulator arm •Then put the specimen into a "biobox" (a cooler-like box with lid to protect the specimens•What specimens you can collect depend on the size and capacity of the biobox•Bioboxesare frequently not subdivided, so you shouldn't mix multiple items of the same species from different sites, unless you have a way to distinguish the specimens

USS Albatross

•Designed for scientific research for the US Fish Commission and launched in 1882•Spent first few years doing fishery surveys in Canada, Bahamas, Gulf of Mexico•1888 moved to Pacific coast of US, Canada, and Mexico•1890 went to many Pacific islands (Fiji, Marshalls, Society, Cook, Carolines, Marquesas) before arriving in Japan and did studies of fishery resources in Japan and off Kamchatka Peninsula, Russia•1904 went to Peru, Panama, Galapagos•1906 to Commander Islands off Kamchatka, Japan, Korea•1907-1910 to Hawaii, Midway, Guam, and Philippines

Trieste

•Don Walsh & Jacques Picard rode this bathyscaphe down to the deepest portion of the Mariana Trench (10,916 m)•Little maneuverability, basically a self-contained elevator

Benthic Trawls

•Dredges, Beam & Otter Trawls, Sledges•Biases: catch fewer burrowing animals, body size based on net opening and mesh size•Good for: biodiversity surveys of invertebrates on or just below surface of bottom

Vertical temperatures

•Temperature is typically fairly even in mixed layer of epipelagic •Transition of thermocline often starts around that 200 m depth and declines quickly through the mesopelagic layer

Pelagic Nets

•Gill nets, trammel (tangle) nets, IKMT and other midwater trawls, demersal trawls that are open mouth up and down, opening/closing nets (MOCNESS)•Biases: body size based on opening size, mesh size, and speed of towing, soft-bodies animals tend to get smushed, very small animals not caught•Good for: fast swimming organisms, larger-bodied animals •MOCNESS - multiple opening-closing net with environmental sensor system•A trigger causes the top bar of the open net to drop down closing that nest and simultaneously opening the next net above•The MOC in the diagram above has its last net open as does the photo below (that net is about to be closed and the whole frame brought on board)•Each net can sample a different depth zone High-speed rope trawl - a midwater net with doors that hydrodynamically hold the mount of the net open

Beginning of Big Science

•Government funding•Networking•Politicking•Manipulating/inspiring the public's imagination

Phytoplankton in marine system

•Great phylogenetic diversity•Photosynthetic -chlorophyll ais common to all, many other accessory pigments•Some partially heterotrophic•Can be unicellular or in colonies; simple in structure•Most species are eukaryotic, except for cyanobacteria and prochlorophytes•Small size and rapid reproduction•If conditions are right, they can grow rapidly and develop a bloom Restricted to the euphotic zone where light is available for photosynthesisPhytoplankton blooms:• High nutrients - needed for reproduction• Upwelling - one way of getting nutrients• Seasonal conditions -winter accumulation of nutrients from nearby land and spring bloom when waters warm enough for reproduction •Phytoplankton trap the greatest proportion of sun's energy•Base of nearly all marine food webs•For long time, scientists thought all photosynthesis was by larger microplankton (diatoms and dinoflagellates) - called net plankton•This was because the plankton nets they used had relatively large mesh and missed all the smaller size groups

liFE HISTORY of plankton

•Holoplankton-- spend their entire life cycle in the plankton •Meroplankton-- spend a part of their lives in the plankton

Benthic Storms

•In places where strong currents occur at the surface, they can spin off strong eddies that become benthic storms•Off New England & Mid-Atlantic, benthic storms form as cyclones spinning off the underside of the Gulf Stream

Pressure

•Increases predictably by 1 atmosphere (14.7 psi) every 10 m •Mean depth of oceans is 3800 m = 5600 psi (381 atm) •Many deep-sea fishes (>400-500 m depth) lose their gas-filled swim bladders or fill them with oils, waxes, or fats •Affects biological molecules - membranes, enzymes in very deep fishes (>2000 m) •Many enzymes change their shape under high hydrostatic pressure, can lose conformation shape to what they are supposed to bind to •Cell membranes are stiffened with cholesterol molecules, but under high hydrostatic pressure and low temps, cell membranes become too stiff

Other Countries in Ocean Exploration

•Italian circumnavigation by the Vetter Pisani (1882-1885) •Chierchiaand Palumbo using a crude opening-closing net discovered deep-water plankton (i.e. siphonophores) to 2300 m depth. •Carl Chun, inspired by these Italian studies, sampled off Naples finding a rich pelagic fauna exists to 1400 m depth - hypothesized a "ladder of vertical migrations" (Chun, 1887)

DSV2 Alvin

•Launched in 1964 for WHOI and Navy to do deep dives•Self-propelled with thrusters, battery powered•Discovered the first hydrothermal vents on the East Pacific Rise in 1977•Has gone through various upgrades and reconfigurations since the 1960s, one piece of the original sub still is used (a small step outside the entry hatch, you touch it for good luck)Alvin in late 1960sAlvin in 2003

Pelagic Hook And Line

•Long -lines•Biases: selects only carnivores, choice of bait may limit species caught, size of hook limits size of individuals caught•Good for: larger predators •Rod & reel•Biases: selects only carnivores, choice of bait may limit species caught, size of hook limits size of individuals caught, needs electric reel and huge amount of line to get below 660 ft, predators may eat catch as it is being hauled up•Good for: IGFA world records

Dinoflagellates

•Many are photosynthetic, some heterotrophs•Dominant in tropics and subtropics•Flagellated -have two unequal flagella in grooves •Some are armored -- have cellulose plates •Usually solitary, only few form chains •Some species bioluminesce Some produce toxins and are responsible for toxic red tides•saxitoxinsparalytic shellfish poisoning (PSP) •brevitoxinsneurotoxic shellfish poisoning (NSP)•okadaic aciddiarrheal shellfish poisoning•ciguatoxinsciguatera fish poisoning

Oxygen

•Near saturation and not limiting in most of the deep sea •Exceptions: Oxygen Minimum Zone (OMZ) and certain enclosed basins (Santa Barbara Basin, CariacoBasin, Black Sea) •OMZ and anoxic basins may act as barriers

WyvilleThompson and William Carpenter

•North of Scotland between Shetlands and Faroes•Dredged 10 days out of 6 weeks at sea! •Dredged down to 1180 m•Abundant life everywhere, saw several relict species•Brisingidstarfishes, Hexactinellid sponges•Arctic outflows and NA Deep Water (0oC) separated by a ridge from warmer (6.4oC) Gulf-Stream-influenced Atlantic waters •Fauna varied with water temperature

Subdivisions of the Pelagic Realm

•Open waters of ocean are subdivided •Epipelagic is upper 200 m •Mesopelagic from 200-1000 m •Bathypelagic from 1000-4000 m •Abyssopelagic from 4000-6000 m •Hadalpelagic in the trenches below 6000 m •Benthopelagic is animals that swim over the ocean bottom, generally within 100 m of the bottom

Why 200 m depth?

•Photosynthesis greatly reduced •Thermocline •Continental shelf edge

Photosynthesis and light

•Photosynthesis only possible above threshold intensity•Amount of light is result of many features:•Meteorological - clouds•Surface reflection•Latitude and season •Transparency of water•Absorption of light by water•Scattering by particles•Wavelength of light •Function of latitude, season and time of day•When sun is high (45-90°), only 2-3% reflected and lost•When sun is low (<20°) or seas are rough, 13-100% reflected•In tropics, angle is good year round•In temperate zones, angle low in winter•Near poles, angle so low nearly dark all winter•Ice also drops penetration of light

Thermohaline Circulation

•There is a gradual thermohaline circulation to even the deepest parts of the sea, bringing life-giving oxygen •To sink all of this way the oxygen-rich surface water must become very dense (cold and salty)

Pelagic Plankton

•Plankton nets, plankton pumps•Biases: mesh size of net or screen, volume of water sieved, agility of plankton to avoid intake, flow rate of intake, damages fragile gelatinous plankton•Good for: can collect larger zooplankton species •Double MOC 1 m2plankton nets on a towed metal frame (left)•Plankton MOC nets attached to sub for collection at very deep depths (right) •Plankton scanners•Biases: resolution of the scanner, algorithm for species identification•Good for: scanning and counting individuals, fragile gelatinous plankton also counted in some scanners •Sediment traps•Biases: collect material drifting down from surface, mouth size of funnel limits size of particles collected•Good for: examining marine snow, detritus, dust and other material coming from surface

Autonomous Underwater Vehicle

•Programable robot subs that can be sent out to do tasks on their own

How do we map the bottom of the Ocean?

•Satellite sea surface maps•These can resolve objects at least 5 km across •Ship sends a fan-like array of sonar pings out and records the echoes•Maps the depth of a wide swath of the bottom•To get complete coverage of an area, you typically do side-by-side swaths, called "mowing the lawn"•Mapping the bottom topography can be very helpful in deciding on sites for your investigation

Prince of Monaco

•Series of cruises on Hirondelle, Princess Alice, Princess Alice II, between 1885 and 1914•Technological advances using wire, steam winches, large closing trawls, baited traps to abyssal depths•Areas of study - N.E. Atlantic, Mediterranean•Circulation of N. Atlantic studied with drifters•Sardine fishery off N. Spain, marine mammals•Successful trawling to 6035 m off Cape Verde (deepest until 1947)•Confirmed vertical migrations by deep pelagic fauna•Used baited traps - confirmed existence of scavengers at depth (lysiannasidamphipod 14 cm long)•Once worked a 120 h continuous station at 5940 m off Portugal •Significantly advanced technology to study deep-sea communities•Migrating bathypelagic fauna exists supporting Chun's "ladder of migrations" hypothesis concerning transport of food to deep ocean•Unique combination of creativity and financial independence•Established Oceanographic Institute of Monaco and it's museum

Benthi Artificial Substrate

•Settlement plates, basalt blocks•Chemistry of substrate may encourage or dissuade some species from settling, when and for how long deployed may determine what settles, long deployment may go through succession of species settling•Good for: counts of juvenile animals settling out during the time of deployment

Multibeam Sonar

•Ship sends a fan-like array of sonar pings out and records the echoes•Maps the depth of a wide swath of the bottom•To get complete coverage of an area, you typically do side-by-side swaths, called "mowing the lawn"•Mapping the bottom topography can be very helpful in deciding on sites for your investigation

Diatoms

•Siliceous shell (like glass; SiO2) called a frustuleresembles a Petri dish with a top and bottom each half is a valveor theca•No flagellae or cilia•Dominant in temperateto polar waters•Diatom frustules sink to the bottom sediments and make an ooze known as diatomaceous earth (used in filters and abrasives) •2 main forms - centric are radially symmetrical and often round; pennate are elongate and bilaterally symmetrical•Some can form long chains of cells•Can reproduce several times per day•Some make domoic acid, an amino acid toxin that causes amnesic shellfish poisoning (ASP)

Other plantkton

•Silicoflagellates - skeleton of small silica scales, abundant in Antarctica•Cryptomonads -abundant in estuaries•Unicellular chlorophytes (green algae) - in estuaries and lagoons, bloom due to coastal pollution

Prochlorophytes

•Similar to cyanobacteria, but use chlorophyll a & b and lack phycobilin accessory pigments•Thylakoids are stacked•Hugely abundant, 106cells/ml•So small they were overlooked until florescence studies of water samples•Typically in lower photic zone•Thought to produce 33-80% of all marine photosynthesis

Pelagic Device for Soft Bodies

•Slurp gun•Biases: only things that fit in mouth of gun, water current when slurping could still damage fragile organisms•Good for: small fishes and mobile invertebrates •Rotary-Actuated Dodecahedron (RAD) Sampler•Biases: only organisms that fit inside dodec, only organisms not startled by closing dodec- slower swimmers•Good for: fragile gelatinous plankton and nekton

Pelagic Acoustic Survey

•Sonar echo-sounder•Biases: density discontinuity needed to create echo, species recognition from sonar echo is limited•Good for: estimating biomass and movements, different frequencies locate different organisms •Hydrophone listening to calls•Biases: species recognition of calls heard, only record when species makes call•Good for: surveys of species with known calls, also unknown calls indicate hidden diversity, can be done continuously

Alexander Aggassiz

•Steamer Blake in Gulf of Mexico and Caribbean•Replacement of hemp with wire rope (less deck volume, more efficient handling)•Abundant fauna dredged to 3567 m depth•Existence of midwater plankton•Reiterated question of food supply to deep sea -sinking of plankton, role of terrestrial debris

Deepsea Challenger

•Sub built by James Cameron to dive in 2012 to the deepest part of the ocean, the Challenger Deep in the Marianas Trench in the Pacific•Built to do photography/videography•Successfully dove once to 10,908 m•Sub was damaged in transport a few years later

Pelagic Visual Observation

•Sub or Remotely Operated Vehicle (ROV)•Biases: see mostly larger macro- and megafauna, noise of sub scares away some species, light of sub scares away some species, sub/ROV has narrow field of view - stuff happens off to side, above, or behind sub•Good for: seeing fragile organisms that are destroyed in traditional nets, seeing behaviors

Johnson and Sea Link 1+2

•Submersibles with Plexiglas sphere for pilot and a scientist, another scientist or two can be in the aft compartment•Built for Harbor Branch Oceanographic Institution and used in 1970s-early 2000s•Because of the Plexiglas sphere, it could only dive to 1000 m, but could explore deep reefs and mesopelagic habitats

Great Ocean Conveyor

•Surface overturn reaches the bottom in the Atlantic south of Greenland and just north of Antarctica •After the water sinks, it spreads through the Atlantic and into the other ocean basins •The water eventually rises to the surface and flows back to the Atlantic •Thought to play a role in regulating earth's climate

Benthic Epifauna

•Visual Observation•Biases: see mostly larger macro- and megafauna but also traces in sediment and more conspicuous microbial mats, noise of sub scares away species, light of sub scares away species, sub/ROV has narrow field of view - stuff happens off to side, above, or behind sub •Good for visual counts of numbers, species richness, percentage cover of visible species •Landers are instruments dropped on the bottom, take readings and/or photos for a period, then release and float to surface to be picked up

Benthic Mobile Macro fauna in coral and rocks

•Visual census via ROV or sub•Biases: larger species identifiable but no distinguishing smaller or more cryptic species from each other•Good for: counts and diversity of larger animals

Benthic Mobile Macrofauna

•Visual survey with baited camera trap•Biases: only see animals that are attracted to bait•Good for: analysis of scavengers coming to bait over time

Pelagic Microbes

•Water sample bottles on CTD•Biases: each bottle only samples at depth the bottle is closed•Good for: microbes in the water at that time and depth

Plankton in Oxygen Minimum Zone

•Waves at surface and photosynthesis of phytoplankton in epipelagic adds enough oxygen to surface waters •Deeper layers of ocean water come from surface waters near the poles, so also lots of dissolved oxygen •Midwater layers in mesopelagic are too far below the epipelagic and too far above the cold water masses from the poles - so oxygen gets depleted, hypoxic (low O2) or anoxic (no O2) •OMZ often around 400-500 m depth

Bermuda Oceanographic Expedition

•William Beebe was a well-known naturalist in the early 20thcentury•Began a series of trawling expeditions from a station he built on NonsuchIsland in Bermuda•Also experimented with ways to go down and see deep-sea animals in the native environment•Otis Barton collaborated with Beebe to design and build a "bathysphere", a pressure resistant sphere of steel they could sit in while it was dropped using a crane on a barge •Beebe described much of this work in a series of research papers and the book "Half Mile Down"•Beebe and his research collaborators, Gloria Hollister, Jocelyn Crane, John Tee-Van described many of the deep pelagic animals collected from an 8 mi2area off NonsuchIsland

functional groups of plankton

•phytoplankton-- plankton that can photosynthesize •zooplankton-- plankton that are animals•bacterioplankton-- heterotrophic and autotrophic bacteria •viroplankton-- viruses