Research Group: Ken Smith (Senior Scientist), Alana Sherman (Senior Engineer), Crissy Huffard (Senior Research Technician), Kathy Dunlop (Postdoctoral Fellow), Henry Ruhl (Collaborator), Larissa Clary (Collaborator)
The primary emphasis of our research is an ongoing long
time-series project that has been conducted over 20
years from 1989 to the present at “Station M” (34o
50’N, 123o 00’W; 4000 meters depth) 220 km
west of the central California coast.
The Station M study represents one of the most detailed investigations of any abyssal area in the world ocean. Over this 25-year time series study, we have continuously monitored the amount of sinking particulate matter through the benthic boundary layer (bottom 600 m of the water column and sea floor). Sinking organic matter is the only source of food to seafloor communities at Station M. We use time-lapse photography to record the dynamic responses of animals there to changes in food availability (see video). The Benthic Rover measures how much oxygen is consumed by microbes and animals living in the sea floor sediments. By measuring how much food makes it to the sea floor, and how much is consumed there, we estimate how much carbon is being sequestered in the deep sea over time. Rising atmospheric and surface ocean temperatures are projected to cause a global decrease in sinking organic matter from the upper water column to the seafloor. Such changes would alter benthic community biomass, composition and functioning. Data from the Station M abyssal time series are being used to model carbon flow to predict how changes in atmospheric and sea surface temperatures will affect deep-sea benthic communities and the oceanic carbon cycle.
Camera Tripod readied for deployment
Bottom of the sea floor at Station M
Sediment Trap being deployed
The sea floor at Sta. M is characterized by silty-clay sediments with little topographic relief (< 100m over 1600 km2). Surface waters of the California Current over this site generally have high primary production by phytoplankton in the spring and summer, although this varies year to year. This temporal signal in surface production is observed throughout the water column and into the sediments.
Measurements at Station M are made with a variety of
instruments. Sinking particulate matter, consisting of
phytoplankton detritus, zooplankton fecal material and
amorphous flocculent material, is collected with
sequencing sediment traps moored at 50 and 600 m above
bottom. Current flow is measured with current meters on
the Rover and on the camera tripod. The activities of
mobile animals just above the sea floor (e.g. grenadier
fishes, jellyfish and sea cucumbers) and on the sediment
(e.g. brittle stars, sea cucumbers, sea urchins) are
observed using a time-lapse camera tripod. Video
transects of the sea floor are taken by the remotely
operated vehicle Doc Ricketts. Oxygen
consumption, a measure of biological activity, of
organisms living in the sediments on the sea floor is
measured by the Benthic
Rover. The Benthic Rover works robotically
on the sea floor for nearly a year a a time, taking
measurements and photographs as it moves along the sea
Sedimentation Event Sensor
ROV Doc Ricketts aboard R/V Western Flyer
Significant findings of these studies at Sta. M are listed below:
- Sinking particulate organic carbon fluxes to abyssal depths and through the benthic boundary layer showed seasonal peaks in summer and fall with considerable inter-annual variability.
- Sinking particulate organic matter fluxes at 600 m above bottom were correlated with the Bakun upwelling index, revealing a time lag of approximately 2 to 3 months between these climatically mediated events at the surface and the particulate fluxes (food supply) at 3500 m depth.
- A strong correlation exists between surface ocean processes and the supply of particulate organic matter to the abyssal sea floor at Sta. M.
- Epibenthic megafauna on the sea floor, including holothurians and echinoids, are very conspicuous in time-lapse camera and camera sled transects. Dramatic shifts in population abundances of the dominant epibenthic species are significantly correlated to El Nino/La Nina events expressed in the Northern Oscillation index when lagged by 14 to 18 months.
- Epibenthic megafauna and smaller macrofauna abundances are correlated to the particulate organic carbon (food supply) entering the benthic boundary layer when examined over periods of time exceeding a decade.
- Sediment community oxygen consumption, a measure of food utilization by the benthic community, was highest in summer and lowest in winter.
- Over an extended time series, the estimate of food
utilization by the benthic community exceeded the supply
of food. Recent large seasonal pulses of food to
the sea floor, beginning in 2012 and continuing through
at least 2014, might provide enough food surplus for
another 20 years of undersupply at Station M.
- Fluctuations in food supply driven by climate variation are ultimately linked to abyssal community structure and processes.
Recent Publications concerning Station M
2014 L.A. Kuhnz, H.A. Ruhl, C.L. Huffard, and K.L. Smith Jr. A benthic megafaunal community in the abyssal northeast Pacific: structural changes over a 24-year time series. Prog. Oceanogr. 124:1–11.
2014 K.L. Smith Jr., A.D. Sherman, C.L. Huffard, P.R. McGill, R. Henthorn, S.Von Thun, H.A. Ruhl, M. Kahru, and M.D. Ohman. Large salp bloom export from the upper ocean and benthic community response in the abyssal northeast Pacific: day to week resolution. Limnol. and Oceanogr. 59(3):745–757.
2014 H.A. Ruhl, B.J. Bett, S.J.M. Hughes, C.H.S. Alt, E.J. Ross, R.S. Lampitt, C.A. Pebody, K.L. Smith, Jr. and D.S.M. Billett. Links between deep-sea respiration and community dynamics. Ecology. 95(6):1651-1662.
2013 R.M. Jeffreys, C. Burke, A.J. Jamieson, B.E. Narayanaswamy, H.A. Ruhl, K.L. Smith Jr, U. Witte. Feeding preferences of abyssal macrofauna inferred from in situ pulse chase experiments. PlosOne. doi: 10.1371/journal.pone.0080510
2013 K.L. Smith, Jr., H.A. Ruhl, M. Kahru, C.L. Huffard and A.D. Sherman. Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific. Proc. Nat. Acad. Sci. 110(49): 19838-19841.
2013 S.E.Wilson, H.A. Ruhl and K.L. Smith, Jr. Zooplankton fecal pellet flux in the abyssal northeast Pacific: a 15 year time-series study.Limnol. Oceanogr. 58: 881-892.
2013 A.S.Kahn, J.B. Geller, H.M. Reiswig and K.L. Smith, Jr. Bathydorus laniger and Docosaccus maculatus (Lyssacinosida; Hexactinellida): two new species of glass sponge from the abyssal eastern North Pacific Ocean. Zootaxa 3646 (4): 386-400.
2013 C. Laguionie-Marchais, D.S.M. Billett, G.L.D. Paterson, H.A. Ruhl, E.H. Soto, K.L. Smith Jr. and S. Thatje. Interannual dynamics of abyssal polychaete communities in the north east Pacific and north east Atlantic – a family level study. Deep-Sea Res. I 175: 175-186.
2012 J.C. Drazen, D.M. Bailey, H.A. Ruhl and K.L. Smith, Jr. The role of carrion supply in the abundance of deep-water fish off California.PLoS ONE 7(11): e49332.doi:10.1371/journal.pone.0049332.
2012 A.S. Kahn, H.A. Ruhl and K.L. Smith, Jr. Temporal changes in deep-sea sponge populations are correlated to changes in surface climate and food supply. Deep-Sea Res. I, 70: 36-41.
2010 M.F. Vardaro. Genetic and anatomic relationships among three morphotypes of the echinoid Echinocrepis rostrata. Invert. Biol. 129, 368-375.
2010 I. Kouridaki, P.N. Polymenakou, A. Tselepides, M. Mandalakis, K.L. Smith, Jr. Phylogenetic diversity of sediment bacteria from the deep northeastern Pacific Ocean: comparison with the deep eastern Mediterranean Sea. International Microbiol. 13, 143-150.
2009 K.L. Smith, Jr., H.A. Ruhl, B.J. Bett, D.S.M. Billett, R.S. Lampitt and R.S. Kaufmann. Climate, carbon cycling, and deep-ocean ecosystems. Proc. Nat. Acad. Sci. 106, 19211-19218.
2009 N. D. Holland, W.J. Jones, J. Ellena, H.A. Ruhl and K.L. Smith, Jr. A new deep-sea species of epibenthic acorn worm (Hemichordata, Enteropneusta). Zoosystema, 31, 333 – 346.
2009 J.C. Drazen, C.F. Phleger, M.A. Guest, P.D. Nichols. Lipid composition and diet inferences in abyssal macrourids of the eastern North Pacific. Mar. Ecol. Prog. Ser. 387,1-14.
2009 M.F. Vardaro, H.A. Ruhl and K.L. Smith, Jr. Climate variation, carbon flux, and bioturbation in the abyssal North Pacific. Limnol. Oceanogr., 54, 2081-2088.
2009 A.D. Sherman and K.L. Smith, Jr. Deep-sea benthic boundary layer communities and food supply: A long-term monitoring strategy. Deep-Sea Res. II, 56, 1754-1762.
2009 P.R. McGill, A.D. Sherman, B.W. Hobson, R.G. Henthorn and K.L. Smith, Jr. Initial deployments of the Rover, an autonomous bottom-transecting instrument platform. J. Ocean. Tech. 4, 9-26.
2009 S.R. Beaupre, E.R.M. Druffel. Source Constraining the propagation of bomb-radiocarbon through the dissolved organic carbon (DOC) pool in the northeast Pacific Ocean. Deep-Sea Res. (1 Oceanogr. Res. Pap.) 56(10) 1717-1726.
2008 H.A. Ruhl, J. A. Ellena and K.L. Smith, Jr. Connections between climate, food limitation, and carbon cycling in abyssal sediment communities. Proc. Nat. Acad. Sci.105, 17006-17011.
2008 J.C. Drazen, B.N. Popp, C.A. Choy, T. Clemente, L. DeForest and K.L. Smith, Jr. Bypassing the abyssal benthic food web: Macrourid diet in the eastern North Pacific inferred from stomach content and stable isotopes analyses. Limnol. Oceanogr. 53, 2644-2654.
2008 E.R.M. Druffel, J.E. Bauer, S. Griffin, et al. Dissolved inorganic radiocarbon in the North Pacific Ocean and Sargasso Sea. Deep-Sea Res. (1 Oceanogr. Res. Pap.) 55(4),451-459.
2008 K.L. Smith, Jr., H.A. Ruhl, R.S. Kaufmann, M. Kahru. Tracing abyssal food supply back to upper-ocean processes over a 17-year time series in the NE Pacific. Limnol. Oceanogr. 53, 2655-2667.
2008 J.A.T. Booth, H.A. Ruhl, L.L. Lovell, K.L. Smith, Jr. Size frequency dynamics of NE Pacific abyssal ophiuroids (Echinodermata: Ophiuroidea). Mar. Biol. 154,933-941.
2008 H.A. Ruhl. Community change in the variable resource habitat of the abyssal NE Pacific. Ecology 89, 991-1000.
2008 A.K. Sweetman, U. Witte. Macrofaunal community composition, food web structure and short-term response to a simulated phytodetrital pulse in the abyssal northeast Pacific Ocean. Mar. Ecol. Prog. Ser. 355,73-84.
2007 H. A. Ruhl. Abundance and size distribution dynamics of abyssal epibenthic megafauna in the northeast Pacific. Ecology 88,1250-1262.
2007 P.R. McGill, A.D. Sherman, B.W. Hobson, R.G. Henthorn, A.C. Chase, K.L. Smith, Jr. Initial Deployments of the Benthic Rover, an Autonomous Bottom-Transecting Instrument Platform for Long-Term Measurements in Deep Benthic Environments. Proceedings of the MTS/IEE Oceans Conference, Vancouver, British Columbia.
2007 M.F. Vardaro, D. Parmley and K.L. Smith, Jr. A study of possible “reef effects” caused by a long-term time-lapse camera in the deep North Pacific. Deep-Sea Res. I. 54, 1231-1240.
2007 J. Jones, E. Macpherson. Molecular phylogeny of the East Pacific squat lobsters of the genus Munidopsis (Decapoda: Galatheidae) with the descriptions of seven new species. J. Crust. Biol. 27(3):477-501.
2007 S.R. Beaupre, E.R.M. Druffel, S. Griffin. A low-blank photochemical extraction system for concentration and isotopic analyses of marine dissolved organic carbon Limnol. Oceanogr.:Methods 5,174-184.
2007 E.A. Hendrycks. A new species of Valettiopsis Holmes, 1908 (Crustacea : Gammaridea : Lysianassoidea) from abyssal waters off California. Zootaxa 1501,45-56.
2006 D.M. Bailey, H.A. Ruhl and K.L. Smith, Jr. Long-term changes in benthopelagic fish abundance in the abyssal Northeast Pacific Ocean. Ecology 87, 549-555.
2006 K.L. Smith, Jr., R.J. Baldwin, H.A. Ruhl, M. Kahru, B.G. Mitchell and R.S. Kaufmann. Climate effect on food supply to depths greater than 4,000 meters in the northeast Pacific. Limnol. Oceanogr. 51, 166-176.
2005 K.L. Smith, Jr., N.D. Holland and H.A. Ruhl. Enteropneust production of spiral fecal trails on the deep-sea floor observed with time-lapse photography. Deep-Sea Res. I. 52, 1228-1240.
2004 J. Hwang, E.R.M. Druffel, S. Griffin, K.L. Smith, Jr., R.J. Baldwin and J.E. Bauer. Temporal variability of delta 14C, 13C and C/N in sinking particulate organic matter at a deep time-series station in the Northeast Pacific Ocean. Global Biogeochem. Cycl. 18, GB4015, doi:10.1029/2004GB002221.
2004 H.A. Ruhl and K.L. Smith, Jr. Shifts in deep-sea community structure linked to climate and food supply. Science 305, 513-515.
2004 E.C. Fisher, R.S. Kaufmann and K.L. Smith, Jr. Variability of epipelagic macrozooplankton/micronekton community structure in the NW Weddell Sea, Antarctica (1995 – 1996). Mar. Biol. 144, 345-360.
2004 I.G. Priede, A.R. Deary, D.M. Bailey and K.L. Smith, Jr. Low activity and seasonal change in population size structure of grenadiers in the oligotrophic abyssal central North Pacific Ocean. J. Fish Biol. 63, 187-196.
2004 J.S. Hwang, E.R.M. Druffel. Lipid-like material as the source of the uncharacterized organic carbon in the ocean? Science 299, 881-884.
2004 E.A. Hendrycks, K.E. Conlan. New and unusual abyssal gammaridean Amphipoda from the north-east Pacific. J. Nat. Hist. 37(19),2303-2368.
2004 J.C. Drazen. A seasonal analysis of the nutritional condition of deep-sea macrourid fishes in the north-east Pacific. J. Fish. Biol. 60(5),1280-1295.
2002 K.L. Smith, Jr., R.J. Baldwin, D.M. Karl and A. Boetius. Benthic community responses to pulses in pelagic food supply: North Pacific Subtropical Gyre. Deep-Sea Res. I. 49, 971-990.