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Peter Etnoyer

The global decrease in seawater pH known as ocean acidification has important ecological consequences and is an imminent threat for numerous marine organisms. Even though the deep sea is generally considered to be a stable environment, it... more
The global decrease in seawater pH known as ocean acidification has important ecological consequences and is an imminent threat for numerous marine organisms. Even though the deep sea is generally considered to be a stable environment, it can be dynamic and vulnerable to anthropogenic disturbances including increasing temperature, deoxygenation, ocean acidification and pollution. Lophelia pertusa is among the better-studied cold-water corals but was only recently documented along the US West Coast, growing in acidified conditions. In the present study, coral fragments were collected at ∼300 m depth along the southern California margin and kept in recirculating tanks simulating conditions normally found in the natural environment for this species. At the collection site, waters exhibited persistently low pH and aragonite saturation states (Omega arag) with average values for pH of 7.66 +- 0.01 and Omega arag of 0.81 +- 0.07. In the laboratory, fragments were grown for three weeks in ...
Coral reefs are iconic ecosystems that support diverse, productive communities in both shallow and deep waters. However, our incomplete knowledge of cold-water coral (CWC) niche space limits our understanding of their distribution and... more
Coral reefs are iconic ecosystems that support diverse, productive communities in both shallow and deep waters. However, our incomplete knowledge of cold-water coral (CWC) niche space limits our understanding of their distribution and precludes a complete accounting of the ecosystem services they provide. Here, we present the results of recent surveys of the CWC mound province on the Blake Plateau off the U.S. east coast, an area of intense human activity including fisheries and naval operations, and potentially energy and mineral extraction. At one site, CWC mounds are arranged in lines that total over 150 km in length, making this one of the largest reef complexes discovered in the deep ocean. This site experiences rapid and extreme shifts in temperature between 4.3 and 10.7 °C, and currents approaching 1 m s−1. Carbon is transported to depth by mesopelagic micronekton and nutrient cycling on the reef results in some of the highest nitrate concentrations recorded in the region. Pr...
The global decrease in seawater pH known as ocean acidification has important ecological consequences and is an imminent threat for numerous marine organisms. Even though the deep sea is generally considered to be a stable environment, it... more
The global decrease in seawater pH known as ocean acidification has important ecological consequences and is an imminent threat for numerous marine organisms. Even though the deep sea is generally considered to be a stable environment, it can be dynamic and vulnerable to anthropogenic disturbances including increasing temperature, deoxygenation, ocean acidification and pollution. is among the better-studied cold-water corals but was only recently documented along the US West Coast, growing in acidified conditions. In the present study, coral fragments were collected at ∼300 m depth along the southern California margin and kept in recirculating tanks simulating conditions normally found in the natural environment for this species. At the collection site, waters exhibited persistently low pH and aragonite saturation states (Ω) with average values for pH of 7.66 ± 0.01 and Ω of 0.81 ± 0.07. In the laboratory, fragments were grown for three weeks in "favorable" pH/Ω of 7.9/1.4...
While the vast majority of data Nautilus collects are digital-high-definition video, still photos, sensor, measurements, and navigation—physical samples are invaluable to scientists. Biological samples are critical in determining the... more
While the vast majority of data Nautilus collects are digital-high-definition video, still photos, sensor, measurements, and navigation—physical samples are invaluable to scientists. Biological samples are critical in determining the species of an organism and may lead to the discovery of a new organism or new knowledge that extends a species’ range or adaptations. Biological samples also permit scientists to study food web and reproductive dynamics as well as growth rates, which are critical for research on fisheries and other natural marine resources. Rock and sediment samples are key to learning more about sedimentation rates, geological formation and history, and marine geohazards that may impact coastal communities.
Massive, long-lived deep-sea red tree corals (Primnoa pacifica) form a solid, layered axis comprised of calcite and gorgonin skeleton. They are abundant on the outer continental shelf and upper slope of the Northeast Pacific, providing... more
Massive, long-lived deep-sea red tree corals (Primnoa pacifica) form a solid, layered axis comprised of calcite and gorgonin skeleton. They are abundant on the outer continental shelf and upper slope of the Northeast Pacific, providing habitat for fish and invertebrates. Yet, their large size and arborescent morphology makes them susceptible to disturbance from fishing activities. A better understanding of their growth patterns will facilitate in-situ estimates of population age structure and biomass. Here, we evaluated relationships between ages, growth rates, gross morphological characteristics, and banding patterns in 11 colonies collected from depths of ~141–335 m off the Alaskan coast. These corals ranged in age from 12 to 80 years old. They grew faster radially (0.33–0.74 mm year-1) and axially (2.41–6.39 cm year-1) than in previously measured older colonies, suggesting that growth in P. pacifica declines slowly with age, and that basal diameter and axial height eventually pla...
Research Interests:
Most of our knowledge about corals comes from shallow water tropical reefs and laboratories. These studies showed us that corals are diverse, delicate, slow-growing, and long-lived. They showed us that reefs are vulnerable to nutrient... more
Most of our knowledge about corals comes from shallow water tropical reefs and laboratories. These studies showed us that corals are diverse, delicate, slow-growing, and long-lived. They showed us that reefs are vulnerable to nutrient input, climate change, and destructive fishing gear, but healthy coral reefs can protect coastal communities, and provide habitat for numerous associated species. Yet, corals are not restricted to tropical reefs. Corals grow in many types of seafloor habitats ranging from the shallows to the abyss, and ...
<p>Profiles of platform edge “fore-reef” dive sites on Overall Bank (A7, A12 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone-0010668-g001" target="_blank">Figure... more
<p>Profiles of platform edge “fore-reef” dive sites on Overall Bank (A7, A12 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone-0010668-g001" target="_blank">Figure 1</a>) and in the Conch Valley (CV1, CV2 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone-0010668-g001" target="_blank">Figure 1</a>). Each fore-reef is bounded on the interior by a trough of varying depth and character. Troughs were generally sandy, with intermittent patch reefs.</p
<p>An image from one of the “A” sites on the fore-reef of Saba Bank (∼25 m) shows an assemblage characterized by sea fans (<i>Gorgonia ventalina</i>), sea plumes (<i>Pseudopterogorgia americana</i>), and the... more
<p>An image from one of the “A” sites on the fore-reef of Saba Bank (∼25 m) shows an assemblage characterized by sea fans (<i>Gorgonia ventalina</i>), sea plumes (<i>Pseudopterogorgia americana</i>), and the <i>Eunicea/Plexaura</i> sp. complex, <i>Eunicea fleuxosa</i>, center. The fore-reef environment consists of a series of reef crests near the platform edge on Saba Bank <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone.0010668-VanderLand1" target="_blank">[4]</a> with diverse and abundant octocoral species.</p
<p>The graph shows a sample-based rarefaction curve (in black) based on 17 shallow and deep dives. The technique employs a Mao Tau estimator <a... more
<p>The graph shows a sample-based rarefaction curve (in black) based on 17 shallow and deep dives. The technique employs a Mao Tau estimator <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone.0010668-Colwell1" target="_blank">[21]</a> of expected species richness with 95% confidence intervals (in light blue). The species accumulation curve is steeply inclined, not approaching asymptote. More gorgonian species remain to be discovered on Saba Bank, though richness is already higher than other study sites in the West Atlantic.</p
<p>Saba Bank is shown relative to its nearest neighbor, Saba. A pale band of color representing 11–20 m depths represents a “fore-reef” extending 50 km along the southeast perimeter of the Bank. Red stars indicate the location of 8... more
<p>Saba Bank is shown relative to its nearest neighbor, Saba. A pale band of color representing 11–20 m depths represents a “fore-reef” extending 50 km along the southeast perimeter of the Bank. Red stars indicate the location of 8 quantitative transects, four on the fore-reef (A sites and CV sites) and four in the plateau (E3, E4, D9, Void) of Saba Bank's interior region. The dashed lines indicate Overall Bank, where a zonation scheme with random sites was in effect. Void was random, Conch Valley was non-random.</p
<p>A non-metric multidimensional scaling (MDS) plot based on Bray-Curtis dissimilarity measures derived from presence and absence of octocoral species in surveys of Florida <a... more
<p>A non-metric multidimensional scaling (MDS) plot based on Bray-Curtis dissimilarity measures derived from presence and absence of octocoral species in surveys of Florida <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone.0010668-Opresko1" target="_blank">[9]</a>, Colombia <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone.0010668-Sanchez1" target="_blank">[10]</a>, and Puerto Rico <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010668#pone.0010668-Garcia1" target="_blank">[11]</a>.</p
Estimates of the number of seamounts occurring worldwide are high and increasing, largely because of improved remote-sensing capabilities. Numbers have grown from a baseline of 15,000 (Wessel, 2001; Marova 2002) to more than 45,000... more
Estimates of the number of seamounts occurring worldwide are high and increasing, largely because of improved remote-sensing capabilities. Numbers have grown from a baseline of 15,000 (Wessel, 2001; Marova 2002) to more than 45,000 seamounts worldwide. High-end estimates are in the hundreds of thousands (Hillier and Watts, 2007; Kitchingman et al., 2007; Wessel, 2007; Wessel et al., 2010). So, it is logical to ask: What is the total area of the seamount biome? If the world's seamount features were assembled into a continuous region, how large would this place be? How would the area of the seamount biome compare to continents, and to other marine biomes? These data would be informative, because terrestrial biomes are fairly well resolved and enumerated (Udvardy, 1975; Woodward, 2003), but marine biomes are less well mapped and understood.
Shore-based submersible operations, from 2006 to 2020, have allowed us to examine megabenthic assemblages along the island margin of Isla de Roatán from depths of about 150 to 750 m, including repeated observations of the same organisms.... more
Shore-based submersible operations, from 2006 to 2020, have allowed us to examine megabenthic assemblages along the island margin of Isla de Roatán from depths of about 150 to 750 m, including repeated observations of the same organisms. These dives were used to photo-document a diverse benthic assemblage and observe the health and condition of the sessile fauna in a well-explored but relatively undocumented area of the Mesoamerican Reef. Samples were collected by dip net, and some dives profiled the water column chemistry in the year 2011. The deep-sea coral assemblage observed off Roatan exhibits high abundance and diversity. The sessile habitat-forming taxa consist primarily of at least 20 different octocorals (e.g., Plexauridae, Primnoidae, Coralliidae, Isididae, and Ellisellidae) and 20 different sponges each (Demospongiae and Hexactinellida), with several known and unknown taxa of Zoantharia, Antipatharia (Bathypathes spp), and Scleractinia (e.g., Desmophyllum pertusum, Dendro...
Saba Bank is a large submerged platform (,2200 km 2), average depth 30 m, located 4 km southwest of Saba Island in Netherlands Antilles, Caribbean Sea. Ships traveling to and from oil terminals on nearby St. Eustatius routinely anchor on... more
Saba Bank is a large submerged platform (,2200 km 2), average depth 30 m, located 4 km southwest of Saba Island in Netherlands Antilles, Caribbean Sea. Ships traveling to and from oil terminals on nearby St. Eustatius routinely anchor on the Bank, damaging benthic megafauna. Gorgonian octocorals are vulnerable to anchor damage, and they are common and conspicuous in shallow water (15–50 m) around the banks. This prompted a rapid assessment of octocoral habitat and diversity. The primary objectives were to estimate total species richness and to characterize habitats vis a vis gorgonians. Landsat imagery and multibeam bathymetry were employed to identify random sites for quantitative transects. A Seabotix LBV200L remotely operated vehicle (ROV) and SCUBA were used to collect and survey to 130 m. A total of 14 scuba dives and 3 ROV dives were completed in 10 days. During that time, 48 octocoral species were collected, including two likely undescribed species in the genera Pterogorgia a...
NOAA's Deep Sea Coral Research and Technology Program (DSCRTP) is compiling a national database of the locations of deep-sea corals and sponges, beginning in U.S. waters. The DSCRTP will make this information accessible to resource... more
NOAA's Deep Sea Coral Research and Technology Program (DSCRTP) is compiling a national database of the locations of deep-sea corals and sponges, beginning in U.S. waters. The DSCRTP will make this information accessible to resource managers, the scientific community, and the public over the World Wide Web. The database fulfills NOAA's requirements under the Magnuson-Stevens Fishery Conservation and Management Act (MSA) to identify and map locations of deep-sea corals and to submit this information for use by regional fishery management councils. At present, there is no comprehensive, national-scale data portal for deep-sea corals and sponges. Given the authorities outlined in the MSA, NOAA's DSCRTP will serve as a central data aggregator and distributor. The DSCRTP will aggregate and make accessible historical records from samples archived in museums, research institutions, and reported in the scientific literature augmented by observations collected during deep-water in...

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