Discovering the Deep: Exploring Remote Pacific MPAs






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The shipboard mission team poses on the bow of the Okeanos Explorer as the Discovering the Deep: Exploring Marine Protected Areas expedition comes to an end.

The shipboard mission team poses on the bow of the Okeanos Explorer as the Discovering the Deep: Exploring Remote Pacific Marine Protected Areas expedition comes to an end. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 29, 2017

Expedition Complete

This morning the ship arrived back in Apia, which is the capital and the largest city within Samoa. While at port, the ship will resupply and personnel will be able to get some much-needed rest. It was a very successful expedition, with all 19 planned dives completed. While the mission personnel are all sad that the Discovering the Deep: Exploring Remote Pacific Marine Protected Areas expedition is complete, they are looking forward to stepping onto solid ground after 23 days at sea. While the mission team gets to go home, the ship’s crew only gets about a week on shore before they are back underway. On April 4, we will begin a mapping-only expedition, focused on the waters American Samoa, including within Rose Atoll Marine National Monument and National Marine Sanctuary of American Samoa; Western Samoa; and the Cook Islands (New Zealand). We will be back again with more exciting remotely operated vehicle dives starting April 27, with the Mountains in the Deep: Exploring the Central Pacific Basin expedition.


 


 

 

 

Sunset seen from the back deck of the Okeanos Explorer as the ship heads back to Apia, Samoa.

Sunset seen from the back deck of the Okeanos Explorer as the ship heads back to Apia, Samoa. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 28, 2017

Mapping Back to Port

The dives for this expedition are complete and the ship is heading back to port. Today was spent transiting back to Apia, Samoa. While transiting, the mapping team was able to tailor the route to add data to previous mapping in this area. During the transit back, the ship personnel prepared the ship for arrival. The ROV and Data engineers used the transit day to begin demobilizing the equipment and storing the data products. The mapping team had watches 24 hours a day to monitor the mapping data collection. The video team worked on completing the final video products for the cruise, including some longer videos on the Pacific Remote Islands Marine National Monument, species of fish encountered during the cruise, and the potential of these remote protected areas as being relief areas for large predators.


 


 

 

 

A caridean shrimp, Heterocarpus, was observed feeding on a type of mid-water dragonfish, possible a stareater, at around 998 meters.

A caridean shrimp, Heterocarpus, was observed feeding on a type of mid-water dragonfish, possible a stareater, at around 998 meters. Click image for credit and larger view.

Two homolid crabs were observed holding claws at around 757 meters depth. It was unclear whether this was potentially aggressive or pre-mating behavior.

Two homolid crabs were observed holding claws at around 757 meters depth. It was unclear whether this was potentially aggressive or pre-mating behavior. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 27, 2017

Dive 19: Ufiata Seamount

The last dive of the expedition began at around 990 meters, at the base of a steep slope, at Ufiata Seamount within the Tokelau Seamount Chain. The seafloor was composed of large and small boulders, interspersed with fine sandy sediments. When an iron-manganese-coated rock was collected, the manipulator marked one of the faces, revealing a lighter color, consistent with carbonate-type rocks. The piles of boulders indicated that these might be landslide debris deposits. At the base of the slope, the fish fauna included an unknown cusk eel, cutthroat and congeriid eels, and several midwater species. Very few attached fauna were found in this area. Mobile animals like sea cucumbers, benthic siphonophores, crabs, and caridean shrimp were more common. Along the steep wall, the seafloor changed to more cracked pavement-like morphology, with thick horizontal blocks, covered with manganese iron oxide coating. The fauna was very patchy, often preferring to encrust on small manganese crust ridges than flat pavement blocks. Here, scientists observed yellow demosponges, homolid crabs holding octocorals, anemones, a two-tone cusk eel, urchins, and sponges. Corals included purple and yellow octocorals and a bamboo whip. As Deep Discoverer progressed up to the summit along the ridge, yellow sponges and white octocorals dominated the seafloor, although in low abundance. All attached fauna were found along the seafloor pavement in iron-manganese-coated cracks with fine sandy sediment. Other fauna included a rattail, squat lobsters, purple and pink octocorals (one pink sample was collected), one bamboo whip, and scleractinians. Homolid crabs and caridean shrimp were the dominant megafaunal crustaceans observed throughout the dive. Some of the shrimp were greater than 10 centimeters long. Some gelatinous invertebrates observed at or near the summit included a maroon colored jellyfish, a medusa, and ctenophores. One sea star was observed at the summit. The most impressive display of predatory behavior was observed on this dive when a caridean shrimp was impaling and consuming a midwater dragonfish while the fish was still alive. The shrimp removed several pieces of fish tissue and stomach contents. It was incredible to watch the feeding activity and the scientists wondered how this shrimp was able to capture the fish, as deep-sea shrimps are often scavengers.


 


 

 

 

Deep Discoverer collected a bubblegum coral with encrusting zoanthid.

Deep Discoverer collected a bubblegum coral with encrusting zoanthid. Click image for credit and larger view.

For the first time this expedition, a chimaera, or ghost fish, was observed around 1853 meters. These fish are distant relatives of sharks and have skeletons made out of cartilage.

For the first time this expedition, a chimaera, or ghost fish, was observed at around 1,850 meters depth. These fish are distant relatives of sharks and have skeletons made out of cartilage. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 26, 2017

Dive 18: Unnamed Seamount (Phoenix Islands Protected Area)

The last dive within Phoenix Islands Protected Area started at around 2,100 meters depth, at the base of a steep wall on an unnamed seamount. The seafloor was composed of scattered boulders interspersed with sandy sediments, with fauna including corals, xenophyophores, sponges, stalked crinoids, a cusk eel, and a purple sea cucumber. Coral associates included crabs, crinoids, and brittle stars. As Deep Discoverer (D2) transitioned to the steep wall, there was a dramatic change in the seafloor geology to linear plates of hard substrate with a botryoidal texture. Abundant fauna observed were encrusting and attached forms, mostly sponges, some of which were very large on long stalks. Corals observed included several different octocorals, black corals, bamboos, corallids, and stoloniferans. Invertebrates along the steep wall included sea stars, red stalked and yellow crinoids, purple sea cucumbers, tunicates, white squat lobsters, and sea urchins (one with an enlarged anal sac). During this portion of the dive, the remotely operated vehicle encountered a large, deep, crevice that was encrusted with octocorals, glass sponges, and crinoids. Around 1,900 meters depth, the terrain changed from a vertical face to a gentle ridge, and dominate biology shifted to unknown primnoid colonies. Along this track, the scientists observed cutthroat eels and a chimaera fish. This area had the largest colonies of octocorals (>1.5 meters across), bamboos, and large sponges. Scientists sampled two species of octocorals given their high dominance, abundance, and the fact that their identification remains unresolved. Continuing up the ridge, the current slowed and the biology shifted from coral-dominated to sponge-dominated terrain. The second dumbo octopus for this expedition was imaged along this feature, at around 1,855 meters. Throughout the remainder of the dive, a few large coral colonies were encountered, including two octocoral species and an internodal bamboo. While D2 reached a shallower depth (1,786 meters) than the target off bottom depth (1,806 meters), it did not reach the summit of this feature. Tomorrow is the final dive of this expedition, at Ufiata Seamount.


 


 

 

 

Several gold coral colonies were observed for the first time on this expedition on this dive within the Phoenix Islands Protected Area (PIPA).

Several gold coral colonies were observed for the first time on this expedition on this dive within the Phoenix Islands Protected Area. Click image for credit and larger view.

Known coral predators, several pencil urchins were seen clinging to corals, likely consuming soft tissue and leaving the bare coral skeleton visible on several branches.

Known coral predators, several pencil urchins were seen clinging to corals, likely consuming soft tissue and leaving the bare coral skeleton visible on several branches. Click image for credit and larger view.

An unknown octopus with a small node on its head was observed crawling along the seafloor around 475 meters.

An unknown octopus with a small node on its head was observed crawling along the seafloor at around 475 meters depths. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 25, 2017

Dive 17: Unnamed Seamount (North of Carondelet Reef)

This dive was on a steep slope along the western side of unnamed seamount within the Phoenix Islands Protected Area. The seafloor had large concavities potentially arisen from a mass wasting event in its geological history. At 746 meters depth, the track was a gradual slope composed of loose dead coral rubble covering sandy sediments. Along here, sponges were the dominant fauna encountered, with different types of tubular, vase-like individuals. Other fauna observed included a red fringed tunicate; an urchin; squat lobsters; and fishes: alfonsinos, congrid eels, and oreo fish. Around 740 meters, the seafloor transitioned to a steep wall of heavily eroded carbonate and a high density of brittle stars, with a north to south current. Along the wall were different kinds of sponges and corals including stony corals (colonial and solitary forms) and octocorals. Invertebrates observed included large shrimp, hermit and homolid crabs, large purple crinoids with myzostomes on cirri, squat lobsters, and sea stars. One crab was observed gleaning material from its anemone hat using its chelipeds. Other fishes included arrow-tooth eels, codlings, brotulas (a species not yet seen on this expedition), and roughies. Around 600 meters, the track progressed along a gradually sloped ridge feature carpeted by buried ophiuroids, with steep drop offs on either side and a current from south to north. Along this feature, the largest coral colonies were observed, including stony corals, bamboos, and other octocorals. A few of the large octocorals had brittle star associates with sinusoidal arms and a bumpy textured disc. Toward the end of the dive, there were several large gold corals (~1.5 meters), some completely covering the host coral skeleton. On one particular colony, the scientists noted the areas of transition from live bamboo tissue to dead skeleton to live zoanthid polyps. Other invertebrates observed included an octopus with a projection on its head and two rows of suckers on each arm, demosponges, a salp, sea stars, stalked crinoid, large vase sponges, and pancake urchins with parasites. Along the ridge, several fish were observed including oreo fish, spike fish, pomfrets, rattail, roughies, beardfish, scorpionfish, deep-sea cardinalfish, goosefish, and a deep-water stingray. Some of the fish observed had gnathiid isopod parasites attached to the fins and scales. Throughout the dive, scientists noted several pencil urchins, known coral predators, on large octocoral fans with areas of bare skeleton in close proximity to the urchins.


 


 

 

 

The purple holothurian Psychropotes sp. feeds on organic sediment deposits on the rocky substrate. This species has a distinct “sail” over its posterior end. The function of the sail or what the animal uses it for isn’t very clear.

The purple holothurian, Psychropotes sp., feeds on organic sediment deposits on the rocky substrate. This species has a distinct "sail" over its posterior end. The function of the sail or what the animal uses it for isn't very clear. Click image for credit and larger view.

A rare mollusc, called a monoplacophoran, was observed at ~5771 meters on the hard pavement of a sedimented plateau.

A rare mollusc, called a monoplacophoran, was observed at ~5,771 meters depth on the hard pavement of a sedimented plateau. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 24, 2017

Dive 16: Hadal Trough ("Kinono")

This was the deepest dive for the expedition, descending to 5,862 meters in a deep trough feature, southwest of the Phoenix Islands. The seafloor was composed of scattered and emplaced rocks coated in manganese iron oxide crust, with brown sediment drape occurring in patches. The sediment appeared more organic rich and darker in color than on the previous dives in the region, speckled with calcareous foram tests. A common theme throughout the dive was the lack of color, both on the steep slope and sedimented ledge at the end of the dive. Much of the taxa lacked tissue pigmentation, which contrasted with the dark color of the seafloor. Scientists observed white anemones, sea cucumbers, brisingids (some with swollen arms indicative of ripe gonadal material), stalked sponges with amphipod associates, comatulid crinoids possibly with eggs, a solitary hydroid, slit shell gastropod, sea pigs, pentagonal brittle star, and a branching bryozoan. Other fauna observed included a large amphipod, red caridean shrimp, carnivorous tunicates, large pink mysid shrimps, fan-shaped xenophyophores, brown globe foraminiferans, a long mud tube with a white polychaete inside, and a cusk eel. Scientists observed some unexpected fauna, including priapulids feeding on the sediment surface, large purple sea cucumbers, and a rare monoplacophoran mollusc. At the end of the dive, along a sedimented plateau composed of hard pavement, was a white sea pen, and the scientists collected the only black coral observed on the dive around 5,775 meters depth. Tomorrow’s dive will be in the vicinity of Carondelet Reef on an unnamed seamount within the Phoenix Islands Protected Area.


 


 

 

 

A velvet whalefish covered with gnathiid isopod parasites was observed for the first time this expedition at ~1300m.

A velvet whalefish covered with gnathiid isopod parasites was observed for the first time this expedition at ~1,300 meters. Click image for credit and larger view.

This Gadomus sp. is related to the rattails, characterized by long, thin projections on its fins.

This Gadomus sp. is related to the rattails, characterized by long, thin projections on its fins. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 23, 2017

Dive 15: Unnamed Seamount (Phoenix Islands Protected Area)

This dive was on an unnamed seamount and the sixth dive within the Phoenix Islands Protected Area (PIPA). The dive spanned from 1,323 to 982 meters depth, beginning on a sedimented slope with scattered boulders and a moderate current, flowing from north to south. Continuing upslope, the seafloor transitioned from large boulders and blocks, interspersed with sediment to large boulders and continuous rock pavements with thin sediment drape. Along the steep slope, the rock had a crustal appearance that had fallen in several areas, revealing the smooth, underlying pavement. Fishes encountered on the dive included cusk eels, rattails, deep-sea spiny eels, tripod fish, velvet whalefish, brotula, oreo fish, an arrow-tooth eel, and cutthroat eels. Yellow plexaurids, bottlebrush chrysogorgids, and large primnoids were observed on large rocky slabs. Other corals observed along the steep slope included sea pens, colonial scleractinians, cup corals, bamboo whips, precious corals, black corals, and octocorals. Several glass sponges were observed during the first part of the dive from about 1,323 to 1,200 meters, covered with associates, including ctenophores, crinoids, ophiuroids, and shrimp. Unknown sea stars were observed feeding on these sponges. We also encountered sea stars feeding on a very large primnoid, with bare coral skeleton present in proximity to the sea star. Other sponges included large vase-like sponges and other globe-shaped glass sponges. Additional invertebrates observed on the exposed rock surfaces and on the sediment surface included sea cucumbers, sea stars, a sea lily, anemones, shrimps, hermit crab, a dandelion benthic siphonophore, a sea urchin, and a homolid crab with a plexaurid hat on a large octocoral. Next up is the deepest dive of this expedition in an unknown trough in PIPA that spans the hadal depths.This dive site is one of the few hadal zones in the Pacific not associated with a known subduction zone or trench.


 


 

 

 

A rare deep-sea cirrate octopod (Grimpoteuthis sp.) uses its fins on either side of its head to gracefully propel itself through the water column around D2. The scientists observed some damage on the arm and fin.

A rare deep-sea cirrate octopod (Grimpoteuthis sp.) uses its fins on either side of its head to gracefully propel itself through the water column around Deep Discoverer. The scientists observed some damage on the octopod's arm and fin. Click image for credit and larger view or click here to watch video of the octopod.

Another first for the expedition and a rare find, the whalefish, less than 10 centimeteres in length, appeared at a depth of ~1,310 meters. Whalefish were named for their large mouths and resemblance to baleen whales, not for their size.

Another first for the expedition and a rare find, the whalefish, less than 10 centimeteres in length, appeared at a depth of ~1,310 meters. Whalefish were named for their large mouths and resemblance to baleen whales, not for their size. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 22, 2017

Dive 14: Unnamed Seamount (Winslow Reef Area)

This dive started on a sedimented seafloor at 1,535 meters depth and progressed up a steep slope on an unnamed seamount within the Winslow Reef Area, Phoenix Islands Protected Area (PIPA). Throughout the dive, we observed several live and dead Walteria-like glass sponges, loaded with associates, including ophiuroids, crinoids, barnacles, shrimp, ctenophores, and sea stars. Sponges, including some encrusting types, were seen on the dive. Iridogorgia cf. magnispiralis was the dominant octocoral present and several colonies were very large, being about 3.7 meters. Other corals observed included an unknown planar Chrysogorgiid octocoral, three species of sea pens, whip and a yellow nodal branching bamboo corals, pink coralliid (Hemicorallium sp.), black coral, and stony corals including unknown cup corals. Additional associates included squat lobsters and barnacles on dead coral skeleton. Fish included cusk eels, rattails, codling, deep-sea spiny eels, a cutthroat eel, and an unknown black fish, later identified as a whalefish. Other invertebrates observed included a blind lobster, stalked crinoids, sea cucumbers, sea stars, sea urchins, homolid crab with anemone associate, and xenophyophores. One of the highlights of the dive was observing a dumbo octopus with a damaged arm and fin taking flight during the first part of the dive. The scientists also observed some examples of carnivory, including a sea spider feeding on an anemone, sea stars feeding on sponges, and gastropods parasitizing a crinoid and grazing on corals. At the conclusion of the dive, the Okeanos Explorer headed south and will be diving at an unnamed seamount in PIPA to the northwest of McKean Island tomorrow.


 


 

 

 

An unknown sea cucumber was observed hanging out on the rock surface.

An unknown sea cucumber was observed hanging out on the rock surface. Click image for credit and larger view.

An oreo fish with characteristic spines on the nose was observed at ~ 1151 meters depth.

An oreo fish with characteristic spines on the nose was observed at ~ 1,151 meters depth. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 21, 2017

Dive 13: Return to Titov Seamount

Our second dive at Titov Seamount started at the base of a steep, sedimented slope at 1,227 meters. On touchdown, Deep Discoverer immediately encountered a rattail previously unobserved on the expedition and synaphobranchid eels. Other fish observed on the dive included several cusk eels, rattails, goosefish, brotula, oreo fish, tripod fish, deep-sea spiny eels, and bristlemouths. On the scattered manganese iron oxide coated boulders and rocks, the scientists observed octocorals, generally oriented perpendicular to the current flow, which was north to south at the base of the slope. As the remotely operated vehicle progressed upslope, the sedimented seafloor was bordered by exposed rock, and several coral colonies were observed attached to the hard substrate. On the rock fringe, there were octocorals, bamboo coral, black corals, stony colonial and solitary corals, and sea pens. Other fauna included crinoids, sea cucumbers, sponges (unknown demosponges and encrusting sponges), sea stars, urchins, red crabs, a tunicate, squat lobsters, xenophyophores, nematocarcinids, and a benthic siphonophore. Along the crest of the seamount, several large boulders and rock features looked like coral gardens, with multiple colonies of deep-sea corals, sponges, and associates. The hard substrate was dominated by yellow plexaurids and primnoids. Throughout the dive, suspended particulate material was observed, possibly indicative of sufficient food supply to sustain these corals. Coral and sponge associates included euryalid serpent stars, barnacles, anemones, polychaetes, amphipods, shrimp, and cephalopod egg cases. The ship will return to the Winslow Reef area tomorrow to add to the limited knowledge of the species in that area.


 


 

 

 

Swimming sea cucumber lifts off from the sediment and takes a swim.

Swimming sea cucumber lifts off from the sediment and takes a swim. Click image for credit and larger view.

A carnivorous sea spider was observed feeding off of a cup coral.

A carnivorous sea spider was observed feeding off of a cup coral. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 20, 2017

Dive 12: Baker Island South

For this dive, the ship returned to the vicinity of Baker Island and dove along a steep slope on the southern ridge of Baker Island. Our initial depth was 1,858 meters and the seafloor was composed of large boulders with exposed rock surfaces interspersed with sandy sediments. A rock was collected along this feature. Several large boulders appeared as if they had been transported downslope, possibly via mass wasting events. There were columnar basalts observed along the slope, covered with thick manganese iron-oxide crust; some had a botryoidal texture (i.e., globular appearance). Transiting up the steep slope, several fish species were encountered, including cusk eels, a batfish, rattails, brotula, cutthroat eels, hake, and several deep-sea spiny eels. Corals observed included black corals, octocorals, whip and branching bamboos, and cup corals. The scientists also observed a colonial hydroid, Solanderia, with a possible egg case, large polychaete, and isopod. Sea stars, urchins, and sea cucumbers, including an unknown purple specimen, were observed on rocks or the sediment surface. Other taxa observed included a few different types of sponges (including encrusting types), a field of unknown dead hexactinellid sponges, anemones, pectinid bivalves, stalked crinoids, and xenophyophores on the sediment and rock surfaces. Associates included ophiocanthids, polychaetes, crinoids, and mysid shrimp. Scientists also observed a sea spider eating a cup coral, which had not been observed before. The dive ended on a short pinnacle composed of a basalt pavement seafloor. On this feature, an unknown bifurcated bamboo was observed and the scientists collected small snips of each stalk to determine if it was one or two individuals. Tomorrow, the ship will transit south and dive along the southwestern slope and crest of the summit at Titov Seamount.


 


 

 

 

Close up of a cirrate octopod egg case (brown) and inner chorion (purple). The octopus embryo will develop within the chorion until it is ready to hatch.

Close up of a cirrate octopod egg case (brown) and inner chorion (purple). The octopus embryo will develop within the chorion until it is ready to hatch. Click image for credit and larger view or watch video about the egg.

A nematocarcinid shrimp uses stilt-like legs to walk along rocks and the sediment.

A nematocarcinid shrimp uses stilt-like legs to walk along rocks and the sediment. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 19, 2017

Dive 11: Howland Island Deep

For this dive, we picked up where we left the seafloor on Dive 09 and transited along a ridge from 2,227 to 2,084 meters depth. Initially, the seafloor was a sedimented plateau surrounded by exposed, high profile rock features. Along the ridge, there was a sedimented slope with a perimeter of rocky ledges, interspersed by rock boulders. Toward the end of the dive, the substrate was composed of continuous hard-rock pavement with high profile, exposed rocky substrate. The dive began at the base of the ridge, on a plateau with several large coral colonies. A small sample of an unknown chrysogorgid octocoral with a width of 1.5 meters was collected. Additional corals encountered along the ridge included other octocorals, seapens, black corals, and whips and an unknown internodal branching bamboo. This dive had typical coral and sponge associates, including crinoids, brittle stars, ctenophores, shrimp, unknown worms, and aplacophorans. One new "associate" observed was a cirrate octopod egg case attached to a paragorgid octocoral. The case was cracked open, revealing the chorion, which may expand as the octopus embryo develops. Other empty brown cases were noted on Dive 09 at a similar depth, attached to a colonial hydroid. Other invertebrates observed, either attached to the rocks or on the sediment surface, included sea cucumbers, sea stars (a possible new species was collected), solitary hydroid, sponges, a hermit crab with a zooanthid house, shrimp with stilt-like legs, xenophyophores, stalked crinoids, an asteroschema on the rock surface without a host (unusual), sea urchins, a gastropod, and a sea spider. Along the ridge, there were at least three fish species, including halosaurs and cusk eels. The ship will be returning to Baker Island tomorrow to continue characterizing the diversity and distribution of organisms within the Pacific Remote Islands Marine National Monument.


 


 

 

 

This pearlfish represents a range extension for this newly described genus.

This pearlfish represents a range extension for this newly described genus. Click image for credit and larger view.

A narcomedusa jelly was observed close to the seafloor, at ~ 560 meters depth.

A narcomedusa jelly was observed close to the seafloor, at ~ 560 meters depth. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 18, 2017

Dive 10: Howland Island Shallow

The fourth dive within the Pacific Remote Islands Marine National Monument began at 587 meters depth, on the north slope of Howland Island. The dive progressed upslope to about 415 meters and then ended along a contour at 357 meters. The goal of the dive was improving the understanding of commercially important fish, as well as protected species within the region. During descent, there were small fish, crustaceans, medusas, pyrosomes, and siphonophores seen in the water column, as well as high concentrations of particulate organic matter. This dive had a very high diversity of fishes, with approximately 38 taxa recorded, some with ectoparasitic isopods attached. Specific fishes included midwater species (e.g., myctophids) and demersal species: goosefish, seatoads, codlings, oreo fish, scorpionfish, rattails, tonguefish, congers, pearlfish, dragonet, roughy, three species of sharks, greeneyes, deep-sea cardinal fish, green-spotted duck billed fish, snake eels, cusk eels, spikefish, armored sea robin, grappos, amberjack, dory, boar fish, and "ocean bass." The two pearlfish observed are representatives from a recently described genus and represent range extensions; they were previously only reported near Indonesia. Upslope, the rock face resembled features on Baker Island, with heavily eroded karstic terrain interspersed with sedimented channels. Large patches of sediment had small carbonate rocks with coral and shell fragments. Several different corals were observed clinging to vertical and near-vertical rock ledges, including precious corals, white and yellow cup corals, branching and whip bamboos, octocorals, black corals including an unknown black coral with long, extended branches, and a colonial hydroid. Dense colonies of black corals and octocorals were observed on gently sloping sedimented terrain. Coral associates observed included large brittle stars, squat lobsters, shrimps, a solitary hydroid, and amphipods. Along the rock walls, on the sediment surface and within burrows, there were several squat lobsters, shrimps, sea urchins, several sponges (one demosponge was collected), a large hermit crab with anemone house, other crab species, and a shy octopus hiding out in the sediment. Several potentially uninhabited tubes were seen on the sedimented slope. Underneath the eroded carbonate overhangs were limid bivalves. In one of the rock ledges was the proboscis of a spoonworm, possibly suspension feeding. Several sea stars encountered on this dive included cookie stars, coral predators, and a slime star.


 


 

 

 

A close-up of the icicle-like matrix of glass sponge spicules with a shrimp perched inside.

A close-up of the icicle-like matrix of glass sponge spicules with a shrimp perched inside. Click image for credit and larger view.

This snailfish was observed on the dive at 2,360 meters detph; snailfish were previously unknown from the region.

This snailfish was observed on the dive at 2,360 meters depth; snailfish were previously unknown from the region. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 17, 2017

Dive 09: Howland Island Deep

This was the deepest of the expedition so far, starting at 2,420 meters depth on a sedimented slope with several exposed rock features. Transiting upslope, the pilot noted a relatively high current. A few different fish species were observed along the slope, including spiny eels, cusk eels, rattails, and an unknown snailfish representing a new record for this region. Similar to the shallow dive at Baker Island, several of the fish had isopod ectoparasites. Other animals found on the sediment surface and rock debris included xenophyophores, sea cucumbers, brachiopods, sponges, stalked crinoids, a sea spider, sea stars, and scale worms. At 2,366 meters, the remotely operated vehicle encountered a steep wall composed of intact and collapsed pillow lava with a few fish including rattails and cusk eels. A carnivorous sponge and a branched sponge, both with multiple associates (polychaetes, ctenophores, brittle stars, hydroids, marine molluscs, amphipods, and crinoids) were collected. Scattered corals occurred on the steep face, including cup corals, black corals, a single stalk bamboo colony, and octocorals, as well as an unusual planar octocoral (with marine mollusc associates). Scientists observed sea stars and tried to collect an unknown one at 2,332 meters, which is deeper than any previous record; unfortunately, we were unable to collect it. At the peak of the steep slope, the terrain transitioned to flatter features with local topographic highs, including large boulders. This area represented a plateau before the start of the main ridgeline. The boulders and exposed rocks were populated with the largest and most diverse corals seen on the entire dive. Scientists imaged different species of octocorals, branched internodal and nodal bamboo corals, hydroid, and ~1.5-meter wide chrysogorgids. Each of the large colonies had at least one associate, including brittle stars, squat lobsters, zooanthids, and crinoids. The dive upslope tomorrow will be an interesting opportunity to see if these multiple fan colonies continue up along the ridgeline.


 


 

 

 

Unlike the benthic sea cucumbers that are often seen on the seafloor, this pelagic holothurian lives its entire life in the water column, relying on suspended particles for its food.

Unlike the benthic sea cucumbers that are often seen on the seafloor, this pelagic holothurian lives its entire life in the water column, relying on suspended particles for its food. Click image for credit and larger view or watch video of the sea cucumber.

The armor-like appearance of the roughy is where it got its name.

The armor-like appearance of the roughy is where it got its name. Click image for credit and larger view or watch video of the fish.

Suspension-feeding limid bivalves were found attached to the interior of eroded caves along steep slope.

Suspension-feeding limid bivalves were found attached to the interior of eroded caves along steep slope. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 16, 2017

Dive 08: Baker Island

This dive was at a depth of 725 meters along the northwest ridge of Baker Island. The seafloor was characterized by a steep rock wall with sedimented slope at the base. This dive had the most fish species so far with observations of midwater myctophids and gonostomatids; oreo fish; beard fish; conger eels; alfonsinos; cusk eels; roughy; goosefish; lanternfish; tonguefish; rattails; deep-sea cardinalfish; green-spotted duckbill fish; snake eels; Randall’s snapper, a distant relative to the dory; lanternbelly; greeneye; dogtooth tuna; spikefish; toadfish; and amberjack. Scientists observed ectoparasites (e.g., gnathiid isopods) on several fishes (ex., cusk eels) attached to the skin on different fins, mouths, and behind the eyes. Upon the steep slope, several coral taxa were observed, including whip and branching bamboo coral, cup corals, mushroom coral, black corals, octocorals, unknown primnoids, and colonial scleractinians. Other invertebrates observed included two crabs, one holding a dead colonial scleractinian skeleton and one with a sponge; encrusting sponges with zooanthids; barrel sponges; an unusual branched sponge; demosponges; corallimorpharian with pink tips on the tentacles; large shrimps; red crabs; sea stars; sea urchins; majid crabs with white and orange banded legs; hermit crabs with anemone houses; and feather stars. Along the steep karst-like rock wall, there were several eroded channels and caverns, some of which hid limid bivalves with tiny cup corals attached to the shells; an octopus; spiny sea urchins; and squat lobsters. These dramatic, cathedral-like rock features continued up the slope to about 423 meters depth, where the seafloor leveled out to a sedimented plain. Upcoming dives at Howland Island will be at a similar depth range, so it will be interesting to see if the observed patterns in the geology, biology, and ecology are consistent across the islands. Additionally, the remotely operated vehicle team replaced the tether containing the fiber optic cables connecting Deep Discoverer to the ship today. This will improve all communications between Deep Discoverer and the ship.


 


 

 

 

Bird-eye view of Titov Seamount. Our dive was along the western ridge line, or tail of the seamount feature.

Bird's-eye view of Titov Seamount. Our dive was along the western ridge line, or tail of the seamount feature. Click image for credit and larger view.

Close up of a chirostylid squat lobster perched on a black coral.

Close up of a chirostylid squat lobster perched on a black coral. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 15, 2017

Dive 07: Titov Seamount

This dive at 1,869 meters on Titov Seamount was the first dive within the Pacific Remote Islands Marine National Monument. The seafloor was characterized by steep rocky slope, with sediment channels and small rock debris. Presence of the rounded rock debris piles indicated that an upper slope failure had occurred some time ago. Several fish were observed at the base of the slope: cusk eels, rattails, and spiny eels. Given the presence of large patches of sandy sediment, there is likely sufficient infaunal prey for these fish to feed on. Transiting upslope, scientists observed several comatulid and stalked crinoids, urchins, an anemone, a chiton, a carnivorous tunicate, a purple polychaete, sea stars, sponges, and a hermit crab with a shiny shell. The stalked red crinoids had polychaete worms attached to the arms and hydroids at the base. A new crinoid had long arms with no pinnules near the tips. Corals attached to the rocks included octocorals, black coral, whip and nodal branching bamboo coral, octocorals, and a cup coral. The slope transitioned to steep rock slabs with very little sediment and several dead coral bases attached to rock surfaces. Multiple new coral species observed included an about four-meter long bamboo whip; other black corals; and octocorals, including a new species only observed at Necker Ridge, some of which were encrusted with zooanthids. Around 1,705 meters, Deep Discoverer transitioned to the ridgeline, which was composed of continuous smooth rock with no sediment drape where the relatively dense particulate organic matter increased. On the ridgeline were sponges, octocorals, and yellow crinoids. Several brittle stars were leaping off a dead bamboo skeleton onto the rock ridge below. Toward the end of the dive, the seafloor pavement transitioned to exposed rock boulders and mounds interspersed with sandy sediment containing sea cucumbers and sea pens. There were additional colonies of octocorals, yellow whips and branched black corals, and candelabra and whip bamboo corals. Two separate carnivorous sea stars were feeding on bamboo coral. Coral associates observed included crinoids, ophiuroids, barnacles, amphipods, and crabs. While this dive had low densities of taxa, scientists observed a high diversity of corals, coral associates, and other invertebrate taxa. An exciting shallow dive at Baker Island tomorrow should promise some interesting and new fish species!


 


 

 

 

The curly-cue shape is a characteristic of this chrysogorgid octocoral, called Iridogorgia.

The curly-cue shape is a characteristic of this chrysogorgid octocoral, called Iridogorgia. Click image for credit and larger view.

A new seastar for the expedition was spotted at the base of a large octocoral at the end of the dive.

A new sea star for the expedition was spotted at the base of a large octocoral at the end of the dive. Click image for credit and larger view.

An unusual green-blue octocoral was spotted at the end of the dive, populated with crinoids and brittle stars. The coral stumped the shore-side scientists, so a collection was requested to allow follow-up identification.

An unusual green-blue octocoral was spotted at the end of the dive, populated with crinoids and brittle stars. The coral stumped the shore-side scientists, so a collection was requested to allow follow-up identification. Click image for credit and larger view.

video Watch video of a siphonophore.

 


NOAA Ship Okeanos Explorer
March 14, 2017

Dive 06: Winslow Reef Complex

Dive 06 began at 1,560 meters on an unnamed seamount west of Winslow Reef complex, within the United State's Exclusive Economic Zone. Moving upslope along sediment channels, scientists observed several fish, including cusk eels, brotula, slickhead, and a cutthroat eel (possibly a gravid female). Other species encountered included several large bamboo colonies attached to boulders, large sponges, octocorals, xenophyophores, and a seastar. As the dive transitioned to a sedimented gradual slope, typical sediment dwellers were observed: sea pens, urchins, sea cucumbers, sea spider, spiny eels, and tripod fish. The final segment of the dive was characterized by sedimented ledges punctuated by high profile rocks and large boulders. Additional fauna encountered on this heterogeneous terrain included different bamboo species including the whip with an amphipod associate and a collected branched form, zooanthids growing on a dead bamboo skeleton, black coral whips, encrusting sponges, and a sea star. Additional fishes included a male halosaur, unknown cusk eels, and cutthroat eels. There were several dead bamboo skeletons and bases scattered throughout the beginning and end of this dive. One base attached to manganese crust was collected to estimate the coral age. Also observed throughout the dive was an unknown yellow bamboo coral collected for identification. At approximately 1,366 meters the summit had exposed rock interspersed with patches of sediment and the largest bamboo colonies attached to the rocks with crinoids and several squat lobsters. On a topographic high, scientists found a very large, green-blue plexaurid coral with several associates (crinoids and brittle stars). Because of the uncertainty about the family-level identification of this coral, a piece was collected with associates. A new sea star was observed at the base of this colony. This dive was characterized by relatively high densities of one species of branched bamboo, with remarkably large colonies occurring at the summit. Given their size and likely old age, there may be long-term environmental stability at this seamount, including adequate food supply, sufficient currents, and minimal direct human impact. However, the large density of dead bamboo bases and rock debris fields down slope may indicate periodic disturbance events, including landslides.


 


 

 

 

A large hake swims past a crinoid.

A large hake swims past a crinoid. Click image for credit and larger view.

A glass sponge seen on Polo Seamount.

A glass sponge seen on Polo Seamount.Click image for credit and larger view.

video Watch video of highlights from the dive.

 


NOAA Ship Okeanos Explorer
March 13, 2017

Dive 05: Polo Seamount

This dive was on Polo Seamount in the Tokelau Seamount Chain and was the third dive within the Phoenix Islands Protected Area. This was the deepest dive to date, starting at 2,134 meters within a sedimented canyon-like feature and transiting up a low-grade slope to 1,834 meters. Similar to Carondelet Reef (Dive 03) and the unnamed seamount (Dive 04), there was a fair amount of particulate organic matter in the water column on descent. Along the sedimented seafloor, scientists observed sea urchins, cup corals, xenophyophores, shrimp, sea cucumbers, two tripod fish, a brotula, two rattails, a sea star, and a sea pen with a purple polychaete. Large boulders were encountered with several attached fauna: corallimorpharian (looks like an anemone), black coral, crinoid, and tunicates with polychaete and anemone associates. At approximately 2,100 meters, the seafloor transitioned to steep exposed rock encrusted with manganese iron oxide. As Deep Discoverer progressed up the rock face, additional corals were added to the observation list: bamboo corals (branching and whip forms), coralliids (precious coral family), octocorals, primnoids, and black corals. Other invertebrates observed along the steep slope included coral associates (barnacles, sea lilies, zoanthids, squat lobsters, and amphipods), stalked sea lilies, tunicates, sea cucumbers, sea stars, anemones, and sponges. Almost every vertical rock face from 2,002 to 1,837 meters was covered with high densities of corals, mostly octocorals and other unknown fan corals. Close to the summit, scientists observed a large hake and a snipe eel. The current was variable and generally from the northeast to the southwest along the steep slope. The dive ended within 15 meters from the top of the knoll, but the seafloor leading to the peak was covered with corals and sponges. The taxa densities and diversity appeared to increase toward the summit, at the same depths where similar patterns were observed on Carondelet Reef. While it is difficult to generalize these patterns based on only two dives, it will be useful to conduct dives at similar depth ranges on other seamounts to examine if this pattern holds true.


 


 

 

 

Squid (Chiroteuthis sp.) holding onto another squid, but it remains unclear whether this is active predation or mating behavior.

Squid (Chiroteuthis sp.) holding onto another squid; it remains unclear whether this is active predation or mating behavior. Click image for credit and larger view.

D2 manipulator jaws are gently grasping the crown of a stalked crinoid (Phrynocrinidae) for a collection. This crinoid species has only previously been observed in the Celebes Sea, off Indonesia.

Deep Discoverer's manipulator jaws are gently grasping the crown of a stalked crinoid (Phrynocrinidae) for a collection. This crinoid species had previously only been observed in the Celebes Sea, off Indonesia. Click image for credit and larger view.

White precious coral (Pleurocorallium cf. kishinouye) and rock collected from the seafloor for coral identification and seamount age analysis.

White precious coral (Pleurocorallium cf. kishinouye) and rock collected from the seafloor for coral identification and seamount age analysis. Click image for credit and larger view.

video Watch video of a goosefish encountered during the dive.

 


NOAA Ship Okeanos Explorer
March 12, 2017

Dive 04: Unnamed Seamount ("Athena")

This dive began at 1,228 meters depth, at an unnamed seamount in the Tokelau Seamount Chain. It was the second dive within the Phoenix Islands Protected Area (PIPA). As with the previous dive at Carondelet Reef, there was a fair amount of particulate organic matter in the water column on the descent. At the base of the slope, there was a weak current to the southeast, and the dominant substrate was steep exposed manganese-coated rock with patches of sediment. At the start of the dive, scientists observed xenophyophores on the sediment surface, several octocorals attached to rocks, and sea pens within the sediment. Heading upslope, coral species spotted included a bamboo whip, at least two different primnoids, and other octocorals. Numerous colonies of a suspected precious coral, Pleurocorallium cf. kishinouye, were observed on rock slabs. Several species of fish were observed along the steep slope: cutthroat eels, cusk-eels, brotulas, snaketooth fish, and a goosefish. Coral and sponge associates included chirostylids, ophiuroids, crinoids, amphipods, polychaetes, and shrimp. Other invertebrates observed on the steep slope included sea stars, long-spined urchins, echinothurids, sponges, stalked crinoids, and anemones. Pelagic organisms were more abundant on this dive and included ctenophores, siphonophores, black medusae, pelagic holothurians, two squids (one holding on to another squid), and midwater fish. Scientists also collected a rock with one colony of an abundant white coral and a snip from the purple coral. The south approach to the seamount's summit revealed large pavement blocks that were fragmented with little sediment drape. Scientists turned off the remotely operated vehicle lights to see if that revealed any fish. The light test was unsuccessful, but the scientists did see tripodfish, blind lobster, isopods, cusk-eels, cutthroat eels, octocoral with associates, and an urchin with puffy spines towards the end of the dive. Notable observations on the dive included crabs gripping sponges, hydroids, or anemones, and an octocoral with possible squid egg cases (at least three colonies observed). Scientists observed several taxa similar to the dive on Swains Island. Several fish observations represent new records for Kiribati and the dive overall enabled increased understanding of deep-sea corals, sponges, and fishes found within PIPA.


 


 

 

 

Precious corals, like this species of Hemicorallium, were common at depths explored on Carondelet Reef. Precious corals have been exploited for their commercial value throughout history. Most coral colonies also were home to sometimes more than one species of brittle stars (ophiuroids). Some brittle stars are thought to have a mutualistic symbiosis with deep-sea corals.

Precious corals, like this species of Hemicorallium, were common at depths explored on Carondelet Reef. Precious corals have been exploited for their commercial value throughout history. Most coral colonies also were home to sometimes more than one species of brittle stars (ophiuroids). Some brittle stars are thought to have a mutualistic symbiosis with deep-sea corals. Click image for credit and larger view.

One bamboo coral observed at Carondelet Reef was truly a behemoth. Bamboo corals are named for their skeleton which has alternating nodes and internodes resembling bamboo shoots. This particular individual was nearly 3m wide. Estimates of the age of this coral could be as high as 300 years old!

One bamboo coral observed at Carondelet Reef was truly a behemoth. Bamboo corals are named for their skeleton, which has alternating nodes and internodes resembling bamboo shoots. This particular individual was nearly three meters wide. Estimates of the age of this coral could be as high as 300 years old! Click image for credit and larger view.

video Watch video of highlights from the dive.

 


NOAA Ship Okeanos Explorer
March 11, 2017

Dive 03: Carondelet Reef

This dive was the most biologically diverse of the dives on the expedition thus far, with scientists documenting at least 32 species of corals, over 21 species of other invertebrates, and five species of fishes. The dive track was on the southwest ridge of Carondelet Reef within the Phoenix Islands Protected Area (PIPA). The first deep dive in this area. The dive began around 1,840 meters and finished along a gradual ridge at 1,587 meters. The start of the dive, in the first 20 meters, was very speciose with at least 11 species of corals, including two types of octocorals (some with eggs), stony corals, four black corals with two branched forms and whips, and large bamboo colonies attached to steep rock faces, plus two species of sponges, and several associates. Hemicorallium was the first precious coral observed on the dives thus far. Most of the fan corals were oriented perpendicular to the dominant current, flowing from the northwest to the southeast. As Deep Discoverer moved upslope, new corals seen included species of black coral, rock pens, sea pens, octocorals, soft corals, and bamboo corals. Cup corals were the only scleractinians documented on the dive. Five species of fish were observed: cutthroat eels not observed on previous dives within American Samoa at similar depths, batfish, and a bristlemouth.

At the gently sloped terrain at around 1,700 meters depth, there were more sedimented ledges and sediment-filled rock fissures. The substrate had several long (greater than one meter) bamboo coral whips and a large bamboo colony, estimated to be 300 years old, with several tendrils securing it to the steep rock ledge. Scientist sampled an octocoral and an unknown sponge with associates. The underside of rock ledges were often populated by small colonies of octocorals. Notable non-coral observations included sponges, predation by a sea star on a bamboo whip, crab with an anemone clasped by its posterior limbs, a benthic siphonophore resembling a pipe organ, and a roughly 17 centimeter-long ribbon worm. With nothing previously known about the deep-sea fauna within PIPA, these observations will help with management of biological resources in the protected area. Future dives will clarify if the diversity and abundance of fauna present on Carondelet Reef is representative of the broader region.


 


 

 

 

A male and female sixgill sharks swim together. The female shark was 13 - 15 feet in length.

A male and female sixgill sharks swim together. The female shark was 13 - 15 feet in length. Click image for credit and larger view or click here to watch video of the sharks.

A barrel sponge that has fallen on the sediment.

A barrel sponge that has fallen on the sediment. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 10, 2017

Dive 02: Pao Pao Seamount

Today's dive started around 544 meters, heading southwest up a steep slope along the northeast side of Pao Pao Seamount and revealing exciting insights into the fish and invertebrate communities within the Tokelau seamount chain. The substrate was composed of exposed hard rock with areas of thick sediment drape. Numerous pteropod shells were found within the sediment. Heading upslope, there were several species of fish, including deepwater cardinalfish, scorpionfish, two species of sharks, spikefish, green spotted duckbill fish, groppo, zeniontids, boarfish, Randall's snapper, and an unknown black and white-striped fish. The slope was populated with several coral species, including colonial stony corals, solitary cup corals, black corals, bamboo whips with polyps loaded with eggs, and large octocoral colonies covered with associates. Two octocoral samples were collected. A large stony coral colony was observed growing in a bush shape around the dead "black" coral skeleton aged at about 1,200 years old, based on the 10-centimeter diameter of the base. Other invertebrates observed included sea stars, large barrel sponges, chirostylids, and feather stars.

Moving onto the summit, scientists observed changes in substrate type, from steep rock ledges and sedimented slope to relatively flat carbonate pavement, interspersed with pits and caves. The fauna included sea stars, octocoral colonies, and pencil urchins. A pencil urchin was observed feeding on an octocoral and several colonies had visibly bare skeleton on the branches, indicating recent predation. Octocoral tissue with associates was collected for identification. Several hermit crabs had gastropod shells, but one was observed with an anemone "shell." Multiple large and small boarfish were associated with the pits and depressions, potentially using them as refuges from the swift currents. Other fish encountered included eight barred grouper, deepwater snappers, amberjack, deepwater stingray, yellow eels, scorpionfish, groppo, hogfish/wrasses, and left-eye flounder. Some of the fish observed represent important commercial fish for the region. Invertebrates at the summit included an octopus, quill worms, brachiopods, and yellow colonial stony corals. At the summit, we saw what looked like fishing line, which represented the first marine debris observed on the dives thus far. Throughout the dive, there was an obvious lack of precious corals present, in contrast to previous CAPSTONE dives within Northwestern Hawaiian Islands.


 


 

 

 

Multibeam bathymetry of Pao Pao Seamount (right) and an unnamed guyot (left) shows one example of nearby seamounts with very different geomorphology. Pao Pao Seamount comes to a very sharp peak at around 300 meters and shows steep flanks while the unnamed feature has a distinct flat top. Biological communities we find on these features may differ greatly at similar depth intervals despite being only 25 kilometers apart from each other.

Multibeam bathymetry of Pao Pao Seamount (right) and an unnamed guyot (left) shows one example of nearby seamounts with very different geomorphology. Pao Pao Seamount comes to a very sharp peak at around 300 meters and shows steep flanks while the unnamed feature has a distinct flat top. Biological communities we find on these features may differ greatly at similar depth intervals despite being only 25 kilometers apart from each other. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 9, 2017

Filling in Gaps Along the Way

The Okeanos Explorer began transiting from Swains Island to Pao Pao Seamount in the Tokelau Seamount Chain which will be our first dive in the waters of New Zealand's Territory of Tokelau. During the roughly 36 hours of transit, the ship collected data with three different types of sonar. You can learn more about these sonars and how the ship maps the seafloor by reading this mission log. This additional mapping will help to fill in the data gaps at the various seamounts. The updated depths of Pao Pao Seamount in particular allowed the scientists to further refine the dive track for the upcoming remotely operated vehicle dive. The scientists hope the Pao Pao Seamount will be an interesting shallow dive starting at about 530 meters. The dive track will begin along the northern ridge of Pao Pao seamount and proceed upslope to the crest of the seamount summit at about 270 meters. The goal of this dive is to continue surveying for fish of commercial importance, as well as characterize deep-sea coral, sponge communities, and seafloor substrate.


 


 

 

 

This deep-sea coral garden at Swains Island hosts numerous species of corals and coral-relatives. In the foreground is a chrysogorgiid octocoral surrounded by translucent anemones. Yellow stony corals like Enallopsammia sp. are visible to the left and throughout the background. Black coral whip colonies grow upwards off the seafloor in thin stalks.

This deep-sea coral garden at Swains Island hosts numerous species of corals and coral-relatives. In the foreground is a chrysogorgiid octocoral surrounded by translucent anemones. Yellow stony corals like Enallopsammia sp. are visible to the left and throughout the background. Black coral whip colonies grow upwards off the seafloor in thin stalks. Click image for credit and larger view.

A long-armed squid in the genus Chiroteuthis swims in front of Deep Discoverer. These squids are pelagic predators using their tentacles and arms to capture and consume prey.

A long-armed squid in the genus Chiroteuthis swims in front of Deep Discoverer. These squids are pelagic predators using their tentacles and arms to capture and consume prey. Click image for credit and larger view or click here to watch video of the squid.

 


NOAA Ship Okeanos Explorer
March 8, 2017

Dive 01: Swains Island

This first dive started at 1,143 meters along the steep slope off the western ridge of Swains Island, within National Marine Sanctuary of American Samoa. The seafloor contained extensive pillow basalt outcrops and fragments coated in manganese iron oxide and interspersed with patches of thin sediment drape. The complex rock substrate was covered with anemones or possibly corallimorphs and populated with stony corals, cup corals, octocorals, and black corals; coral associates including crabs and brittle stars. Fish encountered early in the dive included a slick head and different species of eels. On rock surfaces and sediment patches were shrimp, blind lobster, hermit crab, and sea cucumbers. A sponge, Aspidoscopulia sp., was collected, which represented a new record for this region, and several other sponges were observed. Within the rock outcrops were patches of dead manganese-coated stony coral debris. At 1,114 meters, Deep Discoverer transitioned from patchy to high-density coral cover. A squid was observed prior to the transition from slope to ridge at about 1,100 meters. The ridge was punctuated by large mounds of pillow lava and boulders, often covered with abundant encrusting fauna. Several fish observed only on the ridge included an anglerfish, three types of eels, oilfish, rattails, black scorpion fish, and bristlemouths. New coral observations included the black coral with hermit crab associates and encrusting zoanthids. Other fauna included a sponge, sea urchins, and a swimming polychaete. Sea stars were only observed along the slope, perched on the side of rock faces. The homolid-type crab was found on several corals and rocks, often holding a hydroid or black coral fragment with its posterior-most legs, potentially serving as camouflage. Similar sized “yellow stoney” corals were observed, suggesting a single recruitment event, possibly following a disturbance. Large manganese-coated coral rubble, likely fallen from shallower depths, were found along the ridge. This dive was very interesting because it had potentially higher diversity and abundance of corals and other taxa compared to other dives conducted in the region, stressing the need for follow-up dives at similar depths in the future. Hopefully our next dive at Pao Pao Seamount will be as interesting and as abundant as this one!


 


 

 

 

NOAA Ship Okeanos Explorer docked at the pier at the Port of Apia in Samoa.

NOAA Ship Okeanos Explorer docked at the pier at the Port of Apia in Samoa. Click image for credit and larger view.

 


NOAA Ship Okeanos Explorer
March 7, 2017

Underway

NOAA Ship Okeanos Explorer departed Apia, Samoa's harbor this morning to begin the Discovering the Deep: Exploring Remote Pacific Marine Protected Areas expedition. We are currently transiting north to our first dive site at Swains Island. Swains Island is an atoll geographically located at the southern end of the Tokelau chain of islands and seamounts. It is a unit of National Marine Sanctuary of American Samoa. The goal of this first dive is to gather baseline information on deep-sea habitats and biological communities to better understand their diversity and distribution. Researchers on the previous expedition, the first leg of the 2017 American Samoa expedition, are also excited about collecting rock samples in the area to determine the geologic origins of this island. Given the relative proximity of the recent dives at Rose Atoll and Vailulu'u Seamount, exploring Swains Island will help us understand the distribution and connectivity of biological communities within this sanctuary and the broader geological and ecological connections along the Tokelau Archipelago. Tune in to the live feeds tomorrow to learn more about this uncharted area and get a glimpse of some of the life at depth.


 


 

 

 

 

 

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