Rhian Waller

• University of Gothenburg

Interest in the deep Arctic Ocean is rapidly increasing from governments, policy makers, industry, researchers, and conservation groups, accentuated by the growing accessibility of this remote region by surface vessel traffic. In this review, our goal is to provide an updated taxonomic inventory of benthic taxa known to occur in the deep Arctic Oce...

Little is known of the reproductive traits and dispersal potential of many deep-sea corals, and in-aquarium spawning has been observed for very few species globally. Here, we document the first known observation of larval release by Goniocorella dumosa (Alcock 1902), a habitat-forming deep-sea scleractinian stony coral found in the New Zealand regi...

The presence of corals living in deep waters around the globe has been documented in various publications since the late 1800s, when the first research vessels set sail on multi-year voyages. Ecological research on these species, however, only truly began some 100 years later. We now know that many species of deep-sea coral provide ecosystem servic...

Little is known about the biology of cold-water corals (CWCs), let alone the reproduction and early life stages of these important deep-sea foundation species. Through a three-year aquarium experiment, we described the reproductive mode, larval release periodicity, planktonic stage, larval histology, metamorphosis and post-larval development of the...

The Western Antarctic Peninsula is home to a diverse assemblage of deep-sea species and is warming faster than any other region in the Southern Hemisphere. This study investigated how larval development of the Antarctic cold-water coral Flabellum impensum was affected by temperatures consistent with ocean warming trends predicted for the twenty-fir...

From June 30 through July 29, 2021, the NOAA Ocean Exploration and partners conducted the "2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts" expedition, a telepresence-enabled ocean exploration expedition aboard the NOAA Ship Okeanos Explorer. The mission objectives were to collect critical baseline information about unkno...

Corals nucleate and grow aragonite crystals, organizing them into intricate skeletal structures that ultimately build the world’s coral reefs. Crystallography and chemistry have profound influence on the material properties of these skeletal building blocks, yet gaps remain in our knowledge about coral aragonite on the atomic scale. Across a broad...

In the Gulf of Alaska, commercially harvested fish species utilize habitats dominated by red tree corals (Primnoa pacifica) for shelter, feeding, and nurseries, but recent studies hint that environmental conditions may be interrupting the reproductive lifecycle of the corals. The North Pacific has experienced persistent and extreme thermal variabil...

Deep-sea scleractinian cup corals are prominent members of Southern Ocean megabenthic communities, though little is known about their life history. This study used paraffin histology and scanning electron microscopy to characterize the reproduction of the scleractinian coral Balanophyllia malouinensis (Squires, 1961) from Burdwood Bank in the Drake...

Glacier Bay National Park and Preserve (GBNPP) in Southeast Alaska is a system of glaciated fjords with a unique and recent history of deglaciation. As such, it can serve as a natural laboratory for studying patterns of distribution in marine communities with proximity to glacial influence. In order to examine the changes in fjord-based coral commu...

Red tree corals (Primnoa pacifica) are abundant in the eastern Gulf of Alaska, from the glacial fjords of Southeast Alaska where they emerge to as shallow as 6 m, to the continental shelf edge and seamounts where they are more commonly found at depths greater than 150 – 500 m. This keystone species forms large thickets, creating habitat for many as...

Primnoa pacifica is the most ecologically important coral species in the North Pacific Ocean and provides important habitat for commercially important fish and invertebrates. Ocean acidification (OA) is more rapidly increasing in high-latitude seas because anthropogenic CO2 uptake is greater in these regions. This is due to the solubility of CO2 in...

The OA study was compared to the 2014 reproductive study by Waller and associates. (DOCX)

Information detailing how the corals were arranged in the tanks and protocol for their care for the duration of the OA experiment. (DOCX)

Methods and results of the sprig analysis. (DOCX)

Deep-sea corals are of conservation concern in the North Atlantic due to prolonged disturbances associated with the exploitation of natural resources and a changing environment. As a result, two research cruises in the Gulf of Maine region during 2014 and 2017 collected samples of two locally dominant coral species, Primnoa resedaeformis and Paramu...

Desmophyllum dianthus is a cosmopolitan species usually found at 1000–2500 m depth in the deep ocean, but in the Patagonian fjords can be found in shallow waters up to 8 m due to deep-water emergence. The purpose of this study was to determine the reproductive biology and seasonality of the scleractinian cup coral D. dianthus from the Chilean fjord...

In an ocean with rapidly changing chemistry, studies have assessed coral skeletal health under projected ocean acidification (OA) scenarios by characterizing morphological distortions in skeletal architecture and measuring bulk properties, such as net calcification and dissolution. Few studies offer more detailed information on skeletal mineralogy....

Primnoa pacifica is the most ecologically important coral species in the North Pacific Ocean where it provides important habitat for commercially important fish and invertebrates. Ocean acidification (OA) is more rapidly increasing in high-latitude seas because anthropogenic CO2 uptake is greater in these regions. This is due to the solubility of C...

Cold-water corals provide critical habitats for a multitude of marine species, but are understudied relative to tropical corals. Primnoa pacifica is a cold-water coral prevalent throughout Alaskan waters, while another species in the genus, Primnoa resedaeformis, is widely distributed in the Atlantic Ocean. This study examined the V4-V5 region of t...

Biogeographical patterns among deep sea benthic communities in the Drake Passage remain poorly understood as a consequence of poor sampling resolution and the spatial remoteness of many sea floor features. Hard-bottom features, including at least 20 seamounts, remain uncharacterized with respect to their benthic megafaunal community assemblages. He...

Deep-sea coral and sponge ecosystems are widespread throughout most of Alaska’s marine waters. In some places, such as the central and western Aleutian Islands, deep-sea coral and sponge resources can be extremely diverse and may rank among the most abundant deep-sea coral and sponge communities in the world. Many different species of fishes and in...

Although deep-sea octocorals were historically considered common components of hard bottom communities in the deep waters of the Gulf of Maine region, they are now spatially rare and have been difficult to detect using standard towed-gear surveys. Exploratory ROV and towed camera surveys in 2002-03 and 2013-15 located sites in deep U.S. waters (ca....

The common sea pen (Pennatula aculeata) is a deep, cold-water coral in the soft sediments of the Gulf of Maine, often occurring in dense patches. While providing physical habitat structure, it is routinely removed as bycatch during commercial fishing activities. A study in Atlantic Canada (Baillon et al. 2012) examined sea pens from trawl bycatch a...

This study examined the reproductive ecology of eight Eastern Pacific deep-sea octocorals, collected from Washington to Southern California. The sexuality, reproductive mode, oocyte size, and fecundity of each species were identified using histological techniques. This research increases the knowledge of basic life histories of deep-sea corals. Swi...

White paper regarding exploration for and conservation of deep sea corals in Gulf of Maine

The red tree coral Primnoa pacifica is an important habitat forming octocoral in North Pacific waters. Given the prominence of this species in shelf and upper slope areas of the Gulf of Alaska where fishing disturbance can be high, it may be able to sustain healthy populations through adaptive reproductive processes. This study was designed to test...

Environmental conditions can influence the physiology of marine organisms and have important implications for their reproductive performance and capacity to supply new recruits. This study examined the seasonal reproductive patterns of the coral Montipora capitata in habitats exposed to different sedimentation regimes. Although M. capitata is a mai...

Octocorals had been considered a common component of the seafloor fauna in the Gulf of Maine, but it appears a century of impacts have reduced coral distribution to small refugia. Here we provide a preliminary report of a recent expedition that discovered dense coral garden communities at two sites >200 m depth.

The deep-sea solitary scleractinian, Fungiacyathus marenzelleri (Vaughan, 1906) is found at depths of 300–6328 m, and is cosmopolitan in distribution. Previously this species had been examined from 2200 m depth in the Northeast Atlantic and 4100 m in the Northeast Pacific. This study examines gametogenesis and fecundity of this species from its sha...

Scleractinian corals have a global distribution ranging from shallow tropical seas to the depths of the Southern Ocean. Although this distribution is indicative of the corals having a tolerance to a wide spectrum of environmental conditions, individual species seem to be restricted to a much narrower range of ecosystem variables. One way to ascerta...

The Hawaiian black coral fishery has maintained steady catch levels for over 50 years. However, recent declines in the biomass of commercially valuable Hawaiian black corals question whether regulations need to be redefined for sustainable harvesting. Fishery management efforts are complicated by the limited information on the basic life history an...

Scleractinian coral populations exist in every ocean basin from shallow reefs in the tropics to the depths of the Southern Ocean. These corals have aragonite skeletons and when they die their skeletons can be preserved for hundreds of thousands of years forming a long-term record of their biogeography. Dating these corals has the potential to allow...

Black corals (Cnidaria: Antipatharia) are ecologically important components of the sessile invertebrate fauna, however, due to their preference for deep-water environments (>50 m), very little is known about their basic biology including their reproductive processes. We used histological techniques to examine the sexual reproduction of eight antipa...

The majority of scleractinian corals are hermaphrodites that broadcast spawn their gametes separately or packaged as egg–sperm bundles during spawning events that are timed to the lunar cycle. The egg–sperm bundle is an efficient way of transporting gametes to the ocean surface where fertilization takes place, while minimizing sperm dilution and ma...

Knowledge of the degree to which populations are connected through larval dispersal is imperative to effective management, yet little is known about larval dispersal ability or population connectivity in Lophelia pertusa, the dominant framework-forming coral on the continental slope in the North Atlantic Ocean. Using nine microsatellite DNA markers...

Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the...

The colonization dynamics and life histories of pioneer species determine early succession at nascent hydrothermal vents, and their reproductive ecology may provide insight into their dispersal and population connectivity. Studies on the reproductive traits of two pioneer gastropod species, Ctenopelta porifera and Lepetodrilus tevnianus, began with...

Gametogenesis and reproductive periodicity of the solitary scleractinians Flabellum alabastrum (from the Rockall Trough) and F. angulare (from the Porcupine Seabight) were investigated. Samples were collected between depths from 1370 to 2190 m for F. alabastrum and 2412 to 2467 m for F. angulare. Both species showed gonochorism with a 1:1 sex-ratio...

The USGS Cold-Water Coral Geographic Database (CoWCoG) provides a tool for researchers and managers interested in studying, protecting, and/or utilizing cold-water coral habitats in the Gulf of Mexico and western North Atlantic Ocean. The database makes information about the locations and taxonomy of cold-water corals available to the public in an...

The larval development of three species of deep-water scleractinian, Flabellum thouarsii, F. curvatum and F. impensum, was examined from samples collected from the deep continental shelf off the Western Antarctic Peninsula between 1999 and 2001. All three of these species were gonochoric, with females brooding multiple stages of planulae larvae. Me...

Three species of deep-sea corals were collected from several locations in the Hawaiian Archipelago. These species have been called "precious corals" because of their extensive use in the jewelry industry. Two octocorals Corallium lauuense Bayer, 1956 (red coral) and Corallium secundum Dana, 1846 (pink coral), and a zoanthid, Gerardia sp. (gold cora...

Deep-sea corals have grown for over 200,000 yrs on the New England Seamounts in the northwest Atlantic, and this paper describes their distribution both with respect to depth and time. Many thousands of fossil scleractinian corals were collected on a series of cruises from 2003–2005; by contrast, live ones were scarce. On these seamounts, the depth...

The potential applications of ancient DNA (aDNA) techniques have been realized relatively recently, and have been revolutionized by the advent of PCR techniques in the mid 1980s. Although these techniques have been proven valuable in ancient specimens of up to 100,000 yrs old, their use in the marine realm has been largely limited to mammals and fi...

Here we report the first direct underwater observations of extensive human-caused impacts on two remote seamounts in the Corner Rise complex (north-western Atlantic). This note documents evidence of anthropogenic damage on the summits of Kükenthal peak (on Corner Seamount) and Yakutat Seamount, likely resulting from a limited Russian fishery from t...

Fungiacyathus marenzelleri (Vaughan, 1906) is a deep-water solitary coral, cosmopolitan in distribution that is found at depths of 300–6,328m. This study examined gametogenesis, inter-annual variability and reproductive periodicity of F. marenzelleri collected from Station M (34°50′N, 123°00′W) in the northeast Pacific at a depth of 4,100m. Samples...

The removal of deep-water coral and other large biogenic structures as a consequence of deep-sea fisheries is well documented for seamounts in the SW Pacific and is presently the focus for strong conservation measures across the globe. As continental shelf fish stocks decline and fisheries regulations become stricter, there is continual movement of...

The reproductive biology and gametogenesis of three species of Caryophyllia were examined using histological techniques. Caryophyllia ambrosia, Alcock 1898, C. cornuformis, Pourtales 1868, and C. sequenzae, Duncan 1873, were collected from the Porcupine Seabight and Rockall Trough in the NE Atlantic Ocean. These three ahermatypic solitary corals in...

The reproductive ecology of colonies of Lophelia pertusa (Linné 1758) and Madrepora oculata Linné (1758) from the Porcupine Seabight (Thérèse Mound and South Porcupine Seabight site) and the Darwin Mounds (NE Rockall Trough—L. pertusa only) was investigated using histological techniques. Samples of L. pertusa exhibited seasonal reproduction, wherea...

Little is known of the basic biology and ecology of the numerous species of deep-water scleractinians found in all the world’s oceans. Of all the biological processes, reproduction is the most fundamental. Without knowledge of a species’ reproduction, we know little about how they survive both the environment that is the deep-sea, and the increasin...

p>Deep water corals and coral reefs have gained considerable attention recently, both in the public and scientific domain. These corals inhabit depths from relatively shallow at a few tens of metres, to over 6000m, and most have cosmopolitan distributions. These corals can form complex frameworks that attract a variety of invertebrate and vertebrat...

In May-June 2002, the Galapagos Rift axis was explored during a NOAA Ocean Exploration Program expedition that investigated three sites along the Rift between 86°W and 89.5°W. Two major vent fields with markedly different community structures were discovered near 86° 13'W (Rosebud) and 89° 37'W (Calyfield) and were biologically, geologically and ge...

The reproductive biology and its seasonality were examined in the deep-water, solitary coral Fungiacyathus marenzelleri from 2,200 m depth in the NE Atlantic, using histological techniques. A total of 186 corals were collected using either an Otter trawl (semi-balloon) or Agassiz trawl from the research vessel RRS Challenger between 1979 and 1991....

The Calyfield vent was discovered in June 2002 along the Gal pagos Rift. This vent site is a 60m x 60m field dominate by the Vescomyid clam Calyptogena magnifica and large patches (~1m2) of grey biological material, thinly covering the basalts. Numerous pieces of lobate lava, with this grey covering, were collected by Alvin from this site. Taxonomi...