Cold-water Coral Communities Research Articles

Cold-Water Corals and Anthropogenic Impacts in La Fonera Submarine Canyon Head, Northwestern Mediterranean Sea.

We assess the occurrence and extent of cold-water coral (CWC) species Madrepora oculata and Dendrophyllia cornigera, as well as gorgonian red coral Corallium rubrum, in La Fonera canyon head (Northwestern Mediterranean Sea), as well as human impacts taking place in their habitats. Occurrence is assessed based on Remotely Operated Vehicle (ROV) video imaging. Terrain classification techniques are applied to high-resolution swath bathymetric data to obtain semi-automatic interpretative maps to identify the relationship between coral distribution patterns and canyon environments. A total of 21 ROV immersions were carried out in different canyon environments at depths ranging between 79 and 401 m. Large, healthy colonies of M. oculata occur on abrupt, protected, often overhanging, rocky sections of the canyon walls, especially in Illa Negra branch. D. cornigera is sparser and evenly distributed at depth, on relatively low sloping areas, in rocky but also partially sedimented areas. C. rubrum is most frequent between 100 and 160 m on highly sloping rocky areas. The probable extent of CWC habitats is quantified by applying a maximum entropy model to predict habitat suitability: 0.36 km2 yield M. oculata occurrence probabilities over 70%. Similar predictive models have been produced for D. cornigera and C. rubrum. All ROV transects document either the presence of litter on the seafloor or pervasive trawling marks. Nets and longlines are imaged entangled on coral colonies. Coral rubble is observed at the foot of impacted colonies. Some colonies are partially covered by sediment that could be the result of the resuspension generated by bottom trawling on neighbouring fishing grounds, which has been demonstrated to be responsible of daily increases in sediment fluxes within the canyon. The characteristics of the CWC community in La Fonera canyon are indicative that it withstands high environmental stress of both natural and human origin.

Long-term baited lander experiments at a cold-water coral community on Galway Mound (Belgica Mound Province, NE Atlantic)

A long-term lander employing a baited camera system was developed to study temporal variation in the presence of scavenging fish and invertebrates at a cold-water coral community on Galway Mound (Belgica Mound Province, NE Atlantic). The camera system was tested during two successful long-term deployments for periods of 6 and 12 months respectively. The baited system, consisting of two separate video cameras with infrared lights and a bait dispenser with 24 bait positions, recorded more than 15,500 clips of 17s, regularly spread over both periods. New bait, consisting of sardines in oil, was offered at regular time intervals, and attracted scavengers over the whole period of deployment, and especially the crab Chaceon affinis did still eat from it till the end of the deployments. However, the attractiveness for some scavengers, i.e. amphipods, diminished quite quickly. In addition to invertebrate scavengers, namely C. affinis, two other crab species, amphipods, a shrimp and a starfish, also 7 species of fish were recorded near the bait, of which Lepidion eques was by far the most common. Though there was no concrete evidence for seasonal patterns, the observations showed substantial temporal variation in the abundance of several species, especially the crabs C. affinis and Bathynectes maravigna and the fish Phycis blennoides. It is concluded that long-term deployments of such a baited camera system can produce novel data. For instance such a system could be employed for monitoring impacts of disturbances on the deep-sea floor (e.g. mining), as we infer that mobile scavengers will be among the first organisms to show a visible reaction to any chemically and physically (noise, vibrations) alteration of the environment similar to a mine canary.

Reprint of 'On and off the beaten track: Megafaunal sessile life and Adriatic cascading processes'

Valuable megafaunal sessile assemblages in the southern Adriatic basin present a western–eastern asymmetric distribution. This is particularly evident when considering cold-water coral (CWC) communities, with most diverse and abundant live corals to be found along the western side. On the contrary, only spotty occurrences are documented in the eastern side and at times only in a sub-fossil state. We hypothesize that this asymmetry might derive from differential exposure of the Adriatic floor to polarized hydrological processes. In such a perspective, vigorous albeit a-periodical flushing of deep-sea bottoms at times of cascading processes could be beneficial to sessile deep-sea benthic communities by reinforcing the North Adriatic Dense Water (NAdDW), contrasting excess silting and by enhancing the trophic web. Although no experimental evidence has been yet produced to test this hypothesis, it gains some support by the observation that CWC are flourishing in the general area of the Bari Canyon and adjacent bottoms flushed by dense shelf water (DSW) cascading while they are much less developed on the basin's opposite side, unaffected by this phenomenon.

Benthic O2 uptake of two cold-water coral communities estimated with the non-invasive eddy correlation technique

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 525:97-104 (2015) - DOI: https://doi.org/10.3354/meps11211 Benthic O2 uptake of two cold-water coral communities estimated with the non-invasive eddy correlation technique Lorenzo Rovelli1,*, Karl M. Attard2,3, Lee D. Bryant4,8, Sascha Flögel4, Henrik Stahl1,9, J. Murray Roberts1,5,6, Peter Linke4, Ronnie N. Glud1,2,3,7 1Scottish Association for Marine Sciences, Scottish Marine Institute, Oban PA37 1QA, UK 2Nordic Centre for Earth Evolution (NordCEE), University of Southern Denmark, 5230 Odense M, Denmark 3Greenland Climate Research Centre, Greenland Institute of Natural Resources, 3900 Nuuk, Greenland 4GEOMAR, Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Germany 5Centre for Marine Biodiversity and Biotechnology, School of Life Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK 6Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA 7Arctic Research Centre, University of Århus, 8000 Århus C, Denmark 8Present address: Department of Architecture and Civil Engineering, University of Bath, Bath BA2 7AY, UK 9Present address: Zayed University, Dubai Academic City, Dubai, United Arab Emirates *Corresponding author: lorenzo.rovelli@sams.ac.uk ABSTRACT: The community respiration of 2 tidally dominated cold-water coral (CWC) sites was estimated using the non-invasive eddy correlation (EC) technique. The first site, Mingulay Reef Complex, was a rock ridge located in the Sea of Hebrides off Scotland at a depth of 128 m and the second site, Stjernsund, was a channel-like sound in Northern Norway at a depth of 220 m. Both sites were characterized by the presence of live mounds of the reef framework-forming scleractinian Lophelia pertusa and reef-associated fauna such as sponges, crustaceans and other corals. The measured O2 uptake at the 2 sites varied between 5 and 46 mmol m–2 d–1, mainly depending on the ambient flow characteristics. The average uptake rate estimated from the ~24 h long deployments amounted to 27.8 ± 2.3 mmol m–2 d–1 at Mingulay and 24.8 ± 2.6 mmol m–2 d–1 at Stjernsund (mean ± SE). These rates are 4 to 5 times higher than the global mean for soft sediment communities at comparable depths. The measurements document the importance of CWC communities for local and regional carbon cycling and demonstrate that the EC technique is a valuable tool for assessing rates of benthic O2 uptake in such complex and dynamic settings. KEY WORDS: Eddy correlation · Cold-water coral · Community oxygen exchange · Mingulay Reef Complex · Stjernsund Full text in pdf format PreviousNextCite this article as: Rovelli L, Attard KM, Bryant LD, Flögel S and others (2015) Benthic O2 uptake of two cold-water coral communities estimated with the non-invasive eddy correlation technique. Mar Ecol Prog Ser 525:97-104. https://doi.org/10.3354/meps11211 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 525. Online publication date: April 09, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Macro- and megafauna recorded in the submarine Bari Canyon (southern Adriatic, Mediterranean Sea) using different tools

Macro- and megafauna were recorded in the submarine Bari Canyon (southern Adriatic Sea, Mediterranean Sea) during an oceanographic cruise carried out in May-June 2012 and an experimental fishing survey conducted in November 2013. During the former, a total of 20 benthic samples were taken using a Van Veen grab at depths between 268 and 770 m and 4 deployments of a baited lander, for about 43 hours of video records, were carried out at depths between 443 and 788 m. During the latter, 8 longline fishing operations were conducted from 338 down to 612 m. Eighty-five living benthic and benthopelagic species were recorded: 29 Porifera, 1 Cnidaria, 2 Mollusca, 11 Annelida, 1 Arthropoda, 19 Bryozoa, 3 Echinodermata and 19 Chordata. A total of 51 species are new records for the Bari Canyon, 29 new records for the Adriatic Sea. Among the Porifera Cerbaris curvispiculifer is a new addition for the Italian Sponge Fauna. The first certain record of living specimens for the bryozoan Crisia tenella longinodata is reported. A total of 6 Mediterranean endemic species have been identified: 4 Porifera and 2 Annelida. The bathymetric range of some species has been extended. New information acquired for deep sea species confirms their importance in the structure of cold-water coral communities. This study has updated the knowledge on the biodiversity of the Adriatic Sea, as well as of the Bari Canyon in particular, one of the sites designated as “jewels of the Mediterranean” for which urgent conservation measures are needed.

Differential response of two Mediterranean cold-water coral species to ocean acidification

Cold-water coral (CWC) reefs constitute one of the most complex deep-sea habitats harboring a vast diversity of associated species. Like other tropical or temperate framework builders, these systems are facing an uncertain future due to several threats, such as global warming and ocean acidification. In the case of Mediterranean CWC communities, the effect may be exacerbated due to the greater capacity of these waters to absorb atmospheric CO2 compared to the global ocean. Calcification in these organisms is an energy-demanding process, and it is expected that energy requirements will be greater as seawater pH and the availability of carbonate ions decrease. Therefore, studies assessing the effect of a pH decrease in skeletal growth, and metabolic balance are critical to fully understand the potential responses of these organisms under a changing scenario. In this context, the present work aims to investigate the medium- to long-term effect of a low pH scenario on calcification and the biochemical composition of two CWCs from the Mediterranean, Dendrophyllia cornigera and Desmophyllum dianthus. After 314 d of exposure to acidified conditions, a significant decrease of 70 % was observed in Desmophyllum dianthus skeletal growth rate, while Dendrophyllia cornigera showed no differences between treatments. Instead, only subtle differences between treatments were observed in the organic matter amount, lipid content, skeletal microdensity, or porosity in both species, although due to the high variability of the results, these differences were not statistically significant. Our results also confirmed a heterogeneous effect of low pH on the skeletal growth rate of the organisms depending on their initial weight, suggesting that those specimens with high calcification rates may be the most susceptible to the negative effects of acidification.

Geochemical and physical constraints for the occurrence of living cold-water corals

Cold-water coral communities cover a wide range of possible habitats in terms of latitude, ocean basins, and depth, with ongoing studies continually expanding occurrences in various regions of the global ocean. A range of factors determines the formation of cold-water coral reefs, such as physical, hydrochemical, and biological (e.g. food supply) factors. Recently, more and more modeling studies have emerged using a variety of mathematical approaches have emerged including environmental niche factor analysis (ENFA) and predictive habitat suitability models. However, only few studies have attempted to characterize the underlying suite of hydro-biogeochemical and physical constraints of cold-water coral reefs and to differentiate between pristine reef growth vs. sites with reduced or no coral occurrences. This study concentrates on new data and a compilation of existing data sets on the physical and chemical properties in the NE Atlantic and the Mediterranean. It explores the influence of ambient bottom waters and its characteristics on living cold-water reefs and mounds formed by Lophelia pertusa. Several questions are addressed: (1) what are the physical and geochemical boundary conditions of living cold-water corals? (2) Do these geochemical parameters correlate with proposed physical prerequisites? (3) Is there a general difference in the signature of living and dead coral sites?

Bathymetrical distribution and size structure of cold-water coral populations in the Cap de Creus and Lacaze-Duthiers canyons (northwestern Mediterranean)

Abstract. Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze-Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony position with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large L. pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general, no clear differences were observed in the abundance and in the size structure of the CWC populations between CCC and LDC, despite large differences in particulate matter between canyons.

Fine-scale spatial genetic structure and clonal distribution of the cold-water coral Lophelia pertusa

Determining the spatial genetic structure within and among cold-water coral populations is crucial to understanding population dynamics, assessing the resilience of cold-water coral communities and estimating genetic effects of habitat fragmentation for conservation. The spatial distribution of genetic diversity in natural populations depends on the species’ mode of reproduction, and coral species often have a mixed strategy of sexual and asexual reproduction. We describe the clonal architecture of a cold-water coral reef and the fine-scale population genetic structure (<35 km) of five reef localities in the NE Skagerrak. This study represents the first of this type of analysis from deep waters. We used thirteen microsatellite loci to estimate gene flow and genotypic diversity and to describe the fine-scale spatial distribution of clonal individuals of Lophelia pertusa. Within-population genetic diversity was high in four of the five reef localities. These four reefs constitute a genetic cluster with asymmetric gene flow that indicates metapopulation dynamics. One locality, the Sacken reef, was genetically isolated and depauperate. Asexual reproduction was found to be a highly important mode of reproduction for L. pertusa: 35 genetic individuals were found on the largest reef, with the largest clone covering an area of nearly 300 m2.

Occurrence and behaviour of Paromola cuvieri (Crustacea, Decapoda) in the Santa Maria di Leuca cold-water coral community (Mediterranean Sea)

Occurrence and behaviour of Paromola cuvieri (Crustacea, Decapoda) were recorded by means of the MEMO lander equipped with two digital cameras and deployed in the cold-water coral community of the Santa Maria di Leuca (Mediterranean Sea). A total of 14 individuals were observed at depths between 547 and 648 m; 10 in the coral habitat on coral mounds and 4 off the coral habitat on muddy bottoms. Thirteen specimens recorded were females, one male and all were shown to scavenge the bait. All the specimens carried a sponge on their exoskeleton using the fifth pereiopods. The specimens were distinguishable by the size and shape of the carried sponge. The present observations demonstrate both passive covering behaviour and active behaviour of discouraging approach and attack from competitors or predators, respectively. This study represents the first in situ documentation of Paromola cuvieri behaviour interacting with other deep-sea species in the Mediterranean Sea.

Introduction to the theme section “coral reefs in a changing environment”

This theme section, ‘‘Coral reefs in a changing environment’’, stems from the ASLO Aquatic Sciences Meeting 2009 in Nice, France (January 25–30), where session # 28 (Coral reefs and coral communities in a changing environment) was chaired by Cornelia Maier, Bernhard Riegl and Christian Wild. This session included 12 oral and 9 poster contributions covering a broad range of topics, and attracted a large number of visitors. That the upcoming 2010 European ISRS meeting in Wageningen, the Netherlands, has a similar motto, ‘‘Reefs in a changing environment’’, appears to emphasize the importance and timeliness of the question: How do corals and coral reefs respond to rapid environmental change? Clearly, anthropogenically-induced climate change and pollution alter the chemistry and temperature of seawater at an unprecedented and rapid rate, and constitute a major threat to the survival of tropical, temperate and cold-water coral reefs and coral communities. CO2-induced ocean acidification and warming, along with terrestrial runoff and pollution, negatively affect health, growth and calcification of corals. However, the extent to which these indirect and direct anthropogenic stresses interact and impact corals and coral-generated reef ecosystems needs to be addressed in more detail. The following six contributions to the theme section reflect a high diversity with respect to the scientific contents on both the species and the community level. The manuscripts address the effects of the two groups of parameters linked to global climate change: firstly, indirectly anthropogenically caused effects such as surface temperature (Heyward and Negri 2010; Thompson and Dolman 2010; Naumann et al. 2010) and pH (Ries et al. 2010); and, secondly, directly anthropogenically caused effects such as inorganic nutrient concentrations (Naumann et al. 2010; Tanaka et al. 2010) or natural regular disturbances (Browne et al. 2010) on coral metabolism (Naumann et al. 2010; Tanaka et al. 2010; Ries et al. 2010), coral development (Heyward and Negri 2010) and coral reef community structure and cover (Browne et al. 2010; Thompson and Dolman 2010). In this context, the goals were to identify the relative influence of one or more of the factors related to environmental change. The articles in the theme section focusing on the factor temperature reveal that, below the bleaching threshold, it positively correlates with particulate organic matter (POM) release by scleractinian corals (Naumann et al. 2010), but may also negatively effect the development and distribution of their larvae (Heyward and Negri 2010). Thompson and Dolman (2010) highlight that temperature-induced coral bleaching events, even if they only occur in the frequency and severity of those in the recent past, may lead to a reduction of fast-growing staghorn coral cover in nearshore reefs of the Great Barrier Reef (GBR). This was supported by the finding that mass coral bleaching, in contrast to other stress events such as crown-of-thorns starfish outbreaks and cyclones, resulted in significant changes of benthic community composition and hard coral Communicated by Editor in Chief Prof. Rolf Bak

Introduction: Cold-Water Coral communities in the Mediterranean Sea

Introduction: Cold-Water Coral communities in the Mediterranean Sea

Depth and water mass zonation and species associations of cold-water octocoral and stony coral communities in the southwestern Atlantic

The Southwest Atlantic continental margin between latitudes 21 and 23° S comprises the Campos Basin area. Its continental shelf is some 100 km wide, with the slope starting between 80 and 130 m in depth. The slope is about 40 km wide, extending deeper to the south (2000 m) than to the north (1500 m). Water masses influencing the area include (1) surficial tropical water (TW), 250 to 300 m depth; (2) South Atlantic central water (SACW), below TW 300 to 550 m; (3) Antarctic inter- mediate water (AIW), between 550 and 1200 m depth; and (4) North Atlantic deep water (NADW), 1200 to 3500 m depth. Distributions of octocorals (25 genera, 32 species/morphotypes) and stony corals (27, 11) and associations among taxa and with water masses were analyzed. Different commu- nities were found over 3 depth ranges. Complete dissimilarity was observed between the continental shelf margin/upper slope and the middle-lower slope. The shallower depth range (52 to 760 m) was influenced by TW, SACW and the upper limit of AIW, while 11 species/morphotypes occurred exclu- sively in the middle depths (1000 to 1200 m), under the sole influence of AIW. No species were exclu- sive to the deepest depth range (1200 to 1605 m), which is bathed by NADW. Middle slope areas were distinct from one another, while lower slope areas were more homogeneous. Co-occurrences of spe- cies indicate the type of environment they live in, as soft or hard bottoms. One group of species indicative of cold-water coral communities includes Lophelia pertusa, Enallopsammia spp., Coral- lium niobe and Paragorgia johnsonii.

Particle flux and food supply to a seamount cold-water coral community (Galicia Bank, NW Spain)

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 277:13-23 (2004) - doi:10.3354/meps277013 Particle flux and food supply to a seamount cold-water coral community (Galicia Bank, NW Spain) G. C. A. Duineveld*, M. S. S. Lavaleye, E. M. Berghuis Royal Netherlands Insitute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands *Email: duin@nioz.nl ABSTRACT: In a European effort (Atlantic Coral Ecosystem Study [ACES project]) to determine the key conditions for the occurrence of cold-water corals on the NW Atlantic margin, a coral community on a seamount off NW Spain (Galicia Bank) was studied. Cold-water corals (Lophelia pertusa, Madrepora oculata) grow at a depth of ~800 m as isolated patches amidst small ripples and larger waves of foraminiferal sand. A 17 mo deployment of a near-bottom sediment trap revealed a large seasonal and annual variability in the flux of phytodetritus and carbon. The daily carbon flux in the first 5 mo of 2000 was on average 37 mgC m-2, and in the first 5 mo of 2001 17 mgC m-2. Quantities of faecal pellets and swimmers (copepods, amphipods) were also highly variable. A comparison between the daily carbon flux and the sediment carbon oxidation rate calculated from in situ community oxygen consumption (SCOC), i.e. 17 versus 7 mgC m-2 d-1 respectively, indicated that a surplus of carbon is not oxidised by the sediment community. We argue that the strong tidal currents (max. 30 cm s-1) and the mobile sediment lead to winnowing of the sediment and to near-bed transport of the organic material. The low biomass of the benthic community and the domination of filter-feeders support our arguments. By means of analyses of stable isotopes (δ15N, δ13C) we attempted to find potential food items of the cold-water corals among the particles collected in the sediment trap. The difference between the δ15N signatures of coral tissue (9.5‰) and phytodetritus (2.2‰) was >1 trophic level, indicating that sinking algae are not the sole food source. The δ15N signatures of swimmers caught in the trap, ~10‰, were on the other hand in the same range as those of the corals. A mixed diet of animals and algae could be one explanation for the observed δ15N of corals. The δ13C value of the coral tissue, -20.55‰, excludes a food source consisting of bacteria supported by methane seepage, as suggested by earlier studies. KEY WORDS: Cold-water corals · Particle flux · Stable isotopes · Bottom landers Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 277. Online publication date: August 16, 2004 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2004 Inter-Research.