Deep water bioherms of the scleractinian coral<i>Lophelia pertusa</i>(L.) at 64° n on the Norwegian shelf: Structure and associated megafauna

Buhl‐Mortensen, Lene; Hovland, Martin; Brattegard, Torleiv; Farestveit, Robert

doi:10.1080/00364827.1995.10413586

Cited by 233 publications

(202 citation statements)

References 11 publications

Supporting

Mentioning

193

Contrasting

Order By: Relevance

“…The morphology of the Lophelia reefs observed in this study differs from those described from the Norwegian shelf (Mortensen et al 1995). An offshore reef is typically mound-shaped with a summit of live coral, surrounded by dead coral blocks and coral rubble near the 'foot' of the reef.…”

Section: Biotopescontrasting

confidence: 87%

Diverse and vulnerable deep-water biotopes in the Hardangerfjord

Buhl-Mortensen

Buhl‐Mortensen

2013

Marine Biology Research

View full text Add to dashboard Cite

This study describes the distribution, species composition and environmental characteristics of benthic habitats and biotopes from 38 stations in the Hardangerfjord, based on observations using high-definition video. Faunal composition was primarily related to substrate composition, distance from open ocean and depth (water masses) by using Detrended Correspondence Analysis. Six different biotopes were observed at depths between 100 and 400 m: (1) Lophelia reef, (2) sponge garden, (3) seapen communities, (4) soft bottom coral garden, (5) hard bottom coral garden and (6) cerianthid stands. Three Lophelia reefs were observed between 140 and 230 m depth in the outer part of the fjord. Geodia spp. and other large sponges were abundant on morainic bottom, on sills. Seapen communities occurred on muddy bottoms mainly between 250 and 350 m depth. The soft bottom coral garden comprised the gorgonian Isidella lofotensis, locally with densities up to 167 colonies/100 m 2 . Hard bottom coral gardens with Paragorgia arborea and Paramuricea placomus had a much lower density with a maximum of 33 colonies/100 m 2 . Litter and lost fishing gear were observed on 49% of the locations. Lophelia and sponges were covered with silt to a much higher degree than previously observed offshore. Whether this is caused by naturally higher particle flux in fjords or is due to an increased input from anthropogenic sources cannot be concluded from the present study. In general, anthropogenic activities have lead to increased particle flux in fjords and a demand for monitoring sensitive deep-water habitats to detect related trends of declining biodiversity.

show abstract

Section: Biotopescontrasting

confidence: 87%

Diverse and vulnerable deep-water biotopes in the Hardangerfjord

Buhl-Mortensen

Buhl‐Mortensen

2013

Marine Biology Research

View full text Add to dashboard Cite

show abstract

“…The colonies occur in groups of 5 to 10, generally situated in areas of coral debris with patches of plain sediment. They are not necessarily located between large amounts of dead coral as is the case, for example, in the Haltenbanken-Frpyabanken area or on the Sula Ridge off Norway (Mortensen et al 1995;Freiwald et al 2002). On most of the mound flanks, the transition from bioturbated sediments to the debris facies occurs at a depth of ca.…”

Section: Mound Perseverance: a Case Study In The Magellan Provincementioning

confidence: 99%

The seabed appearance of different coral bank provinces in the Porcupine Seabight, NE Atlantic: results from sidescan sonar and ROV seabed mapping

Huvenne¹,

Beyer

Haas

et al. 2005

Cold-Water Corals and Ecosystems

View full text Add to dashboard Cite

Abstract. Carbonate mounds, identified as deep-water coral banks, have been reported recently from three provinces in the Porcupine Seabight, SW of Ireland. As yet, the mechanisms behind their formation and development are only partly understood. This contribution discusses their seabed appearance and present-day sedimentary environment, based on a large-scale TOB I sidescan sonar mapping carried out in 2002, and on detailed ROV video records from specific sites within the three mound provinces, collected in 2001. The study of the presentday characteristics and variability of these mounds can help to understand their development history in the past.The imagery clearly shows that the sedimentary environment in the Magellan and Hovland Mound provinces in the northern Porcupine Seabight is much quieter than in the current-swept Belgica Mound province on the eastern flank of the basin. In the latter area, for example, gravel lags and coarse sediments are found, together with patches of sorted sands, striations, barchan dunes and sediment waves. The difference in environment results in different mound appearances. The richest coral communities with the most abundant live coral occurrences are found in the Belgica province, while for example on the Magellan Mounds only a few live coral colonies are left. The present-day situation of the coral banks in the Porcupine Seabight thus illustrates the influence of the interplay between current and sediment dynamics on coral growth and mound development.

show abstract

“…Because of the sheltering function and higher habitat complexity of three-dimensionally branched coral skeletons, the diversity of megafauna living in the zones with living or dead coral framework is higher than that in the coral rubble zone (Mortensen et al, 1995). According to Mortensen et al (1995) and Jensen and Frederiksen (1992), the dead coral framework harbors the most diverse macroand megafauna.…”

Section: Introductionmentioning

confidence: 99%

“…According to Mortensen et al (1995) and Jensen and Frederiksen (1992), the dead coral framework harbors the most diverse macroand megafauna. Healthy, living L. pertusa responds to the settlement of sessile organisms by (1) an increase in mucus production and (2) selective sclerenchyme precipitation (Freiwald and Wilson, 1998).…”

Section: Introductionmentioning

confidence: 99%

Microhabitat type determines the composition of nematode communities associated with sediment-clogged cold-water coral framework in the Porcupine Seabight (NE Atlantic)

Raes

Vanreusel

2006

Deep Sea Research Part I: Oceanographic Research Papers

View full text Add to dashboard Cite

The nematofauna associated with a cold-water coral degradation zone in the Porcupine Seabight (NE Atlantic) was investigated. This is the first comprehensive study of nematodes associated with cold-water corals. This research mainly aimed to investigate the influence of microhabitat type on nematode community structure. Three distinct microhabitats for nematodes were distinguished: dead coral fragments, glass sponge skeletons and the underlying sediment. The nematode assemblages associated with these three microhabitats were significantly different from each other. Coral and sponge substrata lie relatively unprotected on the seafloor and are consequently more subjected to strong currents than the underlying sediment. As a result, both large biogenic substrata were characterized by higher abundances of taxa that are less vulnerable and more adapted to physical disturbance, whereas the underlying sediment yielded more slender, sedimentdwelling taxa. Typically epifaunal taxa, such as Epsilonematidae and Draconematidae, were especially abundant on dead coral fragments, where they are thought to feed on the microbial biofilm which covers the coral surface. Several epifaunal genera showed significant preferences for this microhabitat, and Epsilonema (Epsilonematidae) was dominant here. Sponge skeletons are thought to act as efficient sediment traps, resulting in a lower abundance of epifaunal taxa compared to coral fragments. The underlying sediment was dominated by taxa typical for slope sediments. The considerable degree of overlap between the communities of each microhabitat is attributed to sediment infill between the coral branches and sponge spicules. It is assumed that the nematofauna associated with large biogenic substrata is composed of a typical sedimentdwelling background community, supplemented with taxa adapted to an epifaunal life strategy. The extent to which these taxa contribute to the community depends on the type of the substratum. Selective deposit feeders were dominant on sponge skeletons and in the underlying sediment, whereas coral fragments were dominated by epistratum feeders. The presence of a microbial biofilm on the coral fragments is proposed as an explanation for the significant preference of epistratum feeders for this microhabitat. Densities in the underlying sediment were low in comparison with other studies, but biodiversity was higher here than on the coral and sponge fragments, a difference which is attributed to lower disturbance. Nevertheless, the large biogenic substrata provide a microhabitat for rare, epifaunal taxa, and fragments of both substrata within the sediment increase habitat complexity and hence biodiversity. r

show abstract

Deep water bioherms of the scleractinian coralLophelia pertusa(L.) at 64° n on the Norwegian shelf: Structure and associated megafauna

Cited by 233 publications

References 11 publications

Diverse and vulnerable deep-water biotopes in the Hardangerfjord

Diverse and vulnerable deep-water biotopes in the Hardangerfjord

The seabed appearance of different coral bank provinces in the Porcupine Seabight, NE Atlantic: results from sidescan sonar and ROV seabed mapping

Microhabitat type determines the composition of nematode communities associated with sediment-clogged cold-water coral framework in the Porcupine Seabight (NE Atlantic)

Contact Info

Product

Resources

About