Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic
We report a ten-year study of the abundance and activity of megabenthos on the Porcupine Abyssal Plain, northeast Atlantic, together with observations on the occurrence of phytodetritus at the deep-sea floor (4850 m). Using the Southampton Oceanography Centre time-lapse camera system, ‘Bathysnap’, w...
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ftnerc:oai:nora.nerc.ac.uk:108021 2023-05-15T17:41:21+02:00 Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic Bett, B.J. Malzone, M.G. Narayanaswamy, B.E. Wigham, B.D. 2001 http://nora.nerc.ac.uk/id/eprint/108021/ https://doi.org/10.1016/S0079-6611(01)00066-0 unknown Bett, B.J. orcid:0000-0003-4977-9361 Malzone, M.G.; Narayanaswamy, B.E.; Wigham, B.D. 2001 Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic. Progress in Oceanography, 50 (1/4). 349-368. https://doi.org/10.1016/S0079-6611(01)00066-0 <https://doi.org/10.1016/S0079-6611(01)00066-0> Publication - Article PeerReviewed 2001 ftnerc https://doi.org/10.1016/S0079-6611(01)00066-0 2023-02-04T19:33:45Z We report a ten-year study of the abundance and activity of megabenthos on the Porcupine Abyssal Plain, northeast Atlantic, together with observations on the occurrence of phytodetritus at the deep-sea floor (4850 m). Using the Southampton Oceanography Centre time-lapse camera system, ‘Bathysnap’, we have recorded a radical change in the abundance and activity of megabenthos between the two periods of study (1991–1994 and 1997–2000). In 1991–1994, the larger megabenthos occurred at an abundance of c. 71.6/ha and were dominated by large holothurians. In addition, there were very substantial populations of smaller megabenthic ophiuroids (c. 4979/ha). Together, the total megabenthos are estimated to track over some 17 cm2/m2/d (exploiting 100% of the surface of the seabed in c. 2.5 years). In 1997–2000, the larger megabenthos increased to an abundance of c. 204/ha and were joined by exceptional numbers of a small holothurian species (Amperima rosea, 6457/ha) and ophiuroids (principally Ophiocten hastatum, 53,539/ha). The total megabenthos population was tracking at an estimnated rate of c. 247 cm2/m2/d (exploiting 100% of seabed in just 6 weeks). Coincident with these increases in the abundance and activity of the megabenthos, there were apparently no mass depositions of aggregated phytodetritus to the seabed in the summers of 1997–1999. Mass occurrences of phytodetritus had been noted during the summer months of the three years previously studied (1991, 1993 and 1994), with covering between 50 and 96% of the sediment surface. There is a statistically significant (p<0.02) negative correlation between maximum extent of this seabed cover of phytodetritus and seabed tracking by megabenthos. Additional studies [Lampitt et al., Progr. Ocean. 50 (2001)], indicate that there were no substantial changes in surface ocean primary productivity, in export flux, or in the composition of the flux that might otherwise account for the apparent absence of observable concentrations of phytodetritus during the summers of ... Article in Journal/Newspaper Northeast Atlantic Natural Environment Research Council: NERC Open Research Archive Progress in Oceanography 50 1-4 349 368 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
We report a ten-year study of the abundance and activity of megabenthos on the Porcupine Abyssal Plain, northeast Atlantic, together with observations on the occurrence of phytodetritus at the deep-sea floor (4850 m). Using the Southampton Oceanography Centre time-lapse camera system, ‘Bathysnap’, we have recorded a radical change in the abundance and activity of megabenthos between the two periods of study (1991–1994 and 1997–2000). In 1991–1994, the larger megabenthos occurred at an abundance of c. 71.6/ha and were dominated by large holothurians. In addition, there were very substantial populations of smaller megabenthic ophiuroids (c. 4979/ha). Together, the total megabenthos are estimated to track over some 17 cm2/m2/d (exploiting 100% of the surface of the seabed in c. 2.5 years). In 1997–2000, the larger megabenthos increased to an abundance of c. 204/ha and were joined by exceptional numbers of a small holothurian species (Amperima rosea, 6457/ha) and ophiuroids (principally Ophiocten hastatum, 53,539/ha). The total megabenthos population was tracking at an estimnated rate of c. 247 cm2/m2/d (exploiting 100% of seabed in just 6 weeks). Coincident with these increases in the abundance and activity of the megabenthos, there were apparently no mass depositions of aggregated phytodetritus to the seabed in the summers of 1997–1999. Mass occurrences of phytodetritus had been noted during the summer months of the three years previously studied (1991, 1993 and 1994), with covering between 50 and 96% of the sediment surface. There is a statistically significant (p<0.02) negative correlation between maximum extent of this seabed cover of phytodetritus and seabed tracking by megabenthos. Additional studies [Lampitt et al., Progr. Ocean. 50 (2001)], indicate that there were no substantial changes in surface ocean primary productivity, in export flux, or in the composition of the flux that might otherwise account for the apparent absence of observable concentrations of phytodetritus during the summers of ... |
format |
Article in Journal/Newspaper |
author |
Bett, B.J. Malzone, M.G. Narayanaswamy, B.E. Wigham, B.D. |
spellingShingle |
Bett, B.J. Malzone, M.G. Narayanaswamy, B.E. Wigham, B.D. Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic |
author_facet |
Bett, B.J. Malzone, M.G. Narayanaswamy, B.E. Wigham, B.D. |
author_sort |
Bett, B.J. |
title |
Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic |
title_short |
Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic |
title_full |
Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic |
title_fullStr |
Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic |
title_full_unstemmed |
Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic |
title_sort |
temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast atlantic |
publishDate |
2001 |
url |
http://nora.nerc.ac.uk/id/eprint/108021/ https://doi.org/10.1016/S0079-6611(01)00066-0 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
Bett, B.J. orcid:0000-0003-4977-9361 Malzone, M.G.; Narayanaswamy, B.E.; Wigham, B.D. 2001 Temporal variability in phytodetritus and megabenthic activity at the seabed in the deep northeast Atlantic. Progress in Oceanography, 50 (1/4). 349-368. https://doi.org/10.1016/S0079-6611(01)00066-0 <https://doi.org/10.1016/S0079-6611(01)00066-0> |
op_doi |
https://doi.org/10.1016/S0079-6611(01)00066-0 |
container_title |
Progress in Oceanography |
container_volume |
50 |
container_issue |
1-4 |
container_start_page |
349 |
op_container_end_page |
368 |
_version_ |
1766142864823156736 |