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| Titel |
Organic biomarkers in deep-sea regions affected by bottom trawling: pigments, fatty acids, amino acids and carbohydrates in surface sediments from the La Fonera (Palamós) Canyon, NW Mediterranean Sea |
| VerfasserIn |
E. Sañé, J. Martin, P. Puig, A. Palanques |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 12 ; Nr. 10, no. 12 (2013-12-11), S.8093-8108 |
| Datensatznummer |
250085468
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| Publikation (Nr.) |
 copernicus.org/bg-10-8093-2013.pdf |
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| Zusammenfassung |
| Deep-sea ecosystems are in general adapted to a limited variability of
physical conditions, resulting in high vulnerability and slow recovery rates
from anthropogenic perturbations such as bottom trawling. Commercial trawling
is the most recurrent and pervasive of human impacts on the deep-sea floor,
but studies on its consequences on the biogeochemistry of deep-sea sediments
are still scarce. Pigments, fatty acids, amino acids and carbohydrates were
analysed in sediments from the flanks of the La Fonera (Palamós)
submarine canyon (NW Mediterranean Sea), where a commercial bottom trawling
fishery has been active for more than 70 yr. More specifically, we
investigated how trawling-induced sediment reworking affects the quality of
sedimentary organic matter which reaches the seafloor and accumulates in the
sediment column, which is fundamental for the development of benthic
communities. Sediment samples were collected during two oceanographic cruises
in spring and autumn 2011. The sampled sites included trawl fishing grounds
as well as pristine (control) areas. We report that bottom trawling in the
flanks of the La Fonera Canyon has caused an alteration of the quality of the
organic matter accumulated in the upper 5 cm of the seafloor. The use of a
wide pool of biochemical tracers characterized by different reactivity to
degradation allowed for us to discriminate the long-term effects of
trawl-induced sediment reworking from the natural variability caused by the
seasonal cycle of production and sinking of biogenic particles. Differences
between untrawled and trawled areas were evidenced by labile amino acids,
while differences between spring and autumn samples were detected only by the
more labile indicators chlorophyll a and monounsaturated fatty acids.
These results suggest that changes in the biochemical composition of the
sedimentary organic matter caused by bottom trawling can be more relevant
than those associated with natural seasonality and pose serious concerns
about the ecological sustainability of deep-sea trawling activities. |
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