Diversity, abundance, and biomass of deep-sea decapod crustaceans of the Uruguayan continental slope in the Southwestern Atlantic Ocean
Rotllant, G.; Verdi, A.; Santos-Bethencourt, R.; Bahamón, N.; Company, J.B. (2020). Diversity, abundance, and biomass of deep-sea decapod crustaceans of the Uruguayan continental slope in the Southwestern Atlantic Ocean, in: Hendrickx, M.E. Deep-sea pycnogonids and crustaceans of the Americas. pp. 443-472. https://dx.doi.org/10.1007/978-3-030-58410-8_19
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| Author keywords |
Crustaceans; Deep sea; Shannon index; Equity index of Pielou; Species richness; Conservation |
| Auteurs | | Top |
- Rotllant, G.
- Verdi, A.
- Santos-Bethencourt, R.
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- Bahamón, N.
- Company, J.B.
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| Abstract |
The megafauna of deep continental margin of the exclusive economic zone (EEZ) of Uruguay have been little studied. The present study includes deep-sea trawling operations and represents the first analysis in detail of the deep-sea community of decapod crustaceans. Cluster analysis of bottom trawl data indicated that benthic megafauna are grouped in four bathymetric ranges along the continental margin: A, 250 > 1100 m; B, 1100 > 2000 m; C, 2000 > 3000 m; and D, 3000–3800 m, while pelagic species are not grouped by depth strata. The decapod individuals belong to 79 different species from which 64% correspond to shrimps (suborder Dendrobranchiata and infraorder Caridea), and the third most important group corresponds to the infraorder Anomura (18%). From those, previously 67% were not reported off Uruguay and 47% in the southwestern Atlantic Ocean. The bathymetric range of the identified decapods was enlarged by 32%. Moreover, the frequency distribution of species occurrences was rare since 56% of the species were only sampled once, thus indicating that the decapod community of this area is still far unknown. The benthic species were also more diverse than the pelagic decapods, and their abundance and biomass were higher. The biomass of the decapod community was dominated by the geryonid crab, Chaceon notialis, mainly located in the shallowest depth strata (representing 97% of the total biomass). To detect possible changes in the structure, biomass, and diversity of benthic assemblages, we recommend the implementation of long-term monitoring programs in the continental slope off Uruguay before fishing or mining exploitation is developed. |
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