Australonuphis-Violacea New-Species A New Polychaete Onuphidae From The Southeast Pacific Ocean

Volume: 94Start Page: 761End Page: 77

A New Species Of Scale-Worm, Harmothoe-Commensalis (Polychaeta, Polynoidae), From Mantle Cavities Of 2 Chilean Clams

Volume: 106Start Page: 666End Page: 67

A New Species Of Polychaete, Scolelepis anakenae (Polychaeta, Spionidae) From Easter island, South pacific Ocean, With Ecological Comments

Volume: 101Start Page: 767End Page: 77

Aphrodita Bisetosa (Polychaeta : Aphroditidae), A New Species Of Sea Mouse From The Southeastern Pacific Ocean Off Central Chile

Volume: 113Start Page: 493End Page: 49

Presence Of Micronereis In Antarctic Waters And Description Of A New Species, M-Antarctica (Polychaeta: Nereididae: Notophycinae)

Volume: 109Start Page: 645End Page: 65

Water depth and mesoscale oceanography drive neustonic polychaete assemblages in the SE Pacific Ocean

International audienceThis study aimed to assess how oceanographic variables (depth, water temperature, and phytoplankton biomass) and the proximity to islands and seamounts affect the structure of neustonic polychaete assemblages across the SE Pacific Ocean. We used data from 2 oceanographic cruises and online databases to analyze how different environmental variables affect polychaete assemblages sampled at the sea surface. We hypothesized that (1) the proximity to islands and seamounts would have a positive effect on polychaete diversity, since islands and seamounts cause changes in local currents that can promote primary productivity; and that (2) changes in species composition would be related to large spatial scales, since major gradients in oceanographic variables are observed along a longitudinal gradient of the SE Pacific. Thirty polychaete taxa belonging to 14 different families were identified. All polychaetes were collected no further than 350 km from shallow geological features, such as seamounts or oceanic islands, indicating that mesoscale oceanographical processes drive neustonic polychaete assemblages. Polychaete abundance increased towards shallow waters and decreased with increasing distances from shallow geological features. Changes in species composition were related to gradients in latitude, longitude, and increasing distances to coastal systems. The most notable changes in assemblage structure were observed along the longitudinal gradient. These results indicate that the assemblage structure of neustonic polychaetes is the result of the interaction between mesoscale oceanographic processes related to shallow geological features and the major longitudinal gradients in productivity and temperature observed across the SE Pacific Ocean