GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2015-2019  (2)
Document type
Publisher
Years
Year
  • 1
    Publication Date: 2022-05-26
    Description: Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 561 (2016): 189-201, doi:10.3354/meps11915.
    Description: Thalia democratica blooms are a recurrent phenomenon in many coastal areas of the Mediterranean Sea and have significant ecological effects. To better understand the environmental drivers of salp blooms, we conducted 8 surveys to sample T. democratica in contrasting seasonal, temperature and chlorophyll conditions. In each survey, short-term variations in the abundances of different salp stages were assessed by sampling the same population at 30 min intervals. Using these data, we estimated the parameters in a set of stage-classified matrix population models representing different assumptions about the influence of temperature and chlorophyll on each stage. In the model that best explains our observations, only females are affected by changes in water temperature. Whether this is a direct influence of temperature or an indirect effect reflecting low food availability, female reproduction cessation seems to slow population growth under unfavourable conditions. When conditions become favourable again, females liberate the embryo and change sex to male, allowing for mating under extremely low salp densities and triggering the bloom. In contrast to previous findings, our results suggest that females, rather than oozooids, are responsible for the sustainability of salp populations during latency periods.
    Description: This work was founded by the Ministerio de Ciencia e Innovación under the Fishjelly project, the European commission ENPI CBC MED project under the Jellyrisk project and the European LIFE Commission under the Cubomed project. M. G. Neubert acknowledges the support of the US National Science Foundation (DEB-1145017 and DEB-1257545).
    Keywords: Matrix population models ; Pelagic tunicate ecology ; Population latency ; Gelatinous zooplankton blooms
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2020-02-06
    Description: Highlights • We track the preferential pathways of the Mediterranean Outflow Water (MOW). • A topographic analysis method is used to identify the MOW hydrological avenues. • Contour avenues and cross-slope channels have complementary roles steering the MOW. • The MOW is a density-driven current steered by both bottom topography and the Coriolis force. Abstract The Mediterranean Water leaves the western end of the Strait of Gibraltar as a bottom wedge of salty and warm waters flowing down the continental slope. The salinity of the onset Mediterranean Outflow Water (MOW) is so high that leads to water much denser (initially in excess of 1.5 kg m−3) than the overlying central waters. During much of its initial descent, the MOW retains large salinity anomalies – causing density anomalies that induce its gravity current character – and relatively high westward speeds – causing a substantial Coriolis force over long portions of its course. We use hydrographic data from six cruises (a total of 1176 stations) plus velocity data from two cruises, together with high-resolution bathymetric data, to track the preferential MOW pathways from the Strait of Gibraltar into the western Gulf of Cadiz and to examine the relation of these pathways to the bottom topography. A methodology for tributary systems in drainage basins, modified to account for the Coriolis force, emphasizes the good agreement between the observed trajectories and those expected from a topographically-constrained flow. Both contour avenues and cross-slope channels are important and have complementary roles steering the MOW along the upper and middle continental slope before discharging as a neutrally buoyant flow into the western Gulf of Cadiz. Our results show that the interaction between bottom flow and topography sets the path and final equilibrium depths of the modern MOW. Furthermore, they support the hypothesis that, as a result of the high erosive power of the bottom flow and changes in bottom-water speed, the MOW pathways and mixing rates have changed in the geological past.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...