Modelling the Pelagic Ecosystem Dynamics: The NW Mediterranean

A review of papers published on billfish biological research since the 1988 Billfish Symposium highlights the important role these symposia play in disseminating billfish research results and also shows that progress since 1988 has been slow, especially when compared with tuna and other pelagic fishes. One reason for the disparity is that marlin have not yet been successfully held in captivity. Progress has been made in elucidating the trophic biology of billfish and these data are helping to build models of pelagic ecosystem dynamics. The deployment of several types of electronic tags has expedited advances in understanding the short-term movements and depth distribution of billfish, but long-term tracks remain elusive. In part, this may be because insufficient effort has been directed at developing methods for restraining marlin for tag attachment or implantation. Light-based geolocation techniques show great promise for elucidating billfish movements, but appropriate scientific rigour must be applied to the publication of these data. Several suggestions for advancing billfish research are presented.

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Ecosystem dynamics in the Liguro-Provençal Basin: the role of eddies in the biological production.

Mediterranean Marine Science ◽

10.12681/mms.520 ◽

2014 ◽

Vol 15 (2) ◽

pp. 274 ◽

Cited By ~ 4

Author(s):

E. CASELLA ◽

P. TEPSICH ◽

X. COUVELARD ◽

R.M.A. CALDEIRA ◽

K. SCHROEDER

Keyword(s):

Mediterranean Sea ◽

Spring Bloom ◽

Chlorophyll Concentration ◽

Ecosystem Dynamics ◽

Regional Ocean Modeling System ◽

Concentration Data ◽

Ligurian Sea ◽

Nw Mediterranean ◽

Nw Mediterranean Sea

We study numerically the role of mesoscale structures in the Ligurian Sea (NW Mediterranean Sea) as a possible factor affecting the spatial distribution of the chlorophyll spring bloom. We use the Regional Ocean Modeling System (ROMS) configured for the NW Mediterranean Sea (ROMS_NWMed) and satellite derived Altimetric, Sea Surface Temperature and Chlorophyll concentration data, for years 2009 and 2010. Comparison of model output with satellite and in situ data shows agreement between numerical results and observations. There is a significant interannual variability in concentration and distribution of chlorophyll in the basin during the two years of the study. The ROMS_NWMed simulation reveals the formation of a number of mesoscale eddies along the Northern rim Current characterized by a long lifetime and closed streamlines. A significant higher number of eddies is found during the chlorophyll-rich year 2010. The high number of eddies, due to the “eddy pumping mechanism”, generate spatially and temporally localised fluxes of nutrient into the euphotic zone, thus contributing to the fertilization of the Ligurian Sea. Therefore, eddies in the Ligurian rim current can have important effects on the location of development of the main patch of chlorophyll spring bloom and consequently on the local ecosystem dynamics.

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