scholarly journals Exploitation of trawler discards by breeding seabirds in the north-western Mediterranean: differences between the Ebro Delta and the Balearic Islands areas

1997 ◽  
Vol 54 (4) ◽  
pp. 695-707 ◽  
Author(s):  
D Oro
Author(s):  
Rafel MATAMALES-ANDREU ◽  
Francesc X. ROIG-MUNAR ◽  
Oriol OMS ◽  
Àngel GALOBART ◽  
Josep FORTUNY

ABSTRACT Moradisaurine captorhinid eureptiles were a successful group of high-fibre herbivores that lived in the arid low latitudes of Pangaea during the Permian. Here we describe a palaeoassemblage from the Permian of Menorca (Balearic Islands, western Mediterranean), consisting of ichnites of small captorhinomorph eureptiles, probably moradisaurines (Hyloidichnus), and parareptiles (cf. Erpetopus), and bones of two different taxa of moradisaurines. The smallest of the two is not diagnostic beyond Moradisaurinae incertae sedis. The largest one, on the other hand, shows characters that are not present in any other known species of moradisaurine (densely ornamented maxillar teeth), and it is therefore described as Balearosaurus bombardensis gen. et sp. nov. Other remains found in the same outcrop are identified as cf. Balearosaurus bombardensis gen. et sp. nov., as they could also belong to the newly described taxon. This species is sister to the moradisaurine from the lower Permian of the neighbouring island of Mallorca, and is also closely related to the North American genus Rothianiscus. This makes it possible to suggest the hypothesis that the Variscan mountains, which separated North America from southern Europe during the Permian, were not a very important palaeobiogeographical barrier to the dispersion of moradisaurines. In fact, mapping all moradisaurine occurrences known so far, it is shown that their distribution area encompassed both sides of the Variscan mountains, essentially being restricted to the arid belt of palaeoequatorial Pangaea, where they probably outcompeted other herbivorous clades until they died out in the late Permian.


2012 ◽  
Vol 92 (8) ◽  
pp. 1799-1808 ◽  
Author(s):  
Alexandre Gannier ◽  
Estelle Petiau ◽  
Violaine Dulau ◽  
Luke Rendell

Oceanic odontocetes rely on echolocation to forage on pelagic or benthic prey, but their feeding ecology is difficult to study. We studied sperm whale foraging dives during summer in the north-western Mediterranean, using visual and passive acoustic observations. Clicking and creaking activities were recorded during dives of focal whales, at distances <3000 m using a towed hydrophone and DAT recorder. A total of 52 sperm whales were recorded over at least one full dive cycle. Data were obtained for 156 complete dives in total, including sequences of up to nine consecutive dives. Various dive and environmental variables were entered in multiple linear regression and principal components analysis, as well as estimated mass of whales. Creak rate was 0.80 creak/minute on average, with moderate variance. Bigger whales tended to dive longer at greater depths (as suggested by ascent durations), and emitted more creaks during a dive: 20.2 creaks/dive on average for individuals <24 tons, compared to 25.6 creaks/dive for animals >24 tons of estimated mass. For individual whales, creak rates did not vary significantly with size (range 0.78–0.80 creak/minute), but decreased with time of the day, and increased for shorter foraging phases. For different dives, higher creak rates were also observed earlier in the day, and linked to shorter foraging phases and surface durations. Although the exact significance of creak emissions (i.e. foraging attempt or prey capture) is not precisely determined, creak rates may be reliably used to quantify sperm whale foraging when single animal dives can be followed acoustically.


2010 ◽  
Vol 7 (3) ◽  
pp. 809-826 ◽  
Author(s):  
E. Ternon ◽  
C. Guieu ◽  
M.-D. Loÿe-Pilot ◽  
N. Leblond ◽  
E. Bosc ◽  
...  

Abstract. Simultaneous measurements of atmospheric deposition and of sinking particles at 200 and 1000 m depth, were performed in the Ligurian Sea (North-Western Mediterranean) between 2003 and 2007, along with phytoplanktonic activity derived from satellite images. Atmospheric deposition of Saharan dust particles was very irregular and confirmed the importance of sporadic high magnitude events over the annual average (11.4 g m−2 yr−1 for the 4 years). The average marine total mass flux was 31 g m−2 yr−1, the larger fraction being the lithogenic one (~37%). The marine total mass flux displayed a seasonal pattern with a maximum in winter, occurring before the onset of the spring bloom. The highest POC fluxes did not occur during the spring bloom nor could they be directly related to any noticeable increase in the surface phytoplanktonic biomass. Over the 4 years of the study, the strongest POC fluxes were concomitant with large increases of the lithogenic marine flux, which had originated from either recent Saharan fallout events (February 2004 and August 2005), from "old" Saharan dust "stored" in the upper water column layer (March 2003 and February 2005), or alternatively from lithogenic material originating from Ligurian riverine flooding (December 2003, Arno, Roya and Var rivers). Those associated export fluxes defined as "lithogenic events", are believed to result from a combination of forcing (winter mixing or Saharan events, in particular extreme ones), biological (zooplankton) activity, and also organic-mineral aggregation inducing a ballast effect. By fertilising the surface layer, mixed Saharan dust events were shown to be able to induce "lithogenic events" during the stratification period. These events would be more efficient in transferring POC to the deeper layers than the spring bloom itself. The extreme Saharan event of February 2004 exported ~45% of the total annual POC, compared to an average of ~25% for the bloom period. This emphasises the role played by these "lithogenic events", and in particular those that are induced by the more extreme Saharan events, in the carbon export efficiency in the North-western Mediterranean Sea.


ZooKeys ◽  
2019 ◽  
Vol 838 ◽  
pp. 71-84
Author(s):  
Céline Labrune ◽  
Nicolas Lavesque ◽  
Paulo Bonifácio ◽  
Pat Hutchings

A new species of Terebellidae, Pistacolinisp. n., has been identified from the harbour of Banyuls-sur-Mer, north-western Mediterranean Sea. This new species was found in very high densities, exclusively in gravelly sand deposited manually, and was not found in the original source habitat of the gravel. This species is characterized by the colour of the ventral shields with pinkish anterior part and a blood red posterior part in live specimens, a pair of unequal-sized plumose branchiae inserted on segment II and anterior thoracic neuropodia with long-handled uncini. The presence of long-handled uncini even in the smallest specimens constitutes the major difference between Pistacolinisp. n. and other Pista species with a single pair of branchiae such as P.lornensis and P.bansei.


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