scholarly journals Effect of climatic oscillations on small pelagic fisheries and its economic profit in the Gulf of Cadiz

Author(s):  
Jairo Castro-Gutiérrez ◽  
Remedios Cabrera-Castro ◽  
Ivone Alejandra Czerwinski ◽  
José Carlos Báez

AbstractSeveral studies have shown the effect of climatic oscillations on fisheries. Small pelagic fish are of special global economic importance and very sensitive to fluctuations in the physical environment in which they live. The main goal of this study was to explore the relationship between the North Atlantic Oscillation (NAO), the East Atlantic pattern (EA), and the Arctic Oscillation (AO) on the landings and first sale prices of the most representative small pelagic commercial species of the purse-seine fisheries in the Gulf of Cadiz (North East Atlantic), the European anchovy Engraulis encrasicolus and the European sardine Sardine pilchardus. Generalised linear models (GLMs) with different data transformations and distribution errors were generated to analyse these relationships. The best results of the models were obtained by applying a moving average of order 3 to the dataset with a double weighted median. Our results demonstrate relationships between NAO, AO, and EA and European anchovy and sardine landings. These cause an indirect effect on the first sale price in markets through catch variations, which affect the price according to the law of supply and demand. The limitations of this study and management implications are discussed.

2011 ◽  
Vol 289 (1-4) ◽  
pp. 135-149 ◽  
Author(s):  
João C. Duarte ◽  
Filipe M. Rosas ◽  
Pedro Terrinha ◽  
Marc-André Gutscher ◽  
Jacques Malavieille ◽  
...  

Zootaxa ◽  
2011 ◽  
Vol 2919 (1) ◽  
pp. 1 ◽  
Author(s):  
MAGDALENA BŁAŻEWICZ-PASZKOWYCZ ◽  
ROGER N. BAMBER ◽  
MARINA R. CUNHA

Faunal collections from mud-volcano sites in the Gulf of Cadiz, at depths between 355 and 3061 m, have revealed a high diversity (and in some cases high density) of tanaidaceans. A previous paper has described some of the tanaidomorph species found. Records of apseudomorph species from deep-sea chemosynthetic habitats are almost non-existent. The present study reports on seven apseudomorph species from five different genera from this material; two of the species, one in each of the genera Sphyrapus and Pseudosphyrapus are new to science, although there was insufficient material available to describe fully the Pseudosphyrapus species. Two of the other species are reported herein for only the second time. A neotype is erected for Apseudes setiferus Băcescu, and a lectotype for Sphyrapus malleolus Norman & Stebbing; these two, plus Atlantapseudes nigrifrons Băcescu and Fageapseudes retusifrons Richardson are redescribed. The habitus of Apseudes grossimanus is figured. None of the taxa appear to show any morphological features specifically adapted to the peculiar habitat around mud-volcanoes. The genus Collossella is relegated to the synonymy of Fageapseudes. The nonchemosynthetic-habitat-associated species Apseudes coriolis is moved to Taraxapseudes.


Zootaxa ◽  
2011 ◽  
Vol 2769 (1) ◽  
pp. 1 ◽  
Author(s):  
MAGDALENA BŁAŻEWICZ-PASZKOWYCZ ◽  
ROGER N BAMBER ◽  
MARINA R CUNHA

Faunal collections from mud-volcano sites in the Gulf of Cadiz, at depths between 355 and 3061 m, have revealed a high diversity (and in some cases high density) of tanaidaceans. The present study reports on nine new tanaidomorph species from eight different genera from this material. These include representatives of genera known elsewhere from non-ventassociated deep-sea habitats, but notably only the second and third (respectively) representatives of two genera, Coalecerotanais and Cristatotanais, known previously from cold-seep-habitats in the Gulf of Mexico. The genus Spinitanaopsis is synonymized with Cristatotanais. The tanaidacean records to date from hydrothermal vents or cold seeps are collated as a context for the present material. The possibilities of habitat-endemism in tanaidacean taxa associated with reducing environments and their biogeography are discussed.


2004 ◽  
Vol 359 (1442) ◽  
pp. 183-195 ◽  
Author(s):  
G. M. Hewitt

An appreciation of the scale and frequency of climatic oscillations in the past few million years is modifying our views on how evolution proceeds. Such major events caused extinction and repeated changes in the ranges of those taxa that survived. Their spatial effects depend on latitude and topography, with extensive extinction and recolonization in higher latitudes and altitudinal shifts and complex refugia nearer the tropics. The associated population dynamics varied with life history and geography, and the present genetic constitution of the populations and species carry attenuated signals of these past dynamics. Phylogeographic studies with DNA have burgeoned recently and studies are reviewed from the arctic, temperate and tropical regions, seeking commonalities of cause in the resulting genetic patterns. Arctic species show distinct shallow genetic clades with common geographical boundaries. Thus Beringia is distinct phylogeographically, but its role as a refugial source is complex. Arctic taxa do not show the common genetic pattern of southern richness and northern purity in north-temperate species. Temperate refugial regions in Europe and North America show relatively deep DNA divergence for many taxa, indicating their presence over several Ice Ages, and suggesting a mode of speciation by repeated allopatry. DNA evidence indicates temperate species in Europe had different patterns of postglacial colonization across the same area and different ones in previous oscillations, whereas the northwest region of North America was colonized from the north, east and south. Tropical montane regions contain deeply diverged lineages, often in a relatively small geographical area, suggesting their survival there from the Pliocene. Our poor understanding of refugial biodiversity would benefit from further combined fossil and genetic studies.


Author(s):  
P. A. Tyler ◽  
D. S. M. Billett ◽  
J. D. Gage

The Molpadiida is an order of sea cucumbers identified by their stout body, the posterior region narrowing to simulate a tail and the absence of tubefeet. Typically they inhabit muddy environments from shallow water to abyssal depths. In the past the great variability in the taxonomic characters of this order has led to the formation of many genera and species (Heding, 1931, 1935), but more recently it has become apparent that many diagnostic characters change markedly during the life history of these holothurians and as a result fewer species are now recognised (Deichmann, 1940; Pawson, 1977). In a revision of the Atlantic molpadiids Deichmann (1940) recorded just three species from the north-east Atlantic (Molpadia blakei, M. musculus and Hedingia albicans) with a further three species from the Arctic Ocean and Norwegian Sea (M. arctica, M. borealis and Eupyrgus scaber). To these Sibuet (1974) added the new genus and species Cherbonniera utriculus found in the Bay of Biscay.


Author(s):  
Carlos J. Moura ◽  
Marina R. Cunha ◽  
Peter Schuchert

Tubiclavoides striatum, a new species of an athecate hydroid, was found on mud volcanoes, inactive carbonate chimneys, and cold-water coral stands in the Gulf of Cadiz (south-western Iberian Peninsula, Atlantic Ocean). The new family Tubiclavoididae and the new genus Tubiclavoides are proposed to accommodate the new species. The new hydroid is characterized by scattered filiform tentacles, sporosacs developing among the tentacles and hydrocauli covered with striated perisarc, often subdivided into imbricating cones. A full description and illustrations are provided, as well as some notes on the ecology and distribution of the new species.


2020 ◽  
Author(s):  
Aline Mega ◽  
Emilia Salgueiro ◽  
Antje Helga Luise Voelker

<p>The Mid Pleistocene Transition (MPT) was a global climatic event characterized by a drastic change in the deep thermohaline circulation during the glacial periods that resulted in more intense and longer lasting cold periods and cooler sea-surface temperature (SST). These changes might be linked to the atmospheric pCO<sub>2</sub> reduction which in turn led to colder atmospheric temperatures and the expansion of continental ice sheets. In the mid-latitude North Atlantic, high-resolution records documenting the MPT's impact are still limited. Thus, this study's objective is to contribute to the knowledge by reconstructing circulation changes in the subtropical gyre realm off the southwestern Iberian Margin.  We use planktonic foraminifera faunal data from Integrated Ocean Drilling Program (IODP) Site U1387 (Faro Drift, Gulf of Cadiz) to characterize centennial-scale SST variations during the interval from Marine Isotope Stage (MIS) 18 to MIS 28. The results indicate relative stable SSTs during the interglacial and interstadial periods with temperatures around 20°C during summer and 16°C during winter. During MIS 20, 22, 24, and 25 short-termed extreme cold events were recorded when winter temperatures dropped below 5°C, during late MIS 22 even close to 0°C. They mark the terminal stadial events during deglaciation and were related to increased abundance of polar planktonic foraminifera species N. pachyderma that reached values near to 80%. N. pachyderma values. Percentages of that species between 90 and 50% can be found in the polar regions near the Arctic Front and those between 50 and 5% are indicative of subarctic waters. Whereas the terminal stadial events and the first stadial phase of MIS 22 were marked by incursions of polar surface waters to the southern Iberian margin, abrupt cold events during periods of continental ice shield growth of MIS 19, 21, 25 and 28 were associated with subarctic surface waters. During the MPT, the waters off southern Iberia, therefore, experienced cooling events more extreme than during the last glacial cycle.</p>


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