scholarly journals At the crossroads: early Miocene marine fishes of the proto-Mediterranean Sea

Fossil Record ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 233-246
Author(s):  
Konstantina Agiadi ◽  
Efterpi Koskeridou ◽  
Danae Thivaiou
Keyword(s):  
Fish Fauna ◽  
Fish Distribution ◽  
Early Miocene ◽  
Easy Access ◽  
Control Fish ◽  
Climate Control ◽  
The North ◽  
Geological Past ◽  
The North Sea ◽  
Molluscan Assemblage

Abstract. Connectivity and climate control fish distribution today as well as in the geological past. We present here the Aquitanian (early Miocene) marine fish of the Mesohellenic Basin, a restricted basin at the border between the proto-Mediterranean and Paratethyan seas. Based on fish otoliths, we were able to identify 19 species from 17 genera, including two new species: Ariosoma mesohellenica and Gnathophis elongatus. This fish assemblage, in conjunction with the accompanying molluscan assemblage, indicates a variable shelf paleoenvironment with easy access to the open ocean. Although available data on the Indo-Pacific fishes of the early Miocene are very limited, the fish fauna of the Mesohellenic Basin has many elements in common with the North Sea, the NE Atlantic, and the Paratethys.

Diversity, relative abundance, new locality records, and updated fish fauna of the Ross Sea region

2013 ◽  
Vol 25 (5) ◽  
pp. 619-636 ◽  
Author(s):  
Stuart M. Hanchet ◽  
Andrew L. Stewart ◽  
Peter J. McMillan ◽  
Malcolm R. Clark ◽  
Richard L. O'Driscoll ◽  
...  
Keyword(s):  
Ross Sea ◽  
Fish Fauna ◽  
Demersal Fish ◽  
Fish Distribution ◽  
Distribution Data ◽  
Mesopelagic Fish ◽  
Species List ◽  
The North ◽  
Evenness Indices ◽  
Total Species

AbstractTwo surveys were carried out in the Ross Sea region during February and March 2004 and 2008 from the New Zealand RVTangaroa. Fishes were sampled on the continental shelf and slope of the Ross Sea, and on adjacent seamounts to the north, mainly using a large demersal fish trawl and a large mesopelagic fish trawl. Parts of the shelf and slope were stratified by depth and at least three random demersal trawls were completed in each stratum, enabling biomass estimates of demersal fish to be calculated. Fish distribution data from these two surveys were supplemented by collections made by observers from the toothfish fishery. A diverse collection of over 2500 fish specimens was obtained from the two surveys representing 110 species in 21 families. When combined with previous documented material this gave a total species list of 175, of which 135 were from the Ross Sea shelf and slope (to the 2000 m isobath). Demersal species-richness, diversity and evenness indices all decreased going from the shelf to the slope and the seamounts. In contrast, indices for pelagic species were similar for the slope and seamounts/abyss but were much lower for the shelf.

Physical and Biological Conditions in the North Sea

1896 ◽  
Vol 4 (3) ◽  
pp. 233-263
Author(s):  
J. T. Cunningham
Keyword(s):  
Present Article ◽  
North Sea ◽  
Surface Waters ◽  
Fish Fauna ◽  
Marine Fauna ◽  
The North ◽  
Interesting Paper ◽  
The North Sea ◽  
To Come ◽  
The Baltic

IN my report, in the preceding number of this Journal, on my observations in the North Sea, I referred briefly to the problem of the relation between the physical and biological conditions. This problem will afford scope for investigation for some time to come, and the purpose of the present article is to discuss and compare some of the most recent additions to our knowledge of the matter. The paper by Mr. H. N. Dickson, to which I referred in my previous report, was published in the Geographical Journal last March, under the title of “The Movements of the Surface Waters of the North Sea,” and in the Scottish Geographical Journal, in 1894, was published a series of papers by Professor Pettersson on “Swedish Hydrographic Research in the Baltic and the North Seas.” Professor Heincke has discussed the fish fauna of Heligoland, its composition and sources, in an interesting paper in the series issued under the title of “Wissenschaftliche Meeresuntersuchungen,” by the staff of the Biological Station at Heligoland, in association with the Commission for the Investigation of the German Seas, at Kiel. Professor Heincke's paper is contained in Bnd. I., Hft. 1 of this series (1894), and in the same volume are a number of papers dealing on similar lines with other divisions of the marine fauna of the Heligoland Bight.It will be most convenient and logical to start the present discussion with a consideration of the results of Professor Pettersson's work. He found that the Skagerack and Cattegat were filled with layers of water distinguished from one another by differences of salinity, and that the lower layers entered the channel as under–currents, and could be recognised at the surface somewhere in the North Sea.

scholarly journals The fuzzy relationship between trawl and acoustic surveys in the North Sea

2005 ◽  
Vol 62 (8) ◽  
pp. 1556-1575 ◽  
Author(s):  
Steven Mackinson ◽  
Jeroen van der Kooij ◽  
Suzanna Neville
Keyword(s):  
Fuzzy Logic ◽  
North Sea ◽  
Environmental Variables ◽  
Acoustic Energy ◽  
Fish Distribution ◽  
Model Free ◽  
The North ◽  
The North Sea ◽  
Acoustic Surveys ◽  
Trawl Catches

Abstract Adding information on the horizontal and vertical distribution of fish both on and between trawl stations is reason enough to perform acoustic surveys routinely in tandem with annual groundfish trawl surveys. Ideally, acoustic and trawl density indices could be combined to maximize information on fish distribution and provide more reliable estimates of stock size. The core of the problem boils down to the question: “how does what we see on an echosounder relate to what we catch in a net?” The fuzzy logic “model-free estimation” approach presented here sidesteps the need to understand specific mechanisms that determine the nature and variability of any relationship between acoustics and trawl catches. Fuzzy logic models that describe and predict the relationship linking acoustics and environmental variables (inputs) with trawl catches (output) are developed, and the sensitivities and robustness of the approach are discussed. In the models examined, the static environmental variables location and depth proved to be better predictors of trawl catches in the North Sea than the acoustic energy in the first 5 m off the bottom. We suggest that finding the “hidden” relationship between acoustics and trawls will require closer attention to partitioning the acoustics data by species/assemblages and understanding the key gear and behavioural differences responsible for producing the high between-gear variability.

Town and Countryside: Social and Economic Tensions in Fourteenth-Century Flanders

1968 ◽  
Vol 10 (4) ◽  
pp. 458-485 ◽  
Author(s):  
David M. Nicholas
Keyword(s):  
Thirteenth Century ◽  
North Sea ◽  
Western Europe ◽  
Northern Italy ◽  
Easy Access ◽  
Clearing House ◽  
Northern Germany ◽  
Wool Production ◽  
The North ◽  
The North Sea

In the thirteenth century the county of Flanders was the leading commercial and industrial region of Western Europe. It had easy access by water and overland routes to the German Rhineland and to the fairs of Champagne. As the Italians from the later thirteenth century began to use a direct maritime link with the North, Bruges, on the North Sea, became the major clearing house for goods coming from Italy and the Hanse towns of northern Germany. Flanders originally had a large wool production; this led to its early preeminence in textile manufacturing. Although the growing urbanization of thecounty soon severely curtailed facilities for grazing, Flanders easily obtained English wool, which was simultaneously of a higher calibre and a cheaper price than the native product. At a time when the towns of northern Italy were still very largely finishers of cloth brought from outside, the towns of Flanders, and particularly the five great towns of Bruges, Ghent, Ypres, Lille, and Douai, had prosperous industries in textiles of varying types, but specialized in luxury cloths designed for export.

scholarly journals Fish otoliths from the early Miocene of Chile: a window into the evolution of marine bony fishes in the Southeast Pacific

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Werner W. Schwarzhans ◽  
Sven N. Nielsen
Keyword(s):  
New Zealand ◽  
Fish Fauna ◽  
Single Species ◽  
Early Miocene ◽  
Tropical Region ◽  
Time Interval ◽  
The North ◽  
Taxonomic Description ◽  
Bony Fishes ◽  
Pacific Side

AbstractFew fossil fish otolith associations have been described from the Pacific side of the Americas and, except for a single species (Steindachneria svennielseni), none have been described from Pacific South America south of the Central American tropical region. Here, we describe a rich otolith assemblage obtained from fifteen early Miocene outcrop locations along the Chilean coast from about 33°S to about 45°S. More than 2,000 specimens were studied resulting in the recognition of 67 species, with 27 being new to science. This assemblage represents an important new data point distant from any previously known otolith-based fish fauna, with the nearest coeval associations being from the Caribbean Province in Venezuela, which lies about 5000 km to the north, and New Zealand, which is about 9000 km to the west. The fauna represents a mixture of offshore and shallow water fishes and is rich in myctophids, paralichthyids (Citharichthys), ophidiids (Lepophidium), steindachneriids, and macrourids. Typical tropical American fishes are nearly completely absent, with the exception of Steindachneria and certain anguilliforms. The mesopelagic faunal component, chiefly Myctophidae, shows a striking resemblance to the well-known coeval fish fauna from New Zealand, and both are interpreted as representing an early South Pacific mesopelagic bioprovince. The strong correlation with the mesopelagic otolith-based fish fauna from New Zealand constricts the time interval of the sampled sediments to the middle Burdigalian (approximately 17.5 to 18.5 Ma). All otoliths obtained from the early Miocene of Chile relate to extant fish groups of the area and few exotic components not currently present in the East Pacific. The sole exception is a morpho-type described as Navidadichthys which has an unresolved relationship, possibly with the Prototroctidae, a family that is today endemic to the freshwater and nearshore marine environments of Australia and New Zealand. The new taxa are in the sequence of taxonomic description: Pterothrissus transpacificus n. sp., Pythonichthys panulus n. sp., Chiloconger chilensis n. sp., Gnathophis quinzoi n.sp., Rhynchoconger chiloensis n. sp., Navidadichthys mirus n. gen. et n. sp., Maurolicus brevirostris n. sp., Polyipnus bandeli n. sp., Lampanyctus ipunensis n. sp., Physiculus pichi n. sp., Coelorinchus fidelis n. sp., Coelorinchus rapelanus n. sp., Nezumia epuge n. sp., Paracarapus chilensis n. gen. et n. sp., Lepophidium chonorum n. sp., Lepophidium mapucheorum n. sp., Sirembola supersa n. sp., Spectrunculus sparsus n. sp., Pseudonus humilis n. sp., Capromimus undulatus n. sp., Agonopsis cume n. sp., Cottunculus primaevus n. sp., Kuhlia orientalis n. sp., Citharichthys parvisulcus n. sp., Citharichthys vergens n. sp., Achirus australis n. sp., Achirus chungkuz n. sp.

Astronomical calibration of a key Early Eocene Boreal section: implications for the climate response to the North Atlantic Igneous Province

2021 ◽  
Author(s):  
Nicolas Thibault ◽  
Thierry Adatte ◽  
Jorge E. Spangenberg
Keyword(s):  
Magnetic Susceptibility ◽  
North Sea ◽  
North Atlantic ◽  
Fish Fauna ◽  
Early Eocene ◽  
The North ◽  
Igneous Province ◽  
The North Sea ◽  
The North Atlantic ◽  
North Atlantic Igneous Province

<p>Sections of the Fur formation exposed on the islands of Fur and Mors (N. Jutland, Denmark) expose well-preserved diatomites and over 140 interbedded ash layers spanning >1 Myr of the Early Eocene from the top part of the Paleocene-Eocene Thermal Maximum (PETM; 55.9 Ma). The Fur Formation is a Konzentrat-Lagerstätten with an extremely rich fish fauna as well as numerous exquisitely preserved invertebrates, vertebrates, plant material, and siliceous microfossils. Due to its peculiar bentonite record, the Fur formation also constitutes a reference for the North Sea area, recording phases of active North Atlantic Igneous Province (NAIP) volcanism. Recently, a sea-surface temperature (SST) record was derived from Tex<sub>86</sub> values for this formation, showing anomalously cool SSTs immediately after the PETM (~11–23°C, Stokke et al., 2020) while near-freezing bottom-water temperatures (BWTs) have been inferred from clumped isotopes analysis of giant glendonite crystals (Vickers et al., 2020). The section is constrained by three radiometric dates of ash layers but cyclostratigraphic analysis of the section has proved difficult due to the apparent homogeneity of the diatomite and multitude of interbedded ash layers. We performed a high-resolution analysis of the magnetic susceptibility and carbon isotopes on bulk organics (δ<sup>13</sup>C<sub>org</sub>) from across the top PETM to the top of the Silstrup Mb. The magnetic susceptibility depicts all the apparent ash layers as well as additional hidden ash layers with peaks of various heights, and thus constitutes an excellent stratigraphic tool for its potential of correlation to other sections and deep-sea sites of the North Atlantic. Our δ<sup>13</sup>C<sub>org </sub>record is characterized throughout by periodicities of 65 to 90 cm and 3.6 m that match well precession and short-eccentricity cycles. Long-term trends and filtered 100 kyr cycles from our record correlate very well to the recent benthic δ<sup>13</sup>C Cenozoic compilation, leading to an astronomical calibration of the section which spans ~1300 kyr from 55.88 to 54.6 Ma. Our calibration allows for a precise illustration of the drastic contrast between the post-PETM warm tropical SSTs/BWTs and the surprisingly cool SSTs/BWTs of the North Sea.</p><p>References</p><p>Stokke, E.W., et al., 2020, Earth and Planetary Science Letters 544, 116388.</p><p>Vickers, M.L., et al., 2020, Nature Communications 11, 4713.</p>

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