scholarly journals Population biology of monkfish Lophius americanus

2008 ◽  
Vol 65 (7) ◽  
pp. 1291-1305 ◽  
Author(s):  
R. Anne Richards ◽  
Paul C. Nitschke ◽  
Katherine A. Sosebee

Abstract Richards, R. A., Nitschke, P. C., and Sosebee, K. A. 2008. Population biology of monkfish Lophius americanus. – ICES Journal of Marine Science, 65: 1291–1305. This paper provides an overview of the biology of monkfish in US waters of the Northwest Atlantic Ocean using data from resource surveys spanning the period 1948–2007. Monkfish exhibited seasonal onshore–offshore shifts in distribution, migrated out of the southern Mid-Atlantic Bight (MAB) in mid-spring, and re-appeared there in autumn. Sex ratios at length for fish 40–65-cm long were skewed towards males in the southern MAB, but approximated unity elsewhere, suggesting that a portion of the population resides outside sampled areas. Growth was linear at 9.9 cm year−1 and did not differ by region or sex. Maximum observed size was 138 cm for females and 85 cm for males. Length at 50% maturity for males was 35.6 cm (4.1 years old) in the north and 37.9 cm (4.3 years old) in the south; for females 38.8 cm (4.6 years old) in the north and 43.8 cm (4.9 years old) in the south. Ripe females were found in shallow (<50 m) and deep (>200 m) water in the south, and in shallow water (<50 m) in the north.

2020 ◽  
Vol 84 (1) ◽  
pp. 93
Author(s):  
Ana García-Alegre ◽  
Esther Román-Marcote ◽  
Jesús Gago ◽  
Gonzalo González-Nuevo ◽  
Mar Sacau ◽  
...  

Seabed litter of the Flemish Pass area (NW Atlantic Ocean) was analysed and described using data from the EU-Spain groundfish survey (2006-2017 period). This study presents baseline information on seabed litter in this area. The Flemish Pass is located in areas beyond national jurisdiction within the Northwest Atlantic Fisheries Organization Regulatory Area Division 3L. A total of 1169 valid bottom trawl hauls were analysed (104-1478 m depth). Litter was found in 8.3% of the hauls, with mean densities of 1.4±0.2 items km–2 and 10.6±5.2 kg km–2. An increasing pattern with depth was found, the highest densities of seabed litter being identified in the deepest areas located in the Flemish Pass channel and down the northeastern flank of the Grand Bank. Fishing was found to be the main source of marine litter, and 61.9% of the hauls with litter presence showed litter included in the fisheries-related litter category. Whereas in most cases the litter was composed of small fragments of rope, in other cases it was composed of entire fishing gears such as traps. Plastics, metal and other anthropogenic litter were the next most abundant categories, accounting for 18.6%, 16.5% and 12.4% of the total, respectively.


Zootaxa ◽  
2021 ◽  
Vol 4948 (2) ◽  
pp. 275-286
Author(s):  
RODOLFO CORRÊA DE BARROS ◽  
ROSANA MOREIRA DA ROCHA

Two new species of the genus Styela are described, with very rare characteristics in this genus: both are shallow-water and tropical, with more than two gonads in each side of the body. Styela panamensis sp. nov. is described from specimens collected in Bocas del Toro, Atlantic coast of Panama, and Styela multicarpa sp. nov. from specimens collected in Espírito Santo, Brazil and Margarita Island, Venezuela. They are probably native to the south Caribbean and S. multicarpa sp. nov. is introduced in Brazil. 


1953 ◽  
Vol S6-III (1-3) ◽  
pp. 187-204
Author(s):  
Pierre Bout

Abstract Volcanologic and geomorphic studies in southwestern Iceland show that (1) the basalt breccias of the palagonite deposits exhibit striking analogies with those of Velay (Haute-Loire, France), and similarly seem to be of directly eruptive origin; (2) the fissured domes of certain basalts are the effect of dilatation during cooling; (3) the topography is controlled not only by volcanism but also by four systems of fractures; (4) present eolian action is due to winds from the north and northeast (glaciers) or south and southeast (Atlantic Ocean); (5) dreikanter basalt blocks are now being formed only on the south coast, those in the interior having been formed earlier in times of more extensive glaciation; (6) polygonal soils were formed by shrinkagefollowing pressures developed by winter ice, the size of the polygons depending on whether segmentation was easy (small polygons) or difficult (large polygons).


2010 ◽  
Vol 23 (17) ◽  
pp. 4538-4555 ◽  
Author(s):  
Kevin H. Goebbert ◽  
Lance M. Leslie

Abstract Tropical cyclone (TC) activity over the southeast Indian Ocean has been studied far less than other TC basins, such as the North Atlantic and northwest Pacific. The authors examine the interannual TC variability of the northwest Australian (NWAUS) subbasin (0°–35°S, 105°–135°E), using an Australian TC dataset for the 39-yr period of 1970–2008. Thirteen TC metrics are assessed, with emphasis on annual TC frequencies and total TC days. Major findings are that for the NWAUS subbasin, there are annual means of 5.6 TCs and 42.4 TC days, with corresponding small standard deviations of 2.3 storms and 20.0 days. For intense TCs (WMO category 3 and higher), the annual mean TC frequency is 3.0, with a standard deviation of 1.6, and the annual average intense TC days is 7.6 days, with a standard deviation of 4.5 days. There are no significant linear trends in either mean annual TC frequencies or TC days. Notably, all 13 variability metrics show no trends over the 39-yr period and are less dependent upon standard El Niño–Southern Oscillation (ENSO) variables than many other TC basins, including the rest of the Australian region basin. The largest correlations with TC frequency were geopotential heights for June–August at 925 hPa over the South Atlantic Ocean (r = −0.65) and for April–June at 700 hPa over North America (−0.64). For TC days the largest correlations are geopotential heights for July–September at 1000 hPa over the South Atlantic Ocean (−0.7) and for April–June at 850 hPa over North America (−0.58). Last, wavelet analyses of annual TC frequencies and TC days reveal periodicities at ENSO and decadal time scales. However, the TC dataset is too short for conclusive evidence of multidecadal periodicities. Given the large correlations revealed by this study, developing and testing of a multivariate seasonal TC prediction scheme has commenced, with lead times up to 6 months.


2019 ◽  
pp. 128-163
Author(s):  
Sarah A. Woodin ◽  
Susan S. Bell ◽  
Jon Grant ◽  
Paul V. R. Snelgrove ◽  
David S. Wethey

Geophysics ◽  
1979 ◽  
Vol 44 (6) ◽  
pp. 1022-1033 ◽  
Author(s):  
L. D. McGinnis ◽  
R. M. Otis

Velocities were obtained from unreversed, refracted arrivals on analog records from a 48‐channel, 3.6-km hydrophone cable (3.89 km from the airgun array to the last hydrophone array). Approximately 200 records were analyzed along 1500 km of ship track on Georges Bank, northwest Atlantic Ocean, to obtain regional sediment velocity distribution to a depth of 1.4 km below sea level. This technique provides nearly continuous coverage of refraction velocities and vertical velocity gradients. Because of the length of the hydrophone cable and the vertical velocity gradients, the technique is applicable only to the Continental Shelf and the shallower parts of the Continental Slope in water depths less than 300 m. Sediment diagenesis, the influence of overburden pressure on compaction, lithology, density, and porosity are inferred from these data. Velocities of the sediment near the water‐sediment interface range from less than 1500 m/sec on the north edge of Georges Bank to 1830 m/sec for glacial deposits in the northcentral part of the bank. Velocity gradients in the upper 400 m range from [Formula: see text] on the south edge of the bank to [Formula: see text] on the north. Minimum gradients of [Formula: see text] were observed south of Nantucket Island. Velocities and velocity gradients are explained in relation to physical properties of the Cretaceous, Tertiary, and Pleistocene sediments. Isovelocity contours at 100-m/sec intervals are nearly horizontal in the upper 400 m. Isovelocity contours at greater depths show a greater difference from a mean depth because of the greater structural and lithological variation. Bottom densities inferred from the velocities range from 1.7 to [Formula: see text] and porosities range from 48 to 62 percent. The most significant factor controlling velocity distribution on Georges Bank is overburden pressure and resulting compaction. From the velocity data we conclude that Georges Bank has been partially overridden by a continental ice sheet.


1976 ◽  
Vol 54 (9) ◽  
pp. 1538-1541
Author(s):  
R. E. Zurbrigg ◽  
W. B. Scott

A new myctophid species, Diaphus hudsoni, was captured in the South Atlantic Ocean, and is described. It is similar to Diaphus subtilis Nafpaktitis, which occurs in the North Atlantic Ocean, but is definitely distinct with its slender, more numerous gill rakers (total 23–25), and non-continuous AOp–Prc series. The AO series numbers 5 + 5–6. The holotype is deposited in the Royal Ontario Museum, ROM 27569.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Annalea Beard ◽  
Leeann Henry ◽  
Samantha Cherrett ◽  
Alistair D.M. Dove

AbstractData from 369 sightings of mobulid rays from St Helena Island, Cardno and Bonaparte seamounts in the South Atlantic are summarised. 50 % (183) of sightings were observed from a boat, 48 % (176) of sightings were encountered in water, of which 95 % (168) were whilst actively scuba diving. 2 % (10) of mobulid ray sightings were observed from land. Sightings data indicate that the Chilean devil ray Mobula tarapacana (Philippi, 1892) is a frequent visitor to St Helena and is present all year. We document the first photographic evidence of the presence of oceanic manta, Mobula birostris (Walbaum, 1792) at St Helena. Two solitary individuals were photographed off the north coast of St Helena in June 2018. These sightings confirm previous unverified reports on the species occurrence and extend the known distribution range of M. birostris in the open South Atlantic Ocean to 16°S.


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