Modelling Atlantic mackerel spawning habitat suitability and its future distribution in the north‐west Atlantic

2019 ◽  
Vol 29 (1) ◽  
pp. 84-99
Author(s):  
Baye Mbaye ◽  
Thomas Doniol‐Valcroze ◽  
Pablo Brosset ◽  
Martin Castonguay ◽  
Elisabeth Van Beveren ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Spawning Habitat ◽  
North West ◽  
Atlantic Mackerel ◽  
The North

Development and evaluation of a habitat suitability model for young lake sturgeon (Acipenser fulvescens) in the North Channel of the St. Clair River, Michigan

2017 ◽  
Vol 74 (7) ◽  
pp. 1000-1008 ◽  
Author(s):  
Joseph R. Krieger ◽  
James S. Diana
Keyword(s):  
Habitat Suitability ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Suitable Habitat ◽  
Spawning Habitat ◽  
Catch Per Unit Effort ◽  
High Quality ◽  
Habitat Suitability Modeling ◽  
The North ◽  
River Bends

We evaluated the quantity, quality, and spatial distribution of riverine nursery habitat for larval, young-of-year (YOY), and juvenile (<500 mm) lake sturgeon (Acipenser fulvescens) in the North Channel of the St. Clair River (SCR), Michigan, using habitat suitability modeling (HSM) and fish collections. This HSM was developed using georeferenced habitat information on substrates, invertebrate densities, benthic flow velocities, and water depth. High-quality habitat comprised 29.1% of the study area, primarily in river bends and other areas where water velocities were highly varied. In all, 283 larval lake sturgeon were collected, with the majority found in high-quality habitat (81%) and heavily clustered in three locations (91.2% of total catch). Substrate composition and benthic flow velocity were the best indicators of observed larval catch-per-unit-effort (CPUE) patterns. Available data on captured YOY and juveniles were used to corroborate modeled habitat output and revealed strong associations between modeled habitat conditions and young lake sturgeon presence. An abundance of suitable habitat for young lake sturgeon within the North Channel of the SCR suggests that lack of suitable spawning habitat or high mortality early in life limits recruitment success in this system.

scholarly journals The genetic composition of feeding aggregations of the Atlantic mackerel (Scomber scombrus) in the central north Atlantic: a microsatellite loci approach

2020 ◽  
Vol 77 (2) ◽  
pp. 604-612
Author(s):  
Davið Gíslason ◽  
Sarah J Helyar ◽  
Guðmundur J Óskarsson ◽  
Guðbjörg Ólafsdóttir ◽  
Aril Slotte ◽  
...  
Keyword(s):  
North Atlantic ◽  
Microsatellite Loci ◽  
Migration Patterns ◽  
Fish Stocks ◽  
North West ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
The North ◽  
Specific Contribution ◽  
Impacts Of Climate Change

Abstract The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the northeast Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in stock size accompanied by changing summer migration patterns, which have resulted in an expansion further north and north west than previously recorded. This study uses microsatellite loci to confirm the differentiation among NEA and northwest Atlantic (NWA) mackerel spawning populations and to assess the level of structuring within these populations. In addition, to enable population-specific exploitation rates to be factored into fisheries management, we identified the origin of individuals composing the expanding feeding aggregations in the central north Atlantic (Greenland, Iceland, Faroes), with all aggregations tested originating from spawning populations in the NEA. This study showed that microsatellite loci were useful to assess the contribution of NEA and NWA populations to mixed feeding aggregations across the north Atlantic for large pelagic fish stocks but were not powerful enough to evaluate the specific contribution of known stocks within NEA and NWA.

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

The North West Passage

2014 ◽  
Author(s):  
Roald Amundsen ◽  
Godfred Hansen
Keyword(s):  
North West ◽  
The North

Russian Oil: Production and Exports

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto
Keyword(s):  
Baltic Sea ◽  
Statistical Data ◽  
Oil Production ◽  
The Baltic Sea ◽  
North West ◽  
The North ◽  
Oil Transportation ◽  
Sea Ports ◽  
The Baltic

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.

Paleoecological study of bottom sediments of the lake Goluboye (Karelian Isthmus) according to the results of diatom analysis

2019 ◽  
pp. 265-269
Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Bottom Sediments ◽  
Modern Science ◽  
Karelian Isthmus ◽  
The Baltic Sea ◽  
Diatom Analysis ◽  
North West ◽  
The North ◽  
Important Direction ◽  
The Baltic

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.

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