Seasonal variation in weight and biochemical composition of the tissues of the queen scallop, Chlamys opercularis, from the Clyde Sea area

1979 ◽  
Vol 59 (3) ◽  
pp. 605-621 ◽  
Author(s):  
A. C. Taylor ◽  
T. J. Venn
Keyword(s):  
Body Weight ◽  
Seasonal Variation ◽  
Biochemical Composition ◽  
Comparative Data ◽  
Irish Sea ◽  
Seasonal Cycles ◽  
Pecten Maximus ◽  
The North ◽  
Clyde Sea ◽  
Sea Area

A number of studies exist on the seasonal cycles of body weight and tissue biochemistry of several species of bivalve from the Clyde Sea area (Ansell & Trevallion, 1967; Ansell, 1974, et seq), including two members of the Pectinidae, namely Chlamys septemradiata (Müller) (Ansell, 1974) and Pecten maximus L. (Comely, 1974). Some comparative data are available for Chlamys opercularis (L.) from Manx waters (Soemodihardjo, 1974) and for P. maximus from the north Irish Sea (Stanley, 1967).

Histriobdella homari on nephrops norvegicus from the irish sea and clyde sea area

1997 ◽  
Vol 77 (2) ◽  
pp. 557-559 ◽  
Author(s):  
R.P. Briggs ◽  
R.J.A. Atkinson ◽  
M. McAliskey ◽  
A. Rogerson
Keyword(s):  
North Sea ◽  
Irish Sea ◽  
English Channel ◽  
Southwestern Part ◽  
Nephrops Norvegicus ◽  
The North ◽  
The North Sea ◽  
The Irish Sea ◽  
Clyde Sea ◽  
Sea Area

Histriobdella homari is a polychaete annelid belonging to the Order Eunicida and Family Histriobdellidae. Histriobdella homari is normally found in the gill chambers or among the eggs of the lobster Homarus vulgaris from the English Channel (Roscoff) and in the southwestern part of the North Sea (George & Hartmann-Schroder, 1985). Two independent sightings of H. homari living on the pleopods of Nephrops norvegicus from the Irish Sea and Clyde Sea area are reported.

scholarly journals The effects of trawling on the physical condition of the Norway lobster Nephrops norvegicus in relation to seasonal cycles in the Clyde Sea area

2009 ◽  
Vol 66 (3) ◽  
pp. 488-494 ◽  
Author(s):  
R. J. Milligan ◽  
A. Albalat ◽  
R. J. A. Atkinson ◽  
D. M. Neil
Keyword(s):  
Physical Condition ◽  
Seasonal Effects ◽  
Seasonal Cycles ◽  
Physical Damage ◽  
Nephrops Norvegicus ◽  
Emergence Period ◽  
Norway Lobster ◽  
Emergence Patterns ◽  
Clyde Sea ◽  
Sea Area

Abstract Milligan, R. J., Albalat, A., Atkinson, R. J. A., and Neil, D. M. 2009. The effects of trawling on the physical condition of the Norway lobster Nephrops norvegicus in relation to seasonal cycles in the Clyde Sea area. – ICES Journal of Marine Science, 66: 488–494. The fishery for Norway lobster, Nephrops norvegicus, is the most valuable in Scotland, but few studies have examined the physical condition of the animals trawled. This study aimed to determine the extent of physical damage caused by trawling to Nephrops in the Clyde Sea area in relation to trawl duration, sex, size, and moult stage. Longer trawls (2.5–4 h) corresponded to increased damage in “hard” (intermoult) Nephrops compared with short (1 h) or very short (15 min) trawls, but there was no correlation in “soft” (late intermoult or recently moulted) or “jelly” (immediate post-moult) Nephrops. This effect appeared to be limited to Nephrops with a carapace length (CL) of 20.0–29.9 mm. Seasonal effects were also observed, with numbers of jelly Nephrops highest in May 2006, corresponding to a peak in female prevalence in the catches, an increase in the mean CL of females, and greater damage in females. The proportion of females was higher than males from May to September 2006, and it is suggested that this corresponds to female emergence patterns. As quality will be low, it may be pertinent to avoid fishing during the peak emergence period to maximize the quality and profitability of catches.

Clyde Nephrops: biology and fisheries

1986 ◽  
Vol 90 ◽  
pp. 501-518 ◽  
Author(s):  
N. Bailey ◽  
F. G. Howard ◽  
C. J. Chapman
Keyword(s):  
Growth Rate ◽  
Physical Environment ◽  
Sexual Maturity ◽  
Size Composition ◽  
Fishing Effort ◽  
Ovary Development ◽  
Organic Carbon Content ◽  
The North ◽  
Clyde Sea ◽  
Sea Area

SynopsisThe fishery for Norway lobsters Nephrops norvegicus began in the 1950s and has since become one of the most valuable assets of the Clyde Sea Area. Landings of Nephrops reached a peak of 26001 in 1972. Following a decline in landings up to 1975 there has been a further increase to over 45001 in 1983, valued at £4–5 million. Most of the landings are made by inshore trawlers working from Ayr, Troon, Girvan, Largs, Campbeltown and Tarbert. Recently a small creel fishery has developed in some sea lochs. The abundance of the stock appears to have been maintained; landings per unit of fishing effort have fluctuated without any obvious trend.Since September, 1979. several aspects of the biology of Nephrops have been studied in an area south of the Little Cumbrae at the north end of the east Arran Basin. Data are presented on the density, size composition, growth rate, reproductive biology and feeding of Nephrops in this area. The results are compared with those obtained for other Nephrops populations, revealing some unusual features of Clyde Nephrops. In the Clyde, densities were lower than in a number of other areas, while growth rate was much higher and animals grew to larger sizes. Sexual maturity was attained at a larger size in Clyde Nephrops and studies of ovary development revealed that considerable numbers of large females did not reproduce annually, in contrast to some other areas. Recent observations suggest that the biological characteristics of Nephrops populations in an area may be influenced by features of the local physical environment such as the particle size distribution and organic carbon content of the sediment. Differences between Clyde Nephrops and those from other areas are discussed in relation to this.

Mussels as biomonitors of point and diffuse sources of trace metals in the clyde sea area, Scotland

1999 ◽  
Vol 39 (12) ◽  
pp. 233-240 ◽  
Author(s):  
B. S. Miller
Keyword(s):  
Trace Metals ◽  
Good Evidence ◽  
Point Sources ◽  
Aqueous Environment ◽  
Clear Trend ◽  
Diffuse Sources ◽  
The North ◽  
Point And Diffuse Sources ◽  
Clyde Sea ◽  
Sea Area

Following a series of international conferences on pollution of the North Sea, the UK Government committed itself in 1990 to reducing the inputs of certain dangerous substances reaching the aqueous environment from point and diffuse sources. The target was a 50% reduction in loadings over the period 1985-95. Metals loadings from rivers and sewage works to the Clyde Sea Area are presented for the period 1990-97. These are compared to trace metals body burdens in mussels collected from shores throughout the Clyde Sea Area over the period 1980-97. For most metals, no clear trend either increasing or decreasing was observed in metals loadings from point sources or in mussel body burdens. The exceptions were cadmium, which showed downward trends with time in loadings and in concentrations in Clyde Estuary mussels, and lead, which showed a downward trend in mussel concentrations. Metals loadings from point sources may have reached baseline levels, below which further reductions will be difficult to achieve. Elevated mussel body burdens of specific metals provided good evidence that some shores are severely affected by point source inputs, others by bulk contamination from far-field point sources, and others by diffuse sources of metals.

spatial distribution patterns of basking sharks on the european shelf: preliminary comparison of satellite-tag geolocation, survey and public sightings data

2005 ◽  
Vol 85 (5) ◽  
pp. 1083-1088 ◽  
Author(s):  
e.j. southall ◽  
d.w. sims ◽  
j.d. metcalfe ◽  
j.i. doyle ◽  
s. fanshawe ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Population Distribution ◽  
Distribution Patterns ◽  
Irish Sea ◽  
Distribution Maps ◽  
North East ◽  
The North ◽  
Current Concerns ◽  
Clyde Sea ◽  
Satellite Tag

current concerns about the population levels of the basking shark (cetorhinus maximus) in the north-east atlantic have prompted a need to understand population distribution, habitat preference and centres of abundance. in this study, spatial distribution maps derived from satellite-tag geolocations, boat surveys and public sightings data were compared. the broad distribution patterns revealed by these different methods are similar, but there are considerable differences in density distributions. surface sightings data show high densities, or ‘hotspots’ in the hebridean sea, clyde sea, irish sea and close inshore around devon and cornwall. tag geolocations, in contrast, identified two areas where individuals spent considerable time outside the distributions indicated by surveys and public sightings: the celtic sea and western approaches of the english channel. the reason for this disparity and its implications for population estimates for the species are discussed.

scholarly journals On the Fertility of Marine Cladocera with a Note on the Formation of the Resting Egg in Evadne Nordmanni Loven and Podon Intermedius Lilljeborg

1947 ◽  
Vol 26 (4) ◽  
pp. 551-561 ◽  
Author(s):  
C. Cheng
Keyword(s):  
Seasonal Variation ◽  
Sexual Reproduction ◽  
Inverse Relationship ◽  
Statistical Study ◽  
Reproductive Capacity ◽  
Positive Correlation ◽  
Resting Egg ◽  
The Mean ◽  
Clyde Sea ◽  
Sea Area

A statistical study was made of the fertility of Evadne nordmanni, Podon intermedius, P. leuckarti and P. polyphemoides in the Clyde Sea-Area and of the former two species off Plymouth. The mean fertility of parthenogenetic females varies with different species. This is not correlated with the size of the species.Within the species, Evadne nordmanni and Podon intermedius, there exists, in general, a positive correlation between the size and the fertility of parthenogenetic females.The fertility of Evadne nordmanni is subject to seasonal variation. This is not correlated with fluctuations in the abundance of diatoms.An inverse relationship was observed in Evadne nordmanni between the reproductive capacity of parthenogenetic females and the intensity of sexual reproduction.A brief account was given of the formation of the resting egg in Evadne nordmanni and Podon intermedius.

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