Seasonal Changes in General Condition and Lipid Content of Cod from Inshore Waters

1967 ◽  
Vol 24 (3) ◽  
pp. 607-612 ◽  
Author(s):  
P. M. Jangaard ◽  
H. Brockerhoff ◽  
R. D. Burgher ◽  
R. J. Hoyle
Keyword(s):  
Seasonal Variation ◽  
Nova Scotia ◽  
Lipid Content ◽  
General Condition ◽  
Seasonal Variations ◽  
Seasonal Changes ◽  
Oil Content ◽  
Gadus Morhua ◽  
Male Fish ◽  
Inshore Waters

The seasonal variations in lipid content and general "condition" of cod, Gadus morhua L., from an inshore population have been determined.Four female and four male fish were chosen from 20 live cod brought in monthly from Terence Bay, Halifax County, Nova Scotia, the fish were pooled and the lipid content determined on the flesh, livers, and gonads. The flesh lipids varied from 0.57% to 0.74% and the oil content of the livers from 15% to 75%.The general "condition" of the fish as expressed by [Formula: see text], the liver condition by [Formula: see text], and the fat content of the liver all showed seasonal variation with maxima in the fall and minima in the spring. KF varied from 0.79 to 1.05 and KL from 1.0 to 4.5. No seasonal variation in the amount of flesh lipids could be detected.

Some notes on the biology of the snake blenny, Lumpenus lampretaeformis on the west coast of Scotland

1979 ◽  
Vol 59 (2) ◽  
pp. 413-419 ◽  
Author(s):  
J. D. M. Gordon ◽  
J. A. R. Duncan
Keyword(s):  
Growth Rate ◽  
Seasonal Variation ◽  
West Coast ◽  
Seasonal Variations ◽  
Rapid Growth ◽  
The West ◽  
Harpacticoid Copepods ◽  
Rapid Growth Rate ◽  
Inshore Waters ◽  
Made In

Large catches of the snake blenny, Lumpenus lampretaeformis, have been made in the inshore waters of the west coast of Scotland. Analysis of these catches confirm the view that this species shows marked seasonal variations in abundance. The species lives for up to 9 years and has a rapid growth rate in the first 2 years. It feeds mainly on meiobenthic organisms, of which polychaetes, harpacticoid copepods, ostracods and nematodes are the most important. The reason for the seasonal variation in catch rate is discussed and it is speculated that it may result from the fossorial habit of the adults and the parental care of the eggs.

Inter-Annual Distributions of Larval and Pelagic Juvenile Cod (Gadus morhua) in Southwestern Nova Scotia determined with two Different Gear Types

1989 ◽  
Vol 46 (4) ◽  
pp. 591-602 ◽  
Author(s):  
Iain M. Suthers ◽  
Kenneth T. Frank
Keyword(s):  
Nova Scotia ◽  
Gadus Morhua ◽  
Empirical Support ◽  
Single Type ◽  
Sampling Effort ◽  
Limited Sampling ◽  
Inshore Waters ◽  
Made In ◽  
Spawning Sites ◽  
Pelagic Juvenile

Ichthyoplankton surveys conducted during 1979 on the Scotian Shelf have shown coincident egg and larval distributions for cod (Gadus morhua) and other related groundfish species. These data have been used by other investigators to support the larval retention hypothesis, in spite of three limitations: the exclusive use of a single type of small sampling gear, limited sampling landward of the 50-m isobath, and analysis of data collected in a single year. During May of 1985, 1986, and 1987 two gear types were used, from the shelf to coastal waters in southwestern Nova Scotia to assess the horizontal distributions of larval and pelagic juvenile cod. Tucker trawl collections made in each year revealed a cohort of cod [Formula: see text] that was not evident in the smaller gear, which effectively sampled cod larvae < 10 mm. During 1985 and 1986, when both larvae and juveniles were abundant, their distributions coincided. The mixture of sizes of cod from 3–45 mm reduced the importance of using multiple gear types. The interannual location of young cod shifted markedly between the nearshore and offshore demonstrating that a single year of sampling effort is inadequate to assess their distribution. Nearshore sampling revealed high densities of young cod as much as three-fold greater than offshore. The inshore waters may serve as a nursery area for young cod originating from offshore spawning sites. Our results confirm the existence of two important sampling limitations of previous cod ichthyoplankton surveys that reduce their utility as empirical support for the retention hypothesis.

Seasonal variation in temperature preference of juvenile Atlantic cod (Gadus morhua), with evidence supporting an energetic basis for their diel vertical migration

1991 ◽  
Vol 69 (5) ◽  
pp. 1302-1307 ◽  
Author(s):  
Donald S. Clark ◽  
John M. Green
Keyword(s):  
Seasonal Variation ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Energetic Efficiency ◽  
Temperature Preference ◽  
Ambient Temperatures ◽  
Inshore Waters ◽  
Conception Bay

Juvenile (3-year-old) Atlantic cod (Gadus morhua) from Broad Cove, Conception Bay, Newfoundland, exhibit seasonal variation in temperature preference. Laboratory studies show that juvenile cod from ambient temperature water prefer temperatures that correlate closely with seasonal changes in the temperature of the inshore waters that they inhabit. A similar pattern is shown by fish held in 10 °C water over winter, indicating that variation in temperature preference is not simply a response to changing ambient temperatures but occurs in an anticipatory manner that allows them to maintain their physiologically optimal temperature at a seasonally appropriate level. The results also support the hypothesis that the diel vertical migration of juvenile cod in summer increases energetic efficiency by reducing metabolic costs in nonfeeding hours.

Effect of body lipid content is linked to nutritional adaptation in the acclimation responses of mesic-adapted Paederus to seasonal variations in desiccation stress

2021 ◽  
Vol 131 ◽  
pp. 104226
Author(s):  
Lee-Jin Bong ◽  
Chia-Yu Wang ◽  
Satomi Shiodera ◽  
Takashi F. Haraguchi ◽  
Masayuki Itoh ◽  
...  
Keyword(s):  
Lipid Content ◽  
Seasonal Variations ◽  
Desiccation Stress ◽  
Body Lipid

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

Seasonal Variation in the Physiological Response of Atlantic Cod (Gadus morhua) to Low Salinity

1992 ◽  
Vol 49 (6) ◽  
pp. 1149-1156 ◽  
Author(s):  
J.-D. Dutil ◽  
J. Munro ◽  
C. Audet ◽  
M. Besner
Keyword(s):  
Skeletal Muscle ◽  
Seasonal Variation ◽  
Osmotic Pressure ◽  
Principal Components ◽  
Physiological Response ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Low Salinity ◽  
Natural Photoperiod ◽  
Highly Correlated

Plasma Na+, Cl−, K+, osmotic pressure, Cortisol, glucose, and protein, blood hemoglobin and hematocrit, and water content of skeletal muscle were measured at regular intervals during a 28-d period following the transfer of Atlantic cod (Gadus morhua) to waters of 7, 14, 21, and 28‰ (control) salinity. These experiments were repeated four times at 3-mo intervals under natural photoperiod and temperatures (0–10 °C). Exposure to 7‰ salinity caused large decreases in plasma Na+ in winter (25 mmol/L over 14 d) and in spring (32 mmol/L over 7 d) when the lowest value for the year was reached (156 mmol/L). Transfer to 14 and 21‰ salinity resulted in a slight decrease (maximum 4%) in plasma Na+ which was much smaller than the seasonal variation (14%) observed in controls. Hydration of skeletal muscle occurred only at 7‰ (2.3% maximum), but these changes were small compared with the seasonal variation (3.9%) observed in the controls. Principal components and clustering analyses showed that all ionic and osmotic variables measured were highly correlated while being only weakly associated with the condition or reproductive status of the fish. There were no indications that acclimation to low salinity was stressful for cod.

Global mapping of seasonal variations in tides from tide gauge and satellite altimeter data

2021 ◽  
Author(s):  
Inger Bij de Vaate ◽  
Henrique Guarneri ◽  
Cornelis Slobbe ◽  
Martin Verlaan
Keyword(s):  
Seasonal Variation ◽  
Sea Level ◽  
Seasonal Variations ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Altimeter Data ◽  
Tide Gauges ◽  
Tidal Constituents ◽  
The Arctic Region

&lt;p&gt;The existence of seasonal variations in major tides has been recognized since decades. Where Corkan (1934) was the first to describe the seasonal perturbation of the M2 tide, many others have studied seasonal variations in the main tidal constituents since. However, most of these studies are based on sea level observations from tide gauges and are often restricted to coastal and shelf regions. Hence, observed seasonal variations are typically dominated by local processes and the large-scale patterns cannot be clearly distinguished. Moreover, most tide models still perceive tides as annually constant and seasonal variation in tides is ignored in the correction process of satellite altimetry. This results in reduced accuracy of obtained sea level anomalies. &lt;/p&gt;&lt;p&gt;To gain more insight in the large-scale seasonal variations in tides, we supplemented the clustered and sparsely distributed sea level observations from tide gauges by the wealth of data from satellite altimeters. Although altimeter-derived water levels are being widely used to obtain tidal constants, only few of these implementations consider seasonal variation in tides. For that reason, we have set out to explore the opportunities provided by altimeter data for deriving seasonal modulation of the main tidal constituents. Different methods were implemented and compared for the principal tidal constituents and a range of geographical domains, using data from a selection of satellite altimeters. Specific attention was paid to the Arctic region where seasonal variation in tides was expected to be significant as a result of the seasonal sea ice cycle, yet data availability is particularly limited. Our study demonstrates the potential of satellite altimetry for the quantification of seasonal modulation of tides and suggests the seasonal modulation to be considerable. Already for M2 we observed changes in tidal amplitude of the order of decimeters for the Arctic region, and centimeters for lower latitude regions.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;div&gt;Corkan, R. H. (1934). An annual perturbation in the range of tide. &lt;em&gt;Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character&lt;/em&gt;, &lt;em&gt;144&lt;/em&gt;(853), 537-559.&lt;/div&gt;

scholarly journals Effect of Seasonal Variation on Clinical Outcome in Patients with Chronic Conditions: Analysis of the Commonwealth Scientific and Industrial Research Organization (CSIRO) National Telehealth Trial (Preprint)

2017 ◽  
Author(s):  
Ahmadreza Argha ◽  
Andrey Savkin ◽  
Siaw-Teng Liaw ◽  
Branko George Celler
Keyword(s):  
Seasonal Variation ◽  
Length Of Stay ◽  
Clinical Outcome ◽  
Seasonal Variations ◽  
Chronic Conditions ◽  
Hospital Admissions ◽  
Australian Capital Territory ◽  
Home Telemonitoring ◽  
The Impact ◽  
At Home

BACKGROUND Seasonal variation has an impact on the hospitalization rate of patients with a range of cardiovascular diseases, including myocardial infarction and angina. This paper presents findings on the influence of seasonal variation on the results of a recently completed national trial of home telemonitoring of patients with chronic conditions, carried out at five locations along the east coast of Australia. OBJECTIVE The aim is to evaluate the effect of the seasonal timing of hospital admission and length of stay on clinical outcome of a home telemonitoring trial involving patients (age: mean 72.2, SD 9.4 years) with chronic conditions (chronic obstructive pulmonary disease coronary artery disease, hypertensive diseases, congestive heart failure, diabetes, or asthma) and to explore methods of minimizing the influence of seasonal variations in the analysis of the effect of at-home telemonitoring on the number of hospital admissions and length of stay (LOS). METHODS Patients were selected from a hospital list of eligible patients living with a range of chronic conditions. Each test patient was case matched with at least one control patient. A total of 114 test patients and 173 control patients were available in this trial. However, of the 287 patients, we only considered patients who had one or more admissions in the years from 2010 to 2012. Three different groups were analyzed separately because of substantially different climates: (1) Queensland, (2) Australian Capital Territory and Victoria, and (3) Tasmania. Time series data were analyzed using linear regression for a period of 3 years before the intervention to obtain an average seasonal variation pattern. A novel method that can reduce the impact of seasonal variation on the rate of hospitalization and LOS was used in the analysis of the outcome variables of the at-home telemonitoring trial. RESULTS Test patients were monitored for a mean 481 (SD 77) days with 87% (53/61) of patients monitored for more than 12 months. Trends in seasonal variations were obtained from 3 years’ of hospitalization data before intervention for the Queensland, Tasmania, and Australian Capital Territory and Victoria subgroups, respectively. The maximum deviation from baseline trends for LOS was 101.7% (SD 42.2%), 60.6% (SD 36.4%), and 158.3% (SD 68.1%). However, by synchronizing outcomes to the start date of intervention, the impact of seasonal variations was minimized to a maximum of 9.5% (SD 7.7%), thus improving the accuracy of the clinical outcomes reported. CONCLUSIONS Seasonal variations have a significant effect on the rate of hospital admission and LOS in patients with chronic conditions. However, the impact of seasonal variation on clinical outcomes (rate of admissions, number of hospital admissions, and LOS) of at-home telemonitoring can be attenuated by synchronizing the analysis of outcomes to the commencement dates for the telemonitoring of vital signs. CLINICALTRIAL Australian New Zealand Clinical Trial Registry ACTRN12613000635763; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364030&isReview=true (Archived by WebCite at http://www.webcitation.org/ 6xLPv9QDb)

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