The influence of ambient temperature (2-7°C) and oxygen level (1.0-8.3 mi i i) on the development of Baltic cod eggs was investigated in laboratory experimenrs. The incubation period, i.e. the time from fer tilization to 50% hatching, decreased from 27.5 days at 2°C to 13.0 days at 7°C. Reduced oxygen levels did flot significantly affect the time of hatching. Throughout the incubation period hi...

The subject matter of this Bachelor ́s thesis is the Eastern Baltic Sea cod. A literature review has been done regarding how environmental factors such as salinity, oxygen supply and temperature but also the size of the cod populations affects the migration patterns and the habitat choice of the cod. The result of the review shows that, when the eastern Baltic cod population is small, its area o...

A study of the second step or methanogenic stage of a two-stage anaerobic digestion process treating two-phase olive oil mill solid residue (OMSR) was conducted at mesophilic temperature (35 degrees C). The substrate fed to the methanogenic step was the effluent from a hydrolytic-acidogenic reactor operating at an organic loading rate (OLR) of 12.9 g chemical oxygen demand (COD) L(-1) d(-1) and...

This study evaluated the link between swimming endurance and condition of Atlantic cod Gadus morhua that had been fed or starved during the 16 weeks preceding the tests, and assessed whether muscle metabolic capacities explain such links. The condition factor [(somatic mass x fork length(-3))x100] of starved cod was 0.54+/-0.1 whereas that of fed cod was 0.81+/-0.1. In white and red muscle, we ...

Isometric, electrically paced strips of cardiac ventricle from two species of fish (plaice, Pleuronectes platessa; cod, Gadus morrhua) with different tolerance to hypoxia were compared with respect to effects of hypercapnic acidosis. Acidosis was induced by altering the equilibrating gas mixture for the muscle strip chamber from 3% CO2 in 97% 02 to 15% CO2 in 85% O2. The pH was varied further b...

To simulate the filtration and/or degradation of trickling sewage from leaky sewers through the non-water-saturated underground, sewage was trickled through sand of 0.4-2mm from the Rhine valley in glass columns of 125 cm length. For the same sewage the chemical oxygen demand (COD) removal was almost independent of low or high trickling rates. The COD removal efficiency varied, however, from 67...

The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg) in the small scale capture-based aquaculture (CBA). Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60-70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To in...