Ecophysiology of the benthic amphipod Monoporeia affinis in an open-sea area of the northern Baltic Sea: seasonal variations in oxygen consumption and ammonia excretion

1996 ◽  
Vol 126 (4) ◽  
pp. 645-654 ◽  
Author(s):  
K. K. Lehtonen
Keyword(s):  
Oxygen Consumption ◽  
Baltic Sea ◽  
Seasonal Variations ◽  
Ammonia Excretion ◽  
Open Sea ◽  
Sea Area

scholarly journals Metabolism of the mussel Mytilus galloprovincialis from two origins in the Ría de Arousa (north-west Spain)

2000 ◽  
Vol 80 (5) ◽  
pp. 865-872 ◽  
Author(s):  
Jose M.F. Babarro ◽  
María José Fernández-Reiriz ◽  
Uxío Labarta
Keyword(s):  
Oxygen Consumption ◽  
Rocky Shore ◽  
Mytilus Galloprovincialis ◽  
Excretion Rate ◽  
Ammonia Excretion ◽  
Dry Weight ◽  
North West ◽  
Cultivation Period ◽  
Seed Origin ◽  
Ammonia Excretion Rate

Mussel seed Mytilus galloprovincialis (Bivalvia: Mytilidae) from two origins (rocky shore and collector ropes) was cultivated on a raft in the Ría de Arousa (north-west Spain), from seeding to thinning out, for 226 d (November 1995–July 1996) and two aspects of metabolism, oxygen consumption rate (VO2) and ammonia excretion rate (VNH4-N) were studied in situ.The model derived from multiple analysis of oxygen consumption accounted for 91.9% of the variance, based on dry weight of the mussels and the environmental factors quality of food (organic content) and mainly chlorophyll-a. Seed origin also showed significant influence. The seasonal pattern of the oxygen consumption can be attributed mainly to the variation of chlorophyll-a, which showed a higher range of values in the spring months.Origin of seed did not show a homogeneous effect on oxygen consumption throughout the cultivation period. Collector rope mussels showed higher oxygen consumption values at the beginning of the cultivation period and after the first 15 d, but the rocky shore mussels showed a higher oxygen consumption between days 22 and 110. Energy-conserving patterns and lower condition index at the onset of the experiment for rocky shore mussels could explain these initial differences.Multiple analysis on the variation of ammonia excretion rate provided a model that accounted for 72.6% of the variance based on dry weight of mussels, seed origin and the environmental parameters chlorophyll-a and total particulate matter. The rocky shore mussels showed a significantly higher excretion values for most of the cultivation period, although there was no constant tendency throughout. High excretion values were recorded between January and March, whilst for the rest of the cultivation period values were low.The O:N index was higher in collector rope mussels for most of the cultivation period, which may suggest a more favourable energy metabolism and/or a more appropriate nutritional state for these specimens.

Organohalogens of Natural and Industrial Origin in Large Recipients of Bleach-Plant Effluents

1991 ◽  
Vol 24 (3-4) ◽  
pp. 373-383 ◽  
Author(s):  
A. Grimvall ◽  
H. Borén ◽  
S. Jonsson ◽  
S. Karlsson ◽  
R. Sävenhed
Keyword(s):  
Baltic Sea ◽  
Point Sources ◽  
The Baltic Sea ◽  
Long Distance ◽  
Long Distance Transport ◽  
Open Sea ◽  
Receiving Waters ◽  
The Baltic ◽  
Organic Halogens

The long-term fate of chlorophenols and adsorbable organic halogens (AOX) was studied in two large recipients of bleach-plant effluents: Lake Vättern in Sweden and the Baltic Sea. The study showed that there is a long-distance transport (>100 km) of chloroguaiacols from bleach-plants to remote parts of receiving waters. However, there was no evidence of several-year-long accumulation of chloro-organics in the water-phase. A simple water-exchange model for Lake Vättern showed that the cumulated bleach-plant discharges from the past 35 years would have increased the AOX concentration in the lake by more than 100 µg Cl/l, if no AOX had been removed from the water by evaporation, sedimentation or degradation. However, the observed AOX concentration in Lake Vättern averaged only about 15 µg Cl/l, which was less than the average AOX concentration (32 µg Cl/l) in the “unpolluted” tributaries of the lake. Similar investigations in the Baltic Sea showed that non-point sources, including natural halogenation processes, accounted for a substantial fraction of the AOX in the open sea. The presence of 2,4,6-trichlorophenol in precipitation and “unpolluted” surface waters showed that non-point sources may also make a considerable contribution to the background levels of compounds normally regarded as indicators of bleach-plant effluents.

The Ship Domain – A Criterion of Navigational Safety Assessment in an Open Sea Area

2008 ◽  
Vol 62 (1) ◽  
pp. 93-108 ◽  
Author(s):  
Zbigniew Pietrzykowski ◽  
Janusz Uriasz
Keyword(s):  
Artificial Intelligence ◽  
Safety Assessment ◽  
Research Results ◽  
Safe Navigation ◽  
Number Of Factors ◽  
Open Sea ◽  
Sea Area ◽  
Point Of Departure ◽  
Shape And Size

One of the basic tasks in shipping is to ensure safe navigation of vessels. The concept of the ship domain is of major importance in the assessment of a navigational situation and the avoidance of ship collisions. It is difficult to determine a ship domain as its shape and size depend on a number of factors. One question to be answered before the determination of the ship domain is which method to use: statistical, analytic, or expert method using artificial intelligence tools; other questions are connected with domain interpretation. The authors have analyzed the ship domain as a criterion for the assessment of ship navigational safety in an encounter situation in the open sea. The research results are used to answer some of the questions.Part 2 includes definitions of the ship domain and ship fuzzy domain. Part 3, in turn, presents methods of their determination as well as relevant questions. The results of the authors' research, described in Part 4, make up a basis for the determination of the domain and ship fuzzy domain. These have been determined with the so-called dynamic domains as a point of departure. The criteria of ship domain and closest point of approach are compared and discussed. Encounters of various size ships are considered in Part 5. The research and its results are described. Both ship domains and ship fuzzy domains of encountering ships are analyzed. Then, conclusions have been formulated in relation to the effect of the sizes of encountering ships on the shapes and sizes of their domains. Final conclusions are given in Part 6.

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