The Baltic Sea: an outline of its physical oceanography

Kullenberg, Gunnar; Jacobsen, Tone

doi:10.1016/0025-326x(81)90168-5

Cited by 56 publications

(29 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the eastern Baltic Sea, circulation patterns in the upper layer of the Baltic are dominated by wind conditions (Kullenberg & Jacobsen 1981, Moller & Hansen 1994. However, cod eggs are generally located near the permanent halocline at depths of 50 to 70 m and below the sill depths (Wieland et al 1994).…”

Section: Effects Of Wind-induced Transport On Egg and Larval Distribumentioning

confidence: 99%

Eastern Baltic cod:perspectives from existing data on processes affecting growth and survival of eggs and larvae

MacKenzie¹,

John²,

Wieland³

1996

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

ABSTRACT. We review eastern Baltic cod literature to identify areas for future research involving egg and larval stages. Egg and larval abundances have been estimated for several decades in all of the major spawning areas. Using a subset of the available data we show that the timing of peak egg abundance in one of these areas (Bornholm Basln) vanes seasonally by at least 2 mo. Trends in egg and larval abundance over time are not obvious due to differences In gear type, sampling intensity, and survey timing relative to spawning dates Interannual differences in larval transport away from spawning areas may also contribute to variability in abundance estimates The results of broad-scale zooplankton surveys suggest that the abundance and types of potential prey in the Baltic Sea are similar to those in other regions and perhaps suitable for moderate-to-fast larval growth However, few systematic surveys have described food concentrations at appropriate scales for cod larvae, and the species composition of larval diets is unknown. Growth rates for Baltic cod larvae have not been measured and cannot be compared with rates in other areas or to vanatlons in biotic and ab~otlc factors. Large gaps exist in our knowledge of processes affecting egg and larval growth and survival, but some promising areas of research are indicated. In particular the seasonality of spawning, deep water oxygen concentrations, predation on eggs, and larval food production require further investigation

show abstract

Section: Effects Of Wind-induced Transport On Egg and Larval Distribumentioning

confidence: 99%

Eastern Baltic cod:perspectives from existing data on processes affecting growth and survival of eggs and larvae

MacKenzie¹,

John²,

Wieland³

1996

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Below this exists a 10 m layer, termed the upper deep-water pycnocline, which overlies the deep saline (10 to 18 ‰) waters of the Baltic. A seasonal thermocline is found at 30 to 40 m in July to September, with relatively homogeneous surface mixed layer down to the halocline during fall/winter (Kullenberg & Jacobsen 1981, Matthäus & Franck 1992, Møller & Hansen 1994, Schinke & Matthäus 1998.…”

Section: Introductionmentioning

confidence: 98%

Using data storage tags to link otolith macro- structure in Baltic cod Gadus morhua with environmental conditions

Hüssy¹,

Nielsen²,

Mosegaard³

et al. 2009

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

We examined otolith opacity of Baltic cod in relation to environmental conditions in order to evaluate the formation mechanisms of seasonal patterns used in age determination. Adult fish were tagged with data storage tags (DSTs) and a permanent mark was induced in the otoliths by injection of a strontium chloride solution. Based on environmental conditions experienced, fish were classified into different behavioural types: non-reproducing 'non-spawner', and 'spawner' undertaking spawning migrations. Otolith opacity, an indicator of otolith and fish somatic growth and condition, was examined in relation to these environmental drivers. Temperature was the only environmental variable with a significant effect, overlaying a strong size-related effect. The temperature effect was not uniform across behavioural types and spawning periods. Opacity showed a negative correlation with temperature as expected -but in non-spawning fish only. In spawners, the general trend was a decrease in opacity from pre-to post spawning. A significant -but positive -temperature effect was only found in the pre-spawning period. The negative effects during and following spawning were not significant. In spawners, this decoupling leads to an otolith structure with stronger contrasts and more abrupt changes, while in non-spawners, opacity changes more smoothly. The trigger for this decoupling seems to be an interaction between temperature exposure and seasonal variations in food availability and may serve as a tool to identify the occurrence and repetitiveness of spawning in Baltic cod.

show abstract

“…Since the residence time of the water in the Baltic is as long as 25-35 years, and the average depth is not more than about 60 m, sediments here play an essential role in the biogeochemical cycles of nutrient elements and carbon. The semi-permanent anoxic conditions in the Baltic are due to the limited water exchange with the Kattegat and the strong vertical stratification (e.g., Kullenberg and Jacobsen, 1981;Stigebrandt, 2001). These physical characteristics in combination with an increased nutrient supply have led to an increased frequency of cyanobacteria blooms in the Baltic proper since the 1960s (e.g.…”

Section: Introductionmentioning

confidence: 99%

Influence of Natural Oxygenation of Baltic Proper Deep Water on Benthic Recycling and Removal of Phosphorus, Nitrogen, Silicon and Carbon

et al. 2017

View full text Add to dashboard Cite

At the end of 2014, a Major Baltic Inflow (MBI) brought oxygenated, salty water into the Baltic proper and reached the long-term anoxic Eastern Gotland Basin (EGB) by March 2015. In July 2015, we measured benthic fluxes of phosphorus (P), nitrogen (N) and silicon (Si) nutrients and dissolved inorganic carbon (DIC) in situ using an autonomous benthic lander at deep sites (170-210 m) in the EGB, where the bottom water oxygen concentration was 30-45 µM. The same in situ methodology was used to measure benthic fluxes at the same sites in 2008-2010, but then under anoxic conditions. The high efflux of phosphate under anoxic conditions became lower upon oxygenation, and turned into an influx in about 50% of the flux measurements. The C:P and N:P ratios of the benthic solute flux changed from clearly below the Redfield ratio (on average about 70 and 3-4, respectively) under anoxia to approaching or being well above the Redfield ratio upon oxygenation. These observations demonstrate retention of P in newly oxygenated sediments. We found no significant effect of oxygenation on the benthic ammonium, silicate and DIC flux. We also measured benthic denitrification, anammox, and dissimilatory nitrate reduction to ammonium (DNRA) rates at the same sites using isotope-pairing techniques. The bottom water of the long-term anoxic EGB contained less than 0.5 µM nitrate in 2008-2010, but the oxygenation event created bottom water nitrate concentrations of about 10 µM in July 2015 and the benthic flux of nitrate was consistently directed into the sediment. Nitrate reduction to both dinitrogen gas (denitrification) and ammonium (DNRA) was initiated in the newly oxygenated sediments, while anammox activity was negligible. We estimated the influence of this oxygenation event on the magnitudes of the integrated benthic P flux (the internal P load) and the fixed N removal through benthic and pelagic denitrification by comparing with a hypothetical Hall et al.Oxygenation Effect on Benthic Fluxes scenario without the MBI. Our calculations suggest that the oxygenation triggered by the MBI in July 2015, extrapolated to the basin-wide scale of the Baltic proper, decreased the internal P load by 23% and increased the total (benthic plus pelagic) denitrification by 18%.

show abstract

The Baltic Sea: an outline of its physical oceanography

Cited by 56 publications

References 7 publications

Eastern Baltic cod:perspectives from existing data on processes affecting growth and survival of eggs and larvae

Eastern Baltic cod:perspectives from existing data on processes affecting growth and survival of eggs and larvae

Using data storage tags to link otolith macro- structure in Baltic cod Gadus morhua with environmental conditions

Influence of Natural Oxygenation of Baltic Proper Deep Water on Benthic Recycling and Removal of Phosphorus, Nitrogen, Silicon and Carbon

Contact Info

Product

Resources

About