| 1. |
- Deng, Junjie, et al.
(författare)
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A method for assessing the coastline recession due to the sea level rise by assuming stationary wind-wave climate
- 2015
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Ingår i: Oceanological and Hydrobiological Studies. - : Uniwersytet Gdanski. - 1730-413X .- 1897-3191. ; 44:3, s. 362-380
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Tidskriftsartikel (refereegranskat)abstract
- The method introduced in this study for future projection of coastline changes hits the vital need of communicating the potential climate change impact on the coast in the 21th century. A quantitative method called the Dynamic Equilibrium Shore Model (DESM) has been developed to hindcast historical sediment mass budgets and to reconstruct a paleo Digital Elevation Model (DEM). The forward mode of the DESM model relies on paleo-scenarios reconstructed by the DESM model assuming stationary wind-wave climate. A linear relationship between the sea level, coastline changes and sediment budget is formulated and proven by the least square regression method. In addition to its forward prediction of coastline changes, this linear relationship can also estimate the sediment budget by using the information on the coastline and relative sea level changes. Wind climate change is examined based on regional climate model data. Our projections for the end of the 21st century suggest that the wind and wave climates in the southern Baltic Sea may not change compared to present conditions and that the investigated coastline along the Pomeranian Bay may retreat from 10 to 100 m depending on the location and on the sea level rise which was assumed to be in the range of 0.12 to 0.24 m.
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| 2. |
- Järvi, Torbjörn, et al.
(författare)
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Life histories of anadromous salmon males reveal a trade-off between primary and secondary sexual traits
- 2019
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Ingår i: Oceanological and Hydrobiological Studies. - : Uniwersytet Gdanski. - 1730-413X .- 1897-3191. ; 48, s. 279-289
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Tidskriftsartikel (refereegranskat)abstract
- The life-history trade-off between investment in somatic growth and gonadal tissue is caused by individual energy limitations and results in individuals that adopt specific tactics to achieve reproduction. Allocation in primary and secondary sexual traits in Atlantic salmon males was studied by assessing life history traits (smolt size, sea age, growth rate) based on back-calculation of scales, ejaculate energy content (sperm ATP content, mass and density) and the size of secondary sexual traits. We found that males investing less in secondary sexual traits produce ejaculates with a higher energy content. Differences were found in the investment into primary and secondary sexual traits between fish that spent one year in the sea before returning to their spawning grounds (grilse) and multi-sea-winter adults, suggesting that different energy allocation patterns in reproductive effort reflect alternative developmental pathways. These findings are consistent with the pattern where multi-sea-winter male ejaculate investment relies principally on the resource acquisition in the ocean, whereas grilse ejaculate investment relies chiefly on the resource allocation of available surplus energy, thus representing alternative male reproductive tactics.
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| 3. |
- Pastuszak, Marianna, et al.
(författare)
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Reduction of nutrient emission from Polish territory into the Baltic Sea (1988-2014) confronted with real environmental needs and international requirements
- 2018
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Ingår i: OCEANOLOGICAL AND HYDROBIOLOGICAL STUDIES. - : WALTER DE GRUYTER GMBH. - 1730-413X .- 1897-3191. ; 47:2, s. 140-166
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Tidskriftsartikel (refereegranskat)abstract
- Eutrophication of the Baltic Sea is considered a major threat to its ecological status. We present and discuss Polish riverine flow normalized loads of total nitrogen (TN) and total phosphorus (TP) discharged into the Baltic Sea in (i) 1988-2014, (ii) periods of maximum TN (1992-1994), TP (1988-1991) emission, (iii) the reference period (1997-2003) established by the Helsinki Commission (HELCOM), (iv) 2012-2014, last years of our study. Despite considerable nutrient load reductions prior to the HELCOM reference period, Poland is expected to reduce TN and TP loads by 30% and 66%, respectively. In the light of our historical and up-to-date findings defining ecological status of the Baltic Sea, we suggest that the proposed TP load reduction is overestimated and its realization may lead to (i) undesirable consequences for the Baltic ecosystem, (ii) would require a decline in TP concentrations to 0.067 mg P dm(-3) (the Vistula River) and 0.083 mg P dm(-3) (the Oder River), values reported for pre-industrial times. The current nutrient concentrations in the Vistula and Oder safely comply with the requirements of the Water Framework Directive. We also comment on the top-down and bottom-up effect resulting in quantitative and qualitative reorganization of the Baltic ecosystem, a phenomenon already observed in the Baltic Sea.
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