Impact of Climate Change on Fish Population Dynamics in the Baltic Sea: A Dynamical Downscaling Investigation

Understanding how climate change, exploitation and eutrophication will affect populations and ecosystems of the Baltic Sea can be facilitated with models which realistically combine these forcings into common frameworks. Here, we evaluate sensitivity of fish recruitment and population dynamics to past and future environmental forcings provided by three ocean-biogeochemical models of the Baltic Sea. Modeled temperature explained nearly as much variability in reproductive success of sprat (Sprattus sprattus; Clupeidae) as measured temperatures during 1973-2005, and both the spawner biomass and the temperature have influenced recruitment for at least 50 years. The three Baltic Sea models estimate relatively similar developments (increases) in biomass and fishery yield during twenty-first century climate change (ca. 28 % range among models). However, this uncertainty is exceeded by the one associated with the fish population model, and by the source of global climate data used by regional models. Knowledge of processes and biases could reduce these uncertainties.     

Climate Change in the Baltic Sea Region: A Cross-Country Analysis of Institutional Stakeholder Perceptions

Before climate change is considered in long-term coastal management, it is necessary to investigate how institutional stakeholders in coastal management conceptualize climate change, as their awareness will ultimately affect their actions. Using questionnaires in eight Baltic Sea riparian countries, this study examines environmental managers' awareness of climate change. Our results indicate that problems related to global warming are deemed secondary to short-term social and economic issues. Respondents agree that problems caused by global warming will become increasingly important, but pay little attention to adaptation and mitigation strategies. Current environmental problems are expected to continue to be urgent in the future. We conclude that an apparent gap exists between decision making, public concerns, and scientific consensus, resulting in a situation in which the latest evidence rarely influences commonly held opinions.     

Historical change of mercury pollution in remote Yongle archipelago, South China Sea

We collected three ornithogenic coral sand sedimentary profiles from Jinyin Island, Jinqing Island and Guangjin Island of Yongle archipelago, South China Sea and reconstructed the deposition flux of anthropogenic Hg over the past 700 years in the study area. On the whole, the anthropogenic Hg flux is relatively low; it remained at a low level before the Industrial Revolution with a small peak at about 1450-1550 AD, which may record the enhanced metallurgy activity in Ming Dynasty of China. During the 20th century, the deposition flux of anthropogenic Hg increased rapidly, but two troughs occurred during the periods around 1940s and 1970s, corresponding to the economic depression caused by World War II, Civil War in China (1945-1949), and the Culture Revolution (1966-1976) in China. Since the 1970s the deposition flux of anthropogenic Hg has been persistently increasing, apparently the result of fast economic development in East and Southeast Asia countries around South China Sea.     

Characterization of plutonium in deep-sea sediments of the Sulu and South China Seas

Anthropogenic Pu isotopes are important geochemical tracers for sediment studies. Their distributions and sources in the water columns as well as the sediments of the North Pacific have been intensively studied; however, information about Pu in the Southeast Asian seas is limited. To study the isotopic composition of Pu, and thus to identify its sources, we collected sediment core samples in the South China Sea and the Sulu Sea during the KH-96-5 Cruise of the R/V Hakuho Maru. We analysed the activities of ^239+240Pu and the atom ratios of ²⁴⁰Pu/²³⁹Pu using isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The ²⁴⁰Pu/²³⁹Pu atom ratios in the sediments of both areas (inventory weighted mean: 0.251 for the South China Sea and 0.280 for the Sulu Sea) were higher than the global fallout value (0.178 ± 0.019), suggesting the existence of Pu from the Pacific Proving Grounds in the North Pacific. Low inventories of ^239+240Pu in sediments were observed in the South China Sea (3.75 Bq/m²) and the Sulu Sea (1.38 Bq/m²). Most of the Pu input is still present in the water column. Scavenging and benthic mixing processes were considered to be the main processes controlling the distribution of Pu in the deep-sea sediments of both study areas.     

The Effects of Hypoxia on Sediment Nitrogen Cycling in the Baltic Sea

Primary production in the eutrophic Baltic Sea is limited by nitrogen availability; hence denitrification (natural transformation of nitrate to gaseous N₂) in the sediments is crucial in mitigating the effects of eutrophication. This study shows that dissimilatory nitrate reduction to ammonium (DNRA) process, where nitrogen is not removed but instead recycled in the system, dominates nitrate reduction in low oxygen conditions (O₂ <110 μM), which have been persistent in the central Gulf of Finland during the past decade. The nitrogen removal rates measured in this study show that nitrogen removal has decreased in the Gulf of Finland compared to rates measured in mid-1990s and the decrease is most likely caused by the increased bottom water hypoxia.     

Offshore wind power potential of the Black Sea region in Turkey

Majority of the studies on offshore wind power potential assessment is limited to the examination of the wind speed only. This study examines the offshore wind power potential of the Black Sea coastal region in Turkey based on location selection criteria including territorial waters, military areas, civil aviation, shipping routes, pipelines and underground cables, social, and environmental concerns. Wind Atlas Analysis and Application Program (WAsP) is used to do the statistical analysis of wind speed and wind direction data for 20 locations in the Black Sea coastal region. WAsP results are then elaborated based on the location selection criteria for better assessment of offshore wind power utilization. The study reveals that there are limited numbers of locations for offshore wind power generation in the Black Sea region in spite of its long coastline. Moreover, there is a high need for a zoning change for Amasra shores in order to utilize high offshore wind power potential of Amasra. Our finding suggests that location selection criteria other than wind speed should definitely be considered for better assessment of the wind power potential of a region.     

长江口地区的盐水入侵灾害及变化趋势

本文在总结长江口地区现状盐水入侵时空变化规律的基础上,着重分析了在未来海平面上升、长江东线南水北调和三峡水利枢纽工程以及长江口北支综合整治等因素影响下,南支河段盐水入侵强度的变化趋势。     

Monitoring of eutrophication and nutrient limitation in the Izmir Bay (Turkey) before and after Wastewater Treatment Plant

The distribution of inorganic nutrients and phytoplankton chlorophyll-a was investigated and N/P ratios were determined in Izmir Bay during 1996-2001. The average concentrations showed ranges of 0.01-0.19 and 0.01-10 microM for phosphate-phosphorus; 0.11-1.8 and 0.13-27 microM for (nitrate+nitrite)-nitrogen, 0.30-4.1 and 0.50-39 microM for silicate and 0.02-4.3 and 0.10-26 microg l(-1) for chlorophyll-a in the outer and middle-inner bays, respectively. The results are compared with the values obtained from the relatively unpolluted waters of the Aegean Sea. The N/P ratio is significantly lower than the assimilatory optimal (N/P=15:1) in conformity with Redfield's ratio N/P=16:1. Nitrogen is the limiting element in the Izmir Bay. Phosphate, which originates from detergents, is an important source for eutrophication in the bay, especially in the inner bay. In early 2000, a Wastewater Treatment Plant (WTP) began to treat domestic and industrial wastes. This plant treats the wastes about 60% capacity between 2000 and 2001. The sampling periods cover before and after treatment plant. Although the capacity of wastewater plant is sufficient for removal of nitrogen from the wastes, it is inadequate for removal of phosphate. This is also in accordance with the decreasing N/P ratios observed during 2000-2001 (after WTP) in the middle-inner bays.     

Observations on the workshop as a means of improving communication between holders of traditional and scientific knowledge

Traditional ecological knowledge (TEK) and the information and insights it offers to natural resource research and management have been given much attention in recent years. On the practical question of how TEK is accessed and used together with scientific knowledge, most work to date has examined documentation and methods of recording and disseminating information. Relatively little has been done regarding exchanges between scientific and traditional knowledge. This paper examines three workshop settings in which such exchanges were intended outcomes. The Barrow Symposium on Sea Ice, the Exxon Valdez Oil Spill Restoration Program Synthesis/Information Workshops, and the Alaska Beluga Whale Committee illuminate certain features of the preparation, format, and context of workshops or series of workshops and their eventual outcomes and influence. The examples show the importance of long-term relationships among participants and thorough preparation before the actual workshop. Further research should look more systematically at the factors that influence the success of a given workshop and the various ways in which participants perceive success.     

Modeling Nutrient Transports and Exchanges of Nutrients Between Shallow Regions and the Open Baltic Sea in Present and Future Climate

We quantified horizontal transport patterns and the net exchange of nutrients between shallow regions and the open sea in the Baltic proper. A coupled biogeochemical-physical circulation model was used for transient simulations 1961-2100. The model was driven by regional downscaling of the IPCC climate change scenario A1B from two global General Circulation Models in combination with two nutrient load scenarios. Modeled nutrient transports followed mainly the large-scale internal water circulation and showed only small circulation changes in the future projections. The internal nutrient cycling and exchanges between shallow and deeper waters became intensified, and the internal removal of phosphorus became weaker in the warmer future climate. These effects counteracted the impact from nutrient load reductions according to the Baltic Sea Action Plan. The net effect of climate change and nutrient reductions was an increased net import of dissolved inorganic phosphorus to shallow areas in the Baltic proper.