Fisheries in the context of marine spatial planning: Defining principal areas for fisheries in the German EEZ

A method is presented to define principal areas for fisheries at high spatial resolution applicable to be implemented into marine spatial planning procedures. Vessel monitoring system (VMS) data from 2005 to 2006 are acquired to determine vessel-based fishing effort. Principal areas for the German exclusive economic zone (EEZ) are defined as areas in which 75% of the effort of either year is carried out. Examples are given for the 5 most abundant fisheries in the German EEZ in terms of vessel-based effort, i.e. gill netting, pelagic trawling, demersal otter board trawling and beam trawling >300 and <300 HP. A historical comparison for demersal otter board trawling shows relative stability of spatial utilization patterns in the North Sea section of the EEZ.     

Marine ferromanganese concretions from the polish exclusive economic zone: Influence of major inflows of north sea water

Ferromanganese concretions within the Polish Exclusive Economic Zone (EEZ) are found mainly in the depth range 60–70 m on the thresholds between the Bomholm Basin and Slupsk Furrow and between the Gotland and Gdansk Basins. They also occur on elevations of the seafloor within the Bomholm Basin, on the southern slopes of Slupsk Furrow, and on the lower southwestern slopes of the Gotland Basin. They occur mainly as surface deposits on very thin (<0.2 m), poorly sorted lag deposits. The concretions are predominantly discoidal and are formed around a single nucleus of sandstone or erratic rock of variable size. The ferromanganese oxides display internal layering with alternate layers of almost black manganese oxides and buff iron axyhydroxides. The concretions consist mainly of todorokite and quartz, with lesser amounts of feldspar, kaolinite, and montmorillonite. They are characterized by relatively high Fe/Mn ratios (0.9–3.5) and high contents of detrital elements (Ti, Na, K, Ca, and Mg) but low contents of the transition elements (Cu, Zn, Pb, Cr, Co, and Ni). The deposits are associated with the very dynamic environment near the halocline, where internal waves erode the sediment and create conditions of sediment nondeposition favorable for the formation of the concretions. A number of factors contribute to the high abundance of ferromanganese concretions in the Baltic Sea. One is the high input of iron and manganese by the rivers draining into it This is a consequence of the widespread occurrence of bogs and swamps in the catchment area of the Baltic Sea, which results in the river waters having high humic acid contents and low pH. Another major factor is the buildup of dissolved iron and manganese in the anoxic basins of the Baltic Sea during periods of stagnation. These waters are flushed during major inflow events, when oxygenated water from the North Sea displaces the stagnant waters of the anoxic basins. Iron and manganese in these waters are then transported laterally and deposited in the surface of ferromanganese concretions on topographic highs. We believe that the iron is deposited rapidly after such events but that the manganese is deposited over a much longer time period, thus accounting for the layering in the concretions. The rate of deposition of these elements is essentially controlled by the input of oxygen in the waters of the North Sea. These periods of major inflows are grouped but significant events, for concretions occur on average about 11 times per century. We therefore estimate that the concretions have grown much more slowly than previously thought (about 0.013–0.018 mm/yr), and that a concretion 20 mm in diameter would have an age of about 500–800 years. Higher concentrations of heavy metals have been recorded in the outer layers of the concretions, and it is possible that these can serve as indicators of heavy‐metal pollution in the Baltic Sea. The concretions range from sporadic to intermediate abundance. As such, they have no economic potential.     

Environmental genotoxicity and cytotoxicity in the offshore zones of the Baltic and the North Seas

Micronuclei (MN), nuclear buds (NB) and fragmented-apoptotic cells (FA) were analyzed in mature peripheral blood and immature cephalic kidney erythrocytes of flounder (Platichthys flesus), dab (Limanda limanda) and cod (Gadus morhua) from 12 offshore sites in the Baltic Sea (479 specimens) and 11 sites in the North Sea (291 specimens), which were collected during three research vessel cruises in December 2002, 2003 and in September 2004. The highest levels of environmental genotoxicity (frequencies of MN up to 0.5‰, NB – up to 0.75‰) and cytotoxicity (FA – up to 0.53‰) were observed in flatfishes from areas close to oil and gas platforms in the North Sea and in zones related to the extensive shipping and potentially influenced by contamination from large European Rivers (Elbe, Vistula, Oder). In dab from the offshore zones of the North Sea, the levels of nuclear abnormalities were higher as compared to those in dab from the Baltic Sea. Responses in immature kidney erythrocytes were higher than in mature erythrocytes from peripheral blood. MN frequency lower than 0.05‰ (the Baltic Sea) and lower than 0.1‰ (the North Sea) could be suspected as a reference level in the peripheral blood erythrocytes of flatfish.     

2000～2010 年环渤海省市海岸带土地利用变化分析

作为陆海生态系统的交错带,海岸带是地表生态系统最为脆弱的地带,研究海岸带土地利用变化具有重要意义。以环渤海省市海岸带为研究区,基于2000、2005和2010年的Landsat TM/ETM遥感影像进行多时相海岸带土地利用制图,进而分析10 a间的土地利用变化特征,包括土地利用结构、土地利用动态度、土地利用程度区域差异和海陆梯度、海陆格局变化等特征。结果表明:(1)环渤海省市海岸带土地利用以耕地、建设用地和人工湿地为主,2010年比例分别为36.09%、17.16%和15.72%,不同行政单元及不同缓冲带之间土地利用结构空间差异明显。(2)2000~2005年、2005~2010年,土地利用发生转移的面积分别为2 126.419 km2和3 092.39 km2,建设用地扩展占用耕地、人工湿地和滨海自然湿地,以及滨海自然湿地变为人工湿地是主导的变化过程,但不同行政单元及不同缓冲带之间土地利用变化的空间差异明显。(3)2000~2005年、2005~2010年,综合土地利用动态度分别为0.73%和1.06%,17个地市级行政单元综合土地利用动态度以东营和天津较高,各缓冲带内综合土地利用动态度均为随时间不断增加,空间上则由海向陆波动下降。(4)2000~2010年,土地利用程度总体上不断升高,表明海岸带土地利用处于发展期,除沧州和潍坊,其他区域土地利用程度随时间不断上升;各缓冲带土地利用程度均随时间不同程度增长,空间上则由海向陆波动上升。     

Dense water characteristics in the northern Adriatic in the 1967–2000 interval with respect to surface fluxes and Po river discharge rates

Winter thermohaline properties of the northern Adriatic are analysed here with the aim of getting a better insight into dense water formation on the shelf. The hydrographic parameters collected in February in the 1967–2000 interval at two stations, the first located close to the eastern shore (station 1), and the second positioned near the Po river mouth (station 2), are compared. Two types of winter hydrographic conditions are distinguished: type A when bottom salinity and density are higher at station 1 than at station 2 and type B when these parameters are higher at station 2 than at station 1. Type A is more likely to occur in warmer and type B in colder winters. Both A and B distribution types can occur in periods when the Adriatic is under the influence of very saline waters of Mediterranean origin. Interannual changes in density are, at both stations, more dependant on haline than on thermal variations. At both stations temperature was somewhat higher in the early seventies than during the eighties and nineties, while salinity and density were lower in the early seventies and early nineties than in other years of the analysed period. By comparing the 1967–2000 changes in hydrographic conditions in February to monthly values of northern Adriatic surface fluxes and Po river discharge rates, it is shown that winter thermohaline characteristics in the region depend on processes which occur much earlier, i.e. during the previous autumn and late in spring of the preceding year, and even during the previous winter, 12 months before.     

美国岸线现状调查30年进展综述——以美国弗吉尼亚州为例

以美国弗吉尼亚州20世纪70年代和21世纪初两个年代进行的岸线现状调查工作为例,介绍了30年来美国岸线现状调查的目标、指导原则、调查内容、数据来源、报告编写等内容,并与我国20世纪80年代开展的"全国海岸带和海涂资源综合调查"工作以及当前正在开展的"我国近海海洋综合调查与评价"专项的海岸带调查进行了对比,讨论了两国在海岸带调查方面的异同,以及可供借鉴之处。