An integrated river basin-coast-sea modelling scenario for nitrogen management in coastal waters

Linked river basin and coastal water models were applied to analyse the effects of an optimal nitrogen management scenario in the Oder/Odra river basin on water quality in the Oder (Szczecin) Lagoon and the Pomeranian Bay (Baltic Sea). This scenario would reduce nitrogen loads into the coastal waters by about 35%, a level which is similar to the load of the late 1960’s. During summer the primary production and algae biomass in the Oder estuary is limited by nitrogen, which makes a nitrogen management reasonable. The comparison of the late 1960’s and the mid 1990’s shows that an optimal nitrogen management has positive effects on coastal water quality and algae biomass. However, this realistic nitrogen reduction scenario would not ensure a good coastal water quality according to the European Water Framework Directive. A good water quality in the river will not be sufficient to ensure a good water quality in the lagoon. Nitrogen load reductions bear the risk of increased potentially toxic, blue-green algae blooms, especially in the Baltic coastal sea. However, to reach water quality improvements in lagoons and inner coastal waters, nitrogen cuts are necessary. A mere focus on phosphorus is not sufficient.     

Developments in Dutch coastline management: Conclusions from the second governmental coastal report

In 1990 the Dutch government decided to stop any further long-term landward retreat of the coastline. This policy choice for a ‘dynamic preservation’ is primarily aimed at safety against flooding and at sustainable preservation of the values and interests concerning the dunes and beaches. Five years later, a first overview of the benefits and bottlenecks of the new coastal defence policy could be presented, which was published in the second governmental coastal report ‘Kustbalans 1995’ (coastal balance 1995). This consists of three elements: (1) evaluation of the implementation of ‘dynamic preservation’, (2) the consequences of several natural and anthropogenic developments in the coastal zone and (3) integrated coastal zone management. The present report describes experiences of Dutch coastline management and summarizes the main conclusions of the second governmental report. The overall conclusion of the evaluation study is that the 1990 choice for ‘dynamic preservation’ was right. Sand supply is an effective method of coastline maintenance, which also serves functional uses in the beach and dune area. However, nearly a doubling of the supply volume is necessary to compensate for sand losses in the coastal zone. A more integrated management of the coastal zone is necessary to find an equilibrium between the interests of socio-economic development and the maintenance of a natural, dynamic system.     

Developments in dutch coastline management: Conclusions from the second governmental coastal report

In 1990 the Dutch government decided to stop any further long-term landward retreat of the coastline. This policy choice for a ‘dynamic preservation’ is primarily aimed at safety against flooding and at sustainable preservation of the values and interests concerning the dunes and beaches. Five years later, a first overview of the benefits and bottlenecks of the new coastal defence policy could be presented, which was published in the second governmental coastal report ‘Kustbalans 1995’ (coastal balance 1995). This consists of three elements: (1) evaluation of the implementation of ‘dynamic preservation’, (2) the consequences of several natural and anthropogenic developments in the coastal zone and (3) integrated coastal zone management. The present report describes experiences of Dutch coastline management and summarizes the main conclusions of the second governmental report. The overall conclusion of the evaluation study is that the 1990 choice for ‘dynamic preservation’ was right. Sand supply is an effective method of coastline maintenance, which also serves functional uses in the beach and dune area. However, nearly a doubling of the supply volume is necessary to compensate for sand losses in the coastal zone. A more integrated management of the coastal zone is necessary to find an equilibrium between the interests of socio-economic development and the maintenance of a natural, dynamic system.     

Occurrence of the semi-catadromous European eel Anguilla anguilla in the Baltic Sea

Strontium (Sr) and calcium (Ca) contents in the otoliths of yellow and silver European eels [Anguilla anguilla (L.)] collected from coastal waters of the Baltic Sea and a freshwater lake in Sweden were examined by wavelength dispersive X-ray spectrometry with an electron microprobe. The mean Sr/Ca ratios from elver check to otolith edge were significantly higher for the eels from coastal waters (5.39 ± 1.09‰) than for those from the lake (0.71 ± 0.89‰). The evidence indicates that European eels in the Baltic Sea do not necessarily migrate into freshwater streams during the growth phase. Received: 30 September 1999 / Accepted: 6 April 2000     

Coastal setbacks for the Mediterranean: a challenge for ICZM

Coastal development along the Mediterranean coast needs to be tackled with an integrated approach, in order to safeguard people and properties from extreme events, maintain environmental flows and ecosystems functions, protect coastal landscapes and ensure public accessibility to the shore. The complexity of the Mediterranean countries legal and administrative framework and its morphological heterogeneity make the implementation of new the Protocol on ICZM provisions on coastal setbacks,—claiming for a 100 m wide buffer zone where construction is not allowed— a challenge for the success of the initiative. European countries and the European Commission are party to the protocol but the European legal framework lacks of specific provisions addressing the definition of coastal setbacks. Moreover, climate change, in terms of sea level rise and maritime climate, could play a major role in the future position of setback lines. While arbitrary setbacks should be put in place to halt short-term unwise coastal development, science can improve the identification of coastal setbacks by providing integrated methodologies to be implemented at the local level. The objective of this paper is to review concepts and practices in the use of coastal setbacks, in the context of the provisions of the ICZM protocol and taking into account new challenges posed by climate change. A stepwise route map is proposed as a base to identify coastal setbacks, applicable to the Mediterranean region and elsewhere, to be used as a base to improve arbitrary setback approaches.     

Coastal setbacks for the Mediterranean: a challenge for ICZM

Coastal development along the Mediterranean coast needs to be tackled with an integrated approach, in order to safeguard people and properties from extreme events, maintain environmental flows and ecosystems functions, protect coastal landscapes and ensure public accessibility to the shore. The complexity of the Mediterranean countries legal and administrative framework and its morphological heterogeneity make the implementation of new the Protocol on ICZM provisions on coastal setbacks,—claiming for a 100 m wide buffer zone where construction is not allowed— a challenge for the success of the initiative. European countries and the European Commission are party to the protocol but the European legal framework lacks of specific provisions addressing the definition of coastal setbacks. Moreover, climate change, in terms of sea level rise and maritime climate, could play a major role in the future position of setback lines. While arbitrary setbacks should be put in place to halt short-term unwise coastal development, science can improve the identification of coastal setbacks by providing integrated methodologies to be implemented at the local level. The objective of this paper is to review concepts and practices in the use of coastal setbacks, in the context of the provisions of the ICZM protocol and taking into account new challenges posed by climate change. A stepwise route map is proposed as a base to identify coastal setbacks, applicable to the Mediterranean region and elsewhere, to be used as a base to improve arbitrary setback approaches.     

GIS assessment of coastal vulnerability to climate change and coastal adaption planning in Vietnam

Vietnam’s coastal zone provides a diverse range of natural resources and favourable conditions for social and economic development. However, its coastal ecosystems are highly vulnerable, due to several natural coastal hazards, over-exploitation and other human activities. In spite of diverse interventions, Vietnam’s coastal zone continues to experience significant damage from floods, erosion and typhoons. These hazards are being intensified by climate change and associated rising sea levels. This paper assesses the potential vulnerability of Vietnam’s coast to climate change and discusses possible adaptation policies and plan to reduce the impacts. GIS analysis was used for the assessment of coastal vulnerability. Related literature was reviewed to develop detailed understanding of coastal adaptation to climate change. Adaptation policies and plans were appraised to identify potential coastal adaptation policies and plans that could be adapted by Vietnam. It was identified that vulnerability of the coastal zone of Vietnam could not be attributed only to climatic factors, but also to the physical condition of the coastline. Much of Vietnam’s coastline, particularly, areas around the Red River delta and the Mekong River have elevations below 1 m. These coastlines are largely developed and serve as economic centres of the country, which makes the coast more vulnerable to climate change and the rising sea level. The paper concluded that a non-structural approach (coastal buffer zones, building houses on stilts, storm warning systems, growing of flood-resistant crops and elevated storm shelters with medicine and food storage) could be used by Vietnam to adapt her low-lying coastline around the two deltas to climate change as this strategy enables vulnerable areas to be occupied for longer before eventual retreat. However, for these policies to be successful, it should be planned, implemented well in advance, monitored and evaluated over time.     

Introgression and mitochondrial DNA heteroplasmy in the Baltic populations of mussels Mytilus trossulus and M. edulis

A strong clinal change in salinity occurs between the Baltic Sea and the North Sea, Atlantic Ocean, in the Danish Straits, where hybridization zone between mussels Mytilus edulis and M. trossulus has been reported. Eleven samples of mussels were studied from the Danish Straits and the inner Baltic Sea. Extensive introgression of M. edulis alleles from the North Sea into populations throughout the Baltic was ascertained for mitochondrial DNA (mtDNA) and two nuclear markers (ME15–16 and ITS). In the opposite direction, introgression of M. trossulus alleles into the M. edulis background was observed at the EFbis nuclear marker in populations from Kattegat (Danish Straits). While only M. edulis F (female) mtDNA was present in the Baltic, there were still strong differences in frequencies in the control region length variants between the Danish Straits and the inner Baltic samples, and weaker variation in coding region ND2–COIII haplotype frequencies. In the assays of the two mtDNA regions, various patterns of heteroplasmy were detected in 32% of all the studied individual mussels; this includes the presence of distinct, independently inherited M and F mitochondria in males, as well as the presence of two different distinguishable F genomes. The male-inherited M mtDNA genomes are quite common in the mussels from the Danish Straits, but very rare in males from the inner Baltic. Instead, a recombined control region variant (1r), which seems to have taken over the role of the M genome, was present in a number of specimens in the Baltic. Observations of heteroplasmy for two F genomes in some females and males confirm disruptions of the doubly uniparental inheritance mechanism in the hybrid Baltic Mytilus.     

Levels and congener profiles of PCDD/Fs and dioxin-like PCBs in Baltic wild salmon (Salmo salar)

Baltic salmons were caught from two Latvian rivers during the spawning seasons of 2010 and 2011 for the determination of seventeen 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (PCBs). A partially automated clean-up procedure was used for sample preparation, followed by capillary gas chromatography hyphenated to high-resolution mass spectrometry. The concentrations of PCDD/F&;PCB-TEQ ranged from 6.6 to 18.2?ng?kg^?1 fresh weight and this confirms the previous reports of relatively high concentrations of PCDD/Fs, and especially of dioxin-like PCBs in Baltic wild salmon, in most samples exceeding maximum recommended levels (MRLs) in toxicity equivalency quotients (PCDD/F-PCB-TEQ) of the World Health Organization (WHO 1998) according to EC COMMISSION REGULATION No 1881/2006. The results suggest that high consumption of Baltic wild salmon could entail the risk of exceeding the TDI for adults and teenagers. Extra care must be taken when Baltic wild salmon is included in childrens's diet to avoid exceedance of the recommended TDI of 4?pg?kg^?1 body weight for this group.     

Coastal directories and beyond: providing multidisciplinary coastal zone resource information for resource management

Baseline resource information in an easily accessible form is a vital starting point for developing coastal zone management. On behalf of a wide-ranging group of organizations involved in the management of the U.K. maritime zone, the Joint Nature Conservation Committee (JNCC) is compiling a series of 16 regional volumes. The volumes contain multi-disciplinary coastal zone resource information arranged in ten chapters under the general title ‘Coasts and Seas of the UK’. These volumes form part of a series of paper and electronic publications of coastal information being produced by JNCC’s Coastal Directories Project and are designed to meet the needs of planners and all others involved in decision-making and management of the coast.     

Vegetation dynamics on the Łeba Bar/Poland: a comparison of the vegetation in 1932 and 2006 with special regard to endangered habitats

Coastal dune ecosystems are among the most dynamic habitats with high conservation value in Europe but are also under strong anthropogenic pressure regarding coastal protection and recreation. Hence, it is of high importance to know about long-term natural and anthropogenic changes and development of protected dune habitats for nature conservation, as well as for coastal management. This paper aims to identify the vegetation dynamics on the Łeba Bar/Poland over a period of 74 years by cartometric comparison using modern Geographical Information System (GIS). To quantify the rate of vegetation dynamics two aerial photographs dating from 1932 and 2006 were digitalized and analyzed with GIS to produce digital vegetation maps. Information about decrease, increase and stability of vegetation types of this area are discussed. The results show that there has been a clear reduction in the total area of bare sand and a considerable increase of woodlands and dense grass communities. Nevertheless, the remaining extensive drift sand areas and deflation hollows on the Łeba Bar offer one of the most important habitats for pioneer vegetation on bare sand of migrating dunes and dunes at the Southern Baltic coast. The present work proved the need to observe the future development of the vegetation communities and to implement management measures to maintain the dynamic of this unique dune landscape.     

Habitat utilization and alteration by the invasive burrowing isopod, Sphaeroma quoyanum, in California salt marshes

In recent years the pace of exotic species introduction and invasion has accelerated, particularly in estuaries and wetlands. Species invasions may affect coastal ecosystems in many ways. Alteration of sedimentary environments, through structure formation and burrowing, has particularly dramatic effects on coastal habitats. This study examines modification of channel bank and marsh edge habitat by the burrowing Australasian isopod Sphaeroma quoyanum Milne Edwards, in created and natural salt marshes of San Diego Bay and San Francisco Bay. Abundance and distribution patterns of this isopod species, its relationships with habitat characteristics, and its effects on sediment properties and bank erosion were examined seasonally, and in several marsh microhabitats. Mean isopod densities were 1541 and 2936 individuals per 0.25 m² in San Francisco Bay, and 361 and 1153 individuals per 0.25 m² in San Diego Bay study sites during December and July 1998, respectively. This isopod forms dense, anastomosing burrow networks. S. quoyanum densities did not differ as a function of location within creeks or location in natural versus created marshes. Burrows, which are on average 6 mm wide and 2 cm long, were associated with firm sediments containing high detrital biomass. Although erosion is a natural process along salt marsh banks, enclosure experiments demonstrated that isopod activities can enhance sediment loss from banks. In areas infested with S. quoyanum, losses may exceed 100 cm of marsh edge per year. The effects of habitat alteration by this invading species are likely to increase in severity in the coastal zone as these ecosystems become degraded. Received: 30 March 2000 / Accepted: 21 September 2000     

Interactions between water and land in The Netherlands

The Netherlands are one of the most densely populated coastal countries in the world and there is only limited space for living, working, transport and recreation, while there is also the need to preserve and expand valuable natural habitats. In order to solve many existing and future conflicts of interest, and in order to create ‘added value’, strategies are developed to optimize the use of water-land systems. The principle of ‘building with nature’ is applied in order to integrate land in sea and water in land in such a way that future generations will be able to use coastal resources in a sustainable way, including a minimal effort to maintain the coastline and the promotion of a multiple-use system. The concept of Integrated multifunctional sustainable coastal zone development is introduced. This concept deals with a balanced approach to the lack of space for present and future coastal uses in relation to each other, to the hinterland, and to the sea. Flexible master plans are developed, taking into account many functions of the coastal zone, and facilitating adaptation to future developments—e.g. impacts of climate change and relative sea level rise. In this regard increasing the flexibility of the coastal zone is of vital importance. Large-scale coastal land reclamations in The Netherlands are dealt with, based on two different principles: (1) polder systems (low lying land reclamations surrounded and protected by dikes), (2) systems of ‘building with nature’—land reclamation protected by man-made foreshores, beaches and dunes. In the latter type new flexible dynamic-equilibrium coasts are created for many functions, while coastal vulnerability is reduced and a flexible coast is developed.     

Photosynthetic production and its regulating factors in the Baltic Sea

Measurements of primary production in the Baltic Sea over a period of 2 years (1969/1971) by the ¹⁴C method are reported. The rate of total annual production for the Baltic Sea proper and the Gulf of Finland including coastal areas appears to lie between 35 and 40 gC·m², a rate which can be assumed as characteristic for oligotrophic waters with a low production rate. An apparent increase in productivity between the 2 years could be noted. Calculations for the water mass below the halocline show that between 0.7 and 0.8 ml/l oxygen is used up during a period of 3 months required for the development of anoxic conditions. The major portion of the organic matter in the Baltic Sea undergoes decomposition in the sub-photic zone above the halocline. The ratio of organic material in deep water to the total available oxidizable matter appears to remain constant with time; therefore, the apparent increase in productivity in the photic layer does not affect apprecibly the development of anoxic conditions in deep water. Of the different areas investigated, the Gulf of Finland seems to be the most productive. In the southern Baltic Sea, the rate of production over 5 years between 1966 and 1971 has not changed appreciably. In fact, it shows a trend toward a slight decrease, whereas, in other areas of the Baltic Sea, the rate of production indicates an apparent increase. Comparison with oceanic coastal areas of the west coast of Sweden shows that the rate of production there is higher than in the Baltic Sea. Of the micronutrients controlling productivity in the photic layer of the Baltic Sea, nitrate has a stronger limiting effect on plant growth than phosphate, a fact which is in agreement with existing conceptions on the subject. Dissolved iron does not seem to exert any appreciable influence on the productivity.     

Artisanal fishing and coastal conservation in West Africa

Artisanal fishing is an activity which has long occupied an important place on the West African coast. In less than 20 years, the increasingly widespread use of motors in fishing boats and cold storage facilities both on board and on land have enabled fishermen to master the constraints of space and time. Furthermore, globalization has created a demand for new products, thus influencing the behaviour of fishermen and consequently the status of some fish, turtle and marine mammal species. Development policies for artisanal fishing do not adequately reflect the importance of these changes. They tend to use inappropriate scales of reference, be it spatially (national borders take precedence over ecosystems) or temporally (the long-term consequences of development plans are seldom considered). Some international conservation organizations are testing promising new approaches to managing resources more sustainably and restoring degraded ecosystems, and their recent experiences can serve as useful examples to others. It is recommended to grant special rights of access to resident fishermen. In defending ‘their’ resources, they will also protect the ecological functions of the area. Close collaboration with administrations and development assistance agencies is needed to assess consequences of political decisions on the use of resources. The important role of marine protected areas as a tool for fishing management should be better documented and strengthened. These areas should not be considered as isolated units but rather as vital parts of a comprehensive system for improved coastal zone management. Consistent with the ecosystem approach, fishermen and their communities, being the main users of coastal resources, should also play a major role in the design and implementation of any fishing management actions.     

Coastal directories and beyond: Providing multidisciplinary coastal zone resource information for resource management

Baseline resource information in an easily accessible form is a vital starting point for developing coastal zone management. On behalf of a wide-ranging group of organizations involved in the management of the U.K. maritime zone, the Joint Nature Conservation Committee (JNCC) is compiling a series of 16 regional volumes. The volumes contain multidisciplinary coastal zone resource information arranged in ten chapters under the general title ‘Coasts and Seas of the UK’. These volumes form part of a series of paper and electronic publications of coastal information being produced by JNCC's Coastal Directories Project and are designed to meet the needs of planners and all others involved in decision-making and management of the coast.     

A general process-based mass-balance model for phosphorus/eutrophication as a tool to estimate historical reference values for key bioindicators,as exemplified using data for the Gulf of Riga

This work describes how a general, process-based mass-balance model (CoastMab) for phosphorus for coastal areas may be used as a tool to estimate realistic values of “natural” or preindustrial reference levels of key bioindicators in coastal science, including the Secchi depth, a standard measure of water clarity, the chlorophyll-a concentration, an operational measure of phytoplankton biomass and the concentration of cyanobacteria, a measure of the concentration of harmful algae. The CoastMab-model is an ecosystem model giving monthly predictions to achieve seasonal variations of basin-wide properties. The selected case-study area, the Gulf of Riga, is sensitive to nutrient loading because of its shallowness and low openness towards the Baltic Proper. The morphometry of any coastal area, as given by the size and form parameters, influences all internal processes, such as sedimentation, resuspension, diffusion in water and from sediments to water, biouptake and retention in biota, stratification, mixing and outflow. There has been no mass-balance modeling for nitrogen (N) in this work because empirical data (from the HELCOM database) clearly indicate that the monthly primary production in the Gulf of Riga is regulated by phosphorus (P) – the mean monthly total-N to total-P ratios are well over 7.2 (the Redfield-ratio) and generally higher than 15 for the data used in this study (from 1992 to 2005). At present anthropogenic loads, the average modeled monthly values for Secchi depth, chlorophyll (Chl), cyanobacteria (CB) and total-P (TP) are 3.2 m, 3.8 μg/l, 78 μg/l and 31.3 μg/l, respectively. If 50% of all anthropogenic sources to the Gulf of Riga via rivers, point sources and diffuse sources were to be removed, these values would be 3.6 m, 3.4 μg Chl/l, 63 μg CB/l and 29.1 μg TP/l. If 60% of the anthropogenic phosphorus fluxes to the Baltic Proper were to be omitted and as well as 75% of all direct anthropogenic sources to the Gulf of Riga, the values would be 4.6 m, 2.7 μg Chl/l, 45 μg CB/l and 25.4 μg TP/l. These values represent the “natural” reference levels and it is not realistic to expect that remedial measures would improve the conditions more than that. Using the CoastWeb-model, similar calculations can be made for any given coastal area and the data necessary for such calculations are discussed in this work.     

Transboundary maritime spatial planning: a Baltic Sea perspective

Maritime Spatial Planning is a new form of spatial planning emerging at the intersection of expanding demands for commercial use of marine space and increasing concerns for marine ecosystems. Many coastal countries around Europe are presently engaged in this field -not only by their national activities but also cooperating across borders through transboundary dialogue, joint strategies and even considering joint planning. In the Baltic Sea region transboundary cooperation takes all these forms. Such activities, including the Plan Bothnia pilot planning of the Bothnian Sea between Sweden and Finland, bring into surface differences in planning procedures and approaches, views on the environment, compatibilities of geographical data and the general complexity of the international-national legal framework. Creativity and transparent, accountable procedures are needed to ensure that such initiatives are both useful and legitimate.     

Use of seaweeds for monitoring trace elements in coastal waters

Concentrations of a wide range of trace elements: arsenic, cadmium, cobalt, chromium, hafnium, nickel, thorium, uranium, zinc and the rare earth elements, cerium, europium, samarium, terbium and ytterbium were determined by instrumental neutron activation analysis in the brown alga,Fucus vesiculosus from Eckwarder Hörne, North Sea and from Rügen, Baltic Sea. Another brown alga,Sargassum filipendula from Sri Lanka, Indian ocean (representing an unpolluted control station) was similarly investigated. Cobalt, chromium and nickel concentrations were highest inF. vesiculosus from the North Sea while zinc was highest in samples from the Baltic Sea, reflecting high levels of these elements in coastal waters of the North and the Baltic sea. Cadmium, cobalt, nickel and zinc levels were lowest inS. filipendula from Sri Lanka, probably demonstrating lower levels of those elements in coastal waters. Concentration levels of hafnium, thorium, uranium, and the rare earth elements were highest inS. filipendula. Two years later in 1994,S. filipendula along withUlva sp. (green alga) was resampled from the same sampling site, and in addition to the above elements, six other trace elements (Ag, Ba, Br, Rb, Se and Sr) were determined.Sargassium filipendula showed a particular affinity for Ag, As, Br and Sr. For the other elements, marginal concentration differences were observed betweenS. filipendula andUlva sp., probably reflecting the regional background levels. Substantially higher concentrations of Hf, Th, U, and the rare earths were found again in the 1994Sargassum andUlva samples, reflecting the effect of a substrate rich in rare earth elements. The brown algae used in this study may be used to monitor trace elements in coastal waters.     

Ecological research for integrated coastal zone management: Introduction

Two Special Features on integrated coastal zone management, especially along the Mediterranean Sea, result from a MeDCOAST conference held in Hammamet (Tunisia). 20–25 October 2001. In this first Special Feature some papers are presented on ecological and biological research related to integrated coastal zone management. All over Europe coastal environments are threatened by human activities such as urbanization, industrial development, fisheries, aquaculture, recreation and tourism. Research has to be developed that can be applied to similar case studies in different countries. Methods of monitoring are necessary and baseline data have to be available in order to judge the significance of changes in the abjotic and biotic environment. Examples of studies included in this Special Feature are mainly from southern banks of the Mediterranean Sea but there is also an example from Estonia and one from the Canary Islands.