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Vlaardingen, Netherlands

Paalvast P.,Ecoconsult | van der Velde G.,Radboud University Nijmegen | van der Velde G.,Netherlands Center for Biodiversity Naturalis
Marine Pollution Bulletin | Year: 2011

The effects of four climate change scenarios for the Netherlands on the distribution of the shipworm upstream of the Rhine-Meuse estuary are described. Global warming will cause dry and warmer summers and decreased river discharges. This will extend the salinity gradient upstream in summer and fall and may lead to attacks on wooden structures by the shipworm. Scenarios including one or two degree temperature increases by 2050 compared to 1990 with a weak change in the air circulation over Europe will lead to an increased chance of shipworm damage upstream from once in 36 years to once in 27 or 22 years, respectively; however, under a strong change in air circulation, the chance of shipworm damage increases to once in 6 or 3 years, respectively. The upstream expansion of the distribution of the shipworm will also be manifested in other northwest European estuaries and will be even stronger in southern Europe. © 2011 Elsevier Ltd. Source

Paalvast P.,Ecoconsult | van der Velde G.,Radboud University Nijmegen | van der Velde G.,Naturalis Biodiversity Center
Ocean and Coastal Management | Year: 2014

Around 0AD, the Rhine-Meuse estuary in the southwest of the Netherlands was a typical coastal plain estuary. Drainage of peatland and land subsidence behind the dunes later caused the sea to penetrate into the land. Most of the peat was eroded, and by 1000AD the so-called Delta area had turned into a landscape of large estuaries and intertidal zones. Rotterdam developed from a small fishing village on the banks of the tidal river "Nieuwe Maas" from the 14th century onwards into the largest seaport of Europe in 2013. The Rotterdam harbour area situated in the northern part of the Delta area includes the former Europoort harbour, and is nowadays known as Rijnmond. The hydrology of the area is controlled by the drainage regime of the sluices in the Haringvliet barrier that was constructed as part of the "Delta Works" project to protect the southwest of the Netherlands against storm surges. The sluices are opened at slack tide to discharge river water to the sea and are always closed at flood tide.As a baseline study for environmental and ecological reconstruction and development, we describe in detail the loss of intertidal soft sediment ecotopes due to land reclamation, harbour development and river training works (straightening of the navigational channel) in the tidal rivers, and the expansion of hard substrate ecotopes (quay walls, groynes, training walls, riprap, concrete, stones etc.) in the Rijnmond area in the 19th and 20th centuries. Within 135 years, more than 99% of the original 4775ha of characteristic pristine soft sediment estuarine ecotopes have disappeared. In the same period, 338ha of hard intertidal substrate zone was constructed. Such trends can also be observed in harbour areas elsewhere, and have ecological and environmental consequences for estuarine areas in particular.Restoration of soft substrate estuarine ecotopes can be achieved by opening the Haringvliet Sluices at both ebb and flood tide, which would restore large-scale estuarine dynamics to the northern part of the Rhine-Meuse estuarine system. This will have a highly favourable effect on many ecosystem services. The Dutch division of the Word Wild Life Fund has launched a new proposal for a safer and more attractive South-West Delta area. It comprises the reopening of the sea inlets such as the Haringvliet by removing the barriers, and building climate-proof dikes in combination with natural wetlands. In case of storm surges, the hinterland could be protected with a new generation of barriers that do not hamper the free transport of sediment, tides and animals. Based on 30 ecosystem services or subservices, it was calculated that opening the Haringvliet inlet would lead to an increase in Total Economic Value (TEV) of at least 500 million Euro per year. The costs of removing old barriers and the construction of new ones was not included in the calculations. © 2014 Elsevier Ltd. Source

Paalvast P.,Ecoconsult | van Wesenbeeck B.K.,Deltares | van der Velde G.,Radboud University Nijmegen | van der Velde G.,Netherlands Center for Biodiversity Naturalis | de Vries M.B.,Deltares
Ecological Engineering | Year: 2012

Underwater environments in ports are designed for harbour activities solely. However, by simple and cost-effective measures, suitable habitat for underwater flora and fauna can be created. This is expected to have positive effects on higher trophic levels, such as fish, and improve water quality, by enlarging filter feeder biomass. In this study we developed 'pole hulas' and 'pontoon hulas', consisting of hanging ropes of different materials. The pole hulas are made up of many 6. mm thick and 55. cm long strings just above and below the mean low water level (MLWL) around poles. The pontoon hulas resemble raft like structures with 12. mm thick and 150. cm long ropes within the open space of mooring pontoons. The first experimentation with these structures was executed in the polyhaline harbours of the port of Rotterdam. The pole hulas were rapidly colonised by a variety of organisms. Above MLWL a seaweed community dominated on the strings. Below MLWL Mytilus edulis (the Blue mussel) was found to be the dominating species after a few months. In the dense layer of M. edulis on both pole hulas and pontoon hulas many mobile soft-bottom amphipods and young ragworms occurred, which means that colonisation on these structures compensate for biodiversity loss of bottom fauna due to dredging and disturbance by propellers of ships. Settlement of the exotic Crassostrea gigas (Pacific or Japanese oyster) did not occur on the strings of the pole hulas, the ropes of the pontoon hulas and not on the poles with hulas.Wet biomass (including shells) on pole hulas was positively correlated with depth and on average 4.4-11.4 times higher compared to biomass on reference poles. Colonization of the pontoon hula ropes was similar to colonization of the pole hulas below MLWL. Biomass production per rope was density dependent and optimal density of ropes was estimated at 4-8ropesm -2. Biomass (mainly M. edulis) on the ropes of pontoon hulas decreased to a half from the edge to the heart of the hula demonstrating the limitation of food by competition.It was concluded that ecological engineering in the port of Rotterdam with simple structures such as pole and pontoon hulas strongly enhances sessile biological production and biodiversity. This is likely to result in a positive impact on local water quality, and, if applied at larger scales, may have positive influences on the remains of Rhine-Meuse estuary. © 2012 Elsevier B.V. Source

Paalvast P.,Ecoconsult | van der Velde G.,Radboud University Nijmegen | van der Velde G.,Netherlands Center for Biodiversity Naturalis
International Biodeterioration and Biodegradation | Year: 2011

During the period 2004-2008 the distribution, settlement, and growth of first-year shipworms (Teredo navalis L., 1758) was studied by exposing fir and oak panels in the Port of Rotterdam area, which is situated in the Rhine-Meuse estuary in the Netherlands and covers the complete salinity gradient. Shipworms were found yearly in the western large polyhaline harbours. On only a few occasions were they were found in harbours that showed large seasonal and daily fluctuations in salinity. In 2006 the shipworm was found in fir panels 20km upstream from the polyhaline harbours, demonstrating their ability to travel with the tidal currents over considerable distances and to settle once the abiotic conditions become favourable. Although the water temperatures allowed them to breed from April until November, infestations were not found before September, and from the size of the animals in the panels it was concluded that in the Port of Rotterdam area they spawned from August until the end of November. The settlement height was negatively correlated with the distance of the panels to the sea floor. In the first season after settlement they showed a substantial growth rate of 0.18cmday-1. The longest shipworm found measured 36.8cm after 4-5 months of growth after settlement. Infestations and growth were lower in oak than in fir wood. In 2006 the maximum consumption of wood by individuals settled in the same year in panels at the bottom accounted for 12.4%. Shell size and body length of the animal after the first season of growth showed a significant positive logarithmic relation. In both 2006 and 2007 a similar relation between the average boring tube diameter and the length of the animals was found. Lower river discharges leading to salinisation of the eastern part of the Port of Rotterdam area create conditions favourable for the shipworm, with serious consequences for the piles upon which the quays are built. © 2011 Elsevier Ltd. Source

Borsje B.W.,University of Twente | Borsje B.W.,Deltares | van Wesenbeeck B.K.,Deltares | Dekker F.,Deltares | And 5 more authors.
Ecological Engineering | Year: 2011

Traditionally, protection of the coastal area from flooding is approached from an engineering perspective. This approach has often resulted in negative or unforeseen impacts on local ecology and is even known to impact surrounding ecosystems on larger scales. In this paper, the utilization of ecosystem engineering species for achieving civil-engineering objectives or the facilitation of multiple use of limited space in coastal protection is focused upon, either by using ecosystem engineering species that trap sediment and damp waves (oyster beds, mussel beds, willow floodplains and marram grass), or by adjusting hard substrates to enhance ecological functioning. Translating desired coastal protection functionality into designs that make use of the capability of appropriate ecosystem engineering species is, however, hampered by lack of a generic framework to decide which ecosystem engineering species or what type of hard-substrate adaptations may be used where and when. In this paper we review successful implementation of ecosystem engineering species in coastal protection for a sandy shore and propose a framework to select the appropriate measures based on the spatial and temporal scale of coastal protection, resulting in a dynamic interaction between engineering and ecology. Modeling and monitoring the bio-physical interactions is needed, as it allows to upscale successful implementations and predict otherwise unforeseen impacts. © 2010 Elsevier B.V. Source

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