RESUMO
Eco-engineering of coastal infrastructure aims to address the insufficient intertidal habitat provided by coastal development and flood defence. There are numerous ways to enhance coastal infrastructure with habitat features, but a common method involves retrofitting artificial rockpools. Often these are 'bolt-on' units that are fixed to existing coastal infrastructure but there is a paucity of literature on how to optimise their arrangement for biodiversity. In this study, 24 artificial rockpools were installed at three levels between High Water Neaps and Mean Tide Level on a vertical concrete seawall on the south coast of the UK. The species abundance of the rockpools and adjacent seawall were surveyed at low tide for 2 years following rockpool installation and compared. Over the course of the study, sediment had begun to accumulate in some of the rockpools. At the 2-year mark, the sediment was removed and assessed for macrofauna. Algal biomass of the seawall and rockpools was estimated using previously obtained dry weight values for the dominant algae taxa. After 2 years, it was determined that artificial rockpools successfully increase species richness of seawalls, particularly at higher tidal levels where water-retaining refugia are crucial for many species. The rockpools hosted 37 sessile taxa and 9 sessile taxa were recorded on the seawall. Rockpools increased the vertical elevation for brown canopy-forming seaweeds by providing better attachment surfaces. Although the retained sediment only hosted 3 infaunal species, it was observed to provide shelter for shore crabs during surveys. As sea levels and ocean and air temperatures continue to rise, vertical eco-engineering arrangements will play a crucial role in allowing species to migrate up the tidal zone, negating habitat loss and localised extinction.
RESUMO
Despite the repeated calls to stop, most notably in a technical publication of the International Union for Pure and Applied Chemistry (IUPAC), the use of the term 'heavy metal' appears not to have declined in the scientific literature and there is little evidence that the IUPAC instructions and those of other publications have had any measurable impact on this widespread usage. Indeed, the use of the term is increasing rather than declining. Four options are presented to solve this dilemma.
Assuntos
Metais Pesados/normas , Terminologia como Assunto , Química/normas , Bases de Dados Bibliográficas , Ferramenta de Busca , SemânticaRESUMO
Landfills have been the primary method of waste disposal within the UK for many years, and are often associated with land reclamation. The landfill in Christchurch Harbour, considered in this study, has a straight artificial channel which runs from the edge of the landfill to the estuary. This channel has increased the levels of metals in the marshland and acts, in effect, as a drainage system. The degree of metal mobility in soils and sediments is typically determined by using sequential extraction schemes (SESs), but the effectiveness and precision of these procedures are disputed. A simpler and more resilient approach is the application of partial/single extraction schemes (PESs). Both schemes, however, can only assess the theoretical readiness of a metal to migrate at a certain time/place and under certain conditions-they do not gauge the actual migration and therefore can only have predictive abilities at best. In this study, the metal distribution in an intertidal area between a landfill and an estuary has been determined using the actual distribution patterns in the ground and comparing them with the theoretical mobility based on the standardised PES procedure DIN 19730. It was found that this procedure can predict the actual migration in the marshland rather well; however, in the vicinity of the channel no correlation between the mobility and dispersion could be detected and the actual movement is much higher than the PES outcomes generally indicated.
Assuntos
Monitoramento Ambiental , Metais/análise , Nitratos/química , Eliminação de Resíduos , Solo/análise , Fracionamento Químico/métodos , Monitoramento Ambiental/economia , Monitoramento Ambiental/métodos , Metais/isolamento & purificaçãoRESUMO
The relationships among the Aurearenophyceae, Phaeothamniophyceae, Phaeophyceae and Xanthophyceae lineages of the Heterokontophyta SI clade are not well known. By adding previously unexamined taxa related to these classes in a five gene phylogeny (SSU rRNA, atpB, psaA, psaB, rbcL), we recovered an assemblage of taxa previously unrecognized. We propose the class Phaeosacciophyceae class. nov., that includes Phaeosaccion collinsii, Phaeosaccion multiseriatum sp. nov., Phaeosaccion okellyi sp. nov., Antarctosaccion applanatum, Tetrasporopsis fuscescens, Tetrasporopsis moei sp. nov., and Psammochrysis cassiotisii gen. & sp. nov. We re-examine the literature for Chrysomeris, Nematochrysis, Chrysowaernella and the invalid name "Giraudyopsis" and conclude some taxa in previous studies are misidentified or misnamed, i.e. Chrysomeris and Chrysowaernella, respectively. We also show that Nematochrysis sessilis var. vectensis and Nematochrysis hieroglyphica may belong in the recently described class Chrysoparadoxophyceae. The phylogenetic relationships of Phaeobotrys solitaria and Pleurochloridella botrydiopsis are not clearly resolved, but they branch near the Xanthophyceae. Here we describe a new class Phaeosacciophyceae, a new order Phaeosacciales, a new family Tetrasporopsidaceae, a new genus Psammochrysis and four new species.
Assuntos
Filogenia , Estramenópilas/classificação , DNA de Protozoário/genética , DNA Ribossômico/genética , Especificidade da Espécie , Estramenópilas/genéticaRESUMO
Sediment quality guidelines (SQGs) are an important tool for the assessment of contamination in marine and estuarine sediments. Although such guidelines are not definitive indicators of toxicity, they can have a high predictive ability and are a vital tool for identifying areas with potentially adverse biological effects. In the present study, 15 sets of common SQGs have been compared, including values for Australia/New Zealand, Canada, Hong Kong, Norway, the Netherlands, the USA and regions within the USA (Puget Sound/Washington, New York and Florida). The majority of these SQGs are based on the weight-of-evidence approach. In particular, the sub-group of TEL/PEL-based values have a very high degree of comparability; values not belonging to this uniform group show substantial variations.
Assuntos
Poluentes Ambientais/análise , Sedimentos Geológicos/química , Metais/análise , Geografia , Guias como AssuntoRESUMO
With increasing coastal infrastructure and use of novel materials there is a need to investigate the colonisation of assemblages associated with new structures, how these differ to natural and other artificial habitats and their potential impact on regional biodiversity. The colonisation of Europe's first artificial surf reef (ASR) was investigated at Boscombe on the south coast of England (2009-2014) and compared with assemblages on existing natural and artificial habitats. The ASR consists of geotextile bags filled with sand located 220m offshore on a sandy sea bed at a depth of 0-5m. Successional changes in epibiota were recorded annually on differently orientated surfaces and depths using SCUBA diving and photography. Mobile faunal assemblages were sampled using Baited Remote Underwater Video (BRUV). Distinct stages in colonisation were observed, commencing with bryozoans and green algae which were replaced by red algae, hydroids and ascidians, however there were significant differences in assemblage structure with depth and orientation. The reef is being utilised by migratory, spawning and juvenile life-history stages of fish and invertebrates. The number of non-native species was larger than on natural reefs and other artificial habitats and some occupied a significant proportion of the structure. The accumulation of 180 benthic and mobile taxa, recorded to date, appears to have arisen from a locally rich and mixed pool of native and non-native species. Provided no negative invasive impacts are detected on nearby protected reefs the creation of novel yet diverse habitats may be considered a beneficial outcome.
Assuntos
Recifes de Corais , Animais , Clorófitas/crescimento & desenvolvimento , Inglaterra , Peixes/crescimento & desenvolvimento , Invertebrados/crescimento & desenvolvimento , Rodófitas/crescimento & desenvolvimento , Têxteis , Urocordados/crescimento & desenvolvimentoRESUMO
Understanding long-term persistence and variability in species populations can help to predict future survival, growth and distribution; however, sustained observations are exceedingly rare. We examine and interpret a remarkable record of the calcareous brown alga Padina pavonica (Phaeophyceae) at its northern limit on the south coast of England (50°N, 1-3°W) from 1680 to 2014, which is probably the longest compilation and review of any marine algal species. Over this period, which extends from the middle of the Little Ice Age to the present, there has been considerable variability in temperature and storminess. We identified a significant number of site extinctions in the second half of the nineteenth century, which coincided with cooler conditions and stormier weather. To interpret these changes, we measured recruitment, growth and production of tetraspores at sheltered and exposed sites in 2012-2014, years which had low and high spring temperatures. Potential spore production was greater at the sheltered site due to a longer growing period and survival of larger fronds. Delayed growth in the cooler spring resulted in smaller fronds and lower potential production of tetraspores by early summer. Yet in the warmer year, rapid initial growth caused higher sensitivity to damage and dislodgement by summer storms, which also limited potential spore production. Antagonistic responses to multiple stressors and disturbances make future predictions of survival and distribution difficult. Fronds of Padinapavonica are sensitive to both temperature and physical disturbances, yet vegetative perennation appears to have enabled population persistence and explained the longevity of remaining populations.