Experimental assessment of oyster transfers as a vector for macroalgal introductions

Introduction of non-indigenous species can alter marine communities and ecosystems. In shellfish farming, transfer of livestock, especially oysters, is a common practice and potentially constitutes a pathway for non-indigenous introductions. Many species of seaweeds are believed to have been accidentally introduced in association with these transfers, but there is little direct evidence.

The European oyster (Ostrea edulis) and its epibiotic succession

This study aimed to investigate intra- and inter-site differences in the epibiota on the European oyster Ostrea edulis of different ages and on hard substrata to assess their contribution to biodiversity. This research has shown that shells of O. edulis do show higher species diversity than non-living hard substrata and as oysters grow larger epibiotic diversity will increase. This investigation has revealed that O. edulis possesses biogenic engineering qualities and the value of O. edulis as a vehicle for increasing biodiversity should not be underestimated. Relatively few studies have examined the shell surfaces of Ostrea edulis, which, together with their associated epifauna provide a large portion of the natural hard substrata for sessile filter-feeding organisms, including oysters, in coastal and estuarine ecosystems. It can be considered a keystone species which has an influence on intertidal and subtidal community structures.

Reproductive Patterns and Tidal Effects on Spat Settlement of Mytilus Edulis Populations in Dundrum Bay, Northern Ireland

The gametogenic and spat settlement patterns of two Mytihis edulis beds were studied in Dundrum Inner Bay, Northern Ireland. There was evidence of gonad development throughout the year with the main development period between November and March. Spawning was protracted, lasting from May to November. Slight inter-annual and inter-population differences in the riming of the phases were observed but the cycles at both beds were broadly similar to each other and to those of other British and Irish sites. Settlement occurred throughout the year and there was evidence of both primary and secondary spat settlement at both sites. Although the reproductive cycles were similar, distinct seasonal and inter-site differences in spatfall were apparent. At the Downshire Bridge bed, settlement peaked during summer and was dominated by spat in the 0•;5-1•0 mm size range. At Ballykinler, settlement levels were highest in the winter months and larger (>1 mm) spat dominated the samples. The orientation of spat collection pads also significantly affected numbers of the larger (>1 mm) spat. Collectors facing the flood tide attracted significantly more secondary settlers than ebb-facing collectors. This effect varied seasonally and was greater at the Ballykinler bed. It is suggested that hydrodynamic regimes may be an important factor in the differences in settlement patterns of M. edulis.

Bay Area Women in Creative Music

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Electrical Based Sensors and Remote Monitoring System for Assessing the Corrosion Related Activity in Concrete at Hangzhou Bay Bridge

Concrete structures in marine environments are subjected to cyclic wetting and drying, corrosion of reinforcement due to chloride ingress and biological deterioration. In order to assess the quality of concrete and predict the corrosion activity of reinforcing steel in concrete in this environment, it is essential to monitor the concrete continuously right from the construction phase to the end of service life of the structure. In this paper a novel combination of sensor techniques which are integrated in a sensor probe is used to monitor the quality of cover concrete and corrosion of the reinforcement. The integrated sensor probe was embedded in different concrete samples exposed to an aggressive marine environment at the Hangzhou Bay Bridge in China. The sensor probes were connected to a monitoring station, which enabled the access and control of the data remotely from Belfast, UK. The initial data obtained from the monitoring station reflected the early age properties of the concretes and distinct variations in these properties were observed with different concrete types.