Colin J.L. Taylor

Setting new thermal standards for transitional and coastal (TraC) waters

The construction of a new generation of coastal power stations in the UK and other western European countries has highlighted the absence of robust standards for thermal discharges to transitional and coastal waters. The proposed discharge volumes are greater than hitherto, yet there has been little independent critical examination of their potential impact, whilst much of the existing guidance has been adapted from freshwater practice. This review considers the available knowledge on the tolerance and behaviour of fish and other marine biota to heated effluents. Appropriate ways are suggested of grouping fish species to reflect their sensitivity to thermal effects. The plethora of existing standards are considered and their validity assessed in a framework of predicted seawater temperature rise. Those species or groups of organisms most likely to be affected are identified and finally specific recommendations for thermal standards consistent with long term sustainability are proposed.

Sublethal effects of a chlorinated and heated effluent on the physiology of the mussel, Mytilus edulis L.: a reduction in fitness for survival?

Coastal power stations entrain large volumes of cooling water, requiring biocidal treatment to prevent biological fouling. Discharged effluent is both heated and contaminated with residual traces of biocide and so it is necessary to quantify the impacts of this discharge. Cooling water from Heysham 2 nuclear power station, NW England, UK, is discharged to the intertidal area, via a culvert (to minimise erosion and maximise dilution and dispersion by directing the effluent into the receiving water at all states of the tide) within which the effluent is contained at low water. The culvert and surrounding coastal area support a population of blue mussels (Mytilus edulis). Mussel health was determined along a gradient of exposure, using three physiological indices: Scope for Growth, Gonad Mantle Index and Somatic Condition Index (K Factor). The Mussels within the culvert exhibited reduced physiological index values compared to an external site. A trend was identified down the length of the culvert, representing a gradient of exposure and indicating a potential negative effect on growth and reproductive output.

Fish Impingement and Prevention Seen in the Light of Population Dynamics

Power plant and other industries that have once-through cooling water systems withdraw large amounts of surface water from adjacent water bodies such as rivers, lakes, estuaries and coastal areas. Electricity generation accounts for over 50% of all water usage in the industrialised countries and for almost 75% of industrial usage (Using water well? Studies of power stations and the aquatic environment, 2003). Thermal power plants require 40–60 m3/s cooling water per 1,000 MWe. The cooling water intake structures are specifically designed to provide this amount of cooling water under all circumstances, and many different types of configurations have been developed since the early beginning of electricity production.

Velocity of RFID Tagged Gravel in a Non-uniform Longshore Transport System

ABSTRACT Dolphin, T.; Lee, J.; Phillips, R.; Taylor, C.J.L., and Dyer, K., 2016. Velocity of RFID tagged gravel in a nonuniform longshore transport system. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 363–367. Coconut Creek (Florida), ISSN 0749-0208. Radio-frequency Identification (RFID) tags were embedded into 940 native beach gravel particles and deployed at source on Benhole Beach (Somerset, UK) to develop an understanding of gravel transport along a frontage that is likely to be subjected to construction activity associated with the proposed development of the Hinkley Point C power station. The study lasted for three years, the longest of its kind to be published, and maintained high detection rates (78% on completion) typical of RFID experiments. Tracer distribution through time highlighted non-uniformity in the longshore transport system and that a single average or centroid velocity is meaningless, as it cannot account for alongshore variability – instead methods that can account for alongshore variability in the transport system were needed. Spatial patterns in the density of detected tracer revealed transport pathways. Alongshore variation in tracer velocity was linked to changes in the geomorphology: (i) tracer velocity was slowest over beaches, owing to increased surface roughness, burial and deposition at high elevations; (ii) velocity rose/fell with changes in coastline orientation and wave obliquity; and (iii) the highest velocities were found in areas of exposed smooth rock platform; however small ridges (up to 40 cm) in the rock platform and angular blocks derived from cliff and platform erosion led to significant reductions.