Furthermore, Wilding (2006) observed that, following reef construction, substantial phytodetrital accumulations occurred at the perimeters of two reef modules (research Selleckchem Enzalutamide conducted during July 2002 on reef-modules that are not part of the
current study) and that this was associated with a reduction in redox and macrobenthic changes. The macrobenthic changes included an increase in opportunistic bivalves (Wilding, 2006). However, the seasonal variability in redox, and the spatial extent of measurable change, was not investigated at that time (Wilding, 2006). The purpose of this research was not to test hypotheses of no change or impact (a logical fallacy; Anderson et al., 2000, Gigerenzer, 2004 and Johnson, 1999) but rather to (1) give an estimate, with confidence intervals, of the spatial and temporal patterns in sedimentary redox in close proximity to the reef modules, (2) to use the redox proxy to infer to the broader consequences of reef-proximity to macrobenthic assemblages and (3) make recommendations with regard the likely benthic consequences of the burgeoning offshore renewables industry. The main part of the Loch Linnhe Reef is made of five reef-groups, each reef-group
consisting of six individual modules giving a total of 30 modules (Fig. 1). The three reef-groups (18 modules) that were used in this study (termed A, B and D) were deployed during May, August and September 2003, respectively, and were OSBPL9 selected on the basis of their age-similarity and their location in contrasting current/sedimentary click here regimes. Each reef module, around which the measurements were made, consists of approximately 4000 concrete blocks, each block having external dimensions of 200 × 200 × 400 mm. Each module is between 3 and 4.5 m high, roughly conical in shape, with a diameter of 15–20 m. For the purpose of this study the reef-module’s ‘edge’ consisted of the concrete block that was lying on the sediment corresponding to the random distance located by the diver. Reef groups
A, B and D lie in approximately 18, 15 and 14 m (chart datum) of water respectively (Fig. 1). The redox monitoring work, which spanned 19 months, was conducted in March, May, July and November of 2004 and February, March, May, July, August, September and October in 2005. The reefs had, therefore, been in place at least six months prior to the initiation of sampling. Redox shows considerable heterogeneity over small-scales (Pearson and Stanley, 1979) and, consequently, there was a requirement to take as many measurements as possible around the reef to assess this variability and increase the precision of any main-effect estimates. The requirement for both sufficient replication and a high degree of spatial accuracy (±10 cm) meant that an in situ method of measuring redox was required. In order to achieve this, a waterproof redox probe (Russel pH Ltd.