More bang for your monitoring bucks: Detection and reporting of non-indigenous species.

'Collect once, use often' is a frequently cited principle in both national and international efforts to promote the collection, archiving and sharing of marine monitoring data. Since the implementation of the Marine Conservation Zone (MCZ) evidence collection programme, 67 recommended MCZ sites have been visited and a suite of marine data collected. Here we present how this dataset was utilised outside of the MCZ programme to identify occurrences of non-indigenous species (NIS) around the UK coast. One hundred and thirty-five aquatic species from the Non-native Species Information Portal (NNSIP) register were used to produce a standard list of NIS against which, infauna and epifaunal data records from the MCZ project were compared. A total of 20 NIS were identified across 42 of the 67 sites surveyed. This study demonstrates that with sufficient coordination and management data collected for other purposes can be easily utilised to address additional policy requirements.

Response of intertidal macrofauna to multiple disturbance types and intensities - an experimental approach.

Two of the best-supported theories which describe the effects of disturbance within marine benthic habitats are the organic enrichment 'Successional Model' and the 'Intermediate Disturbance Hypothesis'. Underlying these models, biological mechanisms thought to drive community change include competition, facilitation, inhibition, tolerance and random colonisation. To further examine the effects of disturbance an experimental test of the effects of different types (burial, raking and organic enrichment) and intensities of disturbance on infaunal intertidal communities at two different sites with similar suites of species was carried out. The same type and frequency of disturbance, applied to the two different sites, produced different responses at the species, community and trophic group level. In models that assume a linear relationship between disturbance intensity and effect, knowledge of the intensity of any novel disturbance, combined with the original disturbance regime experienced by a community (i.e. its 'starting point'), should be sufficient to predict final community characteristics. The current results do not conform to such a linear interpretation, as at both sites the intensity of treatments did not always predict the degree of disturbance. Therefore the response to disturbance may depend on site-specific factors such as the history of prior disturbance and the inherent ecological plasticity exhibited by many benthic species. Whilst current models perform well in predicting benthic responses to gross disturbance, detecting subtler effects requires a recognition that community response may depend on the site, the species and the sources of disturbance.

The use of time-series data in the assessment of macrobenthic community change after the cessation of sewage-sludge disposal in Liverpool Bay (UK).

Sewage sludge was disposed of in Liverpool Bay for over 100 years. Annual amounts increased from 0.5 million tonnes per annum in 1900 to approximately 2 million tonnes per annum by 1995. Macrofauna and a suite of environmental variables were collected at a station adjacent to, and a reference station distant from, the disposal site over 13 years, spanning a pre- (1990-1998) and post- (1999-2003) cessation period. Univariate and multivariate analyses of the time-series data showed significant community differences between reference and disposal site stations and multivariate analyses revealed station-specific community development post-disposal. Temporal variability of communities collected at the disposal station post-cessation was higher than during years of disposal, when temporally stable dominance patterns of disturbance-tolerant species had established. Alterations of community structure post-disturbance reflected successional changes possibly driven by facilitation. Subtle faunistic changes at the Liverpool Bay disposal site indicate that the near-field effects of the disposal of sewage sludge were small and therefore could be considered environmentally acceptable.

Macro- and meiofaunal recolonisation of dredged material used for habitat enhancement: temporal patterns in community development.

In recent years, dredged material has become regarded as a potential resource and used to create and/or improve intertidal habitats (i.e., beneficial use). This paper presents the results of a sampling programme to investigate the long-term (42 months post-recharge) macro- and meiofaunal recolonisation processes of a beneficial use scheme in south-east England. While univariate indices of community structure indicated that the scheme's meiofaunal community was never significantly different from that of a nearby reference area, such attributes for macrofauna were continually significantly below those of the reference area, although this was not the case for all reference stations. Multivariate analyses revealed that macro- and meiofaunal community structures were always significantly different from those of the reference communities. We discuss the factors responsible for these observations and propose that assessing recovery of a beneficial use scheme should be undertaken using pre-defined criteria in addition to comparisons with a reference site.

Development of macrofaunal communities on dredged material used for mudflat enhancement: a comparison of three beneficial use schemes after one year.

In recent years, dredged material has become regarded as a potential resource and used to create and/or improve intertidal habitats ('beneficial use' schemes). This paper presents the results of a sampling programme to investigate the short-term macrofaunal recovery of three beneficial use schemes in south-east England in terms of species and functional diversity. Environmental parameters (sediment redox potential, and water, organic carbon and silt/clay contents) and univariate community attributes (total individuals and species, diversity, evenness and biomass) at the recharge sites had attained reference levels at two schemes while assemblages differed significantly in terms of species composition at all three schemes. While trophic group proportionality had re-established at one scheme, an increased grazer dominance was apparent at another while the proportion of sub-surface deposit feeders decreased at the third. Total individuals and species number of the developing communities were negatively correlated with sediment redox potential at 4 cm and % silt/clay, respectively. The implications of these results for monitoring the recovery of future fine-grained beneficial use schemes are discussed.