Do Changes in Current Flow as a Result of Arrays of Tidal Turbines Have an Effect on Benthic Communities?

Arrays of tidal energy converters have the potential to provide clean renewable energy for future generations. Benthic communities may, however, be affected by changes in current speeds resulting from arrays of tidal converters located in areas characterised by strong currents. Current speed, together with bottom type and depth, strongly influence benthic community distributions; however the interaction of these factors in controlling benthic dynamics in high energy environments is poorly understood. The Strangford Lough Narrows, the location of SeaGen, the world’s first single full-scale, grid-compliant tidal energy extractor, is characterised by spatially heterogenous high current flows. A hydrodynamic model was used to select a range of benthic community study sites that had median flow velocities between 1.5–2.4 m/s in a depth range of 25–30 m. 25 sites were sampled for macrobenthic community structure using drop down video survey to test the sensitivity of the distribution of benthic communities to changes in the flow field. A diverse range of species were recorded which were consistent with those for high current flow environments and corresponding to very tide-swept faunal communities in the EUNIS classification. However, over the velocity range investigated, no changes in benthic communities were observed. This suggested that the high physical disturbance associated with the high current flows in the Strangford Narrows reflected the opportunistic nature of the benthic species present with individuals being continuously and randomly affected by turbulent forces and physical damage. It is concluded that during operation, the removal of energy by marine tidal energy arrays in the far-field is unlikely to have a significant effect on benthic communities in high flow environments. The results are of major significance to developers and regulators in the tidal energy industry when considering the environmental impacts for site licences.

On the context-dependent scaling of consumer feeding rates

The stability of consumer-resource systems can depend on the form of feeding interactions (i.e. functional responses). Size-based models predict interactions - and thus stability - based on consumer-resource size ratios. However, little is known about how interaction contexts (e.g. simple or complex habitats) might alter scaling relationships. Addressing this, we experimentally measured interactions between a large size range of aquatic predators (4-6400 mg over 1347 feeding trials) and an invasive prey that transitions among habitats: from the water column (3D interactions) to simple and complex benthic substrates (2D interactions). Simple and complex substrates mediated successive reductions in capture rates - particularly around the unimodal optimum - and promoted prey population stability in model simulations. Many real consumer-resource systems transition between 2D and 3D interactions, and along complexity gradients. Thus, Context-Dependent Scaling (CDS) of feeding interactions could represent an unrecognised aspect of food webs, and quantifying the extent of CDS might enhance predictive ecology.

Benthic assemblages associated with native and non-native oysters are similar

Invasive species can impact native species and alter assemblage structure, which affects associated ecosystem functioning. The pervasive Pacific oyster, Crassostrea gigas, has been shown to affect the diversity and composition of many host ecosystems. We tested for effects of the presence of the invasive C. gigas on native assemblages by comparing them directly to assemblages associated with the declining native European oyster, Ostrea edulis. The presence of both oyster species was manipulated in intertidal and subtidal habitats and reefs were constructed at horizontal and vertical orientation to the substratum. After 12 months, species diversity and benthic assemblage structure between assemblages with C. gigas and O. edulis were similar, but differed between habitats and orientation, suggesting that both oyster species were functionally similar in terms of biodiversity facilitation. These findings support evidence, that non-native species could play an important role in maintaining biodiversity in systems with declining populations of native species.

Community policing in Northern Ireland: a resistance narrative

Policing in stable democratic societies is predominantly concerned with the implementation and practice of the globally accepted philosophy of community policing. However, the subtle complexities of Northern Ireland's transitional landscape present acute problems for the community policing concept, both as a vehicle for police reform and as a tool for increasing the co-production of security through improved community interaction with the police. This article will examine the current position of the Police Service of Northern Ireland (PSNI) and their Policing with the Community policy. Providing an overview of contextual and contemporary developments, it will assess the efficacy with which the PSNI have realised community policing, as espoused in Patten Recommendation 44. It concludes by determining the role and extent of community engagement with policing in Northern Ireland and the resistances and contestations to the implementation of the community policing in a post-conflict society.

Diversifying From Within: Community Policing and the Governance of Security in Northern Ireland

The subtle and complex nature of Northern Ireland's transitional landscape presents acute difficulties for the community policing concept. As the core to the police reforms in the country, its implementation has faltered in the face of institutional inertia within the Police Service of Northern Ireland (PSNI). This has been further exacerbated by a failure of the police to adequately increase the co-production of security through improved engagement and utilization of Northern Ireland's diverse community infrastructures. This paper will assess the delivery of community policing by the PSNI, while exploring their engagement with Northern Ireland's grass-roots community organizations, and specifically those involved with the governance of security at the local level. Thus, through a framework of adaptation, engagement and delivery of community policing by the PSNI within the unique context of Northern Ireland's security ‘otherness’, the paper will explore the key issues to police–community interaction associated with the broader vision of the Independent Commission on Policing (ICP) on community policing.