A comparison of visual and molecular methods for inferring biological communities in aquaculture enriched sediments - Impact assessment and cost-benefit analysis.

Nutrients introduced to the environment by finfish aquaculture pose environmental risks, which can be mitigated by robust environmental monitoring. Biological communities in soft sediments are good indicators of aquaculture derived environmental changes. Traditionally, monitoring programs have visually surveyed macrofauna communities.

Assessing the role of natural kelp forests in modifying seawater chemistry.

Climate change is causing widespread impacts on seawater pH through ocean acidification (OA). Kelp forests, in some locations can buffer the effects of OA through photosynthesis. However, the factors influencing this variation remain poorly understood.

Complexity-functioning relationships differ across different environmental conditions.

Habitat complexity is widely considered an important determinant of biodiversity, and enhancing complexity can play a key role in restoring degraded habitats. However, the effects of habitat complexity on ecosystem functioning - as opposed to biodiversity and community structure - are relatively poorly understood for artificial habitats, which dominate many coastlines. With Greening of Grey Infrastructure (GGI) approaches, or eco-engineering, increasingly being applied around the globe, it is important to understand the effects that modifying habitat complexity has on both biodiversity and ecological functioning in these highly modified habitats.

Conceptualisation of multiple impacts interacting in the marine environment using marine infrastructure as an example.

The human population is increasingly reliant on the marine environment for food, trade, tourism, transport, communication and other vital ecosystem services. These services require extensive marine infrastructure, all of which have direct or indirect ecological impacts on marine environments. The rise in global marine infrastructure has led to light, noise and chemical pollution, as well as facilitation of biological invasions.

Material type influences the abundance but not richness of colonising organisms on marine structures.

Urbanisation of coastal areas and growth in the blue economy drive the proliferation of artificial structures in marine environments. These structures support distinct ecological communities compared to natural hard substrates, potentially reflecting differences in the materials from which they are constructed. We undertook a meta-analysis of 46 studies to compare the effects of different material types (natural or eco-friendly vs.

Testing the efficacy of sea urchin exclusion methods for restoring kelp.

Kelps are ecosystem engineers, which collectively form forests that provide a variety of important ecosystem services for humans and other organisms. Kelp forests are threatened by multiple local and global stressors, one of the most notable is herbivory. Overabundant sea; urchins can consume kelp, leading to a phase shift from productive forests to unproductive; rocky barrens.

Provision of refugia and seeding with native bivalves can enhance biodiversity on vertical seawalls.

Recent studies have suggested that increasing habitat complexity of artificial seawalls by modifying surface heterogeneity could enhance exploitable habitat and therefore species richness and abundance. We tested the effects of adding complex tiles (with crevices/ledges) of different heterogeneity (i.e.

Interacting effects of habitat structure and seeding with oysters on the intertidal biodiversity of seawalls.

The construction of artificial structures, such as seawalls, is increasing globally, resulting in loss of habitat complexity and native species biodiversity. There is increasing interest in mitigating this biodiversity loss by adding topographic habitat to these structures, and/or seeding them with habitat-forming species. Settlement tile experiments, comparing colonisation of species to more and less complex habitats, have been used to inform eco-engineering interventions prior to their large-scale implementation.

Interactive responses of primary producers and grazers to pollution on temperate rocky reefs.

Macroalgal beds provide important habitat structure and support primary production for rocky reef communities, but are increasingly degraded as a result of human pressures. Various sources of pollution can have both direct and interactive effects on stressed ecosystems. In particular, interactions involving invertebrate grazers could potentially weaken or strengthen the overall impact of pollution on macroalgal beds.

Management of local stressors can improve the resilience of marine canopy algae to global stressors.

Coastal systems are increasingly threatened by multiple local anthropogenic and global climatic stressors. With the difficulties in remediating global stressors, management requires alternative approaches that focus on local scales. We used manipulative experiments to test whether reducing local stressors (sediment load and nutrient concentrations) can improve the resilience of foundation species (canopy algae along temperate rocky coastlines) to future projected global climate stressors (high wave exposure, increasing sea surface temperature), which are less amenable to management actions.

Identifying the interacting roles of stressors in driving the global loss of canopy-forming to mat-forming algae in marine ecosystems.

Identifying the type and strength of interactions between local anthropogenic and other stressors can help to set achievable management targets for degraded marine ecosystems and support their resilience by identifying local actions. We undertook a meta-analysis, using data from 118 studies to test the hypothesis that ongoing global declines in the dominant habitat along temperate rocky coastlines, forests of canopy-forming algae and/or their replacement by mat-forming algae are driven by the nonadditive interactions between local anthropogenic stressors that can be addressed through management actions (fishing, heavy metal pollution, nutrient enrichment and high sediment loads) and other stressors (presence of competitors or grazers, removal of canopy algae, limiting or excessive light, low or high salinity, increasing temperature, high wave exposure and high UV or CO2 ), not as easily amenable to management actions. In general, the cumulative effects of local anthropogenic and other stressors had negative effects on the growth and survival of canopy-forming algae.

Global conservation outcomes depend on marine protected areas with five key features.

In line with global targets agreed under the Convention on Biological Diversity, the number of marine protected areas (MPAs) is increasing rapidly, yet socio-economic benefits generated by MPAs remain difficult to predict and under debate. MPAs often fail to reach their full potential as a consequence of factors such as illegal harvesting, regulations that legally allow detrimental harvesting, or emigration of animals outside boundaries because of continuous habitat or inadequate size of reserve. Here we show that the conservation benefits of 87 MPAs investigated worldwide increase exponentially with the accumulation of five key features: no take, well enforced, old (>10 years), large (>100 km(2)), and isolated by deep water or sand.

Effects of a range-expanding sea urchin on behaviour of commercially fished abalone.

Background: Global climate change has resulted in a southerly range expansion of the habitat modifying sea urchin Centrostephanus rodgersii to the east coast of Tasmania, Australia. Various studies have suggested that this urchin outcompetes black-lipped abalone (Haliotis rubra) for resources, but experiments elucidating the mechanisms are lacking.

Methodology/principal Findings: We outline a new framework involving experimental manipulations and Markov chain and Pareto modelling to examine the effects of interspecific competition between urchins and abalone and the effect of intraspecific competition in abalone, assessed as effects on behaviour.

Integrating abundance and functional traits reveals new global hotspots of fish diversity.

Species richness has dominated our view of global biodiversity patterns for centuries. The dominance of this paradigm is reflected in the focus by ecologists and conservation managers on richness and associated occurrence-based measures for understanding drivers of broad-scale diversity patterns and as a biological basis for management. However, this is changing rapidly, as it is now recognized that not only the number of species but the species present, their phenotypes and the number of individuals of each species are critical in determining the nature and strength of the relationships between species diversity and a range of ecological functions (such as biomass production and nutrient cycling).

Effects of two decades of rising sea surface temperatures on sublittoral macrobenthos communities in Northern Ireland, UK.

We examined whether two decades of rising sea surface temperatures have resulted in significant changes in the benthic community and frequency of occurrence of Northern and Southern species in three areas of Northern Ireland, using visual census data collected by SCUBA surveys undertaken during two periods: pre-1986 and post-2006. We found little evidence to suggest that rising sea surface temperatures have contributed to the changes in benthic assemblage structure between the pre-1986 and post-2006 surveys. However, there were slight but not significant declines in extreme Northern species at Rathlin Island, and increases in the mean number and frequency of occurrence of extreme Southern species in all three areas.