Hindsight informs foresight: revisiting millennial forecasts of impacts and status of rocky shores in 2025.

Rocky shorelines are characterised by vulnerability to both land- and sea-derived impacts. They face acute impacts such as pollution from shipping accidents, chronic pollution from point sources, run-off and catchments plus disturbances by food gathering, recreation and sediment deposition in sheltered areas. Coastal urbanisation can both impact natural shores and create impoverished artificial rocky shores.

Unveiling growth and carbon composition of macroalgae with different strategies under global change.

Marine macroalgae ecosystems are increasingly recognized as potential contributors to carbon sequestration within blue carbon strategies. This study investigates how the carbon storage capacity of two macroalgal species with different living strategies, Fucus vesiculosus (k-strategy, slow-growing) and Ulva lactuca (r-strategy, fast-growing), respond to the individual or combined impacts of two drivers of global change, eutrophication and marine heatwaves. Differences in growth, biomass and carbon accumulation were assessed after 7 and 14 days in two experiments (field and laboratory) that tested different combinations of nutrient enrichment (increase nutrient/surface area of 1 g/cm in the field experiment and a concentration of 10 ml/l of Provasoli solution in the laboratory) and warming (5 °C increase) treatments.

The influence of environmental context on community composition in artificial rockpools associated with seawalls.

Artificial structures have become widespread features of coastal marine environments, and will likely proliferate further over the coming decades. These constitute new hard substrata in the marine environment which provide a fundamentally different habitat than natural shores. Eco-engineering solutions aim to ameliorate these differences by combining ecological knowledge and engineering criteria in the construction and modification of artificial substrata.

Habitat structure shapes temperate reef assemblages across regional environmental gradients.

Intertidal artificial habitats are proliferating, but are generally simpler in structure and host lower biodiversity than natural rocky reefs. Eco-engineering aims to enhance the biodiversity of coastal infrastructure, often through physical structural modifications that mimic topographic properties of natural shores. Relationships between biotic assemblages and structural properties of natural and artificial reefs have been extensively studied at sampling scales of up to 1 m.

Using valve gape analysis to compare sensitivity of native Mytilus edulis to invasive Magallana gigas when exposed to heavy metal contamination.

Coastal ecosystems are ecologically and economically important but are under increasing pressure from numerous anthropogenic sources of stress. Both heavy metal pollution and invasive species pose major environmental concerns that can have significant impacts on marine organisms. It is likely that many stresses will occur simultaneously, resulting in potential cumulative ecological effects.

Population structure and reproductive states of the dogwhelk Nucella lapillus differ between artificial structures and natural rocky shores.

Artificial structures are an increasingly common feature of coastal marine environments. These structures are poor surrogates of natural rocky shores, and generally support less diverse communities and reduced population sizes. Little is known about sub-lethal effects of such structures in terms of demographic properties and reproductive potential, both of which may influence the dynamics and long-term viability of populations.

Artificial rockpools: Seaweed colonisation and productivity vary between sites but are consistent across environmental contexts.

Artificial structures are widespread features of coastal environments, but are poor surrogates of natural rocky shores because they generally support depauperate assemblages with reduced population sizes. This has generated significant interest in eco-engineering solutions, including retrofitting seawalls with artificial rockpools to increase water retention and provide microhabitats. Although these have proven effective at individual sites, widespread uptake is contingent on evidence of consistent benefits across a range of contexts.

Colonisation after disturbance on artificial structures: The influence of timing and grazing.

Artificial structures are poor surrogates of natural rocky shores, meaning they generally support depauperate assemblages. These differences may result from a combination of recruitment processes, biotic interactions, and structuring by environmental factors. In this study, plots were cleared on two seawalls and two natural shores at two separate timepoints - in August 2020 (summer) and February 2021 (winter) - and monitored over one year to determine the influence of timing of disturbance on recruitment and succession.

The population structure, sex ratio and reproductive potential of limpets (Patella spp.) on natural shores and artificial structures in the Irish Sea.

Artificial structures often support depauperate communities compared to natural rocky shores. Understanding variation in ecological success across shore types, particularly regarding habitat-forming species or those with structuring roles, is important to determine how artificial structure proliferation may influence ecosystem functioning and services. We investigated the population structure, sex ratio and reproductive potential of limpets on natural shores and artificial structures on Irish Sea coasts.

Artificial shorelines lack natural structural complexity across scales.

From microbes to humans, habitat structural complexity plays a direct role in the provision of physical living space, and increased complexity supports higher biodiversity and ecosystem functioning across biomes. Coastal development and the construction of artificial shorelines are altering natural landscapes as humans seek socio-economic benefits and protection from coastal storms, flooding and erosion. In this study, we evaluate how much structural complexity is missing on artificial coastal structures compared to natural rocky shorelines, across a range of spatial scales from 1 mm to 10 s of m, using three remote sensing platforms (handheld camera, terrestrial laser scanner and uncrewed aerial vehicles).

Fucus vesiculosus populations on artificial structures have potentially reduced fecundity and are dislodged at greater rates than on natural shores.

Artificial structures are widespread features of coastal marine environments. These structures, however, are poor surrogates of natural rocky shores, meaning they generally support depauperate assemblages with reduced population sizes. Little is known about sub-lethal effects of such structures, for example, in terms of demographic properties and reproductive potential that may affect the dynamics and long-term viability of populations.

Sublethal effects of contaminants on marine habitat-forming species: a review and meta-analysis.

Contaminants may affect ecosystem functioning by reducing the fitness of organisms and these impacts may cascade through ecosystems, particularly if the sensitive organisms are also habitat-forming species. Understanding how sub-lethal effects of toxicants can affect the quality and functions of biogenic habitats is critical if we are to establish effective guidelines for protecting ecosystems. We carried out a global systematic review and meta-analysis critically evaluating contaminant effects on properties of habitat-formers linked to ecosystem functioning.

Harnessing positive species interactions as a tool against climate-driven loss of coastal biodiversity.

Habitat-forming species sustain biodiversity and ecosystem functioning in harsh environments through the amelioration of physical stress. Nonetheless, their role in shaping patterns of species distribution under future climate scenarios is generally overlooked. Focusing on coastal systems, we assess how habitat-forming species can influence the ability of stress-sensitive species to exhibit plastic responses, adapt to novel environmental conditions, or track suitable climates.

Diverse effects of invasive ecosystem engineers on marine biodiversity and ecosystem functions: A global review and meta-analysis.

Invasive ecosystem engineers (IEE) are potentially one of the most influential types of biological invaders. They are expected to have extensive ecological impacts by altering the physical-chemical structure of ecosystems, thereby changing the rules of existence for a broad range of resident biota. To test the generality of this expectation, we used a global systematic review and meta-analysis to examine IEE effects on the abundance of individual species and communities, biodiversity (using several indices) and ecosystem functions, focusing on marine and estuarine environments.

Separate and combined effects of copper and freshwater on the biodiversity and functioning of fouling assemblages.

Increased levels of anthropogenic stressors in the marine environment are leading to complex changes in its diversity and functioning. Many marine ecosystems are exposed simultaneously to multiple stressors, and their combined effects are difficult to predict. Climate change will intensify the input of terrestrial pollutants and increase the flow of water to coastal systems through increased precipitation.

The influence of simulated exploitation on Patella vulgata populations: protandric sex change is size-dependent.

Grazing mollusks are used as a food resource worldwide, and limpets are harvested commercially for both local consumption and export in several countries. This study describes a field experiment to assess the effects of simulated human exploitation of limpets Patella vulgata on their population ecology in terms of protandry (age-related sex change from male to female), growth, recruitment, migration, and density regulation. Limpet populations at two locations in southwest England were artificially exploited by systematic removal of the largest individuals for 18 months in plots assigned to three treatments at each site: no (control), low, and high exploitation.

Variation in rocky shore assemblages and abundances of key taxa along gradients of stormwater input.

Stormwater brings freshwater and terrestrially derived contaminants into coastal systems and is predicted to increase with climate change. This study aimed to characterise variation in rocky shore assemblages in relation to stormwater pollution. Intertidal assemblages were sampled in similar habitats at a range of distances (0 m, 10 m, 20 m, 60 m, and 100 m) from stormwater outfalls on three rocky shores north of Dublin.

Impacts of multiple stressors during the establishment of fouling assemblages.

Limited knowledge of the mechanisms through which multiple stressors affect communities and ecosystems limits capacity to predict their effects. Less clear is how stressors impact early colonization of newly available habitats due to scarcity of studies. The present study tested whether copper and freshwater input affect colonization of hard substrata independently or interactively and assessed differences in community respiration and total biomass among early stage assemblages which developed under different regimes of copper and freshwater input.

Response of multi-metric indices to anthropogenic pressures in distinct marine habitats: the need for recalibration to allow wider applicability.

Sustainable exploitation of coastal ecosystems is facilitated by tools which allow reliable assessment of their response to anthropogenic pressures. The Infaunal Quality Index (IQI) and Multivariate-AMBI (M-AMBI) were developed to classify the ecological status (ES) of benthos for the Water Framework Directive (WFD). The indices respond reliably to the impacts of organic enrichment in muddy sand habitats, but their applicability across a range of pressures and habitats is less well understood.

Macroalgal blooms alter community structure and primary productivity in marine ecosystems.

Eutrophication, coupled with loss of herbivory due to habitat degradation and overharvesting, has increased the frequency and severity of macroalgal blooms worldwide. Macroalgal blooms interfere with human activities in coastal areas, and sometimes necessitate costly algal removal programmes. They also have many detrimental effects on marine and estuarine ecosystems, including induction of hypoxia, release of toxic hydrogen sulphide into the sediments and atmosphere, and the loss of ecologically and economically important species.

Large-scale variation in combined impacts of canopy loss and disturbance on community structure and ecosystem functioning.

Ecosystems are under pressure from multiple human disturbances whose impact may vary depending on environmental context. We experimentally evaluated variation in the separate and combined effects of the loss of a key functional group (canopy algae) and physical disturbance on rocky shore ecosystems at nine locations across Europe. Multivariate community structure was initially affected (during the first three to six months) at six locations but after 18 months, effects were apparent at only three.

Distinguishing between direct and indirect effects of predators in complex ecosystems.

1. Global declines in biodiversity have stimulated much research into the consequences of species loss for ecosystems and the goods and services they provide. Species at higher trophic levels are at greater risk of human-induced extinction yet remarkably little is known about the effects of consumer species loss across multiple trophic levels in natural complex ecosystems.

Effects of non-indigenous oysters on microbial diversity and ecosystem functioning.

Invasive ecosystem engineers can physically and chemically alter the receiving environment, thereby affecting biodiversity and ecosystem functioning. The Pacific oyster, Crassostrea gigas, invasive throughout much of the world, can establish dense populations monopolising shorelines and possibly altering ecosystem processes including decomposition and nutrient cycling. The effects of increasing cover of invasive C.

Idiosyncratic species effects confound size-based predictions of responses to climate change.

Understanding and predicting the consequences of warming for complex ecosystems and indeed individual species remains a major ecological challenge. Here, we investigated the effect of increased seawater temperatures on the metabolic and consumption rates of five distinct marine species. The experimental species reflected different trophic positions within a typical benthic East Atlantic food web, and included a herbivorous gastropod, a scavenging decapod, a predatory echinoderm, a decapod and a benthic-feeding fish.