Nuanced impacts of the invasive aquatic plant Crassula helmsii on Northwest European freshwater macroinvertebrate assemblages.

Invasive alien species are considered one of the greatest threats to global biodiversity, and are particularly problematic in aquatic systems. Given the foundational role of macrophytes in most freshwaters, alien aquatic plant invasions may drive strong bottom-up impacts on recipient biota. Crassula helmsii (New Zealand pygmyweed) is an Australasian macrophyte, now widespread in northwest Europe.

The influence of light and temperature on detritus degradation rates for kelp species with contrasting thermal affinities.

Kelp detritus fuels coastal food webs and may play an important role as a source of organic matter for natural carbon sequestration. Here, we conducted ex situ and in situ manipulations to evaluate the role of temperature and light availability in the breakdown of detrital material. We examined degradation rates of two North Atlantic species with contrasting thermal affinities: the 'warm water' kelp Laminaria ochroleuca and the 'cool water' Laminaria hyperborea.

Tropical CO seeps reveal the impact of ocean acidification on coral reef invertebrate recruitment.

Rising atmospheric CO concentrations are causing ocean acidification by reducing seawater pH and carbonate saturation levels. Laboratory studies have demonstrated that many larval and juvenile marine invertebrates are vulnerable to these changes in surface ocean chemistry, but challenges remain in predicting effects at community and ecosystem levels. We investigated the effect of ocean acidification on invertebrate recruitment at two coral reef CO seeps in Papua New Guinea.

The effects of warming on the ecophysiology of two co-existing kelp species with contrasting distributions.

The northeast Atlantic has warmed significantly since the early 1980s, leading to shifts in species distributions and changes in the structure and functioning of communities and ecosystems. This study investigated the effects of increased temperature on two co-existing habitat-forming kelps: Laminaria digitata, a northern boreal species, and Laminaria ochroleuca, a southern Lusitanian species, to shed light on mechanisms underpinning responses of trailing and leading edge populations to warming. Kelp sporophytes collected from southwest United Kingdom were maintained under 3 treatments: ambient temperature (12 °C), +3 °C (15 °C) and +6 °C (18 °C) for 16 days.

Ocean acidification affects fish spawning but not paternity at CO2 seeps.

Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification expected to occur owing to anthropogenic carbon dioxide emissions during this century. We provide the first evidence of the effects of ocean acidification on reproductive behaviour of fish in the wild. Satellite and sneaker male ocellated wrasse (Symphodus ocellatus) compete to fertilize eggs guarded by dominant nesting males.

Long-Term Field Study Reveals Subtle Effects of the Invasive Alga Sargassum muticum upon the Epibiota of Zostera marina.

Invasive species can alter coastal ecosystems both directly, e.g. through competition for substratum and nutrients, and indirectly.

The future of the northeast Atlantic benthic flora in a high CO2 world.

Seaweed and seagrass communities in the northeast Atlantic have been profoundly impacted by humans, and the rate of change is accelerating rapidly due to runaway CO2 emissions and mounting pressures on coastlines associated with human population growth and increased consumption of finite resources. Here, we predict how rapid warming and acidification are likely to affect benthic flora and coastal ecosystems of the northeast Atlantic in this century, based on global evidence from the literature as interpreted by the collective knowledge of the authorship. We predict that warming will kill off kelp forests in the south and that ocean acidification will remove maerl habitat in the north.

Using species-area relationships to inform baseline conservation targets for the deep North East Atlantic.

Demands on the resources of the deep-sea have increased in recent years. Consequently, the need to create and implement a comprehensive network of Marine Protected Areas (MPAs) to help manage and protect these resources has become a global political priority. Efforts are currently underway to implement MPA networks in the deep North East Atlantic.

Tri-trophic consequences of UV-B exposure: plants, herbivores and parasitoids.

In this paper we demonstrate a UV-B-mediated link between host plants, herbivores and their parasitoids, using a model system consisting of a host plant Brassica oleracea, a herbivore Plutella xylostella and its parasitoid Cotesia plutellae. Ultraviolet-B radiation (UV-B) is a potent elicitor of a variety of changes in the chemistry, morphology and physiology of plants and animals. Recent studies have demonstrated that common signals, such as jasmonic acid (JA), play important roles in the mechanisms by which plants respond to UV-B and to damage by herbivores.

Do developmental mode and dispersal shape abundance-occupancy relationships in marine macroinvertebrates?

1. Dispersal is a crucial process in maintaining population structures in many organisms, and is hypothesized as a process underlying the interspecific relationship between abundance and distribution. Here we examined whether there was a link between the dispersal and developmental modes of marine macroinvertebrates and the slopes and elevations of interspecific abundance-occupancy relationships.

Herbivore-induced infochemicals influence foraging behaviour in two intertidal predators.

Herbivore-induced defences appear ubiquitous across most biomes and habitats. Yet the direct correlation between induced changes in host plant chemistry and the population dynamics of the herbivore remain untested in many systems. In plant-herbivore interactions in the terrestrial environment, indirect or tritrophic interactions appear a successful way in which changes in the host plant chemistry induced by prior herbivory can impact on herbivore populations via increased success of natural enemies.

Soil microbial and faunal community responses to bt maize and insecticide in two soils.

The effects of maize (Zea mays L.), genetically modified to express the Cry1Ab protein (Bt), and an insecticide on soil microbial and faunal communities were assessed in a glasshouse experiment. Soil for the experiment was taken from field sites where the same maize cultivars were grown to allow comparison between results under glasshouse conditions with those from field trials.

Induced resistance in intertidal macroalgae modifies feeding behaviour of herbivorous snails.

Herbivory in terrestrial and marine systems can induce changes in plant chemistry affecting the foraging behaviour of herbivores. A model based on terrestrial plant-herbivore interactions predicts herbivory-induced changes in leaf chemistry to be manifested in (1) increased herbivore mobility, (2) increased feeding dispersal and (3) reduced tissue consumption by herbivores. This study is the first to demonstrate that herbivory-induced changes in the tissue chemistry of the brown seaweed Ascophyllum nodosum elicit the same response in the feeding behaviour of the gastropod Littorina obtusata as predicted for herbivorous insects, providing good evidence for the model's validity across different ecosystems.

Root damage and water stress: treatments affecting the exploitation of the buds of common ash Fraxinus excelsior L., by larvae of the ash bud moth Prays fraxinella Bjerk. (Lep., Yponomeutidae).

Damage to the buds of the common ash (Fraxinus excelsior L.) by larvae of the ash bud moth Prays fraxinella Bjerk. was investigated in trees growing in the presence, or absence, of an adjacent ditch.