Digital library

Warming of the planet has accelerated in recent years and is predicted to continue over the next 50 to 100 yr. Evidence of responses to present warming in marine ecosystems include Shifts in the geographic range of species as well as in the composition of pelagic and demersal fish, benthic and intertidal assemblages, Here we provide a review of the changes, in geographic distributions and population abundance of species detected on rocky shores of the NE Atlantic over the last 60 yr. This period encompassed the warm 1950s, a colder period between 1963 and the late 1980s and the recent period of accelerating warming to levels above those of the 1950s. The likely consequences of these responses are then explored. To do this, a summary of the dynamic balance between grazers, macroalgae and barnacles in structuring mid-shore communities is given before outlining experimental work on interactions between key components of rocky shore communities. Modelling and quantitative forecasting were used to predict changes in community composition and dynamics in a warmer world and their consequences for ecosystem functioning discussed. We then identify areas that need further work before making a case for the use of rocky shore species not just as inexpensive indicators of change offshore, but as tractable models to explore the direct and indirect effects of climate change in marine and coastal ecosystems, We also provide a societal perspective emphasising the value of long-term Studies in informing adaptation to climate change.

Background: The hydrolysis of seaweed polysaccharides is the rate limiting step in anaerobic digestion (AD) of seaweeds. Seven different microbial inocula and a mixture of these (inoculum 8) were therefore compared intriplicate, each grown over four weeks in static culture for the ability to degrade Laminaria hyperborea seaweed and produce methane through AD.

Results: All the inocula could degrade L. hyperborea and produce methane to some extent. However, an inoculum of slurry from a human sewage anaerobic digester, one of rumen contents from seaweed-eating North Ronald say sheep and inoculum 8 used most seaweed volatile solids (VS) (means ranged between 59 and 68% used), suggesting that these each had efficient seaweed polysaccharide digesting bacteria. The human sewage inoculum, an inoculum of anaerobic marine mud mixed with rotting seaweed and inoculum 8 all developed to give higher volumes of methane (means between 41 and 62.5 ml g-1of seaweed VS by week four), compared to other inocula (means between 3.5 and 27.5 ml g-1VS). Inoculum 8 also gave the highest acetate production (6.5 mmol g-1VS) ina single-stage fermenter AD system and produced most methane (8.4 mL mmol acetate-1) in phase II of a two-stage AD system.

Conclusions: Overall inoculum 8 was found to be the most efficient inoculum for AD of seaweed. The study therefore showed that selection and inclusion of efficient polysaccharide hydrolysing bacteria and methanogenic archaea in an inoculum offer increased methane productivity in AD ofL. hyperborea. This inoculum will now beingtested in larger scale (10L) continuously stirred reactors optimised for feed rate and retention time to determinemaximum methane production under single-stage and two-stage AD systems

This study compares the environmental performances of two protein sources for aquafeed production: Brazilian soy protein and Norwegian seaweed protein concentrates. The efficiency and sustainability of these two production systems are assessed using a comparative material and substance flow analysis accounting for the transfers of primary energy and phosphorus. The primary energy and phosphorus demand of 1 t of soy protein concentrate is compared to 2 t seaweed protein concentrate to assess commodities with similar protein contents. The primary energy consumption of the latter protein source (172,133 MJ) is found 11.68 times larger than for the soy-based concentrate (14,733 MJ). However, the seaweed protein energy requirement can be reduced to 34,010 MJ if secondary heat from a local waste incineration plant is used to dry the biomass during the late-spring harvest. The seaweed system out- performed the soy system regarding mineral phosphorus consumption since 1 t of soy protein requires 25.75 kg mineral phosphorus while 2 t of seaweed protein require as little as 0.008 kg input. These results indicate that substituting soy protein with seaweed protein in aquafeed leads to an environmental trade- off. The seaweed value chain produces proteins with near zero mineral phosphorus consumption by using naturally occurring marine phosphorus while the soy value-chain produces proteins for roughly 1/ 12th of the primary energy required by seaweed. Based on the current production technology, the seaweed value-chain will require extensive innovation and economies of scale to become energy competitive. Further research should investigate the predictive environmental impacts of a fully developed seaweed protein concentrate value-chain and account for the background emissions and multi-functionality in each system.