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The production of blue mussels is currently reliant upon supply of wild larvae, which is a limiting factor to upscaling production. A potential solution to address this limiting factor is to develop a larval hatchery; however, costs associated with microalgal cultivation to feed the larvae account for around 30% of total costs. Microalgae are classically considered to be photoautotrophic and are cultured under light, in seawater with additional nitrate and phosphate. Many microalgae can be cultured mixotrophically, or heterotrophically, on an organic carbon source which results in an enhanced cell density and altered biochemical profile. Over the course of two feeding trials this study compares larval growth and survival employing current “industry standard” and mixotrophic “designer” microalgal feeds as diets. The “designer” feed employed proved to be as effective as the standard feed and subsequent optimisation demonstrated that a diet tailored towards the development of the larvae performs the most effectively in terms of larval growth. A sequential diet of mixotrophically cultured microalgae, where the primary component of the diet changed as the larvae increased in size, resulted in the greatest larval growth (174.35 μm) and total fatty acid content (7.20% dry weight). First-order modelling indicates that approximately ten times lower volume of mixotrophically cultivated microalgae was required to produce sufficient larval feed. Thus, mixotrophic culture has the potential to reduce the costs of microalgal cultivation and increase the profitability of a mussel larval hatchery.

Changes in the partitioning of dissolved inorganic (DIC) and glucose were elucidated by utilising 13C labelled DIC or glucose, and quantifying the biochemical profile of mixotrophic, heterotrophic and photoautotrophic cultures of the microalga Tetraselmis suecica. Mixotrophic cultivation increases microalgal productivity and changes their biochemical profile, due to an alteration in the partitioning of carbon within the cell. When cultured mixotrophically and heterotrophically, there is enhanced incorporation of carbon into shorter chain saturated fatty acids and non-lipid biomass, compared to photoautotrophic cultivation. Autotrophic culture results in increased total fatty acid content of cultures (4.19% dry weight compared to 2.13%) and shifts the fatty acid profile in favour of long-chain unsaturated fatty acids, such as 18:2 n-(9,12), compared to mixotrophic culture. Quantifying the changes in partitioning between DIC and glucose facilitates tailoring of the biochemical profile to develop “designer” algae. There is a condition specific shift in carbon partitioning into different fatty acid and biochemical fractions in T. suecica, with more inorganic carbon partitioned into 18:2 n-(9,12) in photoautotrophic rather than mixotrophic cultures.

Sustainable expansion of global aquaculture depends on a thorough understanding of environmental impacts. Open-water culture operations produce waste food and faeces, the benthic impacts of which are a focus of regulation. Seabed interactions of wastes are complex, depending on current velocity, seabed substrate and waste material characteristics. The accuracy achieved in modelling intensity and spatial extent of impacts is contingent upon the representation of this interaction and its implications for resuspension. We used benthic flumes to study resuspension processes at 11 salmon aquaculture sites, covering a range of sediment types. Erosion rates and critical entrainment stress were computed at the cage edge and between 100 and 500 m away, characterising seabed erodibility in highly impacted and less impacted sediments. Heavily impacted cage-edge sediments had an erosion threshold (mean 0.02 N m-2) that was an order of magnitude lower, and markedly less heterogeneous, than that of nearby less impacted sediments (mean across sites 0.19 N m-2). This likely reflects a seabed which was smothered by waste material close to the depositional centre. Further out, the covering of waste material is less continuous, thinner, and more admixed with underlying sediments. Bed erosion rates were found to be a linear function of excess stress. The results provide important information on how benthic flumes can be deployed to collect spatial and temporal data for parameterisation of erosion and entrainment processes in numerical waste transport simulation models such as DEPOMOD, and the comparatively large field-based dataset should contribute to the goal of allowing a more realistic representation of particulate waste in these models.

The continuing expansion of seaweed cultivation could assist in ensuring future global food security. The Laminariales species Alaria esculenta and Saccharina latissima are each cultivated for food across their European ranges. The predominant method for cultivating European kelps involves growing juveniles on twine within a hatchery which is then deployed at a farm site. The associated hatchery and deployment cost of this approach are relatively high. A new and innovative methodology—called binder-seeding—can reduce these costs, but, has yet to be validated. We compare the biomass yield and morphology of A. esculenta and S. latissima cultured using either the traditional twine-longline method or binder-seeding onto AlgaeRope and AlgaeRibbon, specially designed textiles. In a controlled growth experiment, A. esculenta had a similar biomass yield on all materials, but fronds were shorter (23 ± 7%) and thinner on the AlgaeRibbon (42 ± 4%) due to a 3–4-fold higher density of developing sporophytes compared to the twine-longline. In contrast, S. latissima gave a 4-fold higher biomass yield on the AlgaeRibbon in June (4.0 kg m−1), but frond morphology was not different between materials, despite a 4-fold higher sporophyte density on the AlgaeRibbon. The stipe length of both species also increased at the higher sporophyte density on the AlgaeRibbon. The AlgaeRope gave an intermediate response or was similar to the twine-longline. These results show that binder-seeding onto the AlgaeRibbon significantly increases the achieved biomass yield in S. latissima. These results can assist cultivators to select the most appropriate method of kelp cultivation depending on morphological/yield requirements of the end use. Further study is needed on the optimisation of the binder-seeding density and its impact on thallus morphology.

Aquaculture and marine renewable energy are two expanding sectors of the Blue Economy in Europe. Assessing the long-term environmental impacts in terms of eutrophication and noise is a priority for both the EU Water Framework Directive and the Marine Strategy Framework Directive, and cumulative impacts will be important for the Maritime Spatial Planning under the Integrated Maritime Policy. With the constant expansion of aquaculture production, it is expected that farms might be established further offshore in more remote areas, as high-energy conditions offer an opportunity to generate more power locally using Marine Renewable Energy (MRE) devices. A proposed solution is the co-location of MRE devices and aquaculture systems using Multi-Purpose Platforms (MPPs) comprising offshore wind turbines (OWTs) that will provide energy for farm operations as well as potentially shelter the farm. Disentangling the impacts, conflicts and synergies of MPP elements on the surrounding marine ecosystem is challenging. Here we created a high-resolution spatiotemporal Ecospace model of the West of Scotland, in order to assess impacts of a simple MPP configuration on the surrounding ecosystem and how these impacts can cascade through the food web. The model evaluated the following specific ecosystem responses: (i) top-down control pathways due to distribution changes among top-predators (harbor porpoise, gadoids and seabirds) driven by attraction to the farming sites and/or repulsion/killing due to OWT operations; (ii) bottom-up control pathways due to salmon farm activity providing increasing benthic enrichment predicated by a fish farm particle dispersal model, and sediment nutrient fluxes to the water column by early diagenesis of organic matter (recycled production). Weak responses of the food-web were found for top-down changes, whilst the results showed high sensitivity to increasing changes of bottom-up drivers that cascaded through the food-web from primary producers and detritus to pelagic and benthic consumers, respectively. We assessed the sensitivity of the model to each of these impacts and the cumulative effects on the ecosystem, discuss the capabilities and limitations of the Ecospace modeling approach as a potential tool for marine spatial planning and the impact that these results could have for the Blue Economy and the EU’s New Green Deal.

The predominant method used for the cultivation of European kelp involves seeding onto twine spools. The selection of a suitable twine is essential. In four experiments, synthetic and natural polymer twines were seeded with either meiospore or juvenile sporophytes of Saccharina latissima. Development was monitored over both the hatchery and outplanting phase at an experiment seaweed farm, Scotland, UK. Twisted twine seeded with meiospores gave 37 ± 21% higher biomass yield than the braided form, despite 46 ± 10% lower sporophyte density during the hatchery period. Twisted twine was also more favourable when sporophyte seeding, increasing juvenile retention by 140%. Three-month-old sporophytes had 50% weaker bioadhesion on polyamide (PA), polyester (PES) and polypropylene (PP) compared to polyvinyl alcohol (PVA). This was reflected in 11–24% higher biomass on PVA following outplanting. However, if the twine surface was treated by corona discharge before seeding, PA, PES and PP achieved an equivalent biomass to PVA. Jute and sisal twine had a toxic effect on the development of meiospores. In contrast, seeding with sporophytes was successful onto jute and sisal, but bioadhesion was weak. Finally, cotton was moderately toxic to meiospores but also had a bioadhesion strength and biomass yield comparable to PVA. We conclude that PVA and corona-treated synthetic twines are excellent for either meiospore or sporophyte seeding. Cotton is a very promising biodegradable twine, although further research is needed to optimise its physical structure. We also conclude that results during the hatchery period do not predict the success of seeded twine following outplanting.

Benthic macroalgae must attach firmly to the substrate to prevent being detached and washed away by water motion. The success of the bioadhesion system can be strongly influenced by surface...

There is growing concern about the impact of rising nutrient loading on aquatic ecosystems and on human health, due to increased urbanisation and associated sewage effluents. This has led to a policy focus on land-use change or agricultural practice change as nutrient mitigation strategies, but these fail to consider the ultimate downstream receiving environments such as marine ecosystems. Within the UK there has been increasing recognition that housing density in certain sensitive locations is impacting the conservation status of marine features, through the increase in nutrient loading to the marine environment. In order to comply with the statutory obligations to protect these marine features, the competent authorities have required developers to mitigate the impact of these additional nutrients. Current approaches include converting agricultural land to woodland and wetland habitats that release less nitrogen than the agricultural land they replace. This difference is used to offset the nutrient loading from the new development, but such a terrestrial-focused catchment-based mass balance approach has a number of limitations. Current solutions for nutrient neutrality in the UK take a narrow land-focused approach that fails to acknowledge the potential contribution of the marine environments to mitigate nutrient enrichment. We propose that marine nature-based solutions offer an economically and ecologically viable alternative to terrestrial schemes, that can reduce the nitrogen loading to the marine environment, increase ecosystem service provision and increase biodiversity.

Systemic therapies targeting transforming growth factor beta (TGFβ) or TGFβR1 kinase (ALK5) have been plagued by toxicities including cardiac valvulopathy and bone physeal dysplasia in animals, posing a significant challenge for clinical development in pulmonary indications. The current work aims to demonstrate that systemic ALK5-associated toxicities can be mitigated through localized lung delivery. Lung-selective (THRX-144644) and systemically bioavailable (galunisertib) ALK5 inhibitors were compared to determine whether lung selectivity is sufficient to maintain local tissue concentrations while mitigating systemic exposure and consequent pathway-related findings. Both molecules demonstrated potent ALK5 activity in rat precision cut lung slices (PCLS; p-SMAD3 half-maximal inhibitory concentration [IC50], 141 nM and 1070 nM for THRX-144644 and galunisertib, respectively). In 14-day repeat-dose studies in rats, dose-related cardiac valvulopathy was recapitulated with oral galunisertib at doses ≥150 mg/kg/day. In contrast, inhaled nebulized THRX-144644 did not cause similar systemic findings up to the maximally tolerated doses in rats or dogs (10 and 1.5 mg/kg/day, respectively). THRX-144644 lung-to-plasma ratios ranged from 100- to 1200-fold in rats and dogs across dose levels. THRX-144644 lung trough (24 h) concentrations in rats and dogs ranged from 3- to 17-fold above the PCLS IC50 across tolerated doses. At a dose level exceeding tolerability (60 mg/kg/day; 76-fold above PCLS IC50) minimal heart and bone changes were observed when systemic drug concentrations reached pharmacologic levels. In conclusion, the current preclinical work demonstrates that localized pulmonary delivery of an ALK5 inhibitor leads to favorable TGFβ pathway pharmacodynamic inhibition in lung while minimizing key systemic toxicities.

“Blue Growth” and “Blue Economy” is defined by the World Bank as: “the sustainable use of ocean resources for economic growth, improved livelihoods and jobs, while preserving the health of ocean ecosystem”. Multi-purpose platforms (MPPs) can be defined as offshore platforms serving the needs of multiple offshore industries (energy and aquaculture), aim at exploiting the synergies and managing the tensions arising when closely co-locating systems from these industries. Despite a number of previous projects aimed at assessing, from a multidisciplinary point of view, the feasibility of multipurpose platforms, it is here shown that the state-of-the-art has focused mainly on single-purpose devices, and adopting a single discipline (either economic, or social, or technological, or environmental) approach. Therefore, the aim of the present study is to provide a multidisciplinary state of the art review on, whenever possible, multi-purpose platforms, complementing it with single-purpose and/or single discipline literature reviews when not possible. Synoptic tables are provided, giving an overview of the multi-purpose platform concepts investigated, the numerical approaches adopted, and a comprehensive snapshot classifying the references discussed by industry (offshore renewables, aquaculture, both) and by aspect (technological, environmental, socio-economic). The majority of the multi-purpose platform concepts proposed are integrating only multiple offshore renewable energy devices (e.g. hybrid wind-wave), with only few integrating also aquaculture systems. MPPs have significant potential in economizing CAPEX and operational costs for the offshore energy and aquaculture industry by means of concerted spatial planning and sharing of infrastructure.

Meiospores of Laminariales macroalgae must select a benthic substratum suitable for their attachment and survival, but also suitable for the development of the sessile sporophyte stage which can grow metres in length. In a controlled four month experiment, meiospores of Saccharina latissima were allowed to settle and develop on twelve different polymer surfaces. Highest meiospore settlement was seen where the attachment force of the developing macroscopic sporophytes was weak (

The macroalga Saccharina latissima holds promise as a widespread crop in northern Europe. Currently, seeded lines are cultured for 1–2 months within a hatchery until they become ≥1 mm sporophytes, which are then outplanted to a farm. Textiles are being developed as a cultivation substrate for macroalgae, however due to their large surface area, these need either direct in-situ seeding at the farm or a very short, high turnover hatchery period. Two materials, Kuralon twine and non-woven textile, were seeded using three S. latissima developmental stages: meiospore, gametophyte or juvenile sporophyte. The gametophyte and sporophyte stages were applied using a binder solution to adhere them to the materials. These were outplanted at a seaweed farm in the Sound of Kerrera, UK. After 5 weeks, fronds were significantly larger (45 ± 25 mm) and more abundant (20 ± 8·20 cm−1) when seeded with sporophytes over gametophytes or meiospores (8 ± 10 mm and 2 ± 2·20 cm−1). This reflects the growth advantage of outplanting juvenile sporophytes, since they are larger and more developed when outplanted. Higher fouling of filamentous algae was seen on the non-woven textile but this did not appear to affect growth. After four months, sporophyte seeded materials had the largest fronds and the greatest fresh mass of 2.1 ± 0.8 kg·20 cm−1, equivalent to simultaneously deployed hatchery reared twine (2.0 ± 0.1 kg·20 cm−1). Gametophyte seeding achieved 0.8 ± 0.6 kg·20 cm−1 while meiospore seeding achieved only 0.1 ± 0.1 kg·20 cm−1. No difference was found between growth on Kuralon twine or non-woven textile (p > 0.05), showing that both are suitable growth substrates. Seeding of juvenile sporophytes onto textile using the binder is demonstrated to be a successful method for the cultivation of S. latissima, and may require only 1% of the hatchery tankage, once optimised. It is expected that this method is transferable to the cultivation of other kelp species.

The phaeophyte macroalgae Sargassum muticum is under investigation as a cultivation crop within its native range in SE Asia, alongside other members of the Sargassum genus. During the critical hatchery phase, germlings are grown to ≥ several millimeters ready for outplanting. By optimising the growth medium and twine substrate used for the germling attachment, hatcheries can become more efficient and cost-effective. An 8-week replicated laboratory experiment investigated these factors. It found that adding 0.125 mL L−1 of saturated germanium dioxide during the first week increased mean germling size by 23% (p 0.05). Six twine substrates were also tested: jute, cotton, polyamide/cotton, polyester, polyvinyl alcohol and polypropylene. Sargassum muticum grew similarly well on all, although attachment success during the first week was highest on the rougher natural fibres, particularly jute. A negative density-dependent effect of germling density on growth was seen across all materials, with the highest growth seen on the materials with the lowest germling density. Jute is recommended as a highly suitable substrate for hatchery cultivation in this species, although the initial density should be carefully controlled to prevent intraspecific competition.

Technology transfer and development is a key requirement for many research funders, yet there is a real paucity of scientifically documented evidence on how this transition is made and how it can be made more effective. The study described here details the experiences of an informal ‘community of practice’ working across research and commercialisation to set up and run a number of integrated multi-trophic aquaculture (IMTA) systems (innovative food systems addressing environmental impacts of traditional aquaculture) across Europe. Interviews were undertaken with seven European aquaculture companies across six countries (Cyprus, Ireland, Italy, Israel, Norway and Scotland), each of which were involved with the IDREEM project ( www.idreem.eu ) which paired aquaculture businesses and research institutions in strategic partnerships to promote rapid implementation of IMTA. This study revealed three main shared experiences: the lack of an existing process for licensing IMTA sites and the temporal hold this put on obtaining a license; issues due to environmental constraints, including storms; and problems of drying and storing for those working with algae. Furthermore, three key lessons were learnt by those involved: the importance of choosing extractive IMTA species based on what is endemic to the area; identifying the correct system configuration may take a lot of trial and error, but simplicity is crucial; a key process was ‘learning by doing’ and a range of skills are required. We conclude that the development of a formal ‘community of practice’, a knowledge-sharing platform where all those engaging in IMTA can work together, would enable further unique insight and innovation in the process. Statement of significance Communities of practice arise from collective learning by individuals or organisations in a shared domain. This paper describes the shared experiences and lessons learnt by one such community, composed of seven aquaculture SMEs implementing integrated multi-trophic aquaculture (IMTA) systems. In doing so, it provides guidance to those wishing to develop commercial scale IMTA in Europe.

For the cultivation of the European phaeophyte macroalgae Laminaria digitata and Saccharina latissima , meiospores are settled onto twines within a hatchery, where they are grown for several months. The twine used is often a customarily selected synthetic polymer, polyamide or polypropylene. However, little is known about the impacts of this choice on hatchery performance. To test the effect of substrate material, we settled and cultured meiospores from both L. digitata and S. latissima , independently on twelve polymer blocks for 4 mo. They were first grown for 2 mon under laboratory conditions, then a further 2 mon in outdoor tanks. Meiospore settlement varied significantly between polymers by up to 15-fold ( p p − 2 , A negative density-dependent effect of sporophyte size and density was observed in both species ( p S. latissima . Those that initially had very high settlement (high density polyethylene, polymethyl methacrylate, polyoxymethylene copolymer/homopolymer and polytetrafluoroethylene) had the lowest final mean lengths, % cover and biomass ( − 1 ) at the end of the experiment. Conversely many of the polymers with the lowest initial settlement (polyamide, polycarbonate, medium density polyethylene and polyvinylchloride) had the highest final mean lengths, % cover and biomass (1.7–4.9 g wet weight·block − 1 ). This reversal of fortunes is discussed regarding discriminatory meiospore settlement, differences in apparent adhesion strength of the seaweed holdfast and the transition of the growing sporophytes from a viscous force dominated boundary layer environment to a turbulent dominated environment with increasing drag as the sporophyte grows.

Blue mussels (Mytilus edulisL.) are important components of coastal ecosystems functioning through benthopelagic coupling and ecosystem engineering. At the same time, mussel production is central in the economy of coastal areas. Therefore, understanding their nutritional, physiological and metabolic processes at key life stages is important for their management, both within food production systems and in wild populations.Lipids are crucial molecules for bivalve growth, but their diversity and roles have been considered from fatty acid (FA) perspective. In this paper, we applied lipidomics to bivalve nutrition. Lipidomics provides a holistic perspective on lipid patterns; by examining the lipidome, important physiological information can be acquired. Here, we use controlled laboratory experiments to elucidate the responses to changes in the diet of newly settled mussels juveniles, one of the most critical life stages. The diets considered in this study are single strains diet ofCylindrotheca fusiformisCCAP 1017/2 – CYL,Isochrysis galbanaCCAP 927/1– ISO,Monodopsis subterraneanCCAP 848/1 – MONO,Nannochloropsis oceanicaCCAP 849/10– NANNO and a commercial algae paste –SP.The diets had a significant effect on spat GR and WI, and according to their efficacy resulted ranked as follows: ISO>NANNO/CYL>SP>MONO. Spat FA composition and neutral lipid content (principally triacylglycerols - TG), were influenced by the diets. Furthermore, untargeted lipidomics also showed shifts in several phospholipid species, with changes related to the essential PUFA available from the diet. TG content, neutral lipids and several TG and FA species were correlated (Spearman R2>0.8 FDR p

Cultivation of kelp has been well established throughout Asia, and there is now growing interest in the cultivation of macroalgae in Europe to meet future resource needs. If this industry is to become established throughout Europe, then balancing the associated environmental risks with potential benefits will be necessary to ensure the carrying capacity of the receiving environments are not exceeded and conservation objects are not undermined. This is a systematic review of the ecosystem changes likely to be associated with a developing seaweed aquaculture industry. Monitoring recommendations are made by risk ranking environmental changes, highlighting the current knowledge gaps and providing research priorities to address them. Environmental changes of greatest concern were identified to include: facilitation of disease, alteration of population genetics and wider alterations to the local physiochemical environment. Current high levels of uncertainty surrounding the true extent of some environmental changes mean conservative risk rankings are given. Recommended monitoring options are discussed that aim to address uncertainty and facilitate informed decision-making. Whilst current small-scale cultivation projects are considered ‘low risk’, an expansion of the industry that includes ‘large-scale’ cultivation will necessitate a more complete understanding of the scale dependent changes in order to balance environmental risks with the benefits that seaweed cultivation projects can offer.

New research is currently underway to explore the potential of macroalgae for the production of biofuels. Marine biofuels in general and macroalgae in particular, offer a number of advantages over terrestrial biofuels including reduced competition for freshwater resources and for land use. Sugars can be extracted from macroalgae and processed into biofuels by anaerobic digestion and fermentation. This process generates significant waste biomass, which, if used, could improve the economic sustainability of the biorefinery sector. Bivalves' aquaculture relies heavily on the production of unicellular algae to feed juvenile individuals and this can represent a bottleneck for the bivalve industry especially in locations where sunlight is limited. Previous research explored the use of macroalgae derived digestate as alternative or integrative feed for juvenile bivalves, exploiting the notion that organic particulate matter (detritus) is an integral part of this animal class natural diet. The prospect of using waste products from the emerging biorefinery industry to solve a bottleneck for aquaculture businesses and, by so doing, improving profitability of both, is an exciting one. In this paper we describe the main nutritional profiles (Protein, Lipid, Carbohydrates and Fatty acids) of the tested diets and investigate the potential for the use of a biorefinery a by-product as replacement option for bivalves' production, by benchmarking it against aquaculture industry standards (live microalgae and commercially available algae paste) and natural detritus constituted by farmed sea urchin digesta. Both the digestate and the natural detritus supported the survival and growth of bivalve spat, especially when used at 50% inclusion rate, over the course of 4-week preliminary trials. Data suggest that a synergistic effect of the nutritional profiles of the diets employed may underpin the observed results. Statement of relevance With this study we compare the biochemical composition and suitability as oyster feed of the Single Cell Detritus produced by S. latissima enzymatic saccharification and natural detritus produced by sea urchin digestive action, with live microalgae as well as commercial algae paste. A comparison between biochemical composition and suitability as aquaculture feed between biorefinery by-products and natural detritus was, to our knowledge, lacking. Results indicate that both the digestate and the natural detritus supported the survival and growth of oyster spat, especially when used at 50% inclusion rate, over the course of 4-weeks trial.

There has been significant interest in the development of integrated multi-trophic aquaculture (IMTA) in Europe. Much of this interest has come from academia and regulators, and while elements within the European aquaculture industry have expressed an interest, to date, the adoption of the concept has been limited. Part of the attraction for regulators and academics is the ecological/economic win/win that is associated with eco-innovation solutions. However, if we are to understand why there has been limited uptake of IMTA in Europe, perhaps it is necessary to look at the issue in terms of trade-offs for the individual farmer or company. Using this viewpoint, we investigate the balance of trade-offs for the individual farmer or company to diversify from a traditional fin-fish production business into an IMTA system. In doing so, we reveal that the bal- ance of trade-offs is currently not sufficiently positive to motivate the large-scale uptake of IMTA in Europe, and we contrast this against the situation in Asia where the balance of trade-offs gives better support for the adoption and practice of IMTA. By better understanding the trade-offs for the individual, it is possible to better understand the conditions that will promote the development of IMTA in Europe.

Mixotrophy, in marine microalgae, is the ability to uptake organic nutrients from the environment, in addition to, or as an alternative to, fixation of carbon through photosynthesis. Many microalgae are capable of mixotrophic and heterotrophic growth, which can be used to maximise culture density, while theoretically lowering production costs compared to photoautotrophy. Here we show that, following screening of three microalgal species for mixotrophic and heterotrophic growth, Tetraselmis suecica and Cyclotella cryptica were capable of mixotrophic growth on glycerol, glucose and acetate and heterotrophically on glucose. Phaeodactylum tricornutum could only be cultured mixotrophically, but when cultured on glycerol cell density increased fourfold compared to photoautotrophic culture. Carbon allocation changed dependent upon carbon source and time of harvesting, with mixotrophic culture of P. tricornutum on glycerol resulting in lower cell length and increased total fatty acid content. These changes can be utilised in the development of a ‘designer alga’.

Fisheries products are globally traded commodities, which have led to varying degrees of social and economic dependency for producing regions. These dependencies become more evident at times of major demand or supply shocks. Resilience to such shocks is intertwined with, and rooted in, the intra-sectoral structure and governance frameworks. This work analyses two large-scale, capital-intensive and export-oriented seafood sectors: Atlantic salmon and North-east Atlantic mackerel, responded to the environmental, economic and geopolitical shocks accompanying their development, from a UK perspective. Intra-firm controls are identified as elements, which have delivered resilience and strength in these two sectors. This work highlights the central, yet different role of the UK government in increasing their resilience and underlying producing regions. Our work contributes to the broader context of regional development and changing global food demand identifying both domestic and external threats to sustainability. Our approach aims to expand the debate around seafood production from ‘food security’ to a transdisciplinary analysis, which incorporates wider economic, social, and ecological sustainability aspects.

Three formulated diets were tested to evaluate their effects on gonad quality in Paracentrotus lividus. Experiments were conducted in parallel by the Consiglio Nazionale delle Ricerche (CNR) of Taranto (trial 1) and the University of Genoa (trial 2), in land-based systems. In both trials, somatic and gonadsomatic index (GSI) were measured and the nutritional profile of the sea urchins has determined significant variations in the biochemical composition. Sea urchins fed the experimental diets contained higher levels of nutrients (protein and lipid and carbohydrate) compared to wild sea urchins. However, total polyunsaturated fatty acids (PUFAs), especially EPA and DHA, and the n-3/n-6 ratio were lower in urchins fed with formulated diets. In both trials, sea urchins fed with diet 2 (SABS) showed a similar profile with PUFAs higher than SAFAs and MUFAs, the highest UNS/SAT ratio, although the highest n3/n6 ratio was observed in the group fed diet 3 (CNR). Atherogenicity, thrombogenicity, and hypocholesterolemic/hypercholesterolemic indices showed the best values in sea urchins fed diet 2 in both trials.

Through increased interest in the use of macroalgae for biofuel production, the concept of a biorefinery approach has been developed to improve its economic viability. This paper looks at the use of seaweed residue after enzymatic saccharification of the seaweeds Saccharina latissima, Alaria esculenta and Ulva lactuca as a novel feed component for the aquaculture industry. Chemical composition analysis was used to evaluate the impact of enzymatic treatment on the nutritional aspect of seaweed residue. During saccharification, the relative ash and carbohydrate content was reduced, but total nitrogen, total carbon and lipid content increased in all three species. In addition, the saccharification of S. latissima and A. esculenta resulted in the elimination of polyphenols, further enhancing the nutritional value of the residue. The residue supported the survival and growth of bivalve spat and commercially valuable sea urchins over the course of 3-week preliminary trials.

Phaeophyte macroalgae of the genus Sargassum, including Sargassum muticum, are under investigation as a cultivation crop. Overgrowth or grazing reduces the value and productivity of the crop. This can occur both in the hatchery and during growth at sea, although juvenile stages are especially vulnerable. A decontamination protocol could be used to prevent this. Following a screening procedure, sodium hypochlorite (NaClO) and potassium iodide (KI) were selected for further study. The lethal concentrations for protozoans associated with S. muticum zygotes were 1 % KI, 0.75 % NaClO or a combination of 0.5 % KI and 0.38 % NaClO. A 3-min exposure to these treatments was able to eliminate protozoa from branchlets 20–80 % of the time. NaClO caused large reductions in the operating efficiency of photosystem II (Fq ’/Fm ’), particularly in juveniles (74 ± 17 %), which had still not fully recovered after 17 days. This also halved juvenile density and caused negative growth. One percent KI reduced Fq ’/Fm ’ in adults by 29 ± 11 %, with recovery by day 10. In juveniles, growth was reduced by 65 % and Fq ’/Fm ’ by 61 ± 11 % with recovery after 17 days. A combined treatment of 0.5 % KI and 0.38 % NaClO had far milder effects: reducing adult and juveniles Fq ’/Fm ’ by 6 ± 3 and 34 ± 9 % respectively, with full recovery by day 10. A reduction in juvenile growth was also seen between day 0–10 (32 %); however, size was no different to the control by day 20. This combined treatment is therefore suitable for decontamination of both juveniles and adult S. muticum tissue.

Seaweeds are receiving increasing attention as third generation biofuels, which do not compete for land or freshwater with agricultural crops and have a high polysaccharide content. Seaweed growth is dependent on the presence of suitable physical and chemical conditions. The selection of cultivation sites with suitable characteristics is therefore essential for the successful establishment of European seaweed mariculture. The growth conditions of the site directly impact the biomass yield and composition of the crop, which in turn control the conversion efficiency of biomass to bioenergy. This review focuses on three European brown phaeophyte kelp species which may be suitable for large-scale offshore cultivation: Laminaria digitata , Saccharina latissima and Sacchoriza polyschides . It describes the known responses of each to a number of important physical and chemical parameters: temperature, salinity, water motion, nutrient concentrations, carbon dioxide/pH, light and ultra-violet radiation. It also reports density effects on their growth rate and what is known concerning the impact of disease and grazing. Conclusions are made on the conditions necessary for the optimal growth of each species for biofuel production. Where conditions are sub-optimal, this review has made recommendations for the most suitable species for a particular set of environmental conditions.

The phaeophyte macroalga Saccharina latissima is gaining economic importance as an aquaculture crop. To decrease costs associated with the hatchery, the time required for meiospores to develop into sporophytes ready for outplanting must be minimised and survivorship maximised. The settlement and juvenile development of S. latissima was examined in a series of experimental manipulations. It was determined that (1) Meiospore settlement should be conducted in the dark in nutrient-enriched medium. (2) Continued nutrient enrichment in the hatchery increased growth and survival of the developing sporophytes. (3) It is best to use the diatom inhibitor germanium dioxide only during settlement and the first week of light exposure, rather than continuously or not at all. This treatment leads to the highest survival rate and sporophyte length. (4) Pre-treating the settlement surface with a commercial yeast extract can increase settlement and early development size; however, over-application can be highly detrimental leading to reduced survival, size and patchy growth.

Coral skeletal δ13C can be a paleo-climate proxy for light levels (i.e., cloud cover and seasonality) and for photosynthesis to respiration (P/R) ratios. The usefulness of coral δ13C as a proxy depends on metabolic isotope effects (related to changes in photosynthesis) being the dominant influence on skeletal δ13C. However, it is also influenced by kinetic isotope effects (related to calcification rate) which can overpower metabolic isotope effects and thus compromise the use of coral skeletal δ13C as a proxy. Heikoop et al. (2000) proposed a simple data correction to remove kinetic isotope effects from coral skeletal δ13C, as well as an equation to calculate P/R ratios from coral isotopes. However, despite having been used by other researchers, the data correction has never been directly tested, and isotope-based P/R ratios have never been compared to P/R ratios measured using respirometry. Experimental coral bleaching represents a unique environmental scenario to test this because bleaching produces large physiological responses that influence both metabolic and kinetic isotope effects in corals. Here, we tested the δ13C correction and the P/R calculation using three Pacific and three Caribbean coral species from controlled temperature-induced bleaching experiments where both the stable isotopes and the physiological variables that cause isotopic fractionation (i.e., photosynthesis, respiration, and calcification) were simultaneously measured. We show for the first time that the data correction proposed by Heikoop et al. (2000) does not effectively remove kinetic effects in the coral species studied here, and did not improve the metabolic signal of bleached and non-bleached corals. In addition, isotope-based P/R ratios were in poor agreement with measured P/R ratios, even when the data correction was applied. This suggests that additional factors influence δ13C and δ18O, which are not accounted for by the data correction. We therefore recommend that the data correction not be routinely applied for paleo-climate reconstruction, and that P/R ratios should only be obtained by direct measurement by respirometry.

Lipids are key biomolecules within the coral holobiont, serving as energy reserves and promoting bleaching tolerance. To better understand the physiological implications of bleaching and recovery on lipid acquisition and storage, an isotope pulse-chase labeling experiment was conducted on treatment (bleached) and control (non-bleached) Hawaiian corals Porites compressa and Montipora capitata after 1 and 11 months on the reef. After 1 month on the reef, 75% of the carbon in newly acquired lipids in treatment corals of both species was heterotrophic in origin, which is two times higher than that in control corals. However, stored lipids in both treatment and controls were hugely dominated by heterotrophic C in P. compressa (i.e., 75–100%) and by photoautotrophic C in M. capitata (i.e., 90–100%). After 11 months on the reef, elevated levels of heterotrophic C input in lipid acquisition and storage were only seen in treatment P. compressa . Many previously measured physiological parameters are recovered in P. compressa after 8 months, suggesting that the need for increased heterotrophic C input for lipids appears to last beyond recovery of all other parameters, indicating that P. compressa is not yet fully recovered even after 11 months. In M. capitata , lipid acquisition and storage were 28–52% heterotrophic in origin and 48–72% photoautotrophic and, along with many previously measured physiological parameters, were fully recovered after 11 months on the reef. However, the evidence suggests that carbohydrate and possibly protein acquisition was not fully recovered even after 11 months. These species-specific differences in lipid acquisition and storage mechanisms, and response patterns to temperature stress indicate that corals may take more than 11 months to recover from bleaching and that heterotrophic carbon is critical to coral lipids, especially when bleached.

International audience; * To meet the Convention on Biological Diversity's Aichi Target 11 on marine biodiversity protection and Aichi Target 6 on sustainable fisheries by 2020, as well as the Sustainable Development Goal (SDG) 2 on food security and SDG 14 on oceans by 2030, there is an urgent need to rethink how best to reconcile nature conservation and sustainable development. * This paper argues for effective governance to support processes that apply principles of sustainable development and an ecosystem approach to decide about economic activities at sea such as aquaculture. It describes opportunities, benefits and synergies between aquaculture and MPAs as a basis for wider debate. The scope is not a comprehensive analysis of aquaculture and MPAs, but rather to present examples of positive interactions between aquaculture activities and MPAs. The unintended negative consequences are also discussed to present balanced arguments. * This work draws from four workshops held in 2015 and 2016 and used to collect information from about 100 experts representing various sectors and perspectives. * It is recognized that aquaculture is an important activity in terms of sustainable development. It can play a role in providing food security, poverty alleviation and economic resilience, in particular for MPA local communities, and contribute to wild stock enhancement, as an alternative to overfishing and for providing services to the ecosystem. * This study showed that there is a need from both aquaculture and MPA sides for clarity of objectives and willingness for open and extensive dialogue. The paper concludes by describing a number of tools and methods for supporting greater synergies between aquaculture and MPAs. * The results from this work have already helped to build a common understanding between conservation and aquaculture and initiate a rapprochement for increasing synergies.

Pigments were extracted from tests of individual sea urchins, Psammechinus miliaris , collected from a sea loch in Scotland. The extracts were red brown-to-orange in colour and yielded UV spectra with maxima at 475, 320 and 270 nm characteristic of polyhydroxylated naphthoquinone pigments (PHNQs) identified in other sea urchins. The yield of total phenols from the tests was relatively low (1–2 mg/g dry weight) but in line with levels found in tests from other sea urchin species. The extracts displayed reasonable antioxidant capacity assayed using the FRAP assay. After selection by solid phase extraction, the extracts were analysed by liquid chromatography-mass spectrometry (LC–MS). The LC–MS data suggested that the pigmentation was due to a range of spinochrome and echinochrome PHNQ components. Most of these components have been noted previously but there was evidence for sulphated forms which have not been identified before. The role and potential utility of these pigments in food applications is discussed.

The effects of formulated feeds on Paracentrotus lividus broodstock performances and carotenoid compositions were investigated. Performance of offspring derived from each dietary treatment was compared to determine whether maternal provisioning of nutrients affected offspring development and survival under commercial culture conditions. At the end of the experimental period (3 months), urchins were induced to spawn, relative fecundity measured, and offspring derived from each treatment were reared independently and survival up to competence assessed. Carotenoid composition of the gonads was also measured. Data showed that the highest dietary protein content significantly improved somatic growth, whereas higher lipid content increased gonadal index (GI) consistent with the use of gonads as nutrient storage in sea urchins. Nonetheless, gonad lipid concentration was not significantly different between treatments indicating that higher dietary lipid content favoured gonadal size rather than increase lipid content of the gonadal tissue. Interestingly, GI and fecundity were not correlated, although the latter may have been enhanced by dietary xanthophyll. This suggests the importance of including carotenoids in broodstock diets to enhance hatchery outputs. This study also indicated that, although broodstock diet can influence fecundity, it had no significant impact on larval survival, which could instead be influenced by rearing conditions.

The effects of dietary fatty acids on the composition of Paracentrotus lividus gonads were investigated to determine whether dietary inputs affect their relative abundance during gametogenesis. Egg and embryo FA compositions were compared with that of mature gonads to understand how maternal FA is transferred to the offspring. Urchins were fed an experimental Pellet diet in comparison to brown Kelp (Laminaria digitata). FA profiles of diets, gonads, eggs and embryos revealed the presence in gonads of FA that was absent in the diets and/or higher in contents of some long-chain polyunsaturated fatty acid (LC-PUFA). Moreover, some unusual FA, such as non-methylene interrupted (NMI), was found in gonads, eggs and embryos, but not in the diets, suggesting that P. lividus may be capable of synthesizing this FA and accumulating them in the eggs. A description of gonad FA profiles during gametogenesis is reported for the first time and data suggest that eicosapentaenoic and docosahexaenoic acids are accumulated during gametogenesis, while arachidonic acid is highly regulated and is the only LC-PUFA clearly accumulated into the eggs along with NMI. Further studies are required to determine if maternal provisioning of FA has the potential to influence sea urchin production outputs and to increase hatchery profitability.

The concept of combining bioenergy with carbon capture and storage (BECCS) has been identified as one mechanism to achieve energy production with a net negative atmospheric carbon emission. Conventional geological carbon capture and storage involves large capital outlay and recurring expense. Therefore there is increased interest in coupling biological carbon capture and sequestration with biomass production. Systems such as low-input high-diversity native grasslands and biochar production have been heralded as carbon negative biofuels. Another potential production system for bioenergy with biological carbon capture and storage (BEBCCS) is the large-scale cultivation of seaweed (macroalgae) for biofuels. Marine biofuels offer considerable advantages over terrestrial first-generation biofuels in terms of their low land use, fresh water and fertilizer requirements. In addition, they also offer considerable potential in the field of BEBCCS. Macroalgae rapidly accumulate biomass and as part of this process, a significant proportion (estimates range up to 60%) of the carbon they fix photosynthetically is released into the water. A proportion of this released dissolved organic carbon (DOC) is highly labile and enters the bacterial loop and is rapidly remineralized back to CO2. However, a proportion is known to be resistant to biological degradation and enters the refractory DOC pool. The marine DOC pool is the largest organic carbon pool on the planet and the refractory component is known to have a turnover period of 100s-1000s years. The release of refractory DOC from macroalgae combined with biofuel production offers the potential for large scale carbon negative fuel production. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd

Sea urchin gonad is a valuable food product. The world urchin harvest increased from 48 000 tonnes in 1982 to a peak of 120 000 tonnes in 1995 mainly due to the expansion of the Chilean, Canadian and US (Californian and Maine) fisheries (Andrew, Agatsuma, Ballesteros, Bazhin, Creaser, Barnes, Botsford, Bradbury, Campbell, Dixon, Einarsson, Gerring, Hebert, Hunter, Hur, Johnson, Juinio-Menez, Kalvass, Miller, Moreno, Palleiro, Rivas, Robinson, Schroetr, Steneck, Vadas, Woodby & Xiaoqi 2002). However, this was followed by a sharp decline during the late 90′s and first decade of the new millennium (Pearce 2010) mainly due to overfishing. Japan is considered as the main sea urchin consumer in 1995 importing over 6000 metric tonnes of sea urchin gonads with a value of 251 million dollars. By 2007, Japanese imports had increased by 300% (Pearce 2010). The retail price of unprocessed fresh sea urchin in Europe varies greatly depending on the season, country, species and retailer type and can vary between 0.30 and 3 € per individual, whereas the price of processed gonads can reach 150 € kg . Research on sea urchin culture has been developing rapidly, especially in Europe, to develop methods for intensive cultivation and roe enhancement of Strongylocentrotus droebachiensis, Paracentrotus lividus (Grosjean, Spirlet, Gosselin, Vaitilingon & Jangoux 1998; Bottger, Devin & Walker 2006) and Psammechinus miliaris (Kelly, Hunter, Scholfield & McKenzie 2000; Cook & Kelly 2007). Among these species, P. lividus is the most consumed in Europe and therefore it is considered as a good candidate for the diversification of European aquaculture (Grosjean et al. 1998). However, the expansion of the industry in Europe is dependant on a reliable supply of juveniles. P. lividus is highly prolific with up to 10 million eggs per female, however, larval survival, which is at best 5% of the eggs stocked under standard commercial conditions, remains a key commercial bottleneck limiting the potential development of echinoculture. Although a number of studies have investigated larval diets to improve echinoplutei survival (Pedrotti & Fenaux 1993; Kelly et al. 2000; Jimmy, Kelly & Beaumont 2003; Carcamo, Candia & Chaparro 2005; Liu, Kelly, Cook, Black, Orr, Zhu & Dong 2007; Carboni, Vignier, Tocher & Migaud 2012), there has been less effort on the optimization of rearing protocols to improve larval survival. Rearing systems used for sea urchin larviculture usually involve a static system with complete water exchange every 2 or 3 days (Pedrotti & Fenaux 1993; Kelly et al. 2000; Liu et al. 2007). However, already in 2000, Russell described the potential advantages of flow through system for echinoplutei rearing. Moreover, it has been demonstrated in many other marine species, such as Abalone, Haliotis sp. (Olin & McBride 2000), Lobster Hommarus gammarus (Olin 2000) and bivalves, such as pearl oyster, Pinctada margaritifera and clams (Southgate & Ito 1998; Braley 1993)

Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar). There is sparse evidence to indicate that climate change is affecting aquaculture in the UK and Ireland. Impacts to date have been difficult to discern from natural environmental variability, and the pace of technological development in aquaculture overshadows effects of climatic change. However, this review of broader aquaculture literature and the likely effects of climate change suggests that over the next century, climate change has the potential to directly impact the industry. Impacts are related to the industry's dependence on the marine environment for suitable biophysical conditions. For instance, changes in the frequency and strength of storms pose a risk to infrastructure, such as salmon cages. Sea-level rise will shift shoreline morphology, reducing the areal extent of some habitats that are suitable for the industry. Changes in rainfall patterns will increase the turbidity and nutrient loading of rivers, potentially triggering harmful algal blooms and negatively affecting bivalve farming. In addition, ocean acidification may disrupt the early developmental stages of shellfish. Some of the most damaging but least predictable effects of climate change relate to the emergence, translocation and virulence of diseases, parasites and pathogens, although parasites and diseases in finfish aquaculture may be controlled through intervention. The spread of nuisance and non-native species is also potentially damaging. Rising temperatures may create the opportunity to rear warmer water species in the UK and Ireland. Market forces, rather than technical feasibility, are likely to determine whether existing farmed species are displaced by new ones.

Macroalgae play a major role in the carbon cycle of coastal ecosystems. A significant proportion of this production is consumed in situ, representing a major pool of carbon whose ultimate fate is poorly understood. In a controlled laboratory study using fatty acid analysis, the transformation of long-chain polyunsaturated fatty acids (LC-PUFAs) was studied. LC-PUFAs are a key food quality parameter at the level of both individual organisms and ecosystems. Sea urchins delivered LC-PUFAs to sediments in very low concentrations through the production of faecal pellets, while concentrating LC-PUFAs in the gonad and subsequently in larvae. Both the gonad and the larvae represent a rich source of LC-PUFAs to the pelagic and benthic food webs. The exact nature of this transformation and its subsequent transfer up the food chain is dependent on the species that consumes the primary productivity. Hence biogeochemical cycling in the coastal environment is dependant not only on gross primary production by macroalgae, but also on who consumes that primary productivity.

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death in the world today. Bronchodilators, particularly muscarinic antagonists and β2 agonists, are recommended for patients with moderate to severe COPD. Dual-pharmacology muscarinic antagonist– β2 agonist (MABA) molecules present an exciting new approach to the treatment of COPD by combining muscarinic antagonism and β2 agonism in a single entity. They have the potential to demonstrate additive or synergistic bronchodilation over either pharmacology alone. Due to this enticing prospect, several companies have now reported MABA discovery efforts through a conjugated/linked strategy with one candidate (GSK-961081) demonstrating clinical proof of concept. Several MABA crystal forms have been identified, satisfying the requirements for inhaled dosing devices. There are significant challenges in designing MABAs, but the potential to achieve enhanced bronchoprotection in patients and facilitate ‘triple therapy’ makes this an extremely important and exciting area of pharmaceutical research.

Reef-forming corals cycle carbon (C) between the coral host, their endosymbiotic algae, and their skeleton. At elevated sea-surface temperatures this relationship breaks down and the corals bleach by expelling their endosymbiotic algae or these algae lose their photosynthetic pigments. The effect of thermally induced bleaching on the C cycling of 2 ecologically important coral species was investigated. The acquisition and assimilation of photoautotrophically and heterotrophically acquired C was examined via pulse-chase labeling experiments in thermally bleached and non- bleached Montipora capitata and Porites compressa corals. In non-bleached corals photoautotrophic and heterotrophic C were acquired and assimilated very differently. Namely, photoautotrophically acquired C was used to meet short-term metabolic demands and calcification, whereas heterotroph- ically acquired C was retained in both the coral host and endosymbiotic algae. In bleached corals there was a dramatic reduction in the assimilation of photoautotrophically acquired C by the endosymbiotic algae, in the translocation of C from the algae to the coral host, and in the C assimi- lated in the skeleton. The level of heterotrophically acquired C assimilated into bleached corals was similar to that in non-bleached corals, and was a direct source of organic C to the endosymbiotic algae. This host-to-endosymbiotic algal supply of heterotrophic C may stimulate endosymbiotic algal recovery. These findings show the importance of both photoautotrophic and heterotrophic C to coral function and demonstrate that both play a crucial role in the recovery from bleaching.

Biphenyl-2-yl-carbamic acid 1-{9-[(R)-2-hydroxy-2-(8-hydroxy-2-oxo-1,2-dihydro-quinolin-5-yl)-ethylamino]-nonyl}-piperidin-4-yl ester (THRX-198321) is a single molecule composed of a muscarinic acetylcholine receptor (mAChR) antagonist moiety, represented by the fragment MA, linked by a C9 polymethylene chain to a β(2)-adrenoceptor (β(2)AR) agonist moiety, represented by the fragment 8-hydroxy-5-((R)-1-hydroxy-2-methylamino-ethyl)-1H-quinolin-2-one (BA). THRX-198321 exhibited high affinity for mAChR (M(2) pK(I,App) = 10.57 ± 0.09; M(3) pK(I,App) = 10.07 ± 0.11) and β(2)AR (pK(I,App) = 9.54 ± 0.15), with potent mAChR antagonist (M(2) pK(I,Fn) = 9.69 ± 0.23; M(3) pK(I,Fn) = 10.05 ± 0.17) and β(2)AR agonist (pEC(50) = 9.25 ± 0.02) activities. Consistent with multivalent interactions, THRX-198321 binding affinity was >300-fold higher at mAChR and 29-fold higher at β(2)AR relative to its monovalent fragments biphenyl carbamic acid piperidinyl ester (MA) and BA, respectively. THRX-198321 was a competitive antagonist at mAChR (M(2) pK(B) = 9.98 ± 0.13; M(3) pK(B) = 10.31 ± 0.89), whereas THRX-198321 agonist activity at β(2)AR was competitively inhibited by propranolol. Interactions of THRX-198321 with an allosteric site on mAChR and a novel extracellular allosteric site on β(2)AR, respectively, were detected by measuring THRX-198321-evoked changes in the dissociation rates for the orthosteric radioligands, [N-methyl-(3)H]scopolamine methyl chloride (M(2) pEC(50,diss) = 6.73 ± 0.10; M(3) pEC(50,diss) = 5.02 ± 0.14) and [4,6-propyl-(3)H]dihydroalprenolol (β(2)AR pEC(50,diss) = 3.82 ± 0.25). The carbostyril-linker fragment (BA-L) binds to the allosteric site of mAChR (M(2) pEC(50,diss) = 5.06 ± 0.03; M(3) pEC(50,diss) = 4.15 ± 0.25), whereas the MA fragment binds to the allosteric site of β(2)AR (pEC(50,diss) = 3.60 ± 0.18). Collectively, these observations suggest that THRX-198321 exhibits a multivalent bimodal orientation in the orthosteric and allosteric binding pockets of mAChR and β(2)AR, a phenomenon that may be unique to this class of molecule.

The elevated accumulation of certain essential long-chain polyunsaturated fatty acids (PUFA) during reproductive maturation can place a significant demand on lipid metabolism. As lipid metabolism is closely linked with protein metabolism, protein intake during maturation may significantly influence transport proteins and enzyme activity which is responsible for supplying the essential fatty acids for gamete development. The present study investigated the influence of increased protein intake on the accumulation of certain long-chain PUFA in two species of commercially valuable sea urchin, Paracentrotus lividus and Psammechinus miliaris during maturation. Sea urchins were fed three macroalgal diets over a 90-day period. These diets included the red alga Palmaria palmata, which had been grown in seawater enriched with two levels of ammonia-N, which produced a high protein content (41%) or low protein content (32%). The third diet (or reference diet) used the brown macroalga Laminaria saccharina with a 23% protein content. The fatty acid composition of the gonads was determined by GC. Feeding the high protein diet had no effect on the maturation and total lipid in the gonad compared with the low protein diet, however, it did significantly increase the levels of docosahexaenoic acid DHA 22:6n-3 in the mature gonad tissue in P. miliaris and P. lividus. In contrast, only P. miliaris exhibited higher levels of arachidonic acid ARA 20:4n-6 when fed the high protein diet. The present study suggests that elevated protein levels can promote the accumulation of DHA and ARA in gonadal tissue during maturation, although the extent of the influence is species-specific and highlights the importance of understanding the complexities and inter-connectivity between protein and lipid metabolism when producing commercially valuable species.