Kelp forests are being degraded and/or lost in many regions, and as such, interest in active kelp restoration approaches to reinstate forests is growing. ‘Green gravel’ is a promising new kelp restoration technique that involves seeding small rocks with kelp zoospores, rearing the gametophyte and juvenile sporophyte stages in aquaria before outplanting them at restoration sites. However, to be considered a viable approach to kelp forest restoration, the efficacy of this technique needs to be assessed across a range of environmental contexts and kelp species. Here, we aimed to understand the utility of green gravel as a kelp restoration technique for wave-exposed intertidal shores. Two substrate types – gravel and cobbles – were seeded with Saccharina latissima, reared in the aquarium and outplanted at two sites along the northeast coast of England. Outplanted rocks were monitored for retention, and the density and length of S. latissima. Juvenile sporophytes persisted on both rock types, although declines in density and variations in length were observed over time. Substrate retention was low, with gravel more likely to be removed from restoration sites compared to cobbles, and all outplanted rocks were lost after eight months. While our initial testing of the green gravel restoration technique on wave-exposed shores was not successful, our results provide important insights for developing/refining the technique and a baseline for comparison for future efforts. However, prior to commencing large-scale kelp restoration in wave-exposed areas using green gravel, further testing of the technique and comparisons with other restoration approaches are needed.

There is evidence that seaweed production can involve a variety of physical risks, but there has been little study of how wider contextual factors – such as enterprise size, economic and business relations, and forms of employment arrangements – may affect workers’ safety. This study explores the impact of such aspects on workers’ experiences of occupational safety and health (OSH) risks and their management in the developing seaweed industry, in North West Europe. Based on qualitative findings from a survey and discussions with owners/managers, workers and stakeholders in the industry, the study identified a number of issues relating to OSH in seaweed production. These include the predominance of micro small enterprises, the presence of significant risks to health and safety and limitations in the capacity of owners/managers to address them, as well as structural and economic factors in the sector that promote precarious work, and the low visibility and inaccessibility of micro and small enterprises (MSEs) to both public and private regulations. The paper discusses experiences of these issues in the emergent industry and relates them to the wider literature about work health and safety in micro and small firms and precarious and non-standard forms of work, typically found in agriculture and food production. Findings point to the need for better orchestration of public and private regulatory influences and further research to determine if strategies that are seen as successful in other sectors could be transferred to the emergent European seaweed industry.

This study aimed to identify the longitudinal association between seaweed and type 2 diabetes mellitus (T2DM) in the Korean population. Data from 148 404 Korean adults aged 40 years and older without a history of T2DM, cardiovascular disease or cancer at baseline were obtained from the Korean Genome and Epidemiology Study data. The participants’ seaweed intake was obtained using a validated semi-quantitative food frequency questionnaire, and the diagnosis of T2DM was surveyed through a self-reported questionnaire during follow-up. The hazard ratio (HR) and 95 % confidence interval (CI) for T2DM were calculated using the Cox proportional hazard regression, and the dose–response relationship was analysed using a restricted cubic spline regression. Participants had a mean follow-up period of 5 years. Participants with the highest seaweed intake had a 7 % lower risk of T2DM compared with the group with the lowest intake (95 % CI (0·87, 0·99)). Interestingly, this association was stronger in those with normal weight (HR: 0·88, 95 % CI (0·81, 0·95)), while no association was observed in participants with obesity. Spline regression revealed an inverse linear relationship between seaweed intake and T2DM risk in participants with normal weight, showing a trend where increased seaweed intake is related to lower instances of T2DM (Pfor nonlinearity = 0·48). Seaweed intake is inversely associated with the onset of T2DM in Korean adults with normal weight.

This study provides new species records (NRs) of macroalgal assemblages present in rocky habitats from the South Shetland Islands (SSI) and north-eastern Antarctic Peninsula (EAP), Weddell Sea. Surveys were conducted during the summers of 2013/2014 to 2017/2018 at Elephant, Deception, Half Moon and Vega islands. Data from the present study and those available in the literature from the western Antarctic Peninsula (WAP) were combined to provide an updated checklist, giving insights into macroecology and potential changes in thermohaline circulation patterns. A total of 48 macroalgal taxa were identified from our sampling, with eight representing NRs to the EAP sector of the Weddell Sea and five representing NRs to the SSI. Statistical differences among the assemblages from the SSI, WAP and EAP were identified. NRs, including opportunistic species and new information about the biogeographical distributions of species reported here, give insights into ecoregional connectivity and environmental changes. This study updates macroalgal diversity records in regions that are currently experiencing the impacts of climate change. Future and ongoing monitoring for conservation purposes is required to detect non-native species, new dispersal pathways and patterns related to thermohaline anomalies in Antarctic waters.

Bunodeopsis pelagica is one of the few species of sea anemones known to be found in the floating algae of Sargassum spp. It has been reported in the North Atlantic, particularly in the Canary Islands and the coast of Jamaica. The present study is the first to report the occurrence of B. pelagica in the Mexican Atlantic, found as epiphyte on Sargassum natans off Alacranes reef (southern Gulf of Mexico) and in Puerto Morelos reef (Mexican Caribbean), revealing that this species is much more widespread than has been reported. Bunodeopsis pelagica is mainly distinguished from other species of Bunodeopsis by having simple minute protuberances on its column, while its congeners have larger and much more developed vesicular projections. With the record of B. pelagica, the number of known species of actiniarian sea anemones from the Mexican Atlantic increases to 23.

Enteric fermentation from livestock accounts for over a quarter of the United States' methane emissions. A potent greenhouse gas, methane has 80 times the global warming potential of carbon dioxide over a 20-year period. An emerging focus of research is the incorporation of algae (e.g., kelp, seaweed or microalgae) into livestock feed, with several studies documenting dramatic suppression of enteric methane emissions in cattle. As part of a nationwide multidisciplinary study of using algae feed supplements to reduce methane emissions and improve dairy productivity, we used focus groups and individual interviews to measure organic and conventional dairy farmer's knowledge and opinions of algae-based feed supplements. Our goals were to learn what both organic and conventional dairy farmers know about algae-based feed supplements, why they do or do not feed them to their cows and if they were interested in the methane-reducing potential of these algal-based feeds. We also sought to understand where they get valued information about animal nutrition. We found most farmers were aware of algae-based feed supplements on the market, but organic farmers were more familiar with marketing claims. Farmers reported feeding algae-based feed supplements to address herd health concerns, especially reproductive issues and pink eye, but expressed rising costs of the supplements as an obstacle. Both organic and conventional farmers expressed interest in suppressing methane emissions, but only if incentives are provided. Lastly, participants receive trusted information about feed supplements from their dairy nutritionists, who help them make decisions around feed purchasing and rations.

The macroalgae of the Balleny Islands (66°15′S–67°35′S and 162°30′E–165°00′E) have been infrequently collected and the flora remains poorly known. This chain of islands is located on the edge of the Antarctic Circle in the northern Ross Sea, ~250 km north of the coast of northern Victoria Land, and it represents the most northerly land in the Ross Sea region. As well as being very remote, access to these islands is difficult given the highly variable prevailing ice conditions. We summarize the macroalgal floras of the Balleny Islands and the Ross Sea, including reporting new records, extending the known distribution of other taxa and highlighting the need for further taxonomic research on some of the most common and widespread species. Many of the taxa reported have been collected on few occasions and, as a consequence, there is insufficient material available, including reproductively mature samples, for some species to be fully documented. While these collections are providing intriguing insights into the relationships between the macroalgae found around the Antarctic continent, the full biodiversity of the Balleny Islands remains to be investigated, and further collections are required to enable detailed comparisons with other parts of the Antarctic region.

Type II diabetes is considered the most common metabolic disorder in the developed world and currently affects about one in ten globally. A therapeutic target for the management of type II diabetes is the inhibition of α- glucosidase, an essential enzyme located at the brush border of the small intestinal epithelium. The inhibition of α-glucosidase results in reduced digestion of carbohydrates and a decrease in postprandial blood glucose. Although pharmaceutical synthetic inhibitors are available, these are usually associated with significant gastrointestinal side effects. In the present study, the impact of inhibitors derived from edible brown algae is being investigated and compared for their effect on glycaemic control. Carbohydrate- and polyphenolic-enriched extracts derived from Ascophyllum nodosum, Fucus vesiculosus and Undaria pinnatifida were characterised and screened for their inhibitory effects on maltase and sucrase enzymes. Furthermore, enzyme kinetics and the mechanism of inhibition of maltase and sucrase were determined using linear and nonlinear regression methods. All tested extracts showed a dose-dependent inhibitory effect of α-glucosidase with IC50 values ranging from 0⋅26 to 0⋅47 mg/ml for maltase; however, the only extract that was able to inhibit sucrase activity was A. nodosum, with an IC50 value of 0⋅83 mg/ml. The present study demonstrates the mechanisms in which different brown seaweed extracts with varying composition and molecular weight distribution differentially inhibit α-glucosidase activities. The data highlight that all brown seaweed extracts are not equal in the inhibition of carbohydrate digestive enzymes involved in postprandial glycaemia.

The Neolithisation of Europe involved socio-economic and biological adaptations to new environments. The use of seaweed as livestock fodder, for example, was key to the introduction of animal husbandry to the Orkney archipelago, c. 3500 cal BC. Using stable isotope analysis of faunal remains from Skara Brae, this study provides new evidence for, and clarifies the chronology of, the adoption of seaweed consumption by sheep. The results show that sheep consumed moderate amounts of seaweed from the moment of their introduction to Orkney—a practice that facilitated the successful spread of the farming lifeways to the most remote areas of Europe.

Aquarium release is a vector for introducing nonnative species that threatens the ecological integrity of aquatic systems. Following coastal invasions by released aquarium strains of Caulerpa taxifolia, aquarists began using the macroalgal genus Chaetomorpha. Use of Chaetomorpha now exceeds 50% of U.S. aquarium hobbyists we surveyed. Aquarium strains of this macroalgal genus possess broad environmental tolerances, demonstrate high nutrient uptake and growth rates, and reproduce by fragmentation. Although these characteristics make Chaetomorpha a desirable aquarium inhabitant, they may also promote invasive tendencies if the alga is introduced into a natural ecosystem. We sought to proactively mitigate this potential invasion risk by testing algal disposal techniques that serve as responsible alternatives to releasing viable individuals. We tested methods used by aquarium hobbyists—boiling, microwaving, freezing, desiccation, and exposure to freshwater. We determined the minimum durations that these techniques must be used in order to induce mortality in three aquarium purchases of Chaetomorpha. We found that boiling for at least 1 min, microwaving for at least 15 s, or freezing for at least 24 h were sufficient to induce 100% mortality in 1-cm-long fragments and clumps up to 1.5 g. Desiccation required more than 24 h when exposed to air and 6 d for samples kept in closed containers. Freshwater exposure was effective at 6 d. These results indicate that disposal of excess or unwanted Chaetomorpha via garbage (if destined for a landfill) or indoor plumbing (e.g., sinks and toilets) represent safe alternatives to release. Disposal of algal tissue, shipping water, or tank water containing small algal fragments down stormwater drains, however, could introduce this hardy species into favorable conditions that could result in detrimental biological invasions.

Scientific research has always been concerned with aspects of human health. There are several systems of medicines besides the globally accepted allopathy, which are based on compounds originating from natural products. Recent research has been centred around validation of the traditional knowledge on medicinal products. The traditional systems in India, China and forklore medicines in other parts of the world have indicated the potential of natural products consist of various chemical compounds that could be used as drugs. The search for drugs against five major dreadful diseases namely, cancer, AIDS, heart disease, diabetes and pulmonary disorders that attack the present day human from natural products has been in progress for some time. Microbes, plants and animals are the sources of natural products. In the past five decades, the research on bioactive chemicals from marine algae has been incited and several compounds with biological activity were isolated from algae. Generally, these are secondary metabolites produced for chemical defence against the biotic pressure of predators, consumers and epibionts. These potential drugs are now attracting considerable attention from the pharmaceutical industries due to the necessity of identifying substances that could be utilized for novel therapeutic purposes. Several compounds such as alginate, carrageenans, sulphated and halogenated polysachcharise and other derivatives have been shown to provide drugs that could be antiviral, anticancer and antimicrobial. The present account is on the potential of marine macro-algae for medicinally important products.

The research reported in this Research Communication was undertaken to evaluate the effects of different sources of polyunsaturated fatty acids (PUFA) supplemented in the diet on milk production and milk fatty acid profile of lactating ewes exposed to long term heat stress. The experiment was conducted during summer, involved 32 ewes divided into 4 groups of 8 each, and lasted 6 weeks. The ewes in all groups were fed twice daily and received 1·8 kg/d of oat hay and 1 kg/d of concentrate. Flaxseed group (FS) was supplemented with 250 g/d of whole flaxseed, Ascophyllum nodosum group (AG) was supplemented with 25 g/d of seaweed Ascophyllum nodosum, and the combination group (FS + AG) received both flaxseed and Ascophyllum nodosum supplementation. The control group (CON) was fed with 1 kg/d of pelleted concentrate without PUFA supplementation. Milk samples were collected twice daily per week, and analysed for fat, total protein, casein, and lactose content. At the beginning and then at 2, 4 and 6 week of the experiment each milk sample was analysed for milk fatty acids. Temperature-humidity index (THI) was calculated daily. Supplementation of flaxseed and of the combination of flaxseed and Ascophyllum nodosum increased milk yield. The total content of saturated fatty acids (SFA) in milk decreased for ewes fed FS, followed by FS + AG. On the contrary, monounsaturated fatty acids (MUFA) increased for ewes fed FS and FS + AG. The total n-3 FA was found higher in FS and FS + AG than in AG and CON groups mainly because of the increase in C 18 : 3 n-3 in FS and FS + AG milk. Milk from FS + AG resulted in the highest n-3/n-6 ratio and decreases in atherogenic and thrombogenic indices. The combination of seaweed Ascophyllum nodosum and flaxseed can be suggested as an adequate supplementation to sustain milk production and milk fatty acid profile of sheep during summer season.

To assess the course and status of recovery of rocky intertidal zonation after massive subsidence caused by the 2011 Great East Japan Earthquake, from 2011 to 2013 we censused the vertical distribution of 10 dominant macrobenthic species (six sessile and four mobile species) in the mid-shore zone of 23 sites along the Sanriku coastline, 150–160 km north-northwest of the earthquake epicentre, and compared the vertical distributions of each species with their vertical distributions in the pre-earthquake period. The dynamics of rocky intertidal zonation varied substantially among species. Among sessile species, one barnacle dramatically increased in abundance and expanded its vertical range in 2011, but then decreased and completely disappeared from all plots by 2013. Zonations of other sessile species shifted downward following the subsidence in 2011. With some species, there was no clear change in abundance immediately after the earthquake, but they then began to increase and move upward after a few years; with other species, abundance continuously decreased. There was no clear change in the vertical distribution of any of the mobile species immediately after the earthquake. Abundance of two mobile species was unchanged, but abundance of the others decreased from 2012 and had not recovered as of 2013.

This study was designed to assess the value of seaweeds from the Galician coast as a source of minerals (especially iodine (I) but also other micro-minerals) in organic dairy cattle. It was conducted in an organic dairy farm in the Lugo province that typically represents the organic milk production in NW Spain. The animal’s diet consisted mainly of local forage (at pasture or as hay and silage in the winter) and 5 kg of purchased concentrate/day per animal (representing 23.5% of feed intake). Based on the mineral composition of the diet, the physiological requirements and the EU maximum authorised levels in feed, a supplement composed by Sea Lettuce (Ulva rigida) (as flakes, 80%), Japanese Wireweed (Sargasum muticum) (flakes, 17.5%) and Furbelows (Saccorhiza polyschides) (powder, 2.5%) was formulated to give 100 g/animal per day. Sixteen Holstein Friesian lactating cows were randomly selected and assigned to the control (n=8) and algae-supplemented groups (n=8). Both groups had exactly the same feeding and management with the exception of the algae supplement, which was mixed with the concentrate feed and given to the animals at their morning milking for 10 weeks. Heparinised blood (for plasma analysis) and milk samples were collected at 2-week intervals and analysed for toxic and trace element concentrations by inductively coupled plasma-mass spectrometry or inductively coupled plasma-optical emission spectrometry. The algae supplement significantly improved the animals’ mineral status, particularly I and selenium that were low on the farm. However, the effect of the algae supplement on the molybdenum status in cattle needs further investigation because of its great relevance on copper metabolism in ruminants. The I supply deserves special attention, since this element is at a very high concentration in brown-algae species and it is excreted in the milk proportionally to its concentration in plasma concentrations (mean±s.e. in the algae-supplemented and control groups were 268±54 and 180±42 µg/l, respectively).

Marine protected areas (MPAs) have been depicted as a useful tool for improving fisherymanagement and protecting biodiversity. For example, by acting as source populations, MPAsmay provide a spillover of adults/propagules, enhancing recruitment to surrounding,non-protected waters. However, such positive effect will depend on how a MPAs designmatches population biology and dispersal abilities of the target species. High levels ofintraspecific genetic diversity without pronounced structure have been found in manymarine organisms over large spatial scales (from hundreds to thousands kilometres) but donot hold for other ecologically and economically important species such as coral reeffishes, seagrasses and kelps. In particular, the limited potential for dispersal of manymacroalgae suggests the occurrence of self-sustaining, “closed” populations that contrastwith the “open” populations of many fishes and invertebrates. Consequently, the highresilience of fish/invertebrate populations cannot be generalized to the whole marinerealm. In the present work, we use genetic tools to explore the role of the MPAParc naturel marin d’Iroise in the management of the emblematic kelpLaminaria digitata. While kelps have received much more scientificattention than any other seaweed group, there is still critical baseline knowledge whichneeds to be addressed for their effective management. Our genetic survey of 12 L.digitata populations along the Brittany coast, four of them located within theboundaries of the Parc naturel marin d’Iroise, allowed us to assess theconservation value of these kelp populations. In particular, classical genetic metrics aswell as more recent clustering approaches were used to identify and characterizeManagement Units. Moreover, assignment tests were employed to determine contemporarymigration events and source/sink populations. Our results show that populations withinthis MPA have high conservation value. However, we also identify other populations ofconservation interest.

Gim (Porphyra sp.) and miyeok (Undaria pinnatifida) are the seaweeds most consumed by Koreans. We investigated the association between the intake of gim and miyeok and the risk of breast cancer in a case–control study. Cases were 362 women aged 30–65 years old, who were histologically confirmed to have breast cancer. Controls visiting the same hospital were matched to cases according to their age (sd 2 years) and menopausal status. Food intake was estimated by the quantitative FFQ with 121 items, including gim and miyeok. Conditional logistic regression analysis was used to obtain the OR and corresponding 95 % CI. The average intake and consumption frequency of gim in cases were lower than in controls. The daily intake of gim was inversely associated with the risk of breast cancer (5th v. 1st quintile, OR, 0·48; 95 % CI, 0·27, 0·86; P for trend, 0·026) after adjustment for potential confounders. After stratification analysis was performed according to menopausal status, premenopausal women (5th v. 1st quintile, OR, 0·44; 95 % CI, 0·24, 0·80; P for trend, 0·007) and postmenopausal women (5th v. 1st quintile, OR, 0·32; 95 % CI, 0·13, 0·80; P for trend, 0·06) showed similar inverse associations between gim intake and the risk of breast cancer after an adjustment for potential confounders except dietary factors. Miyeok consumption did not have any significant associations with breast cancer. These results suggest that high intake of gim may decrease the risk of breast cancer.

In order to determine if eastern Pacific green turtles (Chelonia mydas) exhibit feeding preferences samples of recently ingested food items were compared to the food resources available in the marine environment where C. mydas congregates. Stomach samples were collected by conducting gastric lavage and, at the same time, vegetation transects were conducted during spring and winter. Green turtles in our study selectively consumed seaweeds, with Codium amplivesiculatum and Gracialaria textorii as preferred species. Differences in the consumption of species were found across the two mentioned seasons and were consistent with changes in the availability of different algae species in the environment. Based on these results, it is recommended that sea turtle conservation plans along the Baja California Peninsula include Pacific coastal mangrove channels with a high diversity of algae species as priority areas for protection.

In organic pasture systems, the balance of soil fertility is maintained by maximizing the cycling of on-farm nutrients. In this study, the effect of fertility management on dry matter yield in organic pasture systems was examined using an unreplicated 25 factorial design. The factors were nitrogen (N), phosphorus (P), potassium (K), compost and seaweed extract, each at two levels (with [+] and without [−]). The trials were conducted in 2000 and 2001 at two fields on an organic dairy farm in Nova Scotia, Canada. The pasture mix is predominantly perennial ryegrass, orchardgrass and white clover. The fertility treatments were applied in spring, and forage yield was collected from early-, mid- and late-summer harvests. The analysis revealed the significance of several interaction effects, which varied considerably from harvest to harvest. Both +N and +Compost treatments were associated with increased yield. High levels of P and K already present in the soil either diminished or varied the effects of P and K treatments. Seaweed extract enhanced the effectiveness of N and compost, but reduced yield when used alone. The results suggest that the commonly recommended use of seaweed extract for organic pasture management can be detrimental to biomass production unless sufficient nitrogen is provided. Despite the unusually dry weather in the 2 years, the study demonstrated the applicability of unreplicated two-level factorial experiments in agricultural field studies.

The impact of the “Erika” oil spill on the tidal rock pool community, and particularly on two species of sea urchin (Paracentrotus lividus and Psammechinus miliaris), was investigated over a 3-year period, at Piriac-sur-Mer (Department of Loire-Atlantique, France, 47°21.6' N; 2°31.7' W). A dramatic increase in the abundance of two macroalgae Ulva sp. and Grateloupia doryphora occurred following a 100% mortality of sea urchins observed three weeks after the oil spill. The density of sea urchins and of other main herbivores, the periwinkle Littorina littorea and the trochid mollusks Gibbula umbilicalis and Gibbula pennantii, were monitored between January 2000 and March 2003. There was significant inverse relationship between the overall density of herbivores (sea urchins, periwinkles and trochid mollusks) and the percent cover of algae in the tidal pools. The first urchins in the tidal pools were observed two years after the oil spill and it took three years to reach sea urchin densities comparable to the reference value of 63 ind.m−2 obtained before the oil spill.