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The relative daily growth rates of Furcellaria lumbricalis and Coccotylus truncatus at different density levels. The letters indicate homogeneous groups obtained from the post-hoc Bonferroni test of two-way ANOVA analysis
Source publication
In an in situ experiment we evaluated the growth of the red algae Furcellarialumbricalis and Coccotylus truncatus in the Archipelago Sea. The results showedthat the growth rates of both species were similar but that growth decreased withincreasing algal coverage. The effects were more pronounced for C. truncatus thanfor F. lumbricalis. Economic ana...
Contexts in source publication
Context 1
... effect of density was consistent as the interaction term between density and algal species was not significant (two-way-ANOVA, interactive effect of density × algal species, F = 1.74, P > 0.05) (Figure 2). ...
Context 2
... results have important practical implications. Firstly, they suggest that the studied red algae are very resilient, and even when subjected to strong harvesting pressure they are capable of regaining their natural biomasses within one productive season (at low densities, red algae can almost double their biomass; see also Figure 2 for the growth rates). Secondly, despite similar growth rates, intensive harvesting may actually change the dominance structure of the red algae. ...
Citations
... Among these factors, the growth density of macroalgae has the greatest influence on algal growth and photosynthesis. For instance, the biomass of Mazzaella cornucopiae was positively correlated with densities in a range of 4-17 fronds/cm 2 (Scrosati, 1996); increased density was found to include lower growth rates for Furcellaria lumbricalis and Coccotylus truncatus (Kotta et al., 2008), Cystophora scalaris, Undaria pinnatifida, and Xiphophora gladiata (Richards et al., 2011), and also for Fucus serratus (Binzer and Sand-Jensen, 2002). However, the effects of culture density on S. fusiforme have been rarely studied. ...
The commercial seaweed Sargassum fusiforme is adversely affected by the increasing presence of epiphytic macroalgae, mainly Ulva species, during seawater cultivation, especially at high culture densities. In the present study, comparative studies of S. fusiforme and Ulva lactuca were carry out to examine their physiological responses to densities between monoculture and bi-culture. The results showed that, both species of algae showed significant reduction in growth when the density of the cultures (mono-and bi-culture) was increased, although U. lactuca exhibited stronger growth and photosynthetic rate than S. fusiforme in both cultures. Specifically, for S. fusiforme, its maximum quantum yield of PSII (Fv/Fm), light harvesting efficiency (α), soluble carbohydrate (SC) content, and the ratio of SC/SP were all significantly decreased by high density, whereas its nitrate reductase (NR) activity, chlorophyll a (Chl a) and soluble protein (SP) contents were significantly increased in the monoculture. High density also decreased the photosynthesis and contents of SC and SP of U. lactuca in the monoculture. Moreover, the SC contents and NR activities of both S. fusiforme and U. lactuca significantly increased whereas their SP contents decreased in the bi-culture regardless of the culture densities. U. lactuca was dominant because of its potent neighbouring shading and possible allelopathic effects on S. fusiforme. Its nutrients uptake was also more rapid than that of S. fusiforme in bi-culture. The interspecific competition between the two algae became intense with the increasing density. Thus, for the maricultivation of S. fusiforme, a moderate culture density would be preferrable because of the higher photosynthetic efficiency and growth rate of S. fusiforme.
... Estonia, Latvia, and Poland, as well as the marine waters under their jurisdiction (see Figure 1), were chosen as case study countries due to similar environmental conditions; relatively low salinity surface waters at around 5-8 psu (practical salinity unit) in Poland and the Latvian Open Baltic coast, and 2-7 psu in the Gulf of Riga and in the coastal waters and Estonian Archipelago [34][35][36], being one reason. Other reasons, also closely linked to the environmental conditions, were the shared types of native macroalgae species between these countries [37] and the similar history of their use. ...
With the blue economic sectors growing, marine macroalgae cultivation plays an important role in securing food and energy supplies, as well as better water quality in sustainable ways, whether alone or as part of a cluster solution to mitigate the effects of fish farming. While macroalgae cultivation exists in Europe, it is not that widely distributed yet; with increasing marine activities at sea, Maritime Spatial Planning (MSP) needs to ensure social recognition as well as social and spatial representation for such a new marine activity. This comparative case study analysis of MSPs of three eastern Baltic Sea countries explores the levels of support for the development of macroalgae cultivation in MSP and the degree of co-location options for this new and increasingly important sector. It presents new analytical ways of incorporating co-location considerations into the concept of social sustainability. The results of this study support the harmonisation of views on co-location, propose ways of using space to benefit multiple users as well as marine ecosystems, and highlight some of the key social challenges and enablers for this sector.
... Due to the shallowness and the bottom substrate being dominated by fine sediment fractions, water transparency is often very poor. After storm events, the Secchi depth may decrease to 0.5 m, while in the case of prolonged calm weather conditions the photic zone reaches the bottom in about 90 % of this area , Kotta et al., 2008. Drifting mats of Furcellaria lumbricalis and Coccotylus truncates cover soft sediments at depths between 5 and 9 m in the subregion Kassari Bay, the community is maintained by the prevailing circular currents and the ring of islets that surround the area [Martin, 2000, Kotta et al., 2008 (→ Fig. 7.2). ...
... After storm events, the Secchi depth may decrease to 0.5 m, while in the case of prolonged calm weather conditions the photic zone reaches the bottom in about 90 % of this area , Kotta et al., 2008. Drifting mats of Furcellaria lumbricalis and Coccotylus truncates cover soft sediments at depths between 5 and 9 m in the subregion Kassari Bay, the community is maintained by the prevailing circular currents and the ring of islets that surround the area [Martin, 2000, Kotta et al., 2008 (→ Fig. 7.2). Similar communities were also present in the waters of Denmark and Poland but were lost due to overexploitation and eutrophication in the period 1970-1980[Weinberg et al., 2019, Schramm, 1998]. ...
This report No 5.1 is one of the main outputs of the Project CONTRA (2019–2021), which was fulfilled within the Program Interreg Baltic Sea Region. The report was prepared within the Work Package 5 “Innovative technologies for beach wrack handling and toolkit” by experts from CONTRA Project Partners. It represents the results obtained in the
six case studies in the countries with different management systems: Germany (Islands of Rügen and Poel), Denmark (Køge Municipality), Russia (Curonian and Vistula spits) Sweden (Kalmar municipality and Öland) and Poland (Gulf of Gdansk). Each case study is presented in separate chapters, which focuses are indicated in the chapter titles (see Table of contents). Technological aspects of different stages of the beach wrack collection, processing and usage (see Figure below), as well as the management and legislative issues are presented. The last chapter is devoted to Estonian experience.
... The third process, shelf-shading, is one of the most critical biological limitations because it sets an actual threshold for realized photosynthesis along vertical light gradient within macroalgal assemblages (Binzer et al., 2006;Tait and Schiel, 2010). The effect is stronger with increasing algal densities (Kotta et al., 2008;Paalme et al., 2013;Pärnoja et al., 2014) and in extreme cases, e.g., within giant kelp forests, only a fraction of light above algal canopy reaches the basal subcanopy species (Reed and Foster, 1984). This has large but mostly unknown affects on photosynthesis and growth of macroalgal assemblages. ...
An understanding of the nature of scale-dependence in macroalgal production and to quantify how primary production is incorporated into autotrophic biomass requires an assessment of primary production at multiple scales. In this study we experimentally estimated seasonal variability in individual photosynthesis, community production and growth in biomass of the charophyte Chara aspera in the Baltic Sea together with the key environmental variables known to regulate the production of macroalgae. The experiments suggested that the production and growth of C. aspera was defined largely by light and temperature at all studied scales. However, the algal production at the same light levels was systematically lower at the community than an individual level, suggesting the importance of shelf-shading and below-ground processes in natural plant assemblages. Moreover, the observation scale also defined response types between the environment, plant production and growth. This implies that the patterns of variability of the production and growth of macrophytes should always be interpreted in the context of scale and any multiscale model development should involve experimental validation at all important scales.
... 1 and 2). The biomass of this community varies interannually and is related to the regional patterns of temperature, light and wave conditions Paalme et al. 2011) as well as interspecific interactions, i.e. algal density and the share of dominating species in the F. lumbricalis and C. truncatus community (Kotta et al. 2008;Paalme et al. 2013). In two areas of the Baltic Sea (Puck Bay and Central Kattegat), once extensive unattached loose-lying communities of F. lumbricalis are now absent, as a result of eutrophication, pollution and excessive harvest (Austin 1960;Lund and Christensen 1969;Kruk-Dowgiallo 1991;Ciszewski et al. 1992). ...
Wild harvest of seaweed supports small-scale, high-value industries in a number of regions in the world. Information is lacking on how increasing carbon dioxide (CO2) concentrations in seawater could impact seaweeds in wild harvest situations. This study focuses on a mixed unattached loose-lying red algal community of Furcellaria lumbricalis in close association with Coccotylus truncatus that is found in the West Estonian Archipelago Sea, NE Baltic Sea. In Estonian coastal waters, the wild harvest of F. lumbricalis started in 1960s and it has since been used as raw material for furcellaran production. The aim of this study was to determine how ocean acidification may impact the balance of these two red algal species in the community. Mechanistic assessment of the carbon physiology of F. lumbricalis and C. truncatus was used to predict productivity and competitive interactions between these species in a high-CO2 world. Carbon use strategies in macroalgae were determined by analysing the natural abundances of carbon isotopes (δ¹³C), pH drift experiments and photosynthesis vs. dissolved inorganic carbon (DIC) curves. Photosynthesis of F. lumbricalis (operating with a CO2 concentrating mechanism or CCM) performed worse along the broader range of DIC concentrations compared to C. truncatus (non-CCM), especially those characterized under future climate conditions. Therefore, changing seawater carbon chemistry through ocean acidification has the potential to influence the balance of F. lumbricalis and C. truncatus in the community and the efficiency of the wild harvest of this community and the quality of product provided.
... grams P. haitanensis per litre culture media were used by Chen et al. (2016), Chen et al. (2019) and 0.6 gram per litre media by Jiang, Zou, Lou, Deng, and Zeng (2018), and 1.5 g Ulva lactuca per litre media were used by Liu and Zou (2015). In nature, however, growing of algal thalli often varies their biomass densities from almost zero to several and even to tens of grams per litre seawater (Jiang, Zou, Lou, & Yang, 2017;Jiang, Zou, Lou, & Ye, 2017;Kotta, Paalme, Kersen, & Martinet, 2008;Zhang et al., 2019). Such an increased density is generally believed to limit the resources received by individual algae, like light energy, making them adaptively enhance the saturation and compensation irradiance and lower the light-utilizing efficiency or photosynthetic rate (Copertino, Cheshire, & Kildea, 2009;Li et al., 2020;Richards, Hurd, Pritchard, Wing, & Hepburn, 2011). ...
... The increased algal densities significantly reduced the growth and photosynthetic capacity of P. haitanensis (Figure 1 and Figure 2), which was also detected in Gracilaria and Ulva species Li et al., 2020). It may be attributable for the density-caused self-shading of thalli that lowers the light flux onto the individual surface (Hurd, 2000;Kotta et al., 2008), as indicated by the increased pigment content with increasing algal densities (Table 1); consequently, it enhances the light saturation points and reduces the light energy utilized efficiency or photosynthetic rate Li et al., 2020;Richards et al., 2011). On the other hand, as aforesaid the seawater Ci is far below the levels for full demands of macroalgal photosynthesis if only depending on diffusional entry of CO 2 from medium to active site of RubisCO for carboxylation process (Beardall, Beer, & Raven, 1998;Lobban & Harrison, 1997;Zou & Gao, 2002). ...
Growing of Pyropia haitanensis, a commercially farmed macroalga, usually increases their densities greatly during cultivation in natural habitats. To explore how the increased algal densities affect their photosynthetic responses to rising CO2, we compared the growth, cell components and photosynthesis of the thalli of P. haitanensis under a matrix of pCO2 levels (ambient CO2, 400 ppm; elevated CO2, 1,000 ppm) and biomass densities [low, 1.0 g fresh weight (FW) L−1; medium, 2.0 g FW L−1; high, 4.0 g FW L−1]. Under ambient CO2, the relative growth rate (RGR) was 5.87% d−1, 2.32% d−1 and 1.51% d−1 in low, medium and high densities, and elevated CO2 reduced the RGR by 27%, 25% and 12% respectively. Maximal photochemical quantum yield of photosystem II (FV/FM) was higher in low than in high densities, so were the light‐utilized efficiency (α), saturation irradiance (EK) and maximum relative electron transfer rate (rETRmax). Elevated CO2 enhanced the FV/FM in low density but not in higher densities, as well as the α, EK and rETRmax. In addition, elevated CO2 reduced the content of chlorophyll a and enhanced that of carotenoids, but unaffected phycoerythrin, phycocyanin and soluble proteins. Our results indicate that the increased algal densities reduced both the growth and the photosynthesis of P. haitanensis and alleviated the elevated CO2‐induced negative impact on growth and positive impact on photosynthesis. Moreover, the elevated CO2‐induced reduction on growth and promotion on photosynthesis indicates that rising CO2 may enhance the loss of photosynthetic products of P. haitanensis through releasing organic matters.
... In addition to the depth limit of the whole macrophyte community, depth limits of single indicator species can be used, e.g. those of the brown alga Fucus vesiculosus (Kautsky et al. 1986, Torn et al. 2006, the red alga Furcellaria lumbricalis (Kotta et al. 2008) and the common eelgrass Zostera marina (Greve and Krause-Jensen 2005). ...
1.
Changes in living conditions caused by natural variability
or anthropogenic activities elicit distinct responses of species, populations and communities. Bioindication is the recording of such responses and the entity measured is called a “bioindicator”.
2.
A bioindicator can be any relevant component or measure that can be used to estimate the environmental status based on the performance of all types of organisms (prokaryotes, protists, macroalgae, vascular plants, invertebrates, fish, mammals), including bulk measurements such as the chlorophyll a concentration in the seawater or the lower depth limit of macrophytes.
3.
To be able to conclude if environmental change has taken place based on bioindication, it is essential to have knowledge of the specific ecological requirements of the organisms with respect to their habitats.
4.
Bioindication using individuals or species includes e.g. behavioural adaptations, modifications of organ and cell structures and changes in population dynamics.
5.
Bioindication by recording dramatic increases or decreases in the proportion and/or density of species in a community provides a conspicuous sign of environmental change, especially when this includes the extinction of species.
6.
Strong decreases and extinctions of species in a community coupled to immigration
of non-indigenous species
may signify a shift in community composition
that has a bearing on the functioning of the entire ecosystem.
7.
Bioindication is a major tool used in the implementations of the EU environmental legislation
: the Habitats Directive (HD), the Water Framework Directive
(WFD) and the Marine Strategy Framework Directive (MSFD).
... Density of algal material in the farming site should be comparable with natural population density, as suboptimal values decrease growth rate by reducing light penetration to lower fronds ( Paalme et al. 2013a). Our experimental work suggests that the optimal density is ≤10 mg wet weight (WW) cm −3 for unattached F. lumbricalis ( Kotta et al. 2008, Paalme et al. 2013a, which corresponds to a biomass of 200 g DW m −2. However, the attached ecotype has coarser thalli and a more distinctly erect habit than the loose form. ...
There is a growing need for diversification of seaweed aquaculture practices in Europe. In the Baltic Sea very few seaweed species are utilised commercially and only the kelp Saccharina latissima is presently cultivated, although a common red alga – Furcellaria lumbricalis – has the longest harvesting history in the region. Nevertheless, in recent years, there has been an increasing interest in cultivating F. lumbricalis in Estonian coastal waters. Several pilot studies have been initiated to develop techniques for the vegetative propagation of sporophytes and gametophytes. Based on a literature survey, ongoing investigations and expert opinion, a comprehensive overview of the ecophysiological requirements and chemical composition of different forms of F. lumbricalis is given in this review, together with its potential for biotechnological applications. Recommendations for cultivating the species in open water are given. Overall, biotechnological applications of F. lumbricalis rely on high-value biochemicals like furcellaran, R-phycoerythrin, lutein (carotenoids) and phenolic content (antioxidants). Further bioprospecting is needed to estimate the possible content of oxylipins in the alga.
... The volume ratio of F. lumbricalis to C. truncatus was set at 0 : 100, 25 : 75, 50 : 50, 75 : 25, and 100 : 0 in the experiment . Algal densities and proportions represented the realistic values in field conditions (Kotta et al., 2008b; Kersen et al., 2009). Each combination of treatment levels had five replicates (total n = 75). ...
... There exists experimental evidence that the growth of red algae is light limited in the West Estonian Archipelago Sea (Martin et al., 2006a). Due to the shallowness and domination of fine sediment fractions in the bottom substrate the water transparency in the study area is often very poor (Kotta et al., 2008b). After storm events the Secchi depth may decrease to 0.5 m and the light conditions are often suboptimal for the red algal growth. ...
... After storm events the Secchi depth may decrease to 0.5 m and the light conditions are often suboptimal for the red algal growth. Competition for nutrients is not likely as the West Estonian Archipelago Sea is relatively eutrophicated (Lauringson et al., 2012), regular pulses of nutrient-rich waters of the adjacent Gulf of Riga occur (Kotta et al., 2008b), and the studied algae are able to take advantage of these high nutrient events and store nutrients for extensive periods of time (Wallenti-145 nus, 1984; Indergaard and Knutsen, 1990). Thus, the generic density-dependent effects and better performance of F. lumbricalis observed in this experiment are most likely associated with the light limitation of the red algae (this study; Kotta et al., 2008b). ...
The West Estonian Archipelago Sea hosts a loose-lying red macroalgal community dominated by Furcellaria lumbricalis and Coccotylus truncatus. The community is truly unique in European seas. In factorial field experiments we evaluated separate and interactive effects of algal density and the proportions of F. lumbricalis and C. truncatus on their growth rates in a set of monospecific and mixed communities. Our experiment demonstrated that the growth of red algae was density dependent and that increased algal densities resulted in a fall of daily growth rates. An elevated growth of the red algae was observed at their lower proportions in the community. A potential mechanism behind the observed patterns is the light availability for photosynthesis, i.e. light utilization is more efficient in mixed communities.
... Such biomass (density) dependence/self limitation is common in seaweeds and often results from self-shading (e.g. Reed 1990; Arenas et al. 2002; Kotta et al. 2008). The second insight from our survey and experiments is that, in addition to its rapid capacity for increase, Gracilaria breaks down quickly in sedimentary environments. ...
Invasive ecosystem engineers can have far-reaching effects on systems, especially if they provide structure where none was before. The non-native seaweed Gracilaria vermiculophylla has proliferated on estuarine mudflats throughout the southeastern US, including areas (South Carolina and Georgia) that historically were extremely low in seaweed biomass. Quantitative field surveys across 150 km of high salinity estuaries revealed that the density of the native onuphid polychaete Diopatra cuprea and the aboveground height of its biogenic tubes, which Diopatra decorates with drifting debris and seaweed, positively influenced Gracilaria biomass. The abundance of Gracilaria epifauna, composed primarily of amphipods and small snails, increased with Gracilaria biomass at many locations in our field surveys. To examine whether epifauna were facilitated by Gracilaria we experimentally manipulated Gracilaria biomass in two locations. Consistent with the field surveys, we found that increasing Gracilaria biomass facilitated epifauna, particularly amphipods and snails. Epifaunal densities on Gracilaria were higher than on a biologically-inert structural mimic of Gracilaria (plastic aquarium alga), indicating that epifauna colonize Gracilaria because Gracilaria provisions both physical structure and a biological resource. We also quantified the seaweed’s net rate of productivity and decomposition. Primary production of Gracilaria was variable, but massive in some areas (up to 200 % net biomass increase in 8 weeks). The seaweed rapidly degraded upon burial in silty sediments (79 % loss in mass within 10 days) and thus may represent an important new addition to detrital foodwebs. As a copious, novel source of primary production, detritus, and desirable habitat for epifauna, Gracilaria has the potential to transform southeastern US estuaries.
