The study of the element accumulation in marine plants against the backdrop of permanently increasing environmental pollution is of particular importance due to the participation of these plants in ...biogeochemical cycles. The element abundances are highly variable and depend on both the macrophyte species and environment. The purpose of this study was to analyze the elemental composition of widespread marine plants of different taxonomic affiliations collected in the same area of the Black Sea coast. The contents of 74 elements in three species of lower (red, brown, green algae) and one species of higher plants (seagrass) were analyzed using inductively coupled plasma mass spectrometry. High contents of most elements were found in the red alga Ceramium ciliatum and in rhizomes of the seagrass Zostera noltei. In C. ciliatum, high metal bioaccumulation factors were found, which are dependent also on their concentration in the environment. Compared to the higher plant, all the macroalgae accumulated increased amounts of As and I. The seagrass proved to be a good concentrator of Mo and Sb, and relatively high contents of Mn, Co, Ni, Zn, Cd and Ir were registered in its leaves. High contents of Mg, S, Ge, Se and Ta were found in the green alga Ulva rigida, and elevated levels of Al, As, Sr, Zr, Ru, Rh, Pd, Ag, Ba and Re were noted in the brown alga Gongolaria barbata. The enrichment factors for most elements in the sediments were well above 1 with respect to both the local Late Pleistocene sediments and the upper continental crust. The strength of correlations between the element contents in the plants and sediments was found to decrease with the specific surface area growth and appeared to have a lower asymptotic limit of the sediments–seawater correlation strength.
•High contents of most elements were found in the red alga and in seagrass rhizomes.•The macroalgae accumulate higher amounts of As and I compared to the higher plant.•Correlation strength with element contents in sediments weakens with specific area.•The asymptotic limit against the area is the seawater-sediment correlation strength.
This study aims to investigate the influence of three different dichromatic LED light sources and varying photoperiod durations on the mineral content and trace element compositions in cultivated ...Gongolaria barbata under controlled culture conditions. During the experiment, red-blue (RB), blue-green (BG), red-green (RG) and fluorescent lights were examined at 16:16, 12:12, and 8:16 Light: Dark (L:D) photoperiods, and at 150 μmol photon m-2 s-1 intensity of light in all treatments. The elemental compositions of the thallus samples were analyzed for Mg, Ca, K, Na, P, Zn, Mo, Cu, Mn, Cr, Co, Cd, Fe, and As.. Our results showed that macro element and trace element compositions significantly varied among different experimental groups. Regarding the order of abundance, macroelements were ranked as follows: K > Na > Ca > Mg > P. Meanwhile, trace elements followed this order: As > Zn > Mn > Cr > Co > Cu > Cd > Mo > Fe. Among the experiment groups, the highest value of the macro elements was recorded as 1041.3±22.2 mg kg-1 for K, and the lowest value was 26.61±0.02 mg kg-1 for the P. Among the trace elements, for As, the highest value was recorded as 1339.86±5.27 µg kg -1, and the lowest was determined at 1.93±0.04 mg kg-1 for the Fe. The findings highlight that LED lighting conditions can significantly influence the elemental composition of G. barbata.
Bu çalışmanın amacı, kontrol koşullarında yetiştirilen Gongolaria barbata’nın mineral içeriği ve iz element değişimleri üzerinde üç farklı dikromatik LED ışık ve değişen fotoperiyot sürelerinin etkisini araştırmaktır. Deneme aşamasında, kırmızı-mavi (RB), kırmızı-yeşil (RG), mavi-yeşil (BG) ve floresan (F) LEDler, sırasıyla 16:16, 12:12 ve 8:16 Aydınlık:Karanlık (L:D) fotoperiyotlarında, her biri 150 μmol photon m-2 s-1 yoğunluğunda incelenmiştir. Tallusların; Ca, K, Mg, Na, P, Zn, Mo, Mn, Fe, Cu, Cr, Co, Cd ve As kompozisyonları analiz edilmiştir. Sonuçlarımıza göre, makroelement ve iz element kompozisyonları farklı deney grupları arasında önemli varyasyonlar gösterdi. Türde bulunan makroelementlerin sıralaması şu şekildedir: K > Na > Ca > Mg > P, aynı zamanda iz elementler şu sırayı takip etmektedir: As > Zn > Mn > Cr > Co > Cu > Cd > Mo > Fe. Deneme grupları arasında, makro elementlerin en yüksek değeri K elementi için 1041.3±22.2 mg kg-1 olarak belirlenirken, en düşük değer P için 26.607±0.02 mg kg-1 olarak belirlendi. İz elementler arasında ise en yüksek değer As için 1339.86±5.27 µg kg-1 tespit edilirken, en düşük değer Fe için 1.930±0.04 mg kg-1 olarak belirlendi. Bulgular, LED aydınlatma koşullarının G. barbata türünün elementel kompozisyonunu önemli ölçüde etkileyebileceğini vurgulamaktadır.
In this study, the antioxidant activities, total polyphenolic contents of algal extracts from Gongolaria barbata were examined by using ethyl acetate (AcOEt), water(W), and phosphate buffer (PH) as ...solvents. According to the results, EtOH, W, and PB showed medium antioxidant potential with low IC50 values. The highest total flavonoid content was detected in W (6.91±0.09 mg/g Ext., and PB showed the maximum phenolic content (2.29±0.01 mg GAE/g ext.). The chlorophyll a and total carotenoid contents were detected as 40.5±1.20 and 29.13±1.12 (mg/g DW), respectively. Phycoerythrin was 0.002±0.001 (mg/g DW), while phycocyanin content was found as0.04 ±0.01 (mg/g DW). Our results show that PB could be used as an extraction solvent for determining the antioxidant properties of G. barbata instead of ethanol.
Bu çalışmada, Gongolaria barbata'dan elde edilen alg ekstraktlarının antioksidan aktiviteleri, toplam fenolik ve flavonoid içerikleri sırasıyla farklı çözücüler kullanılarak incelenmiştir: etil asetat (AcOEt), su(W) ve fosfat tamponu (PH). Sonuçlara göre EtOH, W ve PB çözücüleri, sırasıyla test edilen iki ticari antioksidan olan BHT ve Vitamin C'den önemli ölçüde daha yüksek olduğu ve düşük IC50 değerleri ile orta düzeyde antioksidan potansiyeli gösterdiği kaydedildi. En yüksek toplam flavonoid içeriği W (6.91±0,09 mg/g Ext.) olarak tespit edildi ve PB en yüksek fenolik içeriği (2.29±0.01 mg GAE/g ext.) gösterdi. Klorofil a ve toplam karotenoid değerleri sırasıyla 40,5±1,20 ve 29,13±1,12 (mg/g DW) olarak ölçüldü. Fikoeritrin 0.002±0.001 (mg/g DW) olarak ölçülürken, fikosiyanin içeriği 0.04 ±0.01 (mg/g DW) olarak bulundu. Çalışmamızın sonucuna göre, Gongolaria barbata’nın antioksidan içerikleri, toplam fenolik ve flavonoid içerikleri incelendiğinde, fosfat tamponunun etanolün yerine kullanılabilecek bir çözücü olduğu belirlenmiştir.
Several anthropogenic factors are responsible for the decline of
Cystoseira sensu lato
(hereafter
Cystoseira
) forests along Mediterranean coasts. Some
Cystoseira
species are already regionally ...extinct, and their decline has been widely recorded. Sustainable and efficient techniques for the restoration of
Cystoseira
are needed. In this context, the objectives of this study were i) to analyse the reproductive traits of three populations of
Gongolaria barbata
from three nearby donor sites in the northern Adriatic Sea, assessing the differences in their reproductive potential and reproductive success; and ii) to evaluate the outplanting success in terms of the effectiveness of
G. barbata
restoration, in relation to the different donor and receiving sites (Miramare MPA and in front of the Marine Biology Station Piran - MBSP) and implemented methods (
ex situ
and hybrid method combining a mesocosm cultivation and a suspended culture in the field). After 2 weeks of cultivation in mesocosms, half of the tiles with germlings were transported to the receiving sites and placed on suspended lantern nets (hybrid method), which were later (after 3 months) transferred to the seabed on concrete plates with protective cages. The remaining tiles were placed on the seabed on concrete plates with protective cages after a 4-week culture (
ex situ
method). At both sites, lantern nets and plates were randomly placed at 3 m depth. Thallus length was measured monthly in each treatment. Seedlings in suspended culture showed lower performance at the Miramare MPA, most likely due to the unfavourable environmental conditions. The satisfactory results obtained at MBSP demonstrate the efficiency of the hybrid method and confirm its potential to reduce the cost and time required for cultivation. Since unpredictable climatic events pose the greatest threat to restoration performance, these challenges must be considered when establishing new restoration practices. Moreover, herbivore regulation is extremely urgent and should be planned and implemented on a larger regional scale.
As a result of several anthropogenic factors,
Cystoseira
sensu lato forests have declined or become regionally extinct in many coastal regions of the Mediterranean. Given the low natural recovery of ...lost populations, research efforts have been encouraged to develop sustainable and efficient restoration of macroalgal forests on a large scale. By promoting growth and fertility of collected thallus branches under controlled laboratory conditions, the availability of seedlings for restoration could be ensured without jeopardizing natural populations. Here we investigated the effect of a commercial algal biostimulant (AlgatronCifo®) on the photophysiology, growth and fertility of
Gongolaria barbata
(Stackhouse) Kuntze (Fucales, Phaeophyceae). In a factorial laboratory experiment, two different temperatures (10 ºC and 14 °C) and two culture media i.e. seawater (SW) and Algatron (AT) were tested. The photosynthetic performance of
G. barbata
doubled after three weeks of culture with AT, while it decreased by 25% when cultivated in SW. The highest photosynthetic performance and growth were achieved at 14ºC with AT, where fertile receptacles also developed, followed by seedling settlements. The thalli cultured in AT had similar or better photosynthetic performance than the initial control thalli. AT-cultured thalli had a greater ability to quench energy via photochemical pathways (q
P
) than those from the SW, which on the contrary, had higher levels of non-photochemical responses (q
N
, NPQ
max
). This limited photosynthetic performance was probably linked to the higher P-limitation experienced under that treatment. The algal biostimulant enhanced the physiological performance and induced fertility of
G. barbata
, demonstrating its valorization potential and setting a new path for improved restoration applications.
Gongolaria barbata plays a crucial role as a habitat-forming Fucales species in the Mediterranean Sea, thriving in shallow, sheltered coastal regions, where it exhibits optimal growth in a ...temperature range of 10 to 25 °C. In the northern Adriatic Sea, a semi-enclosed part of the Mediterranean, there has been a remarkable increase in seawater temperatures in recent decades, often exceeding 28 °C in summer. These high temperatures pose a significant threat to the vulnerable early life stages of G. barbata. This study delves into the effects of four temperatures (15, 18, 24, and 28 °C) on the growth of G. barbata over its first 16 days, closely monitoring mortality, deformities, and overall survival. Our experiments reveal that higher temperatures can result in deformities and increased mortality of germlings. Notably, a temperature of 28 °C resulted in the death of all germlings within the first week, whereas those exposed to 24 °C survived until the second week, albeit with significant deformities prior to death. In contrast, germlings cultivated at 15 and 18 °C exhibited normal development with minimal deformities. These results highlight the susceptibility of the early life stages of G. barbata to temperature-induced stress and provide valuable insights into the potential consequences of rising seawater temperatures in the Mediterranean.
Seaweeds cover a wide range of applications, e.g. as food supplements, in animal feed, as biofuels or as sources of bioactive compounds. The Greek coast in the East Mediterranean is rich in various ...seaweeds that remain unexploited because their chemical and nutritional content has not yet been characterized. In the present study, eight seaweeds belonging to the Rhodophyta, Ochrophyta (class Phaeophyceae) and Chlorophyta were biochemically characterized and evaluated as potential food sources. Total polyphenol content, antioxidant activity, fatty acids and elemental composition were measured.
sp. (Rhodophyta)
(Chlorophyta)
and
(formerly
) (Ochrophyta, Phaeophyceae) had the highest phenolic content and strongest antioxidant activity. Both brown and red seaweeds were rich in minerals, with
(formerly
) (Chlorophyta, Phaeophyceae) and
being the richest in macro- and microelements. The low Na/K ratio in most seaweeds (0.03–3.49) and the high iron content of red and brown algae (1.01–52.40 mg 100 g
of wet tissue) make algal consumption an attractive option. Chlorophyta and Phaeophyceae had the lowest n-6/n-3 PUFA ratios, with α-linolenic acid being the most abundant n-3 PUFA. The green algae
and
had the highest oleic and docosahexaenoic acid content, respectively. Finally, Rhodophyta were the highest producers of eicosapentaenoic acid. The findings confirmed the nutritional value of all seaweeds, highlighting brown seaweeds
,
, and
as potential sources for food supplements and candidate species for seaweed cultivation in Mediterranean coastal waters.
Brown algae from genus
form dense underwater forests that represent the most productive areas in the Mediterranean Sea. Due to the combined effects of global and local stressors such as climate ...change, urbanization, and herbivore outbreaks, there has been a severe decline in brown algal forests in the Mediterranean Sea. Natural recovery of depleted sites is unlikely due to the low dispersal capacity of these species, and efficient techniques to restore such habitats are needed. In this context, the aims of our study were (1) to improve and simplify the current ex situ laboratory protocol for the cultivation of
by testing the feasibility of some cost-effective and time-efficient techniques on two donor sites of
and (2) to evaluate the survival and growth of young thalli during the laboratory phase and during the most critical five months after out-planting. Specifically, the following ex situ cultivation methods were tested: (A) cultivation on clay tiles in mesocosms with culture water prepared by three different procedures (a) filtered seawater with a 0.22 μm filter membrane, (b) filtered seawater with a 0.7 μm filter membrane (GF), and (c) UV-sterilized water, and (B) cultivation on clay tiles in open laboratory systems. After two weeks, all thalli were fixed to plastic lantern net baskets suspended at a depth of 2 m in the coastal sea (hybrid method), and the algal success was monitored in relation to the different donor sites and cultivation protocol. The satisfactory results of this study indicate that UV-sterilized water is suitable for the cultivation of
in mesocosm, which significantly reduces the cost of the laboratory phase. This opens the possibility of numerous and frequent algal cultures during the reproductive period of the species. Additionally, if the young thalli remain in the lantern net baskets for an extended period of several months, they can grow significantly in the marine environment without being exposed to pressure from herbivorous fish.
The global decline of brown algal forests along rocky coasts is causing an exceptional biodiversity loss. Regardless of conservation efforts, different techniques have been developed for large-scale ...restoration strategies in the Mediterranean Sea. In this study we tested ex situ pilot restoration of
(=
) for the first time in Slovenian coastal waters. Healthy apical fronds of the species were collected and the development of recruits on clay tiles was followed under laboratory conditions for 20 days. Despite the experimental difficulties experienced, especially due to the lack of antibiotics to prevent the growth of the biofilm,
recruits were outplanted in the sea on two concrete plates with 48 tiles each, protected by purpose-built cages to avoid grazing by herbivorous fish. The high survival rate of juveniles after four months in the field (89% of the tiles on the plate that was constantly protected) suggests that outplanting
is an operable approach for restoration efforts in the northern Adriatic Sea. Our first experiment in Slovenian coastal waters provides new information for the optimization of the best practices during the laboratory cultivation and addresses the early steps of restoration and introduction of young thalli in the natural environment.
Introduction
Active restoration is the strategy needed to trigger or accelerate the recovery of degraded marine habitats, which provide the goods and services essential for preserving biodiversity ...and human wellbeing. Ecosystem engineers are generally the target species in the ecological restoration of marine ecosystems, and large-sized brown macroalgae (e.g., the
Cystoseira
complex) are a priority due to their crucial ecological importance and vulnerability in many regions of the Mediterranean Sea.
Methods
Here, we present the results of a successful intervention of ecological restoration of
Gongolaria barbata
.
Results and Discussion
One year after the restoration intervention, we observed the recovery of the canopy in terms of ca. 15m
2
with a significant increase in faunal abundance and biodiversity compared with reference areas. However, despite the high restored macroalgal growth rates, the assemblage structure was still significantly different from that of reference pristine areas. Despite the fast faunal colonization of a new 3D habitat linked to the successful re-introduction of the ecosystem engineers (i.e., macroalgae), the complete restoration of the properties of a habitat can be a much longer process. We conclude that, after 1 year, active restoration of macroalgal forests still results in a partial recovery of ecosystem functions (i.e., rehabilitation) rather than a full ecosystem restoration, thus stressing the need for long-term monitoring of restoration interventions.
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