Average Biomass Research Articles

The state of the Ahnfeltia field and species composition of macrophytes in Izmena Bay of Kunashir Island (Southern Kuriles Islands)

Aim: the generalization of long-term results of a study of the Ahnfeltia formation and the species composition and distribution of the macrophytes in Izmena Bay (Kunashir Island).Method: data analysis was carried out on the basis of data obtained in 1989–2019 according on recommended methods of fisheries research.Novelty: data on the state of the Ahnfeltia formation and the species composition and distribution of macrophytes in Izmena Bay of Kunashir.Result: Since 2014, there has been a decrease in all parameters of the Ahnfeltia field: average layer height, biomass, total area and field reserve. The decline was particularly significant in 2019. The likely reason is fishing in the center of the field with fracturing against the backdrop of a general decline in the stock. In despit of a fairly significant species composition of macrophytes in the Izmena Bay, except for two species of sea grasses, in 1989–2019, most often, 3 types of algae are found — Chondrus armatus, Chorda asiatica and Chaetomorpha linum, which form settlements of varying densities. The general list of macrophytes found includes 79 species. Of these, more than 40 species are facultative epiphytes.Practical significance: The results will be used to make recommendations for the sustainable use of the commercial seaweed Ahnfeltia fastigiata var.tobuchiensis.

Estimación de biomasa y carbono aéreo en bosques templados del sur de México

Forest inventories are tools that allow the collection and recording of information for the estimation of volume and biomass in order to determine carbon sequestration in forest biomass using regression techniques. The objective of the study was to generate allometric equation parameters that accurately estimate the biomass and total aboveground carbon content of 25 temperate species from UMAFOR 2012, San Juan Quiahije, Oaxaca. Circular sampling sites of 1000 m2 were established, where the normal diameter and total height of 16 863 trees of 25 species were taken; subsequently, biomass and aboveground carbon content were estimated through allometric equations, using SAS software. The simultaneous potential equation had the best goodness of fit, where the adjusted coefficient of determination (R2adj) was over 87% for total biomass, while the total carbon estimate had an R2adj of 99% for all species. Pinus maximinoi had the highest average biomass (35 971.85 and 2 922.03 kg) and carbon content (17 985.92 and 1 462.01 kg) in branches and stems, respectively.

Carbon stock quantification in a floodplain restoration chronosequence along a Mediterranean-montane riparian corridor

Uncertainty in the global carbon (C) budget has been reduced for most stocks, though it remains incomplete by not considering aquatic and transitional zone carbon stocks. A key issue preventing such complete accounting is a lack of available C data within these aquatic and aquatic-terrestrial transitional ecosystems. Concurrently, quantifiable results produced by restoration practices that explicitly target C stock accumulation and sequestration remain inconsistent or undocumented. To support a more complete carbon budget and identify impacts on C stock accumulation from restoration treatment actions, we investigated C stock values in a Mediterranean-montane riparian floodplain system in California, USA. We quantified the C stock in aboveground biomass, large wood, and litter in addition to the C and total nitrogen in the upper soil profile (5 cm) across 23 unique restoration treatments and remnant old-growth forests. Treatments span 40 years of restoration actions along seven river kilometers of the Cosumnes River, and include process-based (limited intervention), assisted (horticultural planting and other intensive restoration activities), hybrid (a combination of process and assisted actions), and remnant (old-growth forests that were not created with restoration actions) sites. Total C values measured up to 1100 Mg ha−1 and averaged 129 Mg ha−1 with biomass contributing the most to individual plot measurements. From 2012 to 2020, biomass C stock measurements showed an average 32 Mg ha−1 increase across all treatments, though treatment specific values varied. While remnant forest plots held the highest average C values across all stocks (336 Mg ha−1), C values of different stocks varied across treatment type. Process-based restoration treatments held more average biomass C (120 Mg ha−1) than hybrid (23 Mg ha−1) or assisted restoration treatments (50 Mg ha−1), while assisted restoration treatments held more average total C in soil and litter (58 Mg ha−1) than hybrid (35 Mg ha−1) and process-based restoration treatments (37 Mg ha−1). Regardless of treatment type, time was a significant factor for all C stock values. These findings support a more inclusive global carbon budget and provide valuable insight into restoration treatment actions that support C stock accumulation.

The relationship between soil biomass and soil quality index for Kafr El-Dawar region, Beheira Governorate

The current investigation was conducted in the Kafr El-Dawar region to study the relationship between soil microbial biomass and soil quality index. Thirty-nine soil samples were taken for the chemical characteristics used to determine the soil quality index by the Soil Management Assessment Framework (SMAF) procedures. Pearson correlation relationship and Principal components analysis (PCA) between soil quality index and soil parameters were done as well as regression between soil quality index and microbial biomass. For the soil microbial biomass, the lowest value was about 186 mg kg-1 (5% of the total samples). The highest value was about 387 mg kg-1 (5% of the total samples). The average microbial biomass of the samples was about 299 mg kg 1. Approximately 50% of the total samples have a value equal to the average sample value. Higher significant correlation was observed among soil pH with CaCO3 content. Significant correlation was observed among soil pH with Fe and Mn. Soil quality index had a higher significant correlation with Ca, Mg, N, K, Cu, and Zn. P was a more effective factor on soil quality index. The chemical properties had the most impact on the soil quality index. All samples have a soil quality index score of less than 50%. About 69.2% were poor quality (SQI less than 40%), and the rest were moderate quality (SQI between 40 and 60%). Microbial biomass is a key soil characteristic that influences soil quality according to the regression result. Further research should include biological and other physicochemical soil properties to enlarge soil quality index.

The use of thioxopyrimidine derivatives for the regulation of vegetative growth of wheat

The work is devoted to the screening of new effective wheat plant growth regulators based on synthetic compounds, thioxopyrimidine derivatives. The wheat (Triticum aestivum L.) variety Oksamit Mironivskyi was used as the object of the study. Morphometric parameters (average length of shoots and roots (mm), and average biomass of 10 plants (g)) of 4-week-old wheat plants were measured. Treatment of wheat plants with thioxopyrimidine derivatives at a concentration of 10-6 M contributed to the growth and development of shoots and roots compared to control wheat plants treated with distilled water. The regulatory effect of thioxopyrimidine derivatives on the vegetative growth of wheat plants was similar to the regulatory effect of auxin IAA (1H-indol-3-yl)acetic acid) or synthetic compounds, derivatives of sodium and potassium salts of 6-methyl-2-mercapto-4-hydroxypyrimidine (Methyur, Kamethur) and N-oxide-2,6-dimethylpyridine (Ivin) used in the same concentration of 10-6 M. The correlation between the growth regulatory effect and the chemical structure of synthetic compounds, thioxopyrimidine derivatives was established. The selected most active synthetic compounds, thioxopyrimidine derivatives, are proposed to be used to improve the vegetative growth of wheat (T. aestivum L.) variety Oksamit Mironivskyi.

Registration of ‘Independence’ switchgrass

AbstractSwitchgrass (Panicum virgatum L.), a valuable forage and bioenergy crop, is established more easily than other native perennial warm‐season grasses, but its establishment is still slower than that of annual crops. Vigorous switchgrass establishment is crucial for achieving its full potential yield and for effectively competing with weeds for water and nutrient availability. To satisfy this demand, ‘Independence’ (Reg. no. CV‐295, PI 704577) switchgrass was developed at the University of Illinois at Urbana‐Champaign. Independence was selected for establishment vigor, winter survivorship, and high biomass yield for two cycles from ‘Kanlow’. It is characterized by rapid establishment, robust seedling growth, and the capacity to achieve peak production by the second year. Independence is well adapted to USDA hardiness zones 5b–7b. In field experiments conducted from 2016 to 2017, averaged over seven locations and all years, Independence annually yielded 13 Mg ha−1 of biomass, outperforming ‘Cave‐in‐Rock’ by 31%, ‘Liberty’ by 15%, ‘Shawnee’ by 42%, ‘Summer’ by 81%, and ‘Sunburst’ by 129%. In wet marginal sites in Illinois from 2020 to 2023, Independence exhibited an average biomass yield of 12 Mg ha−1, outperforming Shawnee by 31%, Liberty by 27%, and Kanlow by 19%, indicating its potential use on less productive land for annual crops. Independence was publicly released by the University of Illinois at Urbana‐Champaign in October 2021.

Low-cost cultivation of Nannochloropsis oceanica in newly designed photobioreactors and its productivity trends in semi-continuous cultivation under inland outdoor conditions

Most marine microalgae are typically cultivated in coastal areas due to challenges in inland cultivation. In this 185 days experiment, Nannochloropsis oceanica was semi-continuously cultivated inland using different photobioreactors (PBRs). The newly designed 700-liter (L) PBR exhibited tolerance to seasonal changes compared to the 150-L PBRs. The innovative in-situ oxygen release rate (ORR) measurement method results indicated that ORR was influenced by light intensity and temperature. The optimal temperature range for N. oceanica growth was 14–25 ℃, demonstrated cold tolerance and lipid accumulation at low temperatures. The maximum lipid content in 700-L and 150-L PBRs was 29 % and 28 %, respectively. Based on the average biomass productivity, the price of N. oceanica was $11.89 kg−1 (or $3.35 kg−1 based on maximum biomass productivity), which is cheaper than the current market price of $20.19 kg−1. From results, smaller PBRs at the same hydro electricity price are more cost-effective.

Cadmium phytoremediation potential of Houttuynia cordata: Insights from growth, uptake, and rhizosphere mechanisms

Cadmium (Cd) pollutes 7.0 % of China’s land area. This study examined the potential of Houttuynia cordata for Cd phytoremediation because of its ability to accumulate Cd in its growth matrix. H. cordata were planted in plastic pots filled with paddy field soils having low (LCd), medium (MCd), and high (HCd) Cd levels of 0.19, 0.69, and 2.91 mg/kg, respectively. After six months of growth, harvested plant parts were evaluated for Cd uptake and tolerance mechanisms. Metabolomics and metagenomics approaches were employed to investigate the soil rhizosphere mechanism. Results showed that the average plant biomass increased as soil Cd increased. The biomass Cd contents surpassed the allowable Cd limits for food (≤ 0.2 mg/kg) and medicinal uses (≤ 0.3 mg/kg). Cd contents were higher in H. cordata roots (30.59–86.27 mg/kg) than in other plant parts (0.63–2.90 mg/kg), with significantly increasing values as Cd soil level increased. Phenolic acids, lipids, amino acids and derivatives, organic acids, and alkaloids comprised the majority (69 in MCd vs HCd and 73 % in LCd vs HCd) of the shared upregulated metabolites. In addition, 13 metabolites specific to H. cordata root exudates were significantly increased. The top two principal metabolic pathways were arginine and proline metabolism, and beta-alanine metabolism. H. cordata increased the abundance of Firmicutes and Glomeromycota across all three Cd levels, and also stimulated the growth of Patescibacteria, Rozellomycota, and Claroideoglomus in HCd. Accordingly, H. cordata demonstrated potential for remediation of Cd-contaminated soils, and safety measures for its production and food use must be highly considered.

Variation in population assemblage of Acanthuridae and Scaridae across human concentration levels during a bleaching event affecting the coral reefs of Guna Yala, Panama

Abstract Coral reefs are the ocean's most productive ecosystem, supporting a huge amount of biodiversity, and are relied upon by millions of people worldwide. As we progress into the Anthropocene, coral reef ecosystems are increasingly threatened by a swath of pressures. Of the most impactful are El-Niño Southern Oscillation-related heat pulses, which result in the bleaching and potential mortality of coral reefs. Bleaching events, in synergy with other threats, are increasing algal-dominated reefs, which impact the productiveness of coral reef ecosystems. Herbivorous fish are the prominent algal consumers and are essential in controlling algal blooms. Species from the family Acanthuridae and Scaridae are the most conspicuous of herbivorous fish on coral reefs, and through a diverse array of physiological differences compose several unique functional groups. The population distribution of Acanthuridae and Scaridae are directly correlated with coral reef characteristics and composition and can suffer from bleaching events as well. Despite their importance in maintaining reef health and improving resilience to disturbances, there is a very scarce collection of literature that describes the population assemblage of Acanthuridae and Scaridae spp. during bleaching events. This study aims to contribute to this underreported phenomenon. Visual surveys of Acanthuridae and Scaridae species were conducted to measure the average density, mean size, and biomass in terms of coral reef characteristics across a human concentration gradient in Guna Yala, Panama. Results suggest a similar overall abundance of herbivorous fish between the two reef locations, with significantly larger sizes and biomass of A. coeruelus, S. aurofrenatum, S. viride, and S. iseri in reefs further away from human concentration. This correlates with significantly higher rugosity on these reefs. The mean size of each respective species appears to be lower than previously reported across the Caribbean. Additionally, the biomass distribution was strikingly skewed by S. viride which corresponds to almost ¾ of the total biomass. This indicates that the current bleaching event is having drastic impacts on the distribution of herbivorous fish populations, which is exacerbated by proximity to human concentration. This can have very negative consequences for the recovery of these reefs following the bleaching event. Of specific concern are the coral reefs closer to humans. Data from benthic composition surveys show that macroalgae cover and overall coral bleaching are significantly higher compared to reefs far from humans. This study provides vital information that may be useful for future studies to identify coral reef resilience to bleaching events through the scope of Acanthuridae and Scaridae population distribution. Lay Summary The ocean is a crucial and largely unexplored part of our planet. One area that has begun to receive sufficient scientific attention is coral reefs. This is because, despite only covering less than 1% of the ocean’s surface, coral reefs support a quarter of all marine life. This rich environment provides more than a billion people with their primary source of protein and offers coastal protection to hundreds of millions of people. However, the future of coral reefs is under threat. Due to climate change and human pressures, coral reefs are facing mortality on a worldwide scale. Of the most lethal are bleaching events, when the water temperature rises past the threshold of coral, and they turn white and die. At the same time, corals face a daily threat from increasing algae coverage, which can smother and kill the coral. These threats have intensified in the recent few decades and may permanently alter the biodiversity and productivity of coral reefs. Understanding these changes is of utmost importance, and one way to do so is to study the animals that eat algae and give coral a chance to thrive—herbivorous fish. This paper analyzes the population distribution of two herbivorous fish families: Acanthuridae (surgeonfish) and Scaridae (parrotfish) during a bleaching event. Learning how a bleachingevent can impact the presence of these essential species among coral reefs has rarely been accomplished in scientific literature, so this paper offers valuable contributions to a more comprehensive understanding of reef health during bleaching events and our changing world.

Investigation and analysis of the community structure characteristics of zooplankton in Zibo

In order to understand the water ecological environment and the characteristics of plankton community structure in the Zibo area, a survey and study of plankton was conducted in the Zibo Basin in the autumn of 2022. By collecting zooplankton from nine major rivers within the country, a total of 122 species were collected from four phyla. Among them, rotifers are the most abundant, with a total of 77 species, accounting for 63%; Next are protozoa, with a total of 24 species, accounting for 20%; There are a total of 11 species of cladocerans, accounting for 9%; There are 10 species of copepods, accounting for 8%. The average density is 229.58/L, and the average biomass of zooplankton is 2.1997mg/L. The Shannon Wiener diversity index for zooplankton is 3.35. The survey results show that the water quality in the Zibo section is generally in a light pollution state. It is recommended to take further effective measures to strengthen the environmental governance around the watershed, reduce the discharge of domestic sewage, and reduce human activity interference.

Costus speciosus (Koen ex. Retz.) Sm.: a suitable plant species for remediation of crude oil and mercury-contaminated soil.

The aim of this study was to evaluate the efficiency of Costus speciosus (Koen ex. Retz.) Sm. in the degradation of crude oil and reduction of mercury (Hg) from the contaminated soil in pot experiments in the net house for 180days. C. speciosus was transplanted in soil containing 19150mgkg-1 crude oil and 3.2mgkg-1 Hg. The study includes the evaluation of plant biomass, height, root length, total petroleum hydrocarbon (TPH) degradation, and Hg reduction in soil, TPH, and Hg accumulation in plants grown in fertilized and unfertilized pots, chlorophyll production, and rhizospheric most probable number (MPN) at 60-day interval. The average biomass production and heights of C. speciosus in contaminated treatments were significantly (p < 0.05) lower compared to the unvegetated control. Plants grown in contaminated soil showed relatively reduced root surface area compared to the uncontaminated treatments. TPH degradation in planted fertilized, unplanted, and planted unfertilized pot was 63%, 0.8%, and 38%, respectively. However, compared to unvegetated treatments, TPH degradation was significantly higher (p < 0.05) in vegetated treatments. A comparison of fertilized and unfertilized soils showed that TPH accumulation in plant roots and shoots was relatively higher in fertilized soils. Hg degradation in soil was significantly (p < 0.05) more in planted treatment compared to unplanted treatments. The fertilized soil showed relatively more Hg degradation in soil and its accumulation in roots and shoots of plants in comparison to unfertilized soil. MPN in treatments with plants was significantly greater (p < 0.05) than without plants. The plant's ability to produce biomass, chlorophyll, break down crude oil, reduce Hg levels in soil, and accumulate TPH and Hg in roots and shoots of the plant all point to the possibility of using this plant to remove TPH and Hg from soil.

Ecological characteristics and seasonal changes of macrozoobenthos in the waters of Miaodao Archipelago, China

To understand the macrozoobenthic community composition and spatial-temporal distribution characteristics of macrobenthos in the waters of Miaodao Archipelago, Yantai, Shandong and its response to habitat changes, we conducted surveys of macrobenthos and environmental elements in the waters of Miaodao Islands in May (spring), August (summer), and October (autumn) in 2022. Results showed that a total of 127 macrozoobenthic species were recorded, with Mollusca and Annelida (Polychaeta) as the dominant taxa, consisting of 47 and 45 species, respectively. The key dominant species included Sternaspis chinensis, Glycinde bonhourei, Moerella hilaris, and Amphioplus (Lymanella) japonicus. The average annual density and biomass of macrozoobenthos were 190 ind·m-2 and 28.69 g·m-2, respectively. There was no significant seasonal differences in density and biomass. The Shannon diversity index (H), evenness index (J), and richness index (D) averaged 3.10, 0.90, and 2.40, respectively. Cluster analysis results showed low similarity coefficients of community among the three seasons, suggesting a distinct distribution pattern. Factors such as bottom seawater temperature, chlorophyll a, nutrient, sediment grain size, and organic matter content could significantly influence the structure and diversity of macrozoobenthic community. Compared with historical research data, the Changdao National Wetland Nature Reserve and the implementation of enclosure aquaculture have led to notable changes in the dominant species of macrobenthos. Specifically, there was a noticeable decline in both density and H, and an increase in biomass and J. Additionally, body size of benthic fauna was transitioning from small to big.

Canteen waste as food for black soldier fly larvae: risk of heavy metals accumulation? Variability during one year of rearing

Abstract Worldwide, about 244 million t/yr of waste are produced by canteens and restaurant, of which 4.7 million t/yr are generated at the Italian level. Canteen waste (CW) could be used for feeding larvae of insect to obtain new marketable products (e.g. protein meal, frass and chitin). Black Soldier Fly Larvae (BSFL) are voracious and polyphagous species, and CW is a complete food for them. Furthermore, BSFL are capable to bioaccumulate some heavy metals thus allowing to obtain safe organic frass, but the bioaccumulation in larvae intended for feed purpose needs to be evaluated. The CW was sampled once a month and the sampling was carried out for a year from a local canteen, located in the northern part of Italy. The feeding was conducted in quadruplicate in plastic containers (12 l) and 2,000 g of CW and 2,000 5 days-old larvae were allocated in each box. Each trial ended after 7 days and growth performances were evaluated. The results reported an average dry matter final larval biomass, along the year, of 83.8 ± 46.05 g and an average dry matter frass quantity equal to 199.9 ± 140.32 g. The percentage of dry matter for initial diet was 21.7 ± 14.10, for final larval biomass was 34.3 ± 7.39%, and for the residue of 62.2 ± 17.01%. The initial diet, BSFL before and after feeding, and the residue were sampled and oven dried. Elemental analyses were performed with a mass spectrometer in triplicate for evaluating arsenic, lead, cadmium, and mercury quantities within CW, residues and BSFL before and after feeding. This trial certifies the ability of BSFL to accumulate (BAF &gt; 1) arsenic (average of 0.165 ± 0.1480 ppm), lead (average of 0.238 ± 0.1562 ppm), cadmium (average of 0.077 ± 0.0367 ppm), and mercury (average of 0.008 ± 0.0043 ppm) during feeding, and it proves that the bioaccumulation complies with European legal limits on the amount of heavy metals in larvae.

Diatom bloom trigger notable variations in microzooplanktonic ciliate composition, body-size spectrum and biotic-abiotic interaction in the Arctic Ocean

How microzooplanktonic ciliate adaptative strategies differ across diatom bloom and non-diatom bloom areas in the Arctic Ocean remains poorly documented. To address this gap, two different situations were categorized in the Arctic Ocean at summer 2023: diatom bloom stations (DBS) (genus Thalassiosira, chain-like) and non-diatom bloom stations (nDBS). Total abundance of ciliate at 3 m and 25 m in DBS was 2.8 and 1.8 folds higher than in nDBS, respectively. Aloricate ciliates were singled out in both DBS and nDBS, whilst their average abundance and biomass of large size-fraction (>50 μm) in former were 4.5–5.6 folds higher than in latter. Regarding tintinnids, high abundance of Ptychocylis acuta (Bering Strait species) mainly occurred at DBS, coupled with distribution of co-occurring Pacific-origin species Salpingella sp.1, collectively suggested a strong intrusion of Pacific Inflow during summer 2023. Additionally, presence of high abundance of Acanthostomella norvegica and genus Parafavella in nDBS might indicate the trajectory of the Transpolar Drift. Alternatively, tintinnids can serve as credible bioindicators for either monitoring currents or evaluating microzooplankton Borealization. Average abundance of total ciliate within 15–135 μm body-size spectrum in DBS was higher than nDBS. Moreover, spearman's rank correlation between biotic and abiotic analysis revealed that temperature and dissolved oxygen at DBS determined tintinnid species richness and ciliate total abundance, respectively. The results clearly demonstrate that remarkable divergences in large size-fraction of ciliate abundance between DBS and nDBS validate their irreplaceable role in controlling phytoplankton outbreak and associated biological processes in polar seas.

Cage aquaculture of Indian pompano for livelihood diversification of artisanal fishers: Insights from Andhra Pradesh, India

Artisanal fishers fishing in nearshore coastal waters off Visakhapatnam using motorisedcrafts and in estuaries of Krishna using non-motorised crafts were selected for the study.Their annual net operating income varied between US$ 469.63 (₹39,040) and US$ 2698.42(₹2,24,320), respectively. Inspired by the potential of cage farming from the frontlinedemonstrations in marine and estuarine waters and after acquiring appropriate skills,15 individuals from the Traditional Fishermen’s Co-operative Society, Visakhapatnamand 76 individuals from Yanadri Girijana Matsya Sakhara Sangam, Krishna embarked oncage aquaculture of Indian pompano in 15 and 70 cages, respectively. Marine cages werecircular (6 m diameter) and estuarine cages were square (5 m X 5 m), and were stockedwith hatchery-produced Indian pompano (Trachinotus mookalee) fingerlings of 22.6 gweight @ 2500 and 1500 numbers respectively, and were fed with floating pellets at 8-3% ofbiomass. Average body weight, survival and biomass production from marine and estuarinecages after eight months of culture were 843 and 666 g, 96.28 and 91.47% and 2029.0 and913.85 kg respectively. Deducting all capital and operational expenses, annual net operatingincome per unit ranged from US$ 1247.44 (₹1,03,700) to US$ 2632.02 (₹2,18,800); whichrepresented a substantial increase from that of capture fishery. Cluster-cage farming, asadopted, did not adversely impact the water and sediment quality. The current researchoffers novel insights into the bio-growth and economic factors pertinent to commercial cagefarming of Indian pompano. Cage farming in marine and estuarine conditions holds a greatpromise as an alternative source of livelihood for artisanal fishers, thereby bolstering theireconomic sustainability. Keywords:Cage farming, Gross revenue, Indian Pompano, Netoperating income, Small scale fishers

Current state and long-term changes in the taxocene of marine polychaetes of the Karadag Nature Reserve (Republic of Crimea, Russian Federation)

Taxonomic and trophic structure and quantitative development of polychaetes are examined in the marine coastal areas of the Karadag Nature Reserve in 2021–2022. 40 species belonging to 30 genera and 15 families are discovered. From 1938 to 2022, 75 species have been recorded in this area. According to the nutritional spectrum, polyphages are the most represented, phytophages are the least represented. The average number of polychaetes in 2021–2022 is 100 ± 53 ind./m2, the average biomass is 3.55 ± 0.023 g/m2; S. papillocercusthe prevails in the total abundance and biomass, 98 and 99%, respectively. The change in the species composition, abundance and biomass of marine polychaetes of the Karadag Nature Reserve, inhabiting hard bottom substrates (1984–2022) and soft soils (1938–2021), is considered. From 1984 to 2021, 29 species of polychaetes have been recorded on soft substrates, and only two species in 2021–2022: Namanereis littoralis and Saccocirrus papillocercus. In underwater rock assemblages, on the contrary, the largest number of species (38) has been found in 2021–2022, and the smallest (14) in 1938–1940 (a total of 65 species found during 1938–2022). A transformation of the species composition and trophic structure of polychaetes occurred in the coastal biotopes of soft and hard bottom substrates in the marine area of the Karadag Nature Reserve from 1938 to 2022, with a decrease in the number of phytophages, as well as a decrease in quantitative characteristics. Presumably, the de crease in the number and diversity of polychaete worms on soft substrates is associated with a decrease in the macrophyte algae biomass. The results obtained, supplemented by data on the structure of phytocenoses and characteristic of bottom substrates, can be used in environmental monitoring of protected water areas of the Black Sea.

Macrobenthic Community Structure and Water Quality Evaluation in Ulungu River Basin (Northwest China)

In this study, the composition and structure of the macrobenthic community in the Ulungu River Basin was investigated and the water quality status of the basin was evaluated. In May and August 2022, and October 2023, the macrobenthic and water environmental factors at 11 sample sites in the basin were investigated, and the water quality of the basin was evaluated by the Shannon–Wiener index, FBI, and BMWP index. A total of 6101 macrobenthic organisms were collected; these organisms belonged to 3 phyla, 7 classes, 14 orders, 57 families, and 117 genera. Arthropod species accounted for the largest number of species (87.9%). A total of nine dominant species were found: Micronecta sp., Eukiefferiella sp., Baetis sp., Polypedilum sp., Saetheria sp., Ephemerella sp., Limnodrilus sp., Ephemera sp., and Hydropsyche sp. At the temporal level, the average density and biomass of macrobenthos were in the order of August &gt; October &gt; May; at the spatial level, the average density was greater in the tributaries than in the main stream, and the average biomass was greater in the main stream than in the tributaries. The mean values of the Shannon—Wiener index and Margalef richness index were as follows: August &gt; October &gt; May at the temporal level; the mean values of the Pielou evenness index were as follows: May &gt; October &gt; August at the temporal level. At the spatial level, the overall mean value of each diversity index indicated that the tributaries had larger diversity indices than the main stream. The water quality evaluation results revealed that the overall water quality level of the Ulungu River Basin ranges from light pollution to poor quality. Human interference activities greatly impact the water quality of the basin. To restore the ecology of the basin, it is necessary to strengthen the management and control of pollution sources.

Auxin-like and Cytokinin-like Effects of New Synthetic Thienopyrimidine Derivatives on the Growth and Photosynthesis of Wheat

The regulatory effect of new synthetic thienopyrimidine derivatives on the growth and photosynthesis of wheat (Triticum aestivum L.) variety Svitlana in the vegetative phase was studied. The regulatory effect of new synthetic thienopyrimidine derivatives was compared with the regulatory effect of auxin IAA (1H-indol-3-yl)acetic acid) or synthetic plant growth regulators Methyur (sodium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine) and Kamethur (potassium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine). After 2 weeks, morphometric parameters (such as average length of shoots and roots (mm), average biomass of 10 plants (g)) and biochemical parameters (such as content of photosynthetic pigments (µg/ml)) of wheat plants grown from seeds treated with synthetic thienopyrimidine derivatives, or auxin IAA, or synthetic plant growth regulators Methyur and Kamethur at a concentration of 10-6M, were measured and compared with similar parameters of control wheat plants grown from seeds treated with distilled water. The regulatory effect of new synthetic thienopyrimidine derivatives on the morphometric and biochemical parameters of wheat plants was similar or higher compared to the regulatory effect of auxin IAA, or synthetic plant growth regulators Methyur and Kamethur. The relationship between the chemical structure of new synthetic thienopyrimidine derivatives and their regulatory effect on the growth and photosynthesis of wheat plants was revealed. The most biologically active thienopyrimidine derivatives are proposed to be used as new synthetic physiological analogues of auxins and cytokinins to improve growth and increase photosynthesis of wheat (Triticum aestivum L.) variety Svitlana in the vegetative phase.

Decadal changes of macrofauna community in a semi-enclosed Bay of Yueqing in East China Sea

To reveal the long-term variation of macrofauna community in Yueqing Bay, an aquacultural bay famous for its shellfish culturing in the East China Sea, macrofauna samples were collected in three period from 2002 to 2003 and 2006–2007 to 2020–2021. The results show that macrofaunal community structure in this area has changed significantly (ANOSIM, p < 0.01) in nearly two decades with significant decreases in species number, biodiversity index and average biomass. Meanwhile, the taxa composition also changed significantly as the dominance of annelid increased while that of mollusks, echinoderms and vertebrates decreased. As a consequence of the variation of taxa composition and total biomass, macrofauna community showed a tendency of miniaturization as individuals with smaller body size and lower biomass dominated the community. According to the results of CCA analysis, temperature, salinity and dissolved oxygen content were the main environmental factors that restricted the species composition of macrofauna community. Further studies still needed to reveal the main reasons that cause the variation of macrofauna community. Overall, the results of this study suggest that the present status of Yueqing Bay benthic ecosystem is concerning from a macrobenthos perspective, as the biodiversity index and biomass of macrofauna decreased significantly. Effective measures should be taken in urgently to restrain the safety and function of coastal ecosystems.

Projecting contributions of marine protected areas to rebuild fish stocks under climate change

No-take marine protected areas (No-take MPAs) are considered as a major tool for conserving marine biodiversity and ecosystem services. No-take MPAs can also contribute to climate adaptation for exploited fish stocks. Meanwhile, many fish stocks in the world are overfished and management institutions are developing plans to rebuild them. Understanding the potential effects of no-take MPAs on fish stocks under climate change can help develop strategies for climate-resilient stock rebuilding. Here, using a linked climate-fish-fishing model, we undertake simulation experiments to examine the effects of no-take MPAs on biomass and potential catches of 231 exploited fish and invertebrate species in eight marine ecoregions in the Northeast Atlantic under climate change. The simulations include different levels of fishing, no-take MPAs coverage, atmospheric global warming levels, and account for the expected displacement of fishing to the area around the no-take MPAs. Average individual stock biomass is projected to decrease by 5–15% per degree Celsius atmospheric warming. Having 30% of the distribution of over-exploited fish stocks under no-take MPAs together with conservation-focused fisheries management of these stocks are projected to offset the negative impacts on their biomass under 2.6–2.9 °C global warming. Meanwhile, potential catches increase when a portion of the over-exploited fish stocks is protected from fishing as higher biomass in the no-take MPAs spills-over to the surrounding areas. Our findings highlight that no-take MPAs, combined with reducing fishing intensity, can help rebuild over-exploited fish biomass and benefit their dependent fisheries in the Northeast Atlantic under projected climate change in the 21st century.