Revisiting Indonesia's governance and conservation of cetaceans

Over the past few decades, Indonesia's marine conservation governance has been criticized. This article analyzes the overlaps and gaps in domestic law and policy regimes for cetaceans or marine mammal management and examines issues of institutional arrangements and legal frameworks related to cetacean conservation in Indonesia. The legal framework's progress on cetacean governance shows three distinct phases: 1975-1985 (species-focused governance approach), 1990-2009 (area-based approach), and 2010-present (broader marine governance approach). This study reveals that the main shortcoming of the legal framework is unclear mandates and overlapping jurisdictions. This study suggests several urgent policies that should be accommodated in the current legal regime to strengthen cetacean conservation. In addition, this research also recommends creating a collaboration mechanism between institutions and encouraging Indonesia to join as a full member of the International Whaling Commission and the Conservation of Migratory Species of Wild Animals Convention to strengthen cetacean governance and conservation.

In situ devices can culture the microbial dark matter of corals

Most microorganisms found in environmental samples have never been cultured and can often only be explored through molecular or microscopic approaches. Here, we adapt the use of in situ diffusion-based devices to culture "yet-to-be-cultured" microorganisms associated with coral mucus and compare this with a traditional culturing method. The culturability of microorganisms associated with mucus of the coral Pocillopora damicornis increased by 420% and 570% with diffusion growth chambers and microwell chip devices, respectively, compared with the traditional method tested. The obtained cultures represent up to 64.4% of the total diversity of amplicon sequence variants (ASVs) found in the mucus of the coral P. damicornis. In addition, some previously uncultured microorganisms, such as members of the family Nitrosopumilaceae and halophilic/halotolerant bacteria were cultured. Our results validate alternative microbial culturing strategies to culture coral-associated microorganisms, while significantly increasing the culturability of previous microbial dark matter.

The impacts of thermal heterogeneity across microhabitats on post-settlement selection of intertidal mussels

Rapid genetic selection is critical for allowing natural populations to adapt to different thermal environments such as those that occur across intertidal microhabitats with high degrees of thermal heterogeneity. To address the question of how thermal regimes influence selection and adaptation in the intertidal black mussel Mytilisepta virgata, we continuously recorded environmental temperatures in both tidal pools and emergent rock microhabitats and then assessed genetic differentiation, gene expression patterns, RNA editing level, and cardiac performance. Our results showed that the subpopulations in the tidal pool and on emergent rocks had different genetic structures and exhibited different physiological and molecular responses to high-temperature stress. These results indicate that environmental heterogeneity across microhabitats is important for driving genetic differentiation and shed light on the importance of post-settlement selection for adaptively modifying the genetic composition and thermal responses of these intertidal mussels.

Microbiota regulates life-cycle transition and nematocyte dynamics in jellyfish

Jellyfish represent one of the most basal animal groups with complex life cycles. The polyp-to-medusa transition, termed strobilation, is the pivotal process that determines the switch in swimming behavior and jellyfish blooms. Their microbiota plays an essential role in strobilation. Here, we investigated microbiota-mediated host phenotype dynamics during strobilation in the jellyfish Aurelia coerulea via antibiotic-induced microbiome alteration. Microbial depletion delayed the initiation of strobilation and resulted in fewer segments and ephyrae, which could be restored via microbial recolonization. Jellyfish-associated cyanobacteria, which were eliminated by antibiotics in the polyp stage, had the potential to supply retinal and trigger the retinoic acid signaling cascade, which drove the strobilation process. The microbiota regulated nematocyte development and differentiation, influencing the feeding and growth of the jellyfish. The findings improve our understanding of jellyfish-microbe interactions and provide new insights into the role of the microbiota in shaping feeding behavior through nematocyte dynamics.

Switching by cuttlefish of preying tactics targeted at moving prey

Previous studies have demonstrated that the size of the prey relative to the cuttlefish is important to the choice between tentacular strike and jump-on tactics. In the present study, we investigated the decision-making in the cuttlefish's tactical switch when preying on the same size prey. A servomotor system controlling the movement of a shrimp was used to elicit the cuttlefish's preying behavior. The success rate of prey capture and the kinematics of visual attack were examined systematically. The results showed that the jump-on behavior appeared mostly after a miss attack by previous tentacular strike on a moving shrimp. Compared with a visual attack with tentacles, the jump-on tactic has over a shorter attacking distance and wider attacking angles. Thus, these two different preying tactics have different operating ranges relative to the prey. More importantly, the cuttlefish can adjust their preying tactics adaptively depending on their prior preying experience.

Smart utilization of betaine lipids in the giant clam Tridacna crocea

The giant clam Tridacna crocea thrives in poorly nourished coral reef water by forming a holobiont with zooxanthellae and utilizing photosynthetic products of the symbiont. However, detailed metabolic crosstalk between clams and symbionts is elusive. Here, we discovered that the nonphosphorous microalgal betaine lipid DGCC (diacylglycerylcarboxy-hydroxymethylcholine) and its deacylated derivative GCC are present in all tissues and organs, including algae-free sperm and eggs, and are metabolized. Colocalization of DGCC and PC (phosphatidylcholine) evidenced by MS imaging suggested that DGCC functions as a PC substitute. The high content of GCC in digestive diverticula (DD) suggests that the algal DGCC was digested in DD for further utilization. Lipidomics analysis showing the organ-specific distribution pattern of DGCC species suggests active utilization of DGCC as membrane lipids in the clam. Thus, the utilization of zooxanthellal DGCC in animal cells is a unique evolutionary outcome in phosphorous-deficient coral reef waters.

Occurrence of polybrominated diphenyl ethers and benzotriazole UV stabilizers in the hadal amphipod Hirondellea gigas

The accumulation of polybrominated diphenyl ethers (PBDEs) and benzotriazole UV stabilizers (BZT-UVs) were examined in the hadal amphipod Hirondellea gigas caught from a near-land trench off the Japan island (9200 m). H. gigas were collected from two distinct sites: one is located at the outlet of submarine canyons directly connected to land and the other is apart from the outlet and geographically isolated from the first site. The level of the PBDEs in H. gigas at the canyon outlet (mean 219 ng/g lipid weight (l.w.)) was significantly higher than that in the isolated site (mean 42 ng/g l.w.) and BZT-UVs were only detected within the first site (mean 1.5 ng/g wet weight). In addition to vertical transport from the surface water, near-land trenches associated with submarine canyons and troughs may have more complex influx of contaminants through horizontal transportation from the land, resulting in more severe contamination.

Physiological and morphological plasticity in Stylophora pistillata larvae from Eilat, Israel, to shallow and mesophotic light conditions

Mesophotic reefs have been proposed as climate change refugia but are not synonymous ecosystems with shallow reefs and remain exposed to anthropogenic impacts. Planulae from the reef-building coral Stylophora pistillata, Gulf of Aqaba, from 5- and 45-m depth were tested ex situ for capacity to settle, grow, and acclimate to reciprocal light conditions. Skeletons were scanned by phase contrast-enhanced micro-CT to study morphology. Deep planulae had reduced volume, smaller diameter on settlement, and greater algal symbiont density. Light conditions did not have significant impact on settlement or mortality rates. Photosynthetic acclimation of algal symbionts was evident within 21-35 days after settlement but growth rate and polyp development were slower for individuals translocated away from their parental origin compared to controls. Though our data reveal rapid symbiont acclimation, reduced growth rates and limited capacity for skeletal modification likely limit the potential for mesophotic larvae to settle on shallow reefs.

Acclimation in intertidal animals reduces potential pathogen load and increases survival following a heatwave

Intertidal animals can experience intense heat during a heatwave, leading to mortality. The causes of death for intertidal animals following heatwaves have often been attributed to a breakdown in physiological processes. This, however, contrasts with research in other animals where heatwave mortality is attributed to existing or opportunistic diseases. We acclimated intertidal oysters to four treatment levels, including an antibiotic treatment, and then exposed all treatments to a 50°C heatwave for 2 h, replicating what can be experienced on Australian shorelines. We found that both acclimation and antibiotics increased survival and reduced the presence of potential pathogens. Non-acclimated oysters had a significant shift in their microbiome, with increasing abundances of bacteria from the Vibrio genera, including known potential pathogens. Our results demonstrate that bacterial infection plays a pivotal role in post-heatwave mortality. We anticipate these findings to inform the management of aquaculture and intertidal habitats as climate change intensifies.

Mechanosensory signal transmission in the arms and the nerve ring, an interarm connective, of Octopus bimaculoides

Octopuses coordinate their arms in a range of complex behaviors. In addition to brain-based sensorimotor integration and control, interarm coordination also occurs through a nerve ring at the arms' base. Here, we examine responses to mechanosensory stimulation of the arms by recording neural activity in the stimulated arm, the nerve ring, and other arms in a preparation of only the ring and arms. Arm axial nerve cords show graded responses to mechanosensory input and activity is transmitted proximally and distally in the arm. Mechanostimulation of one arm generates spiking in the nerve ring and in other arms. Activity in the nerve ring decreases with distance from the stimulated arm. Spontaneous activity with a range of spiking patterns occurs in the axial nerve cords and the nerve ring. These data show rich interarm signaling that supports arm control and coordination occurring outside of the brain.

A model of decentralized vision in the sea urchin Diadema africanum

Sea urchins can detect light and move in relation to luminous stimuli despite lacking eyes. They presumably detect light through photoreceptor cells distributed on their body surface. However, there is currently no mechanistic explanation of how these animals can process light to detect visual stimuli and produce oriented movement. Here, we present a model of decentralized vision in echinoderms that includes all known processing stages, from photoreceptor cells to radial nerve neurons to neurons contained in the oral nerve ring encircling the mouth of the animals. In the model, light stimuli captured by photoreceptor cells produce neural activity in the radial nerve neurons. In turn, neural activity in the radial nerves is integrated in the oral nerve ring to produce a profile of neural activity reaching spatially across several ambulacra. This neural activity is readout to produce a model of movement. The model captures previously published data on the behavior of sea urchin Diadema africanum probed with a variety of physical stimuli. The specific pattern of neural connections used in the model makes testable predictions on the properties of single neurons and aggregate neural behavior in Diadema africanum and other echinoderms, offering a potential understanding of the mechanism of visual orientation in these animals.

Marine biological injuries and their medical management: A narrative review

The marine environment can be extremely dangerous, and the harm caused by marine organisms when they contact the human body can be especially harmful, even deadly. Contact includes stings, bites, wounds, and consumption as food. In this article, the characteristics of the common marine biological injuries are summarized, the major marine organisms causing damage in China’s marine waters are described, and injury prevention and treatment methods are discussed.

Putative high-level toxicity pathways based on evidence of brevetoxin immunotoxicity in marine fauna

Red tide events, caused by a toxin producing dinoflagellate, Karenia brevis, occur annually in Florida and Texas. These events lead to health risks for both humans and wildlife that utilize coastal environments. Brevetoxins, potent lipophilic neurotoxins produced by K. brevis, modulate immune responses in laboratory studies with model organisms and in the natural environment in both humans and wildlife. Studies show that brevetoxins activate immune cells, stimulate production of gamma-globulins, cytokines, and neutrophils, modulate lysozyme activity, induce apoptosis, and modulate lymphocyte proliferation in marine species. The objective of this review was to summarize brevetoxin-induced immunotoxicity in marine animals based on available peer-reviewed literature about K. brevis blooms and associated health concerns and propose putative toxicity pathways. This review identifies knowledge gaps within current brevetoxin induced immunotoxicity research, including assessing the long-term impacts of brevetoxin exposure, elucidating the mechanistic linkages between brevetoxins and immune cells, and evaluating repeated and chronic versus acute brevetoxin exposure implications on overall organismal health. The putative immunotoxicity pathways based on evidence from brevetoxin-exposure in marine fauna described in this review represent a useful tool and resource for researchers, wildlife managers, and policy makers. This review and proposed putative immunotoxicity pathways will inform decisions regarding the risks of algal blooms, as it pertains to marine animal health.

Microplastics in Seawater, Sediment, and Organisms from Hangzhou Bay

Microplastics (MPs) are widely present in global oceans, and can pose a threat to marine organisms. This study examined the abundance and characteristics of MPs in seawater, sediment, and organism samples collected from Hangzhou Bay. Abundance of MPs in seawater (n = 26) and sediment (n = 26) were 0.77-9.6 items/m³ and 44-208 items/kg dw, respectively. Size of MPs in sediment (mean 2.5 mm, range 0.21-5.3 mm) was significantly (p < 0.05) larger than that in seawater (1.1 mm, 0.13-4.9 mm). Fiber was consistently the predominant shape of MPs in seawater and sediment. The major polymer composition of MPs was polyethylene (PE; mean 47 %) in seawater, but textile cellulose (60 %) was the main polymer type of MPs in sediment. Average abundance of MPs in marine organisms (n = 388) ranged from 0.064 (zooplankton) to 2.9 (Harpodon nehereus) items/ind, with the mean size of 0.19-1.4 mm. MP abundance in marine organisms was not significantly correlated with their trophic level. Fiber was always the predominant shape of MPs in different marine organisms, contributing mean 67 (fish)-93 % (zooplankton) of total MPs. MPs in crustacean (mean 58 %), shellfish (64 %), and cephalopod (29 %) were dominated by textile cellulose. Whereas, PE (mean 44 %) and polypropylene (43 %) were the major polymer compositions of MPs in fish and zooplankton, respectively. To our knowledge, this is the most comprehensive study investigating the occurrence of MPs in environmental matrixes from Hangzhou Bay, which contributes to the better understanding of environmental behaviors of MPs in estuarine sea environment.

What type of plastic do sea turtles in Korean waters mainly ingest? Quantity, shape, color, size, polymer composition, and original usage

Globally, sea turtles are at high risk of ingesting plastic. However, research on plastic ingestion by sea turtles in East Asia is scant, and no quantitative or qualitative investigation has been conducted in Korean waters. This study examined the plastic ingestion of sea turtles stranded, floating, or incidentally captured in Korean waters between 2012 and 2018. The quantity, shape, color, size, polymer type, and original usage of plastic debris (>1 mm) ingested by sea turtles were analyzed after being sorted from the gastrointestinal tracts of 34 turtles (21 loggerheads (Caretta caretta), 9 green turtles (Chelonia mydas), 2 leatherbacks (Dermochelys coriacea), and 2 olive ridleys (Lepidochelys olivacea)). The ingestion frequencies of greens, loggerheads, olive ridleys, and leatherbacks were 100%, 81%, 50%, and 50%, respectively. The mean amount of plastic ingested was 108 ± 253 mg/kg (38 ± 61 n/ind.). The ingested debris tended to be films and fibers (>80%), light in color (white and transparent; 65%), and light polymers (polyethylene, polypropylene, polypropylene [poly (ethylene:propylene)], expanded polystyrene; 93%). The original uses were identified for 187 pieces; single-use plastics (e.g., plastic bag and packaging) and fishing and aquaculture items (e.g., twine and net) were found to dominate. Green turtles (264 ± 433 mg/kg) ingested significantly higher amounts of plastic than loggerheads (72.8 ± 156 mg/kg). Green turtles ingested mostly fibers (51%), such as rope, twine, and net, while loggerheads ingested largely films (61%), such as plastic bags and packaging. Interspecies differences in quantities and shapes of ingested debris may be related to their distinct feeding habits and geographical range of movement. The present study demonstrates that sea turtles foraging in Korean waters are considerably affected by marine plastic debris, and indicates that proper waste management of single-use plastics and fishing gears is urgently needed to mitigate the damage that plastic debris causes to marine wildlife.

Structural diversity and biological activity of natural p-terphenyls

p-Terphenyls are aromatic compounds consisting of a central benzene ring substituted with two phenyl groups, and they are mainly isolated from terrestrial and marine organisms. The central ring of p-Terphenyls is usually modified into more oxidized forms, e.g., para quinone and phenols. In some cases, additional ring systems were observed on the terphenyl-type core structure or between two benzene moieties. p-Terphenyls have been reported to have cytotoxic, antimicrobial, antioxidant and α-glucosidase inhibitory effects. In this review, we will mainly summarize the structural diversity and biological activity of naturally occurring p-Terphenyls referring to the research works published before.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42995-021-00117-8.

Seasonal distribution and ecological risk of phthalate esters in surface water and marine organisms of the Bohai Sea

The spatiotemporal variability and ecological risks related to 16 phthalate esters (PAEs) were investigated in surface water and marine organisms of the Bohai Sea. The average PAE concentrations in the surface water were 8.02, 4.53, and 3.16 μg L^-1 in spring, summer, and winter, respectively. Additionally, suspended particle matter was positive related to PAE content in seawater in spring and winter. The predominant PAEs in both water and biota were dimethyl phthalate (DMP), di-butyl phthalate (DBP), di-isobutyl phthalate (DIBP), and diethylhexyl-phthalate (DEHP). Because they do not exhibit long-distance migratory behavior, Chaeturichthys hexanema, Cynoglossus lighti, and Loligo japonica were good candidate indicator organisms for PAE pollution in Bohai Sea. The risk quotient method revealed that DIBP, DBP, and DEHP posed relatively greater risks to the aquatic system. This research establishes baseline data from which future management strategies to control PAEs in the Bohai Sea can be developed.

Protein-mediated bioadhesion in marine organisms: A review

Protein-mediated bioadhesion is one of the crucial physiological processes in marine organisms, by which they can firmly adhere to underwater substrates. Most marine adhesive organisms are biofoulers, causing negative effects on marine ecosystems and huge economic losses to aquaculture and maritime industries. Furthermore, adhesive proteins in these organisms are promising bionic candidates for high-performance artificial materials with great application value. In-depth understanding of the bioadhesion in marine ecosystems is of dual significance for resolving biofouling issue and developing marine bionic products. Here, we review the research progress of protein-mediated bioadhesion in marine organisms. The adhesion processes such as protein biosynthesis and secretion are similar among organisms, but the detailed features such as compositions, structures, and molecular functions of adhesive proteins are distinct. Hydroxylation, glycosylation, and phosphorylation are important post-translational modifications during the processes of adhesion. The contents of some amino acids such as glycine, tyrosine and cysteine involved in underwater adhesion are significantly higher, which is a sequence feature of barnacle cement and mussel foot proteins. The amyloid structures and conserved domains/motifs such as EGF and vWFA distributed in adhesive proteins are involved in the underwater adhesion. In addition, the oxidative cross-linking also plays an important role in marine bioadhesion. Overall, the unique and common features identified for the protein-mediated bioadhesion in diverse marine organisms here provide background information and essential reference for characterizing marine adhesive proteins and associated functional domains, formulating antifouling strategies, and developing novel biomimetic adhesives.

Bacteroidetes bacteria, important players in the marine sponge larval development process

Bacteroidetes bacteria are frequently found in association with sponges, but their roles in host development are poorly understood. In this study, thirteen bacterial species (12 genera) isolated from the sponge Tedania sp. revealed a common ability to significantly promote sponge larval settlement at rates 30.00-53.33% higher than controls (p < 0.05). Three effective strategies were adapted: (i) two strains formed biofilms enhancing the settlement rate to 56.67-63.33% within three days. (ii) Five strains secreted hydrosoluble molecules improving larval settlement, reaching 59.17%. (iii) Six species produced extracellular vesicles (EVs) that significantly improved settlement by up to 86.67% (p < 0.05). The EV fluorescence demonstrated that they migrated inside the sponge larvae from the planktonic to metamorphosis stage. Generally, marine sponges specifically enrich Bacteroidetes bacteria because of the important player in host development, establishing the basis for reciprocal adaptive co-evolution between the microbial community and animals, even including higher organisms.

Source, distribution and emerging threat of micro- and nanoplastics to marine organism and human health: Socio-economic impact and management strategies

The nature of micro- and nanoplastics and their harmful consequences has drawn significant attention in recent years in the context of environmental protection. Therefore, this paper aims to provide an overview of the existing literature related to this evolving subject, focusing on the documented human health and marine environment impacts of micro- and nanoplastics and including a discussion of the economic challenges and strategies to mitigate this waste problem. The study highlights the micro- and nanoplastics distribution across various trophic levels of the food web, and in different organs in infected animals which is possible due to their reduced size and their lightweight, multi-coloured and abundant features. Consequently, micro- and nanoplastics pose significant risks to marine organisms and human health in the form of cytotoxicity, acute reactions, and undesirable immune responses. They affect several sectors including aquaculture, agriculture, fisheries, transportation, industrial sectors, power generation, tourism, and local authorities causing considerable economic losses. This can be minimised by identifying key sources of environmental plastic contamination and educating the public, thus reducing the transfer of micro- and nanoplastics into the environment. Furthermore, the exploitation of the potential of microorganisms, particularly those from marine origins that can degrade plastics, could offer an enhanced and environmentally sound approach to mitigate micro- and nanoplastics pollution.

Novel Marine Organism-Derived Extracellular Vesicles for Control of Anti-Inflammation

BACKGROUND

Extracellular vesicles (EVs) exhibit potential as functional biomolecules for tissue regeneration and immunomodulation as they play important roles in the physiological communication between cells. EV internal cargo contains miRNAs, proteins, lipids, and so on. Osteoarthritis (OA) is a common joint disease causing disability owing to impaired joint function and pain. EVs originating from animal cells and tissue matrices are also being considered for OA, in addition to research involving non-steroidal therapeutic agents. However, there are no studies on EVs from marine organisms. Hence, we focused on sea cucumber-derived EVs and conducted experiments to set up an extraction protocol and to demonstrate their efficacy to modulate the inflammatory environment.

METHODS

Sea cucumber extracellular matrices (SECMs) were prepared by a decellularization process. Lyophilized SECMs were treated with collagenase and filtered to isolate sea cucumber extracellular vesicles (SEVs). After isolation, we conducted physical characterization and cell activation studies including cytotoxicity, proliferation, and anti-inflammation effect assays.

RESULTS

The physical characterization results showed circular SEVs in the size range of 66-480 nm. These SEVs contained large amounts of protein cargo, infiltrated the synoviocyte membrane without damage, and had a suppressive effect on inflammatory cytokines.

CONCLUSION

This study established an extraction process for EVs from sea cucumber and reported the anti-inflammatory ability of SEVs. Isolated SEVs can be further utilized for tissue regeneration studies and can be compared to various marine or animal-derived EVs.

Bioaccumulation and changes of trace metals over the last two decades in marine organisms from Guangdong coastal regions, South China

Trace metal (Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals were observed in marine organisms with a predomination of Cu and Zn. The metal exposure levels exhibited obvious variations between species with the decreasing order of crab>shellfish>shrimp>fish. The higher metals enrichment seen in shellfish and crab species primarily attributed to their living habits and the higher sediment background values of trace metals. Endpoint bioaccumulation factor (BAF_fd) was used to characterize the bioaccumulation potentials of marine organisms to trace metals, of which Cu and Zn were the most accumulated elements. The exposure of trace metals in the cultured organisms was far lower than those in wild marine organisms, which is probably due to the effect of growth dilution. Comparisons with previous studies demonstrated that the concentration profiles of most trace metals declined over the last one to two decades, except Cu, that increased indistinctively.

Optimization of high molecular weight DNA extraction methods in shrimp for a long-read sequencing platform

Marine organisms are important to global food security as they are the largest source of animal proteins feeding mankind. Genomics-assisted aquaculture can increase yield while preserving the environment to ensure sufficient and sustainable production for global food security. However, only few high-quality genome sequences of marine organisms, especially shellfish, are available to the public partly because of the difficulty in the sequence assembly due to the complex nature of their genomes. A key step for a successful genome sequencing is the preparation of high-quality high molecular weight (HMW) genomic DNA. This study evaluated the effectiveness of five DNA extraction protocols (CTAB, Genomic-tip, Mollusc DNA, TIANamp Marine Animals DNA, and Sbeadex livestock kits) in obtaining shrimp HMW DNA for a long-read sequencing platform. DNA samples were assessed for quality and quantity using a Qubit fluorometer, NanoDrop spectrophotometer and pulsed-field gel electrophoresis. Among the five extraction methods examined without further optimization, the Genomic-tip kit yielded genomic DNA with the highest quality. However, further modifications of these established protocols might yield even better DNA quality and quantity. To further investigate whether the obtained genomic DNA could be used in a long-read sequencing application, DNA samples from the top three extraction methods (CTAB method, Genomic-tip and Mollusc DNA kits) were used for Pacific Biosciences (PacBio) library construction and sequencing. Genomic DNA obtained from Genomic-tip and Mollusc DNA kits allowed successful library construction, while the DNA obtained from the CTAB method did not. Genomic DNA isolated using the Genomic-tip kit yielded a higher number of long reads (N50 of 14.57 Kb) than those obtained from Mollusc DNA kits (N50 of 9.74 Kb). Thus, this study identified an effective extraction method for high-quality HMW genomic DNA of shrimp that can be applied to other marine organisms for a long-read sequencing platform.

Occurrence of phthalic acid esters in marine organisms from Hangzhou Bay, China: Implications for human exposure

Owing to the wide application of phthalic acid esters (PAEs) in the manufacturing of plastic products, they are ubiquitous in the marine environment. However, the occurrence of various PAEs in marine organisms from China has not been well characterized. In this study, 341 marine organism samples (including fish, shrimp, crab, and shellfish) were collected from Hangzhou Bay, China and analyzed for 16 PAEs. Further, the human PAE exposure risks raised from the consumption of marine organisms were evaluated for adults and children. In total, eight PAEs were detected in collected organism samples, with the concentration of total PAEs (∑PAEs) ranging from 64 to 2840 ng/g (mean 238 ng/g). Crab (mean 811 ng/g) samples had the highest mean concentration of ∑PAEs, followed by fish (465 ng/g), shrimp (293 ng/g), and shellfish (261 ng/g) samples. Among detected PAEs, di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DBP), and di-ethylhexyl phthalate (DEHP) were the predominant PAEs, and they collectively accounted for 84-97% of the ∑PAEs concentrations in all samples. The estimated daily intakes of DiBP, DBP, and DEHP were more than one order of magnitude higher than remaining PAEs. Calculated hazard quotient values of PAEs were all <0.1, suggesting non-cancer risks for the general population through the consumption of marine organisms. Overall, for the first time, this study systematically examined the occurrence of multiple PAEs in four types of marine organisms from Hangzhou Bay, China.

Heavy metal concentrations in tissues of marine fish and crab collected from the middle coast of Zhejiang Province, China

Concentrations of the heavy metals As, Cd, Cu, Hg, Pb, and Zn in various tissues of five marine fish species and one crab species collected from the middle coast of Zhejiang Province of China were investigated in this study. The results indicated considerable variation in heavy metal concentrations in different tissues and species. Elevated concentrations of most heavy metals were identified in fish gills and crab gills and hepatopancreas, with some differences by heavy metal type. In addition, carnivorous and benthivorous fish species generally contained relatively high concentrations of heavy metals due to feeding habits and habitats. Geographical variations of heavy metal concentrations in muscle may be attributable to species-dependent differences and terrigenous contamination. The potential health risk assessment suggested that exposure doses of most heavy metals were safe for human consumption, with the exception of As.

Stress across life stages: Impacts, responses and consequences for marine organisms

Population dynamics of marine organisms are strongly driven by their survival in early life stages. As life stages are tightly linked, environmental stress experienced by organisms in the early life stage can worsen their performance in the subsequent life stage (i.e. carry-over effect). However, stressful events can be ephemeral and hence organisms may be able to counter the harmful effects of transient stress. Here, we analysed the published data to examine the relative strength of carry-over effects on the juvenile growth of marine organisms, caused by different stressors (hypoxia, salinity, starvation, ocean acidification and stress-induced delayed metamorphosis) confronted in their larval stage. Based on 31 relevant published studies, we revealed that food limitation had the greatest negative carry-over effect on juvenile growth. In the laboratory, we tested the effects of short-term early starvation and hypoxia on the larval growth and development of a model organism, polychaete Hydroides elegans, and assessed whether the larvae can accommodate the early stress to maintain their performance as juveniles (settlement and juvenile growth). Results showed that early starvation for 3 days (∼50% of normal larval period) retarded larval growth and development, leading to subsequent reduced settlement rate and juvenile growth. When the starvation period decreased to 1 day, however, the larvae could recover from early starvation through compensatory growth and performed normal as juveniles (c.f. control). Early exposure to hypoxia for 3 days did not affect larval growth (body length) and juvenile growth (tube length), but caused malformation of larvae and reduced settlement rate. We conclude that the adverse effects of transient stress can be carried across life stages (e.g. larval to juvenile stage), but depend on the duration of stressful events relative to larval period. As carry-over effects are primarily driven by energy acquisition, how food availability varies over time and space is fundamental to the population dynamics of marine organisms.

Exposure to crack cocaine causes adverse effects on marine mussels Perna perna

Our study aimed to evaluate crack cocaine effects in different life stages of the marine mussel Perna perna. For this purpose, fertilization rate, embryo-larval development, lysosomal membrane stability and DNA strand breaks were assessed. Effect concentrations in gametes and in larval development were found after 1h (IC₅₀=23.53mg·L^-1) and 48h (IC₅₀=16.31mg·L^-1), respectively. The highest tested concentration showing no acute toxicity (NOEC) was 10mg·L^-1, while the lowest observed effect concentration (LOEC) was 20mg·L^-1. NOEC concerning embryo-larval development was 0.625mg·L^-1, while the LOEC was 1.25mg·L^-1. Cyto-genotoxic effects were evidenced in mussels exposed to crack cocaine concentrations ranging from 5 to 500μg·L^-1. Our results report the first data on effects of an illicit drug to marine organisms and should encourage further ecotoxicological studies of these contaminants of emerging concern in coastal ecosystems.

Structural diversity of marine cyclic peptides and their molecular mechanisms for anticancer, antibacterial, antifungal, and other clinical applications

Many cyclic peptides and analogues derived from marine sources are known to possess biological properties, including anticancer, antitumor, antibacterial, antifungal, antiparasitic, anti-inflammation, anti-proliferative, anti-hypertensive, cytotoxic, and antibiotic properties. These compounds demonstrate different activities and modes of action according to their structure such as cyclic oligopeptide, cyclic lipopeptide, cyclic glycopeptide and cyclic depsipeptide. The recent advances in application of the above-mentioned cyclic peptides were reported in dolastatins, soblidotin, didemnin B, aplidine, salinosporamide A, kahalalide F and bryostatin 1 and they are currently in clinical trials. These cyclic peptides are possible novel drugs discovered and developed from marine origin. Literature data concerning the potential properties of marine cyclic peptides were reviewed here, and the structural diversity and biological activities of marine cyclic peptides are discussed in relation to the molecular mechanisms of these marine cyclic peptides.

210Po in the marine biota of Korean coastal waters and the effective dose from seafood consumption

The activity concentrations of ²¹⁰Po were determined in plankton and selected species of macroalgae, crustaceans, molluscs, and fish from Korean coastal waters to understand ²¹⁰Po distribution in these trophic levels and to assess the effective dose of ²¹⁰Po from seafood ingested by the average Korean. The activity concentration of ²¹⁰Po in macroalgae, mixed plankton, anchovy (whole body), abalone muscle, and abalone viscera was 0.97-1.43, 32-137, 59-392, 2.93 ± 0.86, and 1495 ± 484 Bq kg^-1 (w.w.), respectively. Polonium-210 concentration in the whole flesh of mussel and oyster were 47.8 ± 5.9 and 45.3 ± 7.1 Bq kg^-1 (w.w.), respectively. Polonium-210 concentration in the muscle of the five tested species of fish other than anchovy ranged from 0.51 to 5.56 Bq kg^-1 (w.w.), with the lowest amount in a demersal species. In fish, ²¹⁰Po activity concentration was as much as three orders of magnitude higher in viscera than in muscle. The average annual effective ²¹⁰Po dose per average Korean adult, who consumes 42.8 kg of seafood a year (excluding anchovy), was estimated to be 94 μSv y^-1, with 42-71% of this attributed to shellfish. Further studies are required to assess the dose of ²¹⁰Po from anchovy owing to its high activity concentration and the manner in which anchovy is consumed.

Baseline survey of sediments and marine organisms in Liaohe Estuary: Heavy metals, polychlorinated biphenyls and organochlorine pesticides

A geographically extensive investigation was carried out to analyze the concentrations of heavy metals, PCBs and OCPs in the sediments and marine organisms collected from the Liaohe Estuary. In order to determine the spatial distribution and potential ecological risk of heavy metals, the surface sediments were collected from 44 sites in the Liaohe Estuary. The results showed that the heavy metal contents in the sediments were observed in the following order: Cr (11.2-84.8mg/kg)>Cu (1.7-47.9mg/kg)>Pb (4.3-28.3mg/kg)>As (1.61-12.77mg/kg)>Cd (0.06-0.47mg/kg)>Hg (0.005-0.113mg/kg). In comparison with the concentrations of heavy metals and POPs in other regions, the concentrations of As, Pb and DDTs in the Liaohe Estuary were generally low, and other pollutant concentrations were inconsistent with those reported in other regions. The contamination factor (CF), the pollution load index (PLI), the geoaccumulation index and the potential ecological risk index were used to analyze the pollution situation, which showed that the heavy metal pollution in Liaohe Estuary is mainly dominated by Cd and Hg. The concentrations of the four heavy metals varied significantly in the three kinds of tested organisms (fish, mollusk and crustacean), indicating the different accumulative abilities of the species. The results obtained in this study provide useful information background information for further ecology investigation and management in this region.

Antipyretic and anti-inflammatory activities of Thais luteostoma extracts and underlying mechanisms

Thais luteostoma has been utilized as a crude drug whose shell and soft tissue have been widely used for the treatment of heat syndrome in China for thousands of years. The present study was designed to investigate the antipyretic and anti-inflammatory activities of T. luteostoma. T. luteostoma was divided into shell (TLSH) and soft tissue (TLST) samples in the present study. The rat model of yeast-induced fever was used to investigate their antipyretic effects; and the rat model of hind paw edema induced by carrageenan was utilized to study their anti-inflammatory activities, and at the same time, the concentration variations of the central neurotransmitter [prostaglandin E2 (PGE2) and cyclic adenosine monophosphate (cAMP)], inflammatory mediators [tumor necrosis factor (TNFα), interleukin-1β (IL-1), interleukin-2 (IL-2) and interleukin-6 (IL-6)] and ion (Na(+) and Ca(2+)) were also tested. The results showed that TLSH and TLST extracts significantly inhibited yeast-induced pyrexia in rats (P < 0.05), and exhibited more lasting effects as compared to aspirin, and TLSH had the better antipyretic activity than TLST, and that TLSH and TLST could significantly prevent against carrageenan induced paw edema in rats (P < 0.05); and markedly reduced levels of PGE2, cAMP, TNFα, IL-1β, IL-2, IL-6, and Na(+)/Ca(2+). In fever model, TLST could significantly reduce the levels of PGE2 (P < 0.01) in rats' homogenate and TNFα (P < 0.05), IL-1β (P < 0.01) in the plasma than TLSH, whereas TLSH could reduce the content of IL-2 (P < 0.01) and IL-6 (P < 0.01) in plasma and increase the content of Ca(2+) (P < 0.01) in plasma and homogenate more significantly than TLST. In conclusion, T. luteostoma extract has antipyretic and anti-inflammatory activities, which may be mediated through the suppression of production of PGE2, cAMP, Na(+)/Ca(2+), TNFα, IL-1β, IL-2, and IL-6.