Microplastics in corals: An emergent threat Soares, Marcelo de Oliveira; Matos, Eliana; Lucas, Caroline ...
Marine pollution bulletin,
December 2020, 2020-Dec, 2020-12-00, 20201201, Letnik:
161, Številka:
Pt A
Journal Article
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This article seeks to present a summary of knowledge and thus improve awareness of microplastic impacts on corals. Recent research suggests that microplastics have a variety of species-specific ...impacts. Among them, a reduced growth, a substantial decrease of detoxifying and immunity enzymes, an increase in antioxidant enzyme activity, high production of mucus, reduction of fitness, and negative effects on coral-Symbiodiniaceae relationships have been highlighted in recent papers. In addition to this, tissue necrosis, lower fertilization success, alteration of metabolite profiles, energetic costs, decreased skeletal growth and calcification, and coral bleaching have been observed under significant concentrations of microplastics. Furthermore, impairment of feeding performance and food intake, changes in photosynthetic performance and increased exposure to contaminants, pathogens and other harmful compounds have also been found. In conclusion, microplastics may cause a plethora of impacts on corals in shallow, mesophotic, and deep-sea zones at different latitudes; underlining an emerging threat globally.
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•The effects of microplastics on corals have been reviewed.•Microplastics have become the most recent and understudied threat to coral reefs.•The species-specific impacts of microplastics on corals•Investigations are needed into the impact of microplastics in corals at all depths.
Benthic-pelagic coupling processes and the quantity of carbon transferred from the water column to the benthic suspension feeders need multiple intensive sampling approaches where several ...environmental variables and benthos performance are quantified. Here, activity, dietary composition, and capture rates of three Mediterranean gorgonians (Paramuricea clavata, Eunicella singularis, and Leptogorgia sarmentosa) were assessed in an intensive cycle considering different variables such as the seston concentration and quality (e.g., carbon, nitrogen, and zooplankton), the colony branch patterns, and the energetic input of the single species (i.e., mixotrophic and heterotrophic). The three species showed clear differences in their impact on the seston concentration. Paramuricea clavata, the most densely distributed, showed a greater impact on the near bottom water column seston. The lowest impact of E. singularis on the seston could be explained by its mixotrophy and colony branching pattern. Leptogorgia sarmentosa had a similar impact as E. singularis, having a much more complex branching pattern and more than an order of magnitude smaller number of colonies per meter square than the other two octocorals. The amount of carbon ingested in the peaks of the capture rates in the three species may cover a non-neglectable proportion of the potential carbon fluxes.
Marine invertebrates represent a vast, untapped source of bioactive compounds. Cnidarians are represented by nearly 10,000 species that contain a complex mixture of venoms, collagen, and other ...bioactive compounds, including enzymes, oligosaccharides, fatty acids, and lipophilic molecules. Due to their high abundance in coastal waters, several jellyfish taxa may be regarded as candidate targets for the discovery of novel lead molecules and biomaterials and as a potential source of food/feed ingredients. The moon jellyfish
is one of the most common jellyfish worldwide and is particularly abundant in sheltered coastal lagoons and marinas of the Mediterranean Sea, where it first appeared-as an alien species-in the last century, when Pacific oyster cultivation began. In the present study, the antioxidant and lysozyme antibacterial activities associated with extracts from different medusa compartments-namely the umbrella, oral arms, and secreted mucus-were investigated. Extracts from the oral arms of
displayed significant antioxidant activity. Similarly, lysozyme-like activity was the highest in extracts from oral arms. These findings suggest that
outbreaks may be used in the search for novel cytolytic and cytotoxic products against marine bacteria. The geographically wide occurrence and the seasonally high abundance of
populations in coastal waters envisage and stimulate the search for biotechnological applications of jellyfish biomasses in the pharmaceutical, nutritional, and nutraceutical sectors.
Non-indigenous species (NIS) represent one of the greatest threats to biodiversity and ecosystem functioning, altering invaded habitats, competing with native species, and eventually becoming pests. ...The Mediterranean Sea is a marine biodiversity hotspot, with its coasts being densely populated and its living resources fished since ancient times. As a result of such a long history of exploitation, the whole basin is exposed to a wide array of human pressures, with their combined effects on marine ecosystems being amplified by ongoing climate change. Caulerpa cylindracea Sonder, 1845, is a non-indigenous invasive seaweed widely distributed in the coastal habitats of the Mediterranean Sea, which ultimately affects marine biodiversity and ecosystem functioning. Here, a systematic literature analysis on the consumption of the NIS Caulerpa cylindracea by Mediterranean native and NIS species is provided, focusing on the benefits and drawbacks for the native biota and human health. The present review aims to synthetise knowledge and provide tools to manage the occurrence of the invasive seaweed C. cylindracea in the Mediterranean Sea, encouraging an ecosystem-based approach to the management of the ecological, economic, and social effects of the successful expansion of this NIS.
Ecological profiling of non-native species is essential to predict their dispersal and invasiveness potential across different areas of the world. Cassiopea is a monophyletic taxonomic group of ...scyphozoan mixotrophic jellyfish including C. andromeda, a recent colonizer of sheltered, shallow-water habitats of the Mediterranean Sea, such as harbors and other light-limited, eutrophic coastal habitats. To assess the ecophysiological plasticity of Cassiopea jellyfish and their potential to spread across the Mare Nostrum by secondary introductions, we investigated rapid photosynthetic responses of jellyfish to irradiance transitions-from reduced to increased irradiance conditions (as paradigm of transition from harbors to coastal, meso/oligotrophic habitats). Laboratory incubation experiments were carried out to compare oxygen fluxes and photobiological variables in Cassiopea sp. immature specimens pre-acclimated to low irradiance (PAR = 200 μmol photons m-2 s-1) and specimens rapidly exposed to higher irradiance levels (PAR = 500 μmol photons m-2 s-1). Comparable photosynthetic potential and high photosynthetic rates were measured at both irradiance values, as also shown by the rapid light curves. No significant differences were observed in terms of symbiont abundance between control and treated specimens. However, jellyfish kept at the low irradiance showed a higher content in chlorophyll a and c (0.76±0.51SD vs 0.46±0.13SD mg g-1 AFDW) and a higher Ci (amount of chlorophyll per cell) compared to jellyfish exposed to higher irradiance levels. The ratio between gross photosynthesis and respiration (P:R) was >1, indicating a significant input from the autotrophic metabolism. Cassiopea sp. specimens showed high photosynthetic performances, at both low and high irradiance, demonstrating high potential to adapt to sudden changes in light exposure. Such photosynthetic plasticity, combined with Cassiopea eurythermal tolerance and mixotrophic behavior, jointly suggest the upside-down jellyfish as a potentially successful invader in the scenario of a warming Mediterranean Sea.
Jellyfish blooms are frequent and widespread in coastal areas worldwide, often associated with significant ecological and socio-economic consequences. Recent studies have also suggested cnidarian ...jellyfish may act as vectors of bacterial pathogens. The scyphomedusa
is an outbreak-forming jellyfish widely occurring across the Mediterranean basin. Using combination of culture-based approaches and a high-throughput amplicon sequencing (HTS), and based on available knowledge on a warm-affinity jellyfish-associated microbiome, we compared the microbial community associated with
adult jellyfish in the Gulf of Taranto (Ionian Sea) between summer (July 2016) and winter (February 2017) sampling periods. The jellyfish-associated microbiota was investigated in three distinct compartments, namely umbrella, oral arms, and the mucus secretion. Actinobacteria, Bacteroidetes, Chlamydiae, Cyanobacteria, Deinococcus-Thermus, Firmicutes, Fusobacteria, Planctomycetes, Proteobacteria, Rhodothermaeota, Spirochaetes, Tenericutes, and Thaumarchaeota were the phyla isolated from all the three
compartments in the sampling times. In particular, the main genera
and
, belonging to the class Mollicutes (phylum Tenericutes), have been identified in all the three jellyfish compartments. The taxonomic microbial data were coupled with metabolic profiles resulting from the utilization of 31 different carbon sources by the BIOLOG Eco-Plate system. Microorganisms associated with mucus are characterized by great diversity. The counts of culturable heterotrophic bacteria and potential metabolic activities are also remarkable. Results are discussed in terms of
ecology, the potential health hazard for marine and human life as well as the potential biotechnological applications related to the associated microbiome.
Marine bioprospecting is a dynamic research field that explores the oceans and their biodiversity as noteworthy sources of new bioactive compounds. Anthozoans are marine animals belonging to the ...Cnidaria phylum characterized by highly specialized mechanosensory cells used both for defence against predators and prey capture. Here, high concentration of cnidocysts have been isolated from the Mediterranean zoanthid coral Parazoanthus axinellae (Schmidt, 1862) and their antimicrobial potential has been investigated. The cnidocyst extract exerted significant antibacterial activity against some human pathogens capable of developing resistance to conventional antibiotics such as Streptococcus agalactiae and Coccus sp., and against several Vibrio species, including some microbial strains for humans and farmed fish, such as Vibrio alginolyticus, Vibrio anguillarum, Vibrio fischeri, Vibrio harveyi, and Vibrio vulnificus. Results have been discussed in light of both the ecological aspects and biotechnological value of the cnidocyst extract in the nutritional, nutraceutical, and pharmaceutical fields.
The ecological physiology of anthozoans, as well as their resistance to stressors, are strongly influenced by environmental factors and the availability of resources. The energy budget of anthozoans ...can vary seasonally in order to find an equilibrium between the available resources and respiration, polyp activity, growth, and reproduction processes. The variation in the biochemical composition of the animal tissues in these organisms results from a combination of the productivity processes of the water column coupled with the reproductive effort and potential starvation periods of the anthozoans. Here, the seasonal variation in the polyp activity of a slow-growing passive suspension feeder, the octocoral Alcyonium acaule, as well as their carbohydrate, protein and lipid contents, was investigated in a warm temperate environment using in-situ observations and biochemical analyses. Polyp activity exhibited a significant variability that was moderately dependent on season, while an aestivation phenomenon in A. acaule (i.e., a resting period in which the anthozoan is not capable of any polyp activity) during the warmer months is clearly observed. Carbohydrate concentrations in the coral species showed a significant increase in the late winter and spring seasons, and the lipid content increased during the spring. A higher abundance of lipids and carbohydrates coincided with a higher primary productivity in the water column, as well as with the octocoral reproduction period. In late autumn, there was a depletion of these biomolecules, with protein levels exhibiting great variability across sampling times. Complex alterations driven by climate change could affect the energy fluxes that depend on the dead or alive particles that are intercepted by marine animal forests. The obtained findings show a food shortage in late summer and autumn of the benthic suspension feeder A. acaule through the integrative descriptors of the ecophysiology of these anthozoans. This research contributes to the knowledge of energy storage capabilities in benthic suspension feeders in general, highlighting the importance of understanding the limits of resistance to starvation periods through these indicators.
The moon jellyfish Aurelia coerulea (Scyphozoa) is one of the most common and largest jellyfish inhabiting coastal lagoons, confined bays, and marinas of temperate and subtropical coastal waters. The ...annual population dynamics of A. coerulea along with some bacterial parameters (bacterial size and biomass, total coliforms, faecal coliforms, intestinal enterococci, culturable Vibrio spp., and culturable bacteria at 37 °C), sea surface temperature (SST), salinity, and an array of nutrients (ammonia, nitrites, nitrates, phosphates, silicates, total nitrogen, and total phosphorus) were assessed in the Varano lagoon (Adriatic Sea) that is subject to anthropogenic pollution. Statistical analyses revealed that jellyfish outbreaks and their consequent biomass deposition significantly correlated to seawater temperature, total nitrogen, phosphates, and ammonia concentrations while negative correlations appeared with nitrite and nitrate concentrations. In addition, bacterial biomass and Vibrio abundance correlated with each other and temperature, jellyfish density, and total nitrogen. These findings suggest that environmental changes could trigger the occurrence of jellyfish bursts in the lagoon which, in turn, may act as one of the central drivers of processes regulating some bacterial components. The positive relationship between jellyfish flush-and-crash dynamics and SST suggests that ongoing global warming will seemingly increase jellyfish outbreaks.
Several factors contributed, over time, to the Mediterranean monk seal’s sharp population decline. Despite the relative disappearance of documented breeding sub-populations, sightings have been ...collected, in recent decades, from most of the species’ former habitat. The conservation of this endangered marine mammal should also encompass those areas. We conducted our research along the coast of Salento (South Apulia, Italy) as a case study. To collect data on monk seal presence in the area, expected to be characterized by low numbers, we combined three different methodologies: a questionnaire to fishermen, interviews with witnesses of sightings, and a historical review of the species’ presence. The different methodologies allowed us to collect 11 records of recent sightings (after 2000) and 30 records of historical encounters (before 2000), highlighting that the species was already rare in Salento over the last century. Most of the historical information was concentrated between 1956 and 1988 (28 records), suggesting discontinuous occurrence in the area, possibly depending on the lack of monitoring efforts. Furthermore, a broad regional approach should be considered as a more effective path to aid the monk seal recovery, better comprehend the species’ abundance and movements, and eventually contribute to the overall health of ecosystems.
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