The Climate Change Response of Pacific Ocean Squids

Climate change is proving to be a driving factor reshaping the distribution and altering the movement of marine species, dynamics of which are crucial for sustainable development and marine resources management. However, how Pacific Ocean squids – boasting the salient biological features of a one-year life span and strong adaptive abilities, and which support more than 25% of global squid catches – respond to climate change is overlooked. We address this knowledge gap by constructing spatio-temporal generalized additive mixed models based on hundreds of thousands of digitized Chinese squid-jigging logbooks covering three Pacific stocks of two squid species (Ommastrephes bartramii and Dosidicus gigas) spanning 2005 – 2018. Here we show the relationships between environmental variables and local abundance of squids (reflected by response curves) track changes in climate; the squid biomass peaks and troughs coinciding with La Niña and El Niño events, respectively are moderate in contrast to the effects of directional climate change. We find substantial poleward shifts by squids inhabiting low latitude and middle latitudes. These findings have broad implications both for food security and open ocean ecosystem dynamics.

Ecoregional and temporal dynamics of dugong habitat use in a complex coral reef lagoon ecosystem

Mobile marine species display complex and nonstationary habitat use patterns that require understanding to design effective management measures. In this study, the spatio-temporal habitat use dynamics of the vulnerable dugong (Dugong dugon) were modelled from 16 satellite-tagged individuals in the coral reef lagoonal ecosystems of New Caledonia, South Pacific. Dugong residence time was calculated along the interpolated tracks (9371 hourly positions) to estimate intensity of use in three contrasting ecoregions, previously identified through hierarchical clustering of lagoon topographic characteristics. Across ecoregions, differences were identified in dugong spatial intensity of use of shallow waters, deeper lagoon waters and the fore-reef shelf outside the barrier reef. Maps of dugong intensity of use were predicted from these ecological relationships and validated with spatial density estimates derived from aerial surveys conducted for population assessment. While high correlation was found between the two datasets, our study extended the spatial patterns of dugong distribution obtained from aerial surveys across the diel cycle, especially in shallow waters preferentially used by dugongs at night/dusk during high tide. This study has important implications for dugong conservation and illustrates the potential benefits of satellite tracking and dynamic habitat use modelling to inform spatial management of elusive and mobile marine mammals.

Ship traffic connects Antarctica’s fragile coasts to worldwide ecosystems

Antarctica, an isolated and long considered pristine wilderness, is becoming increasingly exposed to the negative effects of ship-borne human activity, and especially the introduction of invasive species. Here, we provide a comprehensive quantitative analysis of ship movements into Antarctic waters and a spatially explicit assessment of introduction risk for nonnative marine species in all Antarctic waters. We show that vessels traverse Antarctica’s isolating natural barriers, connecting it directly via an extensive network of ship activity to all global regions, especially South Atlantic and European ports. Ship visits are more than seven times higher to the Antarctic Peninsula (especially east of Anvers Island) and the South Shetland Islands than elsewhere around Antarctica, together accounting for 88% of visits to Southern Ocean ecoregions. Contrary to expectations, we show that while the five recognized “Antarctic Gateway cities” are important last ports of call, especially for research and tourism vessels, an additional 53 ports had vessels directly departing to Antarctica from 2014 to 2018. We identify ports outside Antarctica where biosecurity interventions could be most effectively implemented and the most vulnerable Antarctic locations where monitoring programs for high-risk invaders should be established.

Jointly modeling marine species to inform the effects of environmental change on an ecological community in the Northwest Atlantic

Single species distribution models (SSDMs) are typically used to understand and predict the distribution and abundance of marine fish by fitting distribution models for each species independently to a combination of abiotic environmental variables. However, species abundances and distributions are influenced by abiotic environmental preferences as well as biotic dependencies such as interspecific competition and predation. When species interact, a joint species distribution model (JSDM) will allow for valid inference of environmental effects. We built a joint species distribution model of marine fish and invertebrates of the Northeast US Continental Shelf, providing evidence on species relationships with the environment as well as the likelihood of species to covary. Predictive performance is similar to SSDMs but the Bayesian joint modeling approach provides two main advantages over single species modeling: (1) the JSDM directly estimates the significance of environmental effects; and (2) predicted species richness accounts for species dependencies. An additional value of JSDMs is that the conditional prediction of species distributions can use not only the environmental associations of species, but also the presence and abundance of other species when forecasting future climatic associations.

Ocean climate connectivity and the future range shifts of marine biodiversity.

Shifting distribution to track suitable climate is a potential strategy for marine species to cope with ocean warming. Yet, the ability of species to successfully reach future climate analogs largely depends on the length of the paths that connect them, and on the exposure of these paths to extreme climates during this transition. Here, we evaluate marine climate connectivity for trajectories between climatic analogs on a global scale. We find that while movement between climatic analogs is more intense in the northern seas of the planet, they require longer trajectories to reach climatic analogs, with high climatic exposure to extreme conditions. On the contrary, the southern seas host areas that have closer climatic analogs, further subjected to a lower exposure to dissimilar climates. These patterns are mirrored in the connectivity properties of the global marine protected areas, highlighting sites which might fail to facilitate connectivity to future climates. Our results suggest that potential shifts between climatic analogs might be subjected to more limitations than those suggested by previous studies, with marine connectivity offering novel insights for the establishment of climate-wise conservation future networks.

NATURAL PRODUCTS WITH ANTI-HERPES ACTIVITIES: IN VIVO STUDIES

Herpes are a group of similar viruses that are responsible for a number of infecting diseases, the most important of which are herpes simplex, herpes zoster and pseudopox. Resistance to traditional antiviral medications is becoming increasingly common, making treatment of such infections even more difficult. For example, the usage of nucleoside analogues like acyclovir to target the DNA-polymerase of the virus on a regular and long-term basis promotes the generation of resistant viruses. As a result, a different treatment is required. Natural products, such as herbal remedies, have been shown to have in vitro and in vivo activity against herpes viruses, and have shown to be a valuable source for new antivirals development and separation. The goal of this review is to highlight the most promising extracts and pure chemicals obtained from plants and marine species that have in vivo anti-herpes simplex virus (HSV-1 and HSV-2) action. Natural products as new anti-HSV medications offer a number of benefits, including fewer side effects, minimal toxicity, and lowered resistance, and a variety ways of deed.

Comparing species detection success between molecular markers in DNA metabarcoding of coastal macroinvertebrates

DNA metabarcoding has great potential to improve marine biomonitoring programs by providing a rapid and accurate assessment of species composition in zoobenthic communities. However, some methodological improvements are still required, especially regarding failed detections, primers efficiency and incompleteness of databases. Here we assessed the efficiency of two different marker loci (COI and 18S) and three primer pairs in marine species detection through DNA metabarcoding of the macrozoobenthic communities colonizing three types of artificial substrates (slate, PVC and granite), sampled between 3 and 15 months of deployment. To accurately compare detection success between markers, we also compared the representativeness of the detected species in public databases and revised the reliability of the taxonomic assignments. Globally, we recorded extensive complementarity in the species detected by each marker, with 69% of the species exclusively detected by either 18S or COI. Individually, each of the three primer pairs recovered, at most, 52% of all species detected on the samples, showing also different abilities to amplify specific taxonomic groups. Most of the detected species have reliable reference sequences in their respective databases (82% for COI and 72% for 18S), meaning that when a species was detected by one marker and not by the other, it was most likely due to faulty amplification, and not by lack of matching sequences in the database. Overall, results showed the impact of marker and primer applied on species detection ability and indicated that, currently, if only a single marker or primer pair is employed in marine zoobenthos metabarcoding, a fair portion of the diversity may be overlooked.

Identification of Bioactive Phytocomponents of Hydroalcoholic Extract of Enhalus acoroides by Gas Chromatography- Mass Spectrometry Analysis

Sea grass are good source of potent drug which has medicinal properties and able to cure human disease. One such marine plant is the Enhalus acoroides which belong to hydrocharitaeceae family. This marine species are widely distributed in the tropics of Indian and western Pacific Ocean and the species were collected from Ramanathapuram district for further process. This study reveals about the bioactive components present in Enhalus acoroides and identified its biological activity by Gas chromatography Mass spectrometry analysis using hydroalcoholic extract. The compounds present in Enhalus acoroides are Benzoic acid, 2- methyl 7- oxa bicyclol heptanes, 1, 3 Nonadiene, silane, ethoxytriethyl. Biological activities of the compounds present in the sample include antioxidant, hypocholesterolemic, antihypertensive, anti-inflammatory, anti-microbial, antiviral and anti-hepatotoxic effect.

Citizen science highlights litter associated with COVID-19 as a potential threat on the island of Mindanao, Philippines: a marine biodiversity hotspot

The on-going COVID-19 pandemic is expected to exacerbate the marine litter problem. The use of disposable personal protective equipment (e.g., facemasks) will result to increase in marine plastics pollution. Here we explored the potential of citizen science to determine the distribution of marine litter associated with COVID-19 in Mindanao, Philippines. Volunteers were invited through social media, contributing geotagged photographs of marine litter associated with COVID-19. Although the information is limited, results showed the possible pervasiveness of marine litter associated with COVID-19. Since the waters surrounding the Southern Philippines is known to host high marine biodiversity, the potential negative interaction of marine litter associated with COVID-19 and marine species is inevitable. The contribution of citizen science to address some of the limitations on marine litter research is highlighted and is recommended to be explored further.