The Status of Marine Megafauna Research in Macaronesia: A Systematic Review

Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement

Ciguatoxins (CTXs) are naturally occurring neurotoxins that can accumulate in fish and cause Ciguatera Poisoning (CP) in seafood consumers. Ciguatoxic fish have been detected in tropical and subtropical regions of the world including the Pacific and Indian Oceans, the Caribbean Sea, and more recently in the northeast Atlantic Ocean. The biogeographic distribution of ciguatoxic fish appears to be expanding; however, the paucity of CTX standards and reference materials limits the ability of public health authorities to monitor for these toxins in seafood supply chains. Recent reports establish that Caribbean Ciguatoxin-1 (C-CTX1) is the principal toxin responsible for CP cases and outbreaks in the northeast Atlantic Ocean and that C-CTX congener profiles in contaminated fish samples match those from the Caribbean Sea. Therefore, in this work, C-CTX reference materials were prepared from fish obtained from the northeast Atlantic Ocean. The collection of fish specimens (e.g., amberjack, grouper, or snapper) was screened for CTX-like toxicity using the in vitro sodium channel mouse neuroblastoma cytotoxicity assay (N2a cell assay). Muscle and liver tissues from toxic specimens were pooled for extraction and purified products were ultimately profiled and quantified by comparison with authentic C-CTX1 using LC-MS/MS. This work presents a detailed protocol for the preparation of purified C-CTX reference materials to enable continued research and monitoring of the ciguatera public health hazard. To carry out this work, C-CTX1 was isolated and purified from fish muscle and liver tissues obtained from the Canary Islands (Spain) and Madeira archipelago (Portugal).

Moher and colleagues introduce PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses. Us...

The constant increase of marine plastic pollution poses an unprecedented risk to oceanic islands, which become increasingly exposed to a hazard of which they have very little control. Located in the Northeast Atlantic Ocean, the Macaronesia is comprised by the Azores, Madeira, Canary Islands, and Cabo Verde. Although past studies suggest that most plastic items collected on these islands are from offshore regions, their actual sources remain unclear to present date. As such, we focus on the characterization of the potential sources and pathways of plastic particles reaching the Macaronesia archipelagos. This is achieved by combining modeled datasets for ocean currents, winds and waves with a Lagrangian tool used to track virtual particles released around the archipelagos for a 10-year period, making a distinction between surface and submerged particles. Global drifter trajectories are also assessed, selecting those that intercept the archipelagos. Our results demonstrate that the North Atlantic subtropical gyre is the most conspicuous feature in particles and drifter trajectories. The Gulf Stream acts as the main pathway for all archipelagos at a regional scale, though with less significance to Cabo Verde. Surface particles are connected to regional sources in a shorter timescale than mixed particles, mainly because of the wind. Intercepting high-windage particle trajectories are dominant at the center of the North Atlantic subtropical gyre, demonstrating that particles originating from the North Atlantic “garbage patch” are most likely to intercept the archipelagos if considerably exposed to the wind. Regarding the connectivity to sources, all archipelagos are significantly exposed to areas of intensive fishing activity, mainly those located in the Gulf Stream (Azores), in international waters off the Portuguese coast (Madeira and Canary Islands) and along the Northwestern African coast (Cabo Verde). The east coasts of Central and North America are the main sources of land-based particles reaching the Azores, Madeira, and Canary Islands, whereas the Northwestern African coast is the main source for land-based particles reaching Cabo Verde. Our results demonstrate how vulnerable the Macaronesian archipelagos are to marine plastic pollution, highlighting the urgency for international cooperation to mitigate the exposure of oceanic islands to marine plastic pollution.

The Conduct and Reporting of Meta-Analyses of Studies of Diagnostic Tests, and a Consideration of ROC Curves: Answers to the January 2010 Journal Club Questions

PRISMA 2020: An Update.

PRISMA 2020

The northeast Atlantic Ocean contains multiple habitats considered critical for shark conservation, including nursery areas, migratory corridors and aggregation sites. In this context, updating knowledge on shark diversity and the threats affecting them in this region is essential to defining priorities and implementing the right management and conservation measures. Here, we show that Cabo Verde, Canarias, Madeira and Azores islands are home to 78 shark species (comprising 26 families), and 56% are threatened with extinction. The Canary Islands revealed the greatest richness (with 56 species), followed by Cabo Verde (53), Madeira (52), and the Azores (45). Cabo Verde presents fewer similarities with the rest of the islands. We also found that: i) Azores share more species with the Canary Islands than Madeira (despite the greater geographical proximity with the latter), and ii) there are no oviparous species in the Cabo Verde archipelago, contrary to the Canary Islands (5), the Azores (4), and Madeira (3). Fishing and habitat degradation are the most relevant anthropogenic pressures for the region, with Cabo Verde having the highest number of endangered species (66%) and a greater magnitude and diversity of threats. As such, this archipelago presents the highest priority area for shark conservation due to the intense industrial fishing in its waters, poor management measures in combination with its greater vulnerability to climate change.

Knowledge of the distribution and residency of pelagic marine megafauna, particularly deep-diving species, is scarce due to their high mobility over difficult-to-access oceanic areas and long periods underwater. However, the threatened status of many of these species, such as the sperm whalePhyseter macrocephalus, increases the need to obtain quantitative data to support conservation measures. In the warm temperate waters of Macaronesia (Eastern North Atlantic), sperm whales occur year-round in a set of island systems (the Azores, Madeira, and the Canaries), mainly in social groups of females and juveniles with the occasional visits of mature males. Although it is known that they perform inter-archipelago movements, information on site fidelity and residency times is still scarce. Here, based on photographic-identification data, site fidelity and residency times of sperm whales were estimated for subareas of the Azores and the Madeira archipelagos, with a preliminary assessment for a subarea of the Canaries. The Azores and Madeira subareas presented similar proportions of individuals with recaptures (~25%), mainly inter-annual, while in the subarea of the Canaries, only <10% of the individuals were recaptured. Standardized Site Fidelity Indexes showed very low values (<0.01) for both the Azores and Madeira subareas. Lagged identification rates based on models including emigration and reimmigration estimated that an average of 44.8 individuals (SE=4.9) spent 12.9 days (SE=1.5) in the Azores before leaving for 99.1 days (SE=12.5), while 8.4 individuals (SE=16.1) spent 0.8 day (SE=6.6) in Madeira before leaving for 8.6 days (SE=6.9), with a very low mortality rate. This study i) indicates a degree of residency of about ¼ of the identified individuals for the Azores and Madeira subareas and ii) supports that these oceanic archipelagos constitute an important habitat for a Vulnerable species in the Atlantic. Moreover, it also highlights the importance of combining data from opportunistic and dedicated surveys and joint national and international efforts toward the conservation of marine megafauna.

<p>Madeira and Canaries are two intraplate hotspots located in the Northeast Atlantic, west of the Moroccan coast.  Within project SIGHT (SeIsmic and Geochemical constraints on the Madeira HoTspot system) we propose to answer the following questions: a) Is Madeira´s volcanism fed by a deep-seated mantle plume? b) Do the Madeira and Canary hotspots have a common or distinct origin? and c) What is the lithospheric nature of the corridor between the Canaries and the Atlas-Gibraltar?</p><p>The recent work of Civiero et al. (2021), combining results from seismic tomography, shear-wave splitting and gravity along with plate reconstruction, revealed that differently evolved upwellings might exist below the volcanic Canary and Madeira islands, with the Madeira hotspot possibly fed by a later-stage plumelet. However, a clear picture of the crust and uppermost mantle is still missing, and questions about how thick the crust is and the eventual presence of crustal underplating still need to be answered. </p><p>We performed an ambient noise tomography using data from 50 seismic stations that we selected carefully to obtain the best inter-station path coverage. We processed the data in the period band between 10 to 50 sec, which will allow us to get, for the first time, a crustal and uppermost mantle tomographic model for the study region. The daily traces were cross-correlated using the phase cross-correlation technique, followed by a time-frequency weighted stack methodology developed by Schimmel et al. (2011). After computing the Rayleigh-wave group-velocity measurements, we inverted them to obtain the 2D group-velocity maps for different periods. In the period band of 10 to <br>20 s, the velocity maps evince low velocities beneath Madeira and Canary Islands and the Gulf of Cadiz region. Higher velocities characterize the remaining oceanic area. When the period increases (36 s) , some of the Canary Islands show slightly higher velocities, whereas others still present lower velocities. As expected, the low-velocity anomaly beneath the Gulf of Cadiz becomes stronger while the ones beneath the islands become weaker. Even so, the islands still show low velocities.</p><p>To determine the depth structure beneath the study area, we extracted velocity values at the different points of the group-velocity maps at different periods. We will then invert them to build a 1D S-wave velocity profile for each grid point as a function of depth. We will discuss the obtained 3D shear-wave velocity maps in the area's geodynamic context.</p><p>This is a contribution to projects SIGHT (Ref. PTDC/CTA-GEF/30264/2017). The authors would like to acknowledge the financial support FCT through project UIDB/50019/2020 – IDL.</p>

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PRISMA 2020: a reporting guideline for the next generation of systematic reviews.

Petrel extinction in Macaronesia (North-East Atlantic Ocean): the case of the genus <i>Pterodroma</i> (Aves: Procellariiformes: Procellariidae)

Weight excess association with severity in children and adolescents with COVID-19: A systematic review.

Systematic Reviews in Medical Education.