Human Poisoning from Marine Toxins: Unknowns for Optimal Consumer Protection

Marine biotoxins are produced by aquatic microorganisms and accumulate in shellfish or finfish following the food web. These toxins usually reach human consumers by ingestion of contaminated seafood, although other exposure routes like inhalation or contact have also been reported and may cause serious illness. This review shows the current data regarding the symptoms of acute intoxication for several toxin classes, including paralytic toxins, amnesic toxins, ciguatoxins, brevetoxins, tetrodotoxins, diarrheic toxins, azaspiracids and palytoxins. The information available about chronic toxicity and relative potency of different analogs within a toxin class are also reported. The gaps of toxicological knowledge that should be studied to improve human health protection are discussed. In general, gathering of epidemiological data in humans, chronic toxicity studies and exploring relative potency by oral administration are critical to minimize human health risks related to these toxin classes in the near future.Support from the following FEDER cofunded-grants. From Conselleria de Cultura, Educacion e Ordenación Universitaria Xunta de Galicia, 2017 GRC GI-1682 (ED431C 2017/01). From CDTI and Technological Funds, supported by Ministerio de Economía, Industria y Competitividad, AGL2014-58210-R, AGL2016-78728-R (AEI/FEDER, UE), ISCIII/PI16/01830 and RTC-2016-5507-2, ITC-20161072. From European Union POCTEP 0161-Nanoeaters -1-E-1, Interreg AlertoxNet EAPA-317-2016, and H2020 778069-EMERTOX

Spatial and temporal patterns of sea surface chlorophyll concentration and environmental forcing in the southern European Atlantic

Phytoplankton biomass dynamic integrates information about the characteristics of the pelagic ecosystem. Temporal and spatial patterns respond to physical processes. Also, phytoplankton abundance and its temporal dynamic largely determine the structure and dynamics of the food web. The southern European Atlantic (48 ºN – 36 ºS) presents differences in continental margin orientation, upwelling intensity, river runoff, a semi-enclosed oceanic domain (Bay of Biscay), and open oceanic waters to the west. Sea surface chlorophyll concentration (SSChl) monthly averages (from satellites) from 1998 to 2012 were analysed at 4x4 km resolution by Empirical Orthogonal Functions. The study area was regionalized according to rotated EOFs and temporal modes were used to resume the SSChl temporal variability in each region. The environmental forcing of temporal modes was analysed against environmental variables by means of Canonical Correspondence Analysis. More than 50% of the variability in oceanic regions was captured by the seasonal signal, with differences in the timing of the spring bloom and with the shape of the seasonal signal related with the latitudinal gradient and the ‘stagnation effect’ of the Bay of Biscay. In French and western Iberian shelves seasonality represented 50%. The difference between shelf and oceanic regions was due to mesoscale processes in shelf areas; i.e. river runoff in the French shelf and coastal upwelling in the western Iberian shelf. Shelf mesoscale processes impose short frequency variability on to the seasonal cycle and increase SSChl levels. The influence that these patterns of spatial and temporal dynamics have on the structure and dynamics of the rest of the food web can be perceived on the spatial patterns of fisheries catches

Estimating the cumulative effects of the nature-based tourism in a coastal dolphin population from southern Kenya

Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006-2013. Our results demonstrated that tourist boat interactions affected dolphins' behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity

Aproximacions demogràfiques per avaluar l’estat de conservació de la baldriga cendrosa Calonectris diomedea i la baldriga balear Puffinus mauretanicus: Demographic approaches for assessing the conservation status of Scopoli’s Shearwater Calonectris diomedea and the Balearic Shearwater Puffinus mauretanicus

In the north-western Mediterranean there are two breeding species of procellariforms from the Procellariidae family: Scopoli’s shearwater Calonectris diomedea and the Balearic shearwater Puffinus mauretanicus. Long-term monitoring carried out in a number of breeding colonies provides enough data to be able to assess the conservation status of both species using demographic approaches that estimate parameters such as survival, recruitment and fertility. This type of approach is recommended because it provides a reliable conservation diagnosis and knowledge of the processes that determine variations in population dynamics. Both species were found to have critically low adult survival rates, unexpected in such long-lived species, which makes these populations unviable under current conditions. This agrees with previous available information on incidental bycatch on fishing gears, and confirms that this threat, together with predation by terrestrial carnivores are of critical concern for the conservation of the populations. The fact that some of the breeding colonies did not show a declining trend indicates that several compensatory mechanisms, such as an immigration rescue effect, may be acting at local level. Nevertheless, all the evidence gathered to date suggests that these compensatory mechanisms are not permanent and that if no action is taken these populations could become extinct. In the case of Scopolis’ shearwater, the global population is much more abundant, so there may be time for mitigation actions to be undertaken. Given the size of the breeding population of Balearic shearwaters, we recommend urgent measures be carried out to reduce adult mortality in this endemic species to prevent its extinction

Essential ocean variables and high value biodiversity areas: Targets for the conservation of marine megafauna

Effective conservation and management measures are needed to face the unprecedented changes that marine ecosystems, and particularly marine megafauna, are suffering. These measures require the identification of highvalue biodiversity areas (HVBAs) which in turn require the identification of the essential ocean variables (EOVs) that shape the environmental envelope of communities (i.e. space defined by a set of environmental variables). The aim of this study was to delineate and characterise the HVBAs for the north and northwestern Spanish seabird and cetacean community taking advantage of the sightings collected during the annual PELACUS oceanographic survey (2007–2016). We used distance sampling methodology to analyse the species detectability based on environmental conditions. Then, we delimitated the HVBAs and identified the EOVs defining the environmental envelope of the community based on a spatio-temporal modelling approach using Generalized Additive Models. Overall, the main environmental variables driving species abundance were the sea surface temperature (SST), the distance to the shelf-break and the chlorophyll-a concentration (Chl-a). The SST and Chla were identified as dynamic EOVs due to their highest relative predictor importance, driving the environmental envelope and shaping areas of higher density. HVBAs were located mainly over the northwestern Spanish waters and decreased towards the inner Bay of Biscay remaining spatially stable over the study period. By identifying community-level HVBAs, we can understand the underlying ecological and oceanographic processes driving the spatio-temporal patterns of biological communities, such as those composed by seabirds and cetaceans. This information would identify conservation targets to assist the allocation of management resources. In addition, the location of HVBAs can help to fulfil the emergent need for sound spatial information to support the implementation of marine spatial planning.En prens