An artificial intelligence approach for identification of microalgae cultures

In this work, a model for the characterization of microalgae cultures based on artificial neural networks has been developed. The characterization of microalgae cultures is essential to guarantee the quality of the biomass, and the objective of this work is to achieve a simple and fast method to address this issue. Data acquisition was performed using FlowCam, a device capable of capturing images of the cells detected in a culture sample, which are used as inputs by the model. The model can distinguish between 6 different genera of microalgae, having been trained with several species of each genus. It was further complemented with a classification threshold to discard unwanted objects while improving the overall accuracy of the model. The model achieved an accuracy of up to 97.27% when classifying a culture. The results demonstrate the effectiveness of the Deep Learning models for the characterization of microalgae cultures, it being a useful tool for the monitoring of microalgae cultures in large-scale production facilities while providing accurate characterization over a wide range of genera.

Carbon footprint, economic benefits and sustainable fishing: Lessons for the future from the Western Mediterranean

Ensuring an economically viable, sustainable and low CO₂ emission extractive fishery is critical in order to achieve the life below water UN sustainable development goals and the climate change commitments of Paris agreement. This challenge is even more relevant in the most overexploited region of the world: The Mediterranean Sea. Here, we use the socio-ecological system of the Spanish Mediterranean commercial fisheries (Northern Alboran Sea, Northern Spain and the Balearic Islands) to develop an integrative impact assessment, including detailed socio-economic, ecosystem indices of the trophic structure of extractive fishery and CO₂ emission analyses combining different gear, vessel size classes as well as a wide range estimation of carbon release from the seafloor by bottom trawling. Northern Alboran Sea preferentially requires reduction in purse seine fishery while in Northern Spain bottom trawling should be reduced first to reach sustainable exploitation. Fuel CO₂ footprint of purse seine and bottom trawling are among the lowest footprints of animal protein production, but considering sweeping released CO₂ from the seafloor the bottom trawling footprint becomes the animal protein production with the highest footprint. Moreover, the lowest bottom released CO₂ estimation overrides 2.7-10 times the CO₂ buried in the seafloor through the biological pump in trawled areas potentially turning the continental shelf from a CO₂ sink to a CO₂ source. Net profit per fuel derived CO₂ emission for all fleets is lower than 1€ kgCO₂^-1, being lowest for large bottom trawler (0.025 € kgCO₂^-1). Thus, urgent mitigation and adaptation measures are necessary to obtain sustainable fishery in terms of net profit, sustainable seafood extraction and CO₂ emission reduction. Our study provides scientific bases to develop these measures such as the restriction of harmful fishing gear in carbon rich river influenced areas, reduction of bottom contact of the fishing gear, favouring purse seine fishery and smaller bottom trawlers.

A spatial risk approach towards integrated marine spatial planning: A case study on European hake nursery areas in the North Alboran Sea

Europe's Blue Growth strategy promotes the intensification of human activities at sea and increases the environmental risk such as the decline of the provision of key ecosystem services and potential conflicts among human activities. The fishing sector, in the Alboran Sea, is economically and culturally one of the most important and relies on overexploited target species such as European hake (Merlucius merlucius). Here we identified and quantified the impact of human pressures on the capacity of marine habitats to support the provision of food as an important ecosystem service. We modelled the spatial distribution of nursery areas of European hake in the Alboran Sea, using General Additive Models (GAM) and overlaid those with European Nature Information System (EUNIS) habitats. A sensitivity analysis of hake nursery areas to cumulative human impacts identified the Bay of Malaga as the most sensitive area with trawling frequencies up to 60 times higher than the habitats recovery time. Further, we identified an increased conflict potential among human activities such as trawling and extraction with the presence of Marine Protected Areas (MPAs), which provide MPAs a high vulnerability similar to that found in unprotected areas. Future scenarios considering the increase of renewable energy and alternative food production show conflicts between aquaculture and MPAs as well as offshore wind farms and offshore shipping. Hence, our results show strong arguments for an integrated spatial management approach, including benthic trawling. We also suggest restricting trawling activities inside MPAs to safeguard the habitats capacity to support ecosystem services. Our spatially explicit assessment framework is transparent and transferable to other Mediterranean regions. Thus, it can function as a model on how to incorporate cumulative effect assessments in marine spatial planning processes.

Fertilization and connectivity in the Garrucha Canyon (SE-Spain) implications for Marine Spatial Planning

Marine Spatial Planning is usually based on benthic georeferenced information or GPS tracked human activities, whereas the pelagic ecosystem is often ignored because of scarce and limited surface information. However, the 3-D pelagic ecosystem plays a key role connecting all the other ecosystems by physical (currents) and biological (migration) processes. According to remote sensing the Garrucha Canyon is oligotrophic, but 3-D sampling reveals subsurface upwelling, and converts it into the richest area around the Cape of Gata. Vertical connectivity by means of zooplankton migration, measured at two sampling stations, is 40 and 220 times faster than microphytoplankton settling and vertical water velocities respectively. Thus coupled physical-biological connectivity models are necessary to estimate the ecosystem connection and the fate of carbon, but also other substances (e.g. radioactivity), that might accumulate throughout the food-web. This is especially important in the Garrucha Canyon and the Coastal Areas Management Programme Levante de Almería where natural heritage and extractive fishery are important for the local economy.

Mesoscale vertical motion and the size structure of phytoplankton in the ocean

Phytoplankton size structure is acknowledged as a fundamental property determining energy flow through 'microbial' or 'herbivore' pathways. The balance between these two pathways determines the ability of the ecosystem to recycle carbon within the upper layer or to export it to the ocean interior. Small cells are usually characteristic of oligotrophic, stratified ocean waters, in which regenerated ammonium is the only available form of inorganic nitrogen and recycling dominates. Large cells seem to characterize phytoplankton in which inputs of nitrate enter the euphotic layer and exported production is higher. But the size structure of phytoplankton may depend more directly on hydrodynamical forces than on the source of available nitrogen. Here we present an empirical model that relates the magnitude of mesoscale vertical motion to the slope of the size-abundance spectrum of phytoplankton in a frontal ecosystem. Our model indicates that the relative proportion of large cells increases with the magnitude of the upward velocity. This suggests that mesoscale vertical motion-a ubiquitous feature of eddies and unstable fronts-controls directly the size structure of phytoplankton in the ocean.

Hemolysins and proteinase inhibitors from sea anemones of the Gulf of Aqaba

Bioactive polypeptides have been isolated from three sea anemone species by gel filtration and ion-exchange chromatography: hemolysins from Gyrostoma helianthus and Radianthus koseirensis and proteinase inhibitors from the latter species and from Rhodactis rhodostoma. The hemolysins (molecular weight about 10,000) are free of phospholipase A activity, possess considerable ichthyotoxicity, and hemolysis is inhibited by sphingomyelin. The main proteinase inhibitor from Rhodactis rhodostoma is composed of 48 amino acids and inhibits trypsin, kallikrein and chymotrypsin, whereas the semipure inhibitor from Rhadianthus koseirensis has very low affinity for serine proteases and does not inhibit chymotrypsin.