VIS-NIR hyperspectral imaging and multivariate analysis for direct characterization of pelagic fish species.

The identification of fish species and their physical and chemical characterization play a crucial role in the fishing industry, fish-food research and the management of marine resources. Traditional methods for species identification, such as expert observation, DNA barcoding and meta-barcoding, though effective, require labor-intensive laboratory work. Consequently, there is a pressing need for more objective and efficient methodologies for accurate fish species identification and characterization.

Effects of elevated CO on the critical oxygen tension (P) and aerobic metabolism of two oxygen minimum zone (OMZ) hypoxia tolerant squat lobster species.

Marine invertebrates living in oxygen minimum zones (OMZ), where low pO and high pCO conditions co-occur, display physiological mechanisms allowing them to deal with these coupled stressors. We measured aerobic metabolic rate (MR) and the critical oxygen tension (P), and calculated the oxygen supply capacity (α) of both the red (Grimothea monodon) and yellow (Grimothea johni) squat lobsters, under two pCO scenarios (~414 and 1400 μatm). We also measured haemolymph pH, haemocyanin oxygen binding affinity (p), and haemolymph lactate content in both species under normoxia, low pCO hypoxia and high pCO hypoxia.

How plastic litter sunk by biofouling recovers buoyancy - The role of benthic predation.

Estimates suggest that the amount of plastic litter discarded in the ocean is several times greater than what remains floating at the sea surface, raising questions about the fate of this marine debris. Fouling-induced sinking of plastic litter is one of the proposed mechanisms responsible for this mass difference. While some of this 'missing' plastic mass may be explained by the effects of fouling, it has also been hypothesized that sinking litter may return to the surface after benthic organisms consume the biofouling.

Evidence of plastic pollution from offshore oceanic sources in southern Chilean Patagonian fjords.

The Chilean Patagonian fjords are globally renowned as one of the few remaining pristine environments on Earth; however, their ecosystems are under significant threat from climatic and anthropogenic pressures. Of particular concern is the lack of research into the impact of plastic pollution on the waters and biodiversity of these fjords. In this study, the marine environment of a secluded and sparsely populated fjord system in southern Patagonia was sampled to assess microplastics in seawater, beaches, bottom sediment, and zooplankton.

A Spatial-Spectral Classification Method Based on Deep Learning for Controlling Pelagic Fish Landings in Chile.

Fishing has provided mankind with a protein-rich source of food and labor, allowing for the development of an important industry, which has led to the overexploitation of most targeted fish species. The sustainable management of these natural resources requires effective control of fish landings and, therefore, an accurate calculation of fishing quotas. This work proposes a deep learning-based spatial-spectral method to classify five pelagic species of interest for the Chilean fishing industry, including the targeted , and and non-targeted and fish species.

Citizen scientists study beach litter along 12,000 km of the East Pacific coast: A baseline for the International Plastic Treaty.

Anthropogenic Marine Litter (AML) accumulating on beaches causes damage to coastal ecosystems and high costs to local communities. Volunteers sampled AML on 130 beaches along the central and southern East Pacific coasts, with AML densities ranging from 0.46 to 2.

Digital Classification of Chilean Pelagic Species in Fishing Landing Lines.

Fishing landings in Chile are inspected to control fisheries that are subject to catch quotas. The control process is not easy since the volumes extracted are large and the numbers of landings and artisan shipowners are high. Moreover, the number of inspectors is limited, and a non-automated method is utilized that normally requires months of training.

Cellulosic and microplastic fibers in the Antarctic fish Harpagifer antarcticus and Sub-Antarctic Harpagifer bispinis.

Human settlements within the Antarctic continent have caused significant coastal pollution by littering plastic. The present study assessed the potential presence of microplastics in the gastrointestinal tract of the Antarctic fish Harpagifer antarcticus, endemic to the polar region, and in the sub-Antarctic fish Harpagifer bispinis. H.

Does the loss of diadromy imply the loss of salinity tolerance? A gene expression study with replicate nondiadromous populations of Galaxias maculatus.

The recurrent colonization of freshwater habitats and subsequent loss of diadromy is a major ecological transition that has been reported in many ancestrally diadromous fishes. Such residency is often accompanied by a loss of tolerance to seawater. The amphidromous Galaxias maculatus has repeatedly colonized freshwater streams with evidence that freshwater-resident populations exhibit stark differences in their tolerance to higher salinities.

Are physiological responses in foraminifera reliable environmental stress bioindicators? A systematic review.

Foraminifera are considered good bioindicators of environmental stress based on morphological abnormalities, but physiological responses occur far earlier and have not been evaluated as pollution markers. The aim of this review was to collate all published articles reporting physiological changes in foraminifera after environmental and anthropogenic stressors, to evaluate their reliability as early markers of environmental stress. We reviewed 70 studies, meeting the inclusion criteria, reporting 13 physiological effects classes after exposure to 17 different stressors.

Slow and steady hurts the crab: Effects of chronic and acute microplastic exposures on a filter feeder crab.

Microplastics are a widespread environmental contaminant. Although detrimental effects on aquatic organisms are well documented, little is known about the long-term effects of microplastic exposure to filter-feeding organisms at ecologically realistic levels. This study investigates the effects of environmentally relevant concentrations of polyethylene micro beads ranging in size from 3 to 30 μm, on the physiology and energetics of a coastal filter-feeding crab Petrolisthes laevigatus.

Body mass and cell size shape the tolerance of fishes to low oxygen in a temperature-dependent manner.

Aerobic metabolism generates 15-20 times more energy (ATP) than anaerobic metabolism, which is crucial in maintaining energy budgets in animals, fueling metabolism, activity, growth and reproduction. For ectothermic water-breathers such as fishes, low dissolved oxygen may limit oxygen uptake and hence aerobic metabolism. Here, we assess, within a phylogenetic context, how abiotic and biotic drivers explain the variation in hypoxia tolerance observed in fishes.

Microplastic concentration, distribution and dynamics along one of the largest Mediterranean-climate rivers: A whole watershed approach.

Microplastics (MPs) have been recognized as one of the most ubiquitous environmental pollutants globally. They have been found in all ecosystems studied to date, threatening biological diversity, ecosystem functioning and human health. The present study aimed to elucidate the environmental and anthropogenic drivers of MP dynamics in the whole catchment of the Biobío river, one of the largest rivers in South America.

Environmental determinants of COVID-19 transmission across a wide climatic gradient in Chile.

Several studies have examined the transmission dynamics of the novel COVID-19 disease in different parts of the world. Some have reported relationships with various environmental variables, suggesting that spread of the disease is enhanced in colder and drier climates. However, evidence is still scarce and mostly limited to a few countries, particularly from Asia.

Aerobic and anaerobic metabolic scaling in the burrowing freshwater crayfish Parastacus pugnax.

Metabolic scaling is a well-known biological pattern. Theoretical scaling exponents near 0.67 and 0.

Age dependent physiological tolerances explain population dynamics and distribution in the intertidal zone: A study with porcelain crabs.

Population dynamics and their response to environmental stressors have been widely studied in intertidal organisms. However, how these dynamics and responses change with animal age have been largely ignored to date. Traditionally, it is assumed that younger organisms are more sensitive than adults to environmental stressors; under this perspective it could be predicted that fully grown organisms should be able to occupy the harsh upper limit of their intertidal habitat.

Diel vertical migration into anoxic and high-pCO waters: acoustic and net-based krill observations in the Humboldt Current.

A select group of marine organisms can enter the Oxygen Minimum Zones (OMZs) and even anoxic waters, while performing diel vertical migration (DVM). DVM of the euphausiid Euphausia eximia off northern Chile in the spring of 2015 was documented based on acoustic measurements using an echo sounder along with net samplings. Dissolved oxygen (DO) concentrations were obtained using a vertical profiler, and water samples were collected to obtain in situ nitrite (NO) concentrations as well as pH, total alkalinity (AT), and therefore carbon dioxide partial pressure (pCO) was estimated.

Genomic basis of the loss of diadromy in Galaxias maculatus: Insights from reciprocal transplant experiments.

Diadromy is known for having major effects on the distribution and richness of aquatic species, and so does its loss. The loss of diadromy has led to the diversification of many species, yet research focusing on understanding its molecular basis and consequences are limited. This is particularly true for amphidromous species despite being the most abundant group of diadromous species.

Early development and metabolic rate of the sea louse Caligus rogercresseyi under different scenarios of temperature and pCO.

Anthropogenic CO emissions have led to ocean acidification and a rise in the temperature. The present study evaluates the effects of temperature (10, 15 and 20 °C) and pCO (400 and 1200 μatm) on the early development and oxygen consumption rate (OCR) of the sea louse Caligus rogercresseyi. Only temperature has an effect on the hatching and development times of nauplius I.

Water column circulation drives microplastic distribution in the Martínez-Baker channels; A large fjord ecosystem in Chilean Patagonia.

We investigated the distribution of microplastics in the water column along a large remote estuarine system located between the Northern and Southern Patagonian Ice Fields in Chilean Patagonia, and connected with the Pacific Ocean through the Gulf of Penas. Microplastic particles were found in all samples, with abundances ranging from 0.1 to 7 particles/m.

Adsorption of polyethylene microbeads and physiological effects on hydroponic maize.

About 90% of the plastic garbage remains in terrestrial ecosystems, and increasing evidence highlights the exposure of crops to plastic particles. However, the potential bioaccumulation of microplastics by plants and their effects on plants' physiology remains unexplored. Here, we evaluated the adsorption, potential uptake, and physiological effects of polyethylene (PE) microbeads in an experimental hydroponic culture of maize.