Article
Biochemistry & Molecular Biology
Li Qian, Shanshan Tian, Su Jiang, Yunping Tang, Tao Han
Summary: This study investigates the protective effect of DHA-PC from Clupea harengus roes against high-fat diet-induced non-alcoholic fatty liver disease (NAFLD). The results suggest that DHA-PC can decrease body weight, liver indexes, serum levels of inflammation markers and oxidative stress markers, improve serum lipid levels, and alleviate intestinal dysbiosis caused by NAFLD. These findings demonstrate that DHA-PC alleviates NAFLD by regulating lipid metabolism and dysbiosis via the gut-liver axis.
Article
Multidisciplinary Sciences
Andreas Novotny, Kinlan Mehdi Goulwen Jan, Jan Dierking, Monika Winder
Summary: This study investigates the diet overlap between planktivorous fish species in the Baltic Sea using DNA metabarcoding and other methods. The results show niche differentiation between herring and stickleback, with rotifers playing an important role in this pattern. The study suggests that rotifers and other understudied soft-bodied prey have an important function in the pelagic food web.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Marine
Muhammad Saladin Prawirasasra, Mirko Mustonen, Aleksander Klauson
Summary: The study found that vocal activity of seals increased during the mating period in late winter, and changes in the sound environment during the freezing period favored ship noise propagation. While environmental risks related to anthropogenic sound were considered low, ship traffic may cause auditory masking for some time for ringed seals.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Fisheries
Marion Claireaux, Thassya C. dos Santos Schmidt, Esben Moland Olsen, Aril Slotte, Oystein Varpe, Mikko Heino, Katja Enberg
Summary: Reproductive investment is a key factor affecting population dynamics and productivity. This study investigated how fishing, environmental factors, and intra-specific competition contribute to variation in reproductive investment of Norwegian spring-spawning herring. The results highlight how fishing can alter the impact of environmental variations on life-history traits through its effects on population-level dynamics.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Environmental Sciences
Francesca Pancaldi, Federico Paez-Osuna, Ana Judith Marmolejo-Rodriguez, Darren Andrew Whitehead, Rogelio Gonzalez-Armas, Martin Federico Soto-Jimenez, Todd O'Hara, Abraham Vazquez-Haikin, Felipe Galvan-Magana
Summary: The Gulf of California is an important hotspot for whale shark aggregation, but is also subject to pollutants such as trace elements. Research showed enrichment of all trace elements in both zooplankton and whale sharks during the period of 2017-2018.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Environmental Sciences
Maris Skudra, Germo Vali, Anda Ikauniece, Miks Papirtis
Summary: This study investigates the upwelling events in the Gulf of Riga, with findings indicating that upwellings are less frequent but longer lasting with larger temperature drops on the eastern coast compared to the western coast. Variability in upwelling characteristics was observed between stations only 30 km apart on the western coast, possibly due to different orientations of the coastline. Satellite data also revealed small upwelling events forming along specific sections of the western coastline. Additionally, it was found that 30% of the upwelling events exhibited an immediate temperature increase following the minimum temperature, suggesting a relationship with a distinct change in wind direction. Simulation results showed smaller density and salinity gradients on the sea surface in the Gulf of Riga compared to larger Baltic Sea gulfs, indicating weaker conditions for baroclinic instabilities and contributing to faster upwelling relaxation in the basin.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Biochemistry & Molecular Biology
Marja Keinanen, Soili Nikonen, Reijo Kakela, Tiina Ritvanen, Mervi Rokka, Timo Myllyla, Jukka Ponni, Pekka J. Vuorinen
Summary: This study investigated the signs of impaired thiamine status in feeding-migrating Atlantic salmon in three Baltic Sea areas. The results showed that the thiamine status of the salmon was mainly affected by the peroxidation of n-3 PUFAs, rather than the intake of dietary lipids as a source of metabolic energy.
Article
Microbiology
Anne W. W. Thompson, Carey P. P. Sweeney, Kelly R. R. Sutherland
Summary: Microbial mortality affects the structure of food webs and carbon flow, and the interactions that shape abundance patterns in diverse ecosystems. The study reveals the underestimated role of mucous mesh feeders in causing microbial mortality in the open ocean, leading to a new understanding of microbial community dynamics.
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Marine & Freshwater Biology
Baptiste Serandour, Kinlan M. G. Jan, Andreas Novotny, Monika Winder
Summary: The study used DNA-metabarcoding to investigate trophic interactions in mesozooplankton predators and the influence of prey availability on their feeding behavior. Results indicated that mesozooplankton feeding strategies vary within species across an environmental gradient. The study also revealed the wide range of prey species that supports the mesozooplankton community and helps to understand the selectivity ability of four zooplankton key species.
JOURNAL OF PLANKTON RESEARCH
(2023)
Article
Fisheries
Susan Kenyon, Martin Pastoors, Steven Mackinson, Thomas Cornulier, C. Tara Marshall
Summary: Fat content plays an important role in the condition and reproductive cycles of fish species. However, quantifying the variability of fat content is challenging without sampling the full reproductive cycle. This study validated the use of high temporal resolution data to measure fat content in North Sea herring and found a strong intra-annual signal that matched herring reproductive status. The study also examined inter-annual variability in the seasonal pattern and peak fat content.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Environmental Sciences
Juris Aigars, Marta Barone, Natalija Suhareva, Ieva Putna-Nimane, Inta Dimante-Deimantovica
Summary: This study compared the distribution and composition of microplastic debris in the Gulf of Riga and the Eastern Gotland Basin in the Baltic Sea. The researchers found that the abundance of microplastic particles varied among different stations, with fibers and fragments being the predominant types, and polyethylene and polypropylene being the main polymer types encountered. The concentrations of micro-debris observed fell within the reported range of values from other regions in the Baltic Sea.
MARINE POLLUTION BULLETIN
(2021)
Article
Environmental Sciences
Young Seok Jeong, Seohwi Choo, Ho Young Soh
Summary: This study investigated the impact of rainfall on the composition and ecological status of zooplankton in a temperate estuary. The findings showed a significant decrease in zooplankton abundance after rainfall, and a high correlation between indicator species abundance and environmental factors. In terms of feeding habits, carnivore proportion decreased while particle feeder proportion increased after rainfall.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Fisheries
Fletcher Sewall, Brenda Norcross, Ron Heintz
Summary: The mortality of juvenile fish in winter is partly dependent on feeding history, with compensatory growth observed in re-fed herring. Winter feeding benefits have limits, as witnessed by minimal growth and reduced gut mass in fully fed herring. The importance of size-dependent winter mortality is highlighted by the highest mortality rates among small herring.
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Francesco Cicala, Maria C. Arteaga, Sharon Z. Herzka, Clara M. Hereu, Sylvia P. A. Jimenez-Rosenberg, Anaid Saavedra-Flores, Javier Robles-Flores, Ricardo Gomez, Paola G. Batta-Lona, Clara E. Galindo-Sanchez
Summary: Zooplankton plays a key role in marine ecosystems, with their distribution and diversity providing crucial information for understanding ecosystem functioning. A study on the open waters of the southern Gulf of Mexico revealed that dissolved oxygen concentration, temperature, and longitude may be important factors explaining spatial and temporal zooplankton variability. Additionally, the use of multilocus approaches can provide more accurate assessments of zooplankton communities.
Article
Fisheries
Leopold Ghinter, Wahiba Ait Youcef, Yvan Lambert, M. Joanne Morgan, Celine Audet
Summary: Understanding biological characteristics is crucial for comprehending environmental constraints on fish populations, particularly in the context of climate change. This study used data from Fisheries and Oceans Canada to investigate the seasonal condition of Greenland Halibut juveniles and differences in life history traits between juveniles in the EGSL and northwest Atlantic. Results showed that juvenile condition was higher in winter and spring in the EGSL, possibly due to pelagic predation activity and prey availability.
TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY
(2021)
Article
Biodiversity Conservation
Girts Baranovskis, Olgerts Nikodemus, Guntis Brumelis, Didzis Elferts
Summary: Biodiversity conservation strategies in many countries involve both state land and private land. In Latvia, strict forest management restrictions can cause conflicts with forest owners, negatively impacting the success of biodiversity conservation goals. Factors such as financial dependence on income from forest harvest and landowner education influence private forest owners' attitudes towards biodiversity conservation.
BIOLOGICAL CONSERVATION
(2022)
Article
Multidisciplinary Sciences
Indrikis A. Krams, Adele Mennerat, Tatjana Krama, Ronalds Krams, Priit Joers, Didzis Elferts, Severi Luoto, Markus J. Rantala, Sigrunn Eliassen
Summary: This study found that male pied flycatchers participating in extra-pair copulations are more likely to assist their neighbors in antipredator defense. These males join predator-mobbing more often, approach predators more closely, and attack predators more aggressively. This cooperative behavior may improve their total offspring production. For females, this mating strategy helps recruit more males to join in antipredator defense, providing better protection and ultimately improving reproductive success.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Forestry
Oskars Krisans, Linda Caksa, Roberts Matisons, Steffen Rust, Didzis Elferts, Andris Seipulis, Aris Jansons
Summary: In urbanized areas, wind disturbances can be intensified due to anthropogenic stresses, posing threats to trees. Eurasian aspen and silver birch are commonly found in urban and peri-urban forests in Europe, and their mechanical stability was evaluated through static pulling tests.
Article
Multidisciplinary Sciences
Tatjana Krama, Ronalds Krams, Maris Munkevics, Jonathan Willow, Sergejs Popovs, Didzis Elferts, Markus Rantala, Jorge Contreras-Garduno, Indrikis A. Krams
Summary: This study compared the reproductive success, elemental composition, and physiological stress of buff-tailed bumblebees in oilseed rape fields and old apple orchards. The results showed that bees in oilseed rape fields had higher reproductive output and lower C/N ratio, while bees in apple orchards had higher body nitrogen concentration.
Article
Plant Sciences
Oskars Krisans, Roberts Matisons, Janis Vuguls, Steffen Rust, Didzis Elferts, Andris Seipulis, Renate Saleniece, Aris Jansons
Summary: In Northern Europe, the shortened periods of frozen soil due to winter warming and increased precipitation aggravate forest stands' susceptibility to wind damage. Stand stability is more affected in moist and loose soil conditions. Silver birch, a widespread species in the Eastern Baltics, is economically important and found on both mineral and peat soils. While it is considered less prone to wind loading during dormant periods, wind damage occurs under moist and non-frozen soil conditions. A study comparing the mechanical stability of silver birch on frozen and non-frozen mineral and peat soils showed improved stability under frozen soil conditions. Higher soil-root anchorage and stem strength contribute to this improvement. However, the relative improvement in soil-root anchorage was larger on mineral soil, possibly due to root distribution. Overall, silver birch had higher estimated loading resistance on peat soil, indicating its suitability for forest regeneration on loose and moist soils.
Article
Forestry
Oskars Krisans, Roberts Matisons, Janis Vuguls, Endijs Baders, Steffen Rust, Didzis Elferts, Renate Saleniece, Aris Jansons
Summary: Forest plantations, especially high-density planted stands, are more susceptible to wind damage compared to naturally regenerated stands. However, by combining different species and using close-to-natural management, the wind resistance of plantations can be improved. This study found that regularly mixed bi-species stands significantly enhanced the stability of canopy silver birch trees, possibly due to the stratification of canopy space and regular rooting network.
Article
Green & Sustainable Science & Technology
Oskars Krisans, Roberts Matisons, Janis Vuguls, Andris Seipulis, Didzis Elferts, Valters Samariks, Renate Saleniece, Aris Jansons
Summary: In the Eastern Baltic region, the frequency and intensity of severe windstorms have increased, posing greater wind damage risks for silver birch trees. The properties of soil-root plate, influenced by soil type, determine the type of fatal failures trees experience under extreme wind loads. Frozen soil conditions enhance soil-root anchorage, increasing the frequency of stem breakage. However, the lack of frozen soil conditions is a major climate risk for forestry in the region.
Article
Green & Sustainable Science & Technology
Marcis Saklaurs, Agnese Anta Liepina, Didzis Elferts, Aris Jansons
Summary: Riparian forests act as transitional zones between terrestrial and aquatic ecosystems, and their management is crucial for promoting ecological functions. A study in Latvia found that riverine forests were less popular for recreation compared to other types of forests, with walking and swimming being the most popular activities. Issues related to forests and water bodies were not the main concerns for respondents, with obstructed fish movement being recognized as the most important problem. Dynamic river basin and river bank management could help restore suitable locations for recreational activities and improve riparian ecosystems.
Article
Forestry
Roberts Matisons, Diana Jansone, Didzis Elferts, Volker Schneck, Jan Kowalczyk, Tomasz Wojda, Aris Jansons
Summary: This study assessed the plasticity of growth response of silver birch to meteorological conditions, and found that its sensitivity to temperature and water availability varies across different regions. At a regional scale, summer water shortage was found to be the main driver of growth.
Article
Forestry
Laura Kenina, Didzis Elferts, Ieva Jaunslaviete, Endijs Baders, Aris Jansons
Summary: This study compares carbon stock between old-growth stands and mature stands in hemiboreal Latvia, contributing to the understanding of carbon storage changes and forest management strategies. The results show that old-growth stands have larger carbon stock but lower annual carbon stock change compared to mature stands. It is important to expand managed stands with larger annual carbon stock increase for climate neutrality.
Article
Oceanography
Atis Labucis, Astra Labuce, Iveta Jurgensone, Ieva Barda, Ingrida Andersone, Anda Ikauniece
Summary: Temporal variations in the primary production of size-fractionated autotrophic plankton community were studied in the eutrophic Gulf of Riga, Baltic Sea. The community was net-autotrophic during spring and summer but net-heterotrophic during autumn. The results indicate a strong co-variation between net primary production (NPP) and <56 μm fractionated community biomass, primarily driven by the small-sized M. rubrum.
Article
Biology
Tatjana Krama, Ronalds Krams, Didzis Elferts, Kathryn E. Sieving, Indrikis A. Krams
Summary: Animals adjust their use of alarm calls depending on social environments. Both adult and juvenile male crested tits warn each other in early winter, and adults do so in the middle of wintering season. The mid-winter reduction of juvenile alarms could increase the chances for juveniles to replace adults. Whether juvenile male crested tits could selectively alter alarm call propensity to endanger adult males is discussed.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Behavioral Sciences
Tatjana Krama, Maris Munkevics, Ronalds Krams, Tatjana Grigorjeva, Giedrius Trakimas, Priit Joers, Sergejs Popovs, Krists Zants, Didzis Elferts, Markus J. Rantala, Eriks Sledevskis, Jorge Contreras-Garduno, Benjamin L. de Bivort, Indrikis A. Krams
Summary: The development of high-throughput behavioral assays has facilitated the study of animal personality. Previous research found that isogenic Drosophila melanogaster flies exhibit individual non-heritable locomotor handedness, which varies across genotypes and neural activity. This study tested whether fruit flies grown with predators show higher variability/lower predictability in their turning behavior and higher survival. The results demonstrated a negative association between the unpredictability of fruit fly turning behavior and the hunting success of their predators, and showed that serotonin controls predator-induced changes in fruit fly turning variability.
FRONTIERS IN BEHAVIORAL NEUROSCIENCE
(2023)
Article
Oceanography
Ralph Tafon, Aurelija Armoskaite, Kira Gee, Michael Gilek, Anda Ikauniece, Fred Saunders
Summary: Community participation and influence are crucial for achieving the sustainable goals of marine spatial planning (MSP) and procedural and distributive justice. However, there is a need to develop equity-based principles and generate empirical accounts of coastal community participation to assess and reform MSP practices. This study presents principles and indicators for coastally equitable and just planning and applies them to assess Latvian MSP practices. The analysis shows the importance of inclusive and localized participation throughout the planning process.
OCEAN & COASTAL MANAGEMENT
(2023)
Article
Plant Sciences
Priyanka Trivedi, Linards Klavins, Anne Linn Hykkerud, Jorens Kviesis, Didzis Elferts, Inger Martinussen, Maris Klavins, Katja Karppinen, Hely Haggman, Laura Jaakola
Summary: This study investigated the chemical composition of bilberry fruit cuticular wax at different latitudes and found that temperature is the main factor affecting the composition of the wax.
FRONTIERS IN PLANT SCIENCE
(2022)
