A bibliometric review on the implications of renewable offshore marine energy development on marine species

Transcriptomic analysis of the response mechanisms of black rockfish (Sebastes schlegelii) under noise stress from offshore wind farms

During the operational phase of offshore wind farms, the generation of low-frequency underwater noise has received widespread attention due to its potential adverse impact on fish health. This study conducted a field survey of underwater noise at offshore wind farms located in Shandong province, China. Subsequently, a small-scale experiment was conducted to study the stress on black rockfish (Sebastes schlegelii). The fish were exposed to noise with dominant frequency of 80 Hz, 125 Hz and 250 Hz. These frequencies are same with the frequencies from wind power noise (wpn) at the actual site. After a 40-day experimental period, transcriptome sequencing was conducted on brain, liver, and kidney tissues of black rockfish to elucidate the underlying molecular mechanisms involved in the response to noise stress originating from offshore wind farms. The results revealed that the 125 Hz group exhibited the highest number of differentially expressed genes (DEGs) between the noise-exposed and control check group (CK group), with a total of 797 in the brain, 1076 in the liver, and 2468 in the kidney. Gene Ontology (GO) analysis showed that DEGs were significantly enriched in entries related to cellular processes, membrane components, binding, and metabolism. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were enriched mainly in metabolism, immunity, apoptosis, signal transduction, and diseases. The findings indicate that prolonged exposure to underwater noise from offshore wind farms may induce metabolic imbalance, immune dysfunction, and an increased risk of myocardial diseases in black rockfish.

Ecological impacts of the expansion of offshore wind farms on trophic level species of marine food chain

The global demand for renewable energy has resulted in a rapid expansion of offshore wind farms (OWFs) and increased attention to the ecological impacts of OWFs on the marine ecosystem. Previous reviews mainly focused on the OWFs' impacts on individual species like birds, bats, or mammals. This review collected numerous field-measured data and simulated results to summarize the ecological impacts on phytoplankton, zooplankton, zoobenthos, fishes, and mammals from each trophic level and also analyze their interactions in the marine food chain. Phytoplankton and zooplankton are positively or adversely affected by the 'wave effect', 'shading effect', oxygen depletion and predation pressure, leading to a ± 10% fluctuation of primary production. Although zoobenthos are threatened transiently by habitat destruction with a reduction of around 60% in biomass in the construction stage, their abundance exhibited an over 90% increase, dominated by sessile species, due to the 'reef effect' in the operation stage. Marine fishes and mammals are to endure the interferences of noise and electromagnetic, but they are also aggregated around OWFs by the 'reef effect' and 'reserve effect'. Furthermore, the complexity of marine ecosystem would increase with a promotion of the total system biomass by 40% through trophic cascade effects strengthen and resource partitioning alternation triggered by the proliferation of filter-feeders. The suitable site selection, long-term monitoring, and life-cycle-assessment of ecological impacts of OWFs that are lacking in current literature have been described in this review, as well as the carbon emission and deposition.

Review of the marine energy environment-a combination of traditional, bibliometric and PESTEL analysis

Marine renewable energy is regarded as a nascent renewable energy resource that is less utilized due to a number of challenges in the sector. This paper focused on using both traditional and bibliometric analysis approaches to review the marine energy industry. It also assessed the various opportunities and challenges in the sector beyond technological challenges using PESTEL analysis. The results from the study identified the availability of renewable energy targets, international and national greenhouse gas (GHG) emissions reduction targets, job creation, skill transfer from offshore industries, renewable support, and low GHG emissions as the major opportunities for the sector. The challenges in the sector include the lack of commonality in device designs, high initial capital costs, lack of appropriate legal and regulatory frameworks, lack of funding, fragmentations in regulatory institutions, bad macro-economic indicators in some countries, environmental challenges, the survivability of the various technologies in the harsh oceanic environment, and strong competition from other renewable energy sources. The outcome of the bibliometric analysis spanning from 2013 to 2023 shows that tidal power is the focus of research in the field, and most studies are either focused on ways to improve its efficiency in terms of technology or on the identification of resource potentials for the siting of the various marine renewable power systems. Recommendations such as strong cooperation between the government and private sector, increased public education, collaboration with existing players in the marine sector, and increased research and development, among others, were proposed for the development of the sector.

Mapping of marine lobster research: A global outlook

This study examined research and development of the commercially important marine lobster, in terms of descriptive metadata and scientometric analysis. We consider a collection of over 9,578 related articles to assess literature patterns and research development trends related to marine lobsters as a topic. Web of Science Core Collection was used to identify, collate, and generate publication trends, a list prominent authors and affiliations involved, countries that actively participated, and the co-citation analysis of the references as well as impactful articles and keywords. There were 149 different countries or states that had relevant publications on lobster research. We found an increase in the number of publications over time, with the USA having the most number of publications, followed by Australia and Canada. A total of 17,782 authors were involved in the field of lobster studies. Canadian researchers had the highest citation count for marine lobster research. Surprisingly, the most impactful keyword was crayfish, followed by neuron and amino acid sequence. Our study identifies the multidisciplinary nature in marine lobster research, which includes fields such as neuroscience and developmental genetics. We find that lobster scientific publications increasingly center on the broader coverage areas of science such as taxonomy and basic biology.

Do magnetic fields related to submarine power cables affect the functioning of a common bivalve?

The aim of the study was to determine the effect of static magnetic field (SMF) and electromagnetic field (EMF), of values usually recorded near submarine cables, on the bioenergetics, oxidative stress, and neurotoxicity in the cockle Cerastoderma glaucum. Bivalves maintained a positive energy balance, but the filtration rate and energy available for individual production were significantly lower in SMF-exposed animals compared to the control treatment. No changes in the respiration were noted but ammonia excretion rate was significantly lower after exposure to EMF. Changes in the activities of antioxidant enzymes and the lipid peroxidation were not observed however, exposure to both fields resulted in increased protein carbonylation. After exposure to EMF a significant inhibition of acetylcholinesterase activity was observed. As the present study for the first time revealed the oxidative damage and neurotoxicity in marine invertebrate after exposure to artificial magnetic fields, the need for further research is highlighted.

No evidence for collateral effects of electromagnetic fields used to increase dissolved oxygen levels on the behavior and physiology of freshwater fishes

Hypoxia in surface waters driven by warming climate and other anthropogenic stressors is a major conservation concern, and technological solutions for water quality remediation are sorely needed. One potential solution involves the use of low-intensity electromagnetic fields (EMFs) to increase dissolved oxygen levels, but potential collateral effects of the EMFs on aquatic animals have not been formally evaluated. We examined the effects of EMF exposure on wild-caught, captive sunfish (Lepomis spp.) over 8-day and 3-day exposures, with and without aeration in mesocosms and stock tanks (respectively). We also quantified ambient fish abundance in close proximity to EMF devices deployed in Opinicon Lake (ON). We found no significant differences in a suite of blood-based stress physiology biomarkers, behaviors, and putative aerobic capacities between EMF and control conditions over 8 days. Aerated mesocosms equipped with activated EMFs consistently had higher oxygen levels in the water than aerated controls. There were no differences in mortality during 3-day oxygen depletion trials under EMF or control conditions, and we detected no differences in fish abundance when the devices were activated in the lake. Our findings suggest that deploying EMF devices in field settings is not likely to exert negative effects on exposed fish populations. PRACTITIONER POINTS: Low-cost, low-energy technological solutions to remediate aquatic hypoxia are sorely needed Electromagnetic fields (EMFs) can increase oxygen flux across air/water interfaces and increase dissolved oxygen levels We found no evidence of negative effects of EMFs on fish physiology or behavior and our results support their use in alleviating hypoxic conditions.