Growth and defense mechanism of Phaeocystis globosa exposed to extremely low frequency electromagnetic fields.

Ecotoxicology and environmental safety · 2025 · Mixed · Low evidence

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MixedLow evidencePaper 5897

Study snapshot

PublicationEcotoxicology and environmental safety · 2025

Study typeother

Reported directionMixed

Evidence ratingLow

Abstract

Marine power cables are increasingly exposing marine ecosystems to artificial extremely low-frequency electromagnetic fields (ELF-EMF). The harmful and periodic outbreaks of Phaeocystis globosa blooms in the Beibu Gulf, though driven by complex factors, raise questions about potential links to ELF-EMF. While existing studies suggest that ELF-EMF promote microalgal proliferation, and electromagnetic conditions in the Beibu Gulf have undergone changes, research exploring their connection remains scarce. To assess the impacts of ELF-EMF on the microalga P. globosa, we expose it to ELF-EMF at three electromagnetic strengths (0, 0.2, 1 millitesla (mT)) over a 24 h period. Analysis of growth indicators, physiology, biochemistry, and the metabolome is performed to identify how this alga responds to ELF-EMF. Exposure to 0.2 mT 24 h and 1 mT 24 h increased cultured P. globosa cell density, enhanced photosynthesis, and increased chlorophyll a content, but decreased protein and carbohydrate accumulation. Metabolome analysis revealed, 916 differently expressed metabolites, of which cyclic adenosine monophosphate (cAMP) and linoleic acid are significantly down-regulated, while γ-aminobutyric acid is significantly up-regulated. Pathway analysis reveals cAMP signaling pathway and linoleic acid metabolism to be inhibited following ELF-EMF exposure. We demonstrate that P. globosa growth was promoted with exposure to ELF-EMF. Under the influence of electromagnetic fields, P. globosa exhibits enhanced growth, reproduction, and photosynthesis, along with stronger stress resistance. Therefore, under changing electromagnetic conditions in the Beibu Gulf, the threat of P. globosa algal blooms may increase. This study sheds light on potential drivers of harmful algal blooms (HABs), suggesting that ELF-EMF may play a role in bloom initiation. However, the exact mechanisms underlying this relationship warrant further investigation to establish causality and ecological relevance.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionmixed

PopulationMicroalga Phaeocystis globosa (cultured)

Sample sizeNot supplied

ExposureELF · 24 h

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

P. globosa exposed for 24 h to ELF-EMF at 0.2 mT or 1 mT showed increased cell density, enhanced photosynthesis, and increased chlorophyll a content, while protein and carbohydrate accumulation decreased. Metabolomics identified 916 differentially expressed metabolites; cAMP and linoleic acid were significantly down-regulated and γ-aminobutyric acid was significantly up-regulated, with pathway analysis indicating inhibition of cAMP signaling and linoleic acid metabolism.

Outcomes measured

Cell density (growth)
Photosynthesis
Chlorophyll a content
Protein accumulation
Carbohydrate accumulation
Metabolome changes (differential metabolites)
cAMP levels
Linoleic acid levels
γ-aminobutyric acid (GABA) levels
Pathway activity: cAMP signaling
Pathway activity: linoleic acid metabolism
Stress resistance (as described)

Limitations

Frequency of the ELF-EMF exposure not reported in the abstract
Sample size and replication not reported in the abstract
Short exposure duration (24 h) limits inference about longer-term effects
In vitro/culture study; ecological relevance and causality for field blooms not established (as noted in abstract)

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": "ELF",
    "source": "marine power cables",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "24 h"
  },
  "population": "Microalga Phaeocystis globosa (cultured)",
  "sample_size": null,
  "outcomes": [
    "Cell density (growth)",
    "Photosynthesis",
    "Chlorophyll a content",
    "Protein accumulation",
    "Carbohydrate accumulation",
    "Metabolome changes (differential metabolites)",
    "cAMP levels",
    "Linoleic acid levels",
    "γ-aminobutyric acid (GABA) levels",
    "Pathway activity: cAMP signaling",
    "Pathway activity: linoleic acid metabolism",
    "Stress resistance (as described)"
  ],
  "main_findings": "P. globosa exposed for 24 h to ELF-EMF at 0.2 mT or 1 mT showed increased cell density, enhanced photosynthesis, and increased chlorophyll a content, while protein and carbohydrate accumulation decreased. Metabolomics identified 916 differentially expressed metabolites; cAMP and linoleic acid were significantly down-regulated and γ-aminobutyric acid was significantly up-regulated, with pathway analysis indicating inhibition of cAMP signaling and linoleic acid metabolism.",
  "effect_direction": "mixed",
  "limitations": [
    "Frequency of the ELF-EMF exposure not reported in the abstract",
    "Sample size and replication not reported in the abstract",
    "Short exposure duration (24 h) limits inference about longer-term effects",
    "In vitro/culture study; ecological relevance and causality for field blooms not established (as noted in abstract)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF-EMF",
    "marine power cables",
    "Phaeocystis globosa",
    "harmful algal blooms",
    "cell density",
    "photosynthesis",
    "chlorophyll a",
    "metabolomics",
    "cAMP",
    "linoleic acid",
    "GABA",
    "Beibu Gulf"
  ],
  "suggested_hubs": [
    {
      "slug": "marine-cables",
      "weight": 0.86,
      "reason": "Study frames ELF-EMF exposure as arising from marine power cables affecting marine ecosystems."
    },
    {
      "slug": "elf-emf",
      "weight": 0.84,
      "reason": "Exposure explicitly described as extremely low-frequency electromagnetic fields at 0.2 and 1 mT."
    },
    {
      "slug": "environmental-ecotoxicology",
      "weight": 0.6,
      "reason": "Ecotoxicology-focused experimental assessment of EMF effects on a marine microalga."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.ecoenv.2025.118507
PubMed: 40527026

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