Toxic Residues in Pacific Ocean Marine Life Raise Concerns About Seafood Safety and Human HealthA comprehensive review article recently published in the journal Science of the Total Environment has unveiled alarming levels of toxins in marine life inhabiting the Pacific Ocean, raising significant concerns about seafood safety and its impact on human health.
Background:
The aquatic ecosystem is highly vulnerable to environmental factors such as climate change and residual toxins. Pollution of the marine environment has the potential to disrupt the ocean’s biological, physical, and chemical balance, leading to severe consequences for marine ecosystems and wildlife.
The Pacific Ocean, one of the world’s largest and deepest oceans, covering approximately 28% of the Earth’s surface, has witnessed a concerning trend. From 2003 to 2012, there was a 50% increase in the influx of chemical pollutants into the Pacific Ocean. This surge in marine pollution has emerged as a significant global public health concern, with far-reaching implications for food safety, food security, and human health.
Residual Toxins in the Pacific Ocean:
Residual toxins found in aquatic organisms can be categorized into two main groups: toxins of marine origin and those linked to human activities. Harmful Algal Blooms (HABs) are marine biotoxins produced by dense aggregations of unicellular algae. These biotoxins can accumulate in various marine species, including tunicates, echinoderms, gastropods, fish, and filter-feeding fauna.
Recent evidence highlights a spatial increase in HABs, particularly in the Asia-Pacific and North-Pacific regions, attributable to climate change and anthropogenic activities. However, no significant temporal increase in HABs has been observed to date.
Cyanobacteria, through photosynthesis, produce cyanotoxins such as saxitoxins and microcystins. The frequency of cyanotoxin production has surged in several regions globally, including the Pacific Northwest.
Persistent organic pollutants, heavy metals, and microplastics are emerging contaminants of concern, primarily originating from industrial facilities, hospitals, agricultural runoff, and landfills.
While interventions like the Stockholm Convention have curbed the release of persistent organic pollutants into aquatic organisms, there has been a sharp rise in microplastic pollution. Recent estimates suggest that the annual release of plastics from the mainland into the ocean may reach 12.7 million tons.
Non-biodegradable and toxic heavy metals, notably mercury, enter the aquatic environment mainly through agricultural runoff, leading to their accumulation in aquatic organisms and subsequent transfer through the food chain. Increased human activities have contributed significantly to rising mercury emissions.
Toxin Exposure in Pacific Ocean Aquatic Life:
Microplastics are a major source of aquatic pollutants, impacting over 100 species, from plankton to large marine animals. In the North Pacific Ocean, polybrominated diphenyl ethers have been detected at elevated levels in the adipose tissue and stomach of seabirds due to their consumption of microplastics.
Accumulation of microplastics in small oceanic creatures residing at the ocean’s depths has been linked to reduced survival rates and population declines. In the Eastern and Northern Pacific Ocean, numerous aquatic species exhibit significantly elevated levels of microplastics in their digestive systems.
Fish species from Indonesia and California fish markets have shown alarming amounts of plastic debris and man-made fibers. These contaminants have known adverse effects on the endocrine, immune, and reproductive systems of marine fish.
Apart from microplastics, toxic chemicals released into the marine environment, such as polychlorinated biphenyls, impact marine mammals, including dolphins and whales, through ingestion of contaminated food, water, or air. These chemicals disrupt endocrine and digestive functions in marine animals.
Impact on Human Health:
Recent estimates reveal a surge in per capita fish consumption from 9 kg in 1961 to 20 kg in 2018. Consumption of contaminated aquatic organisms, particularly fish, poses a significant threat to human health. Residual toxins ingested through contaminated seafood can lead to cognitive impairment, neurological issues, and severe health complications.
Harmful Algal Bloom toxins can cause paralytic shellfish poisoning in humans, resulting in cardiovascular shock or respiratory paralysis.
Cyanotoxins have been linked to adverse effects on human organs, including the liver, nervous system, skin, and digestive system, leading to symptoms such as diarrhea, weakness, muscle tremors, vomiting, abdominal pain, and skin irritation. Cyanotoxins are also associated with the development of primary liver cancer.
Persistent organic pollutants are known to cause chronic health issues in humans, including congenital disabilities, cardiovascular problems, endocrine disruptions, reproductive complications, immune disorders, and cancers.
Consumption of aquatic organisms contaminated with heavy metals, particularly mercury, can have fatal consequences for human health. Mercury’s high toxicity and biomagnification in the food chain are of particular concern, along with the harmful effects of cadmium and arsenic on various physiological systems.
Given the severe health risks associated with contaminated seafood consumption, various measures have been implemented to protect aquatic organisms from toxin exposure. Artificial intelligence and machine learning technologies hold promise for predicting pollution sources, assessing pollution levels, and identifying signs of contamination in seafood products.
In conclusion, the elevated levels of toxins in Pacific Ocean marine life underscore the urgent need for enhanced environmental protection measures and heightened awareness of the risks posed to both marine ecosystems and human health.