0
Article Tier 2 Environmental Sources Marine & Wildlife Sign in to save

Microplastic footprints in sharks and rays: First assessment of microplastic pollution in two cartilaginous fishes, hardnose shark and whitespotted whipray

Marine Pollution Bulletin 2024 4 citations

AI summary Read the abstract

Researchers conducted the first assessment of microplastic pollution in two species of cartilaginous fish, the hardnose shark and whitespotted whipray, from the Persian Gulf and Sea of Oman. They found microplastics in every tissue examined, including intestines, gills, and skin, with fibers and filaments being the most common forms, pointing to fishing gear and wastewater as likely sources. The study reveals that even top marine predators in these waters are heavily contaminated with microplastics.

Polymers
Body Systems
Study Type Environmental

Microplastic (MP) pollution is an emerging environmental problem worldwide and has caused widespread concern both in terrestrial and aquatic ecosystems due to their potential impacts on the human health, and health of aquatic organisms and the environment. Little is known about the exposure of top marine predators to MP contamination (debris 0.1μm - <5mm, also called MPs). For the first time, MPs have been characterized in carnivore demersal elasmobranch specimens of hardnose shark Carcharhinus macloti, and the whitespotted whipray Maculabatis gerrardi. The specimens were from the Persian Gulf and Sea of Oman, and MPs were extracted from their intestines, gills, and skin. MPs were found in every sampled tissue examined: this is higher pollution than previously reported for elasmobranch. The total MPs for these organs were 12.6 MPs/g body mass of sharks, and 17.8 MPs/g in the whiprays on average. The most common MPs found were fibres (59%), and filaments (35%); pointing towards fishing gears and limited wastewater treatment. Fragments, films, and foams were <2.1 %; a less abundant problem. The most abundant MPs sampled were ∼0.5 mm ≤ L< 1 mm (when the limit of detection was 0.1 mm), and blue was the most common MP color hinting intake due to visual confusion. Polycarbonate and nylon were the most abundant polymers in the MPs recovered. The overall findings show that C. macloti and M. gerrardi are vulnerable to plastic and it reflects the critical state of their habitat.

More Papers Like This

Article Tier 2

Microplastics and other anthropogenic fibres in large apex shark species: Abundance, characteristics, and recommendations for future research

AI summary Read the abstract

This study provided the first investigation of microplastics and microfibres in large apex shark species, documenting their presence and characteristics across multiple species. The results confirm that microplastic contamination extends to marine megafauna at the top of the food web.

Article Tier 2

Tropical sharks feasting on and swimming through microplastics: First evidence from Malaysia

AI summary Read the abstract

Researchers examined microplastic contamination in five tropical shark species from Malaysian waters, finding that 100% of the 74 sharks sampled contained microplastics. A total of 2,211 plastic particles were found in gastrointestinal tracts and gills, averaging about 30 particles per shark, with black fibers being the most dominant type and polyester the most common polymer. The study suggests that microplastic uptake may be gender-related in some shark species.

Article Tier 2

Microplastic occurrence in selected aquatic species of the Persian Gulf: No evidence of trophic transfer or effect of diet

AI summary Read the abstract

Researchers examined microplastic contamination in six fish species, one mollusk, and three crustacean species from the Persian Gulf, finding no evidence of trophic transfer of microplastics or dietary effects on contamination levels across species.

Article Tier 2

A First Comparison of Microplastics Abundance between Two Whale Shark Feeding Areas of the Gulf of California, Mexico.

AI summary Read the abstract

Researchers compared microplastic concentrations in water from two whale shark feeding areas in the Gulf of California, Mexico, finding 0.47-0.63 microplastic particles per cubic meter. Films and fibers dominated the particle types, raising concerns because whale sharks are filter feeders that consume large volumes of surface water.

Article Tier 2

Microplastics in fecal samples of whale sharks (Rhincodon typus) and from surface water in the Philippines

AI summary Read the abstract

Researchers documented microplastic ingestion by whale sharks in the Philippines through fecal sample analysis and compared it with surface water contamination, providing direct evidence that these filter-feeding megafauna ingest microplastics in a recognized pollution hotspot.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper