Years ago researchers discovered the extent of discarded plastic floating
in the oceans. One of the first accounts I saw of effects on marine life
was of a sea turtle swallowing a plastic bag and dying of intestinal
blockage. Turtles of that species being one of the few predators on
mature jellyfish, speculation was that the turtle had mistaken the bag
for a jellyfish. There have been whales found dead with hundreds of
pounds of plastic in their digestive tracts.

I have now read that they're finding plastic broken down into smaller and
smaller fragments by ultraviolet light and other factors, and being
ingested by smaller animals. Further, plastic particles seem to be
absorbing smells to the extent that animals are mistaking them for food.

Is plastic detritus having effects on commercially fished species? Are
commercial species ingesting plastic themselves or are the effects
further down the food chain?

My thanks in advance for any replies.

Peter Wezeman
anti-social Darwinist

On Tuesday, 3 September 2019 09:46:24 UTC+5:30, peterw...@hotmail.com wrote:
> Years ago researchers discovered the extent of discarded plastic floating
> in the oceans. One of the first accounts I saw of effects on marine life
> was of a sea turtle swallowing a plastic bag and dying of intestinal
> blockage. Turtles of that species being one of the few predators on
> mature jellyfish, speculation was that the turtle had mistaken the bag
> for a jellyfish. There have been whales found dead with hundreds of
> pounds of plastic in their digestive tracts.
>
> I have now read that they're finding plastic broken down into smaller and
> smaller fragments by ultraviolet light and other factors, and being
> ingested by smaller animals. Further, plastic particles seem to be
> absorbing smells to the extent that animals are mistaking them for food.
>
> Is plastic detritus having effects on commercially fished species? Are
> commercial species ingesting plastic themselves or are the effects
> further down the food chain?
>
> My thanks in advance for any replies.
>
> Peter Wezeman
> anti-social Darwinist

Your observations are really interesting and worrisome. We have done a similar study related to this issue titled "Incidence of microplastics in Villorita cyprinoides from Vemabanad Lake". A summary (abstract) of this research work is given below.

Hope this could be of some interest to you.

Regards,

Gipson Edappazham

https://scholar.google.co.in/citations?user=KtUKtqEAAAAJ&hl=en

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INCIDENCE OF MICROPLASTICS IN VILLORITA CYPRINOIDES FROM VEMABANAD LAKE

Patralika Mukhopadhyay* and Gipson Edappazham
School of Industrial Fisheries, Cochin University of Science and Technology,
Kochi – 682 016, India.

Derived from the polymerization of monomers, plastics are nothing but synthetic organic polymers whose production has inevitably increased in the past few decades. With this increasing production and wider use of plastics, the plastic pollution has become a looming spectre to the marine ecosystem. The presence of plastic wastes in the marine environment can be due to the industrial activities, consumption habits, fishing activities, wide usage of cosmetic products, and also due to improper management of wastes in the system. Among the different forms of plastic pollutants, microplastics are considered as an emerging contaminant of concern due to their possible ecological and biological consequences. Microplastics are referred as the small pieces of plastic which are less than 5 mm in size. Microplastics in the marine environment have become a contemporary issue and is receiving an increased attention in the recent years.

This study analysed the incidence of microplastics in the clams of Vembanad lake of Kerala. In this study, 68 samples of Villorita cyprinoides were collected from three locations viz. Kumbalangi, Kadamakkudy (Mulavukadu) and Thycattussery (Alappuzha district) of Vembanad lake. Microplastics were isolated by incubating the clam tissues in 10% KOH solution at 57°C for 48 hours followed by filtration. The residue obtained after filtration was observed under optical stereo microscope for presence of microplastics. Qualitative attributes like colour and the shape of microplastic (whether fibre, fragment or a film) were also observed and recorded. They were further confirmed by hot needle test.

In this study, microplastics were found at concentrations ranging from 0.14 ±0.20/individual at Thycattussery to 0.18 ± 0.19/individual at Mulavukadu. Across all three sites, fiber particles were the most dominate shape of microplastics (72.72%), followed by films (27.27%). Sizes microplastics ranged from 0.004 mm to 2.815 mm. The present study provides useful background information for further investigations and subsequent development of management policies to monitor and control microplastics in a fragile ecosystem like the Vembanad lake.

Citation:

Mukhopadhyay P. and Edappazham G. 2018. Incidence of microplastics in Villorita cyprinoides from Vemabanad Lake. In: D. Prema, Molly Varghese, Shelton Padua, R.Jeyabaskaran, T. G. Sumithra, K. J. Reshma , Rekha J. Nair, K.S. Sobhana, R. Vidya, N. S. Jeena, Vivekananda Bharathi, Lavanya Ratheesh, E. K. Uma and G. Shylaja (Eds.). National Conference on Marine Debris (COMAD 2018), Book of Abstracts and Success Stories, Marine Biological Association of India, April 11-12, 2018, Kochi, p. 85.

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