Adsorption of microplastic to macroalgae Fucus vesiculosus

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1 Adsorption of microplastic to macroalgae Fucus vesiculosus Nanna B. Hartmann 1*, Clara G. Villaro 1, Ida D. W. Koch 1, Kasper B. Sundbæk 1, Niclas S. Rasmussen 1, Susan L. Holdt The National Food Institute, Technical University of Denmark * nibh@env.dtu.dk

2 My background Ecotoxicology and effects of particle pollutants (nano- and microparticles) 2 For macro-algae specific questions.

3 Microplastics 3 24 October, 2016

4 Microplastics Tiny fragments, pellets or fibres of plastics Often defined as having a size of <5mm (In comparison: sand grains are <2mm) Microplastics are abundant! They have been found in all oceans, on all continents in the deep sea and in coastal waters Originates from primary sources and secondary sources 4

5 Primary and secondary sources of microplastics E.g. degradation of fishing gear, shipping waste, littering at beaches, uncontrolled landfill in coastal areas and along rivers, car tyre particles... E.g. Granules from plastic manufacturing industry and logistics, cosmetics) 5 Rist & Hartmann, 2016, Aquatic ecotoxicity of microplastics and nanoplastics - lessons learned from nanoecotoxicology, submitted

6 Sources of microplastics Primary sources 6 24 October, 2016

7 There are over 150 million tonnes of plastics in the ocean today. In a business-as-usual scenario, the ocean is expected to contain 1 tonne of plastic for every 3 tonnes of fish by 2025, and by 2050, more plastics than fish (by weight). (World Economic Forum, The New Plastics Economy - Rethinking the future of plastics, 2016) 7

8 Effects of microplastics Limited knowledge on effects on marine and freshwater organisms. Physical effects: When animals erroneously ingest micro plastic instead of the feed - may lead to reduced food intake. Toxic effects of additives: When the harmful substances,that are added to the plastics, are released. Micro Plastics as a 'carrier' for other pollutants: When other environmental contaminants adsorb to micro plastic and are transported with them. This may affect the uptake of pollutants in aquatic animals. Impact on the image of marine food products! 8

9 9 Photo credit: Marcus Erikson, 5-Gyres Institute

10 Fucus vesiculosus (bladder wrack) as food source Abundant along all Danish shores One of the most common types of edible seaweed in Denmark Can be purchased dried as whole plants, in flakes and powder Added in as ingredient in products such as pesto Used in many recent seaweed recipes 10

11 Fucus vesiculosus (bladder wrack) & microplastics Image: Azote.se We The showed transfer that of microplastics the benthic seaweed from benthic F. vesiculosus primary producers can retain suspended to consumers microplastics may represent on its a so-far surface, underestimated thereby making pathway them available for the entry for herbivorous of microplastics consumers into coastal food webs 11 Images:

12 The aim of this study To investigate if microplastic adsorb to macroalgae Fucus vesiculosus and thereby pose a threat to the use of seaweed in foods. Investigations: Do fluorescent polystyrene (PS) microplastics adsorb to the surface of F. vesiculosus? Will adsorped microlastic particles be washed of by filtered seawater (rinsing procedures are common before food application) 12

13 Collection of seaweed Just South of Bellevue beach, Copenhagen, DK GPS coordinates: 55,771873; 12, June 2016

This study - experimental design Algal pieces (distal tips, length 6-7 cm) exposed to defined concentrations of fluorescent polystyrene (PS) particles (size: 20 μm, Ex.: 450nm Em.

14 This study - experimental design Algal pieces (distal tips, length 6-7 cm) exposed to defined concentrations of fluorescent polystyrene (PS) particles (size: 20 μm, Ex.: 450nm Em.: 500nm, Phosphorex) suspended in seawater. A total of four tips were placed in a bluecap glass bottle with 50 ml of filtered (0.45 μm) seawater and 2.65 mg/l PS (~ particles/l). Samples were prepared in quadruplicate. A) Samples were agitated for 2h in a rotation box (1 rpm) B) Samples were transferred to clean seawater and agitated for 1h All experiments were carried out at 10 C 14

15 Comparison to environmental concentrations of microplastics 1.7 particles/l >10 um, Norén & Naustvoll ( particles/l >10 um, Norén et al particles/l >1.2 um, Dubaish and Liebezeit 2013 Collection of seaweed GPS coordinates: 55,771873; 12,

16 Counting adsorbed microplastics

17 Number of particles pr cm Results 14 After exposure After rinsing Particles After exposure After rinsing pr. 12cm (avg) 3 Bottle Gradient Gradient No P P P P K K K K Gradient 17

18 Number of particles pr cm Results After exposure After rinsing *** ** * Gradient (Welch) two-sample t-test ***: P 0.001, **: P 0.01: *: P

19 Results Clear reduction in the number of adsorbed microplastics after rinsing. However, some particles are still attached Fewer particles adsorbed to the bladders compared to the rest of the surface. May be related to a difference in surface structure Tendency to higher number of adsorbed particles onto seaweed collected in June compared to seaweed collected in April. Indication of temporal variations? Related to changes in alginate content? Further investigation needed 19

20 Conclusions Microplastic particles are able to adsorb to the surface of macroalgae Fucus vesiculosus Our results indicate that the adsorption is related to the surface structure of the macroalgae and possibly temporal variations in alginate content By rinsing the algae in clean filtered seawater for 1 hours 81-86% of the adsorbed microplastic particles could be removed. However, some were still found on the algae surface. 20

21 Conclusions Experiments were carried out at concentrations MUCH higher than environmental microplatsic concentrations. However: Our results indicate that further studies may be relevant to investigate the adsorption of microplastics to macroalgae in real environmental samples. to explore the efficiency of different rinsing techniques for the removal of microplastics from seaweed for use in food. 21

22 Niclas Clara Kasper Ida 22

23 Thank you for your attention! October, 2016

19th Commission meeting, 19 June 2013. WORKING DOCUMENT of the Commission for the Environment, Climate Change and Energy

19th Commission meeting, 19 June 2013 ENVE-V-036 WORKING DOCUMENT of the Commission for the Environment, Climate Change and Energy OPINION ON THE GREEN PAPER ON A EUROPEAN STRATEGY ON PLASTIC WASTE IN