1. The Effect of Microplastics on the common mussel Mytilus
edulis in North Wales and transfers through the food web.
Robyn Elizabeth Jones- MSc Marine Environmental Protection
Supervisor: Dr Andrew Davies

2. Aim
To discover if the ingestion of microplastics
has a negative effect on the marine biota
exposed.

3. Rationale
The use of plastics is increasing globally- Current
demand for plastic is 245 million tons per year.
Plastic material is
• lightweight
• Strong
• Waterproof
• bio-inert
• easily applicable to industry
Slipperysnake.co.uk
Joanna 2012

4. The break down of marine plastic in the ocean occurs by:
• Wave Action
• UV Radiation
• Internal Waves
• Weathering Processes
Microplastic- Any plastic particle which can pass through a 500 um
sieve but retained by a 67 um sieve.
NOAA 2012
Plastic Soup Foundation
website 2014 5 Gyres 2013 Plastics Europe 2009
Antony Becker 2013

5. Hypotheses
H1: The ingestion of microplastics will have a negative effect on
the marine biota exposed.
H2: The ingestion of microplastics will reduce the feeding
activity of the exposed marine organism compared to controls.
H3: Ingested microplastics can pass from primary (1st)
consumer through to the secondary consumer and bio-
accumulate in the gut.

6. Objectives
To examine the effects of microplastics on the common mussel
Mytilus edulis (model organism) and whether these microplastics
are then passed from the mussel to its predator the dog whelk
Nucella lapillus.
Beach surveys will also be conducted in order to analyse the North
Wales Coastline for plastic contamination.
Marlin 2014 Marlin 2014

7. Methodology
• Mussels between 3-
4cm.
• Collected from non-
contaminated area of
NW (tests).
• 5 different time frames
and 3 different plastic
concentrations.
• For each exposure time, 3 replicates will be taken and for each
plastic concentration 5 replicates will be taken.
• Freezing the organism after the experiment will allow
investigations into the plastic accumulation in the gut and gills.
1

8. 2
• 24 mussels (8x3) will be exposed to 9.6 um plastic
concentrations in exactly the same conditions for 1 hour before
placing with dog whelks.
• The 1st 9 whelks will be exposed to the contaminated mussels
for 30 mins, 1 and 2 hours with the rest exposed for 4, 7, 10, 24
and 48 hours. Controls will be used.
• Guts to be examined after exposure.
Bates Collage 2010
Photolibrary.com 2009

9. 3 4 beaches will be used for this survey of North Wales; Cable Bay,
Aberffraw, Red Wharf Bay and Penmaenmawr.
Plastic at each beach will be
quantified by the number of
plastics (> 5cm) collected in
0.25m quadrats along 3 250m
transects at 10m intervals.
At each location GPS will be
taken for each quadrat and also
for any plastics over 50cm
regardless of quadrats
These GPS positions will then be
input into ArcGIS and analysed
against current environmental
and physical datasets.

10. Statistical Analysis
1- Will include a 2 way ANOVA to see differences between the
plastic concentrations and the exposure time and also all the
mussels from all experiments and concentrations using SPSS.
2- ANOVA to see the differences in the amount of plastic in the
dog whelk after the different exposure times and compared to
the control using SPSS.
Data will be presented in bar charts, scatter plots and maps
(ArcGIS).
Current Biology, Wright et al. 2009

11. Predicted Results
Averageamountofplasticum
Averageamountofplasticum
Time (Hours)Plastic Concentrations
Averageamountingut/gills
Method 1: There will be a higher intake of the smaller particle
and that feeding rate will reduce after 12 hours of exposure due
to the organism feeling “full”.
Method 2: The average number of polystyrene in the dog
whelks will initially increase with exposure time to mussels and
then their presence will steadily decline.
1 2

12. Safety Issues
The major safety issues which have been considered
are:
• To take care whilst collecting the mussels in the field
(Wear suitable shoes, warm waterproof clothing).
• Use of knifes for mussel removal (where necessary).
• Avoid needles and sharp plastic debris during beach
surveys (wear gloves).

13. Limitations
• Laboratory Space
• Access to Ocean Science vehicle for beach surveys
• To my knowledge there are no extended periods where I am
away and out of contact with my supervisor.
Issues to be Resolved
• Further research and meetings regarding food which will
need to be given to the mussels to induce plastic uptake
must be done.
• How to determine the feeding rate.
• Determining contamination from collection sites.

14. Animal Welfare
Organisms will be kept in tanks in the Craig Mair building under
the University's regulations.
• Reared in a suitable environment.
• Fed regularly.
• Minimum disturbance at collection site.
• Monitoring- Visit tanks once a day to check for blockages in
water flow.
Paul Kay/Natural Englandhttp://www.glaucus.org.uk/

15. GANTT Chart

16. References
Andrady A.L. (2011) Microplastics in the marine environment. Marine Pollution Bulletin
62, 1596-1605.
Bakir A., Rowland S.J. and Thompson R.C. (2012) Competitive sorption of persistent
organic pollutants onto microplastics in the marine environment. Marine Pollution Bulletin
64, 2782-2789.
Browne, M.A., Dissanayake A., Galloway T.S., Lowe D.M and. Thompson R.C. (2008)
Ingested Microscopic Plastic Translocates to theCirculatory System of the Mussel, Mytilus
edulis (L.). Environmental Science and Technology 42, 5026-5031.
Cole M., Lindeque P., Halsband C. and Galloway T.S. (2011) Microplastics as contaminants
in the marine environment: A review. Marine Pollution Bulletin 62 2588-2597.
Farrell P. and Nelson K. (2013) Trophic level transfer of microplastic: Mytilus edulis to
Carcinus maenas. Environmental Pollution 177, 1-3.

17. Thank you for Listening!
Questions?
Roger Dancer