Poster presentation by Bianca Tree (BSc Honours candidate at MACE Lab 2016). Winner of the Best Poster award at SCCP 2016.

1. www.postersession.com
Dual uptake of microplastic fibres in the
sea urchin, Tripneustes gratilla L.
Bianca Tree, Gan Moodley and Deborah Robertson-Andersson
University of KwaZulu-Natal, School of Life Sciences
Introduction
Microplastics
 Plastic pollution is an escalating issue worldwide and
production is ever increasing.
 Researchers have only recently discovered the major threat
posed by microplastics. Microplastic fibres raise particular
concern due to their size and shape.
 The aim of this study was to determine the uptake of
microplastic fibres in the sea urchin T. gratilla, given that
there are two possible uptake routes in echinoids.
Figure 2. Presence of microplastic fibres in the gut of
individual sea urchins after 48 hours of feeding on
microplastic treated seaweed.
1 2 3 4 5 6
Presenceofmicroplastic
fibres
Replicates
This investigation highlights the vulnerability of sea urchins (keystone species and ecosystem
engineers) to microplastic pollution via dual uptake mechanisms (feeding & WVS)
 Keystone species have a bigger
effect on their environment
relative to its abundance.
 Sea urchins are both keystone
species & important ecosystem
engineers.
Microfibers are easily taken up into the WVS
of sea urchins. Accumulation of
microplastics in the WVS may cause
blockages within the canals and tubes,
reducing the efficiency of water flow
through the organism.
Water Vascular system (WVS)
Uptake route 1
T. gratilla
Madreporite (= sieve plate)
Water enters the madreporite and goes via the
stone canal to the ring canal.
SEM image of madreporite pores of Stomopneustes
variolaris (220x)
SEM image of madreporite pores T. gratilla
(70.2 ± 4.3 µm) (220 X)
Important for
locomotion,
feeding and gas
exchange.
Figure 1. Average number of fibres taken up into the WVS
of T. gratilla at different microfiber concentrations.
The greater the concentration of
microplastics in the water, the greater the
uptake into the WVS.
Sea urchins and
kin are the only
group to have a
water vascular
system.
1900
microfibres are removed
from a single polyester
jersey every wash!
Microplastics attach to seaweed
surfaces and consequently hinders
algal photosynthesis and therefore
would be available to organisms
feeding on algae.
Low
numbers
High
numbers
Feeding
Uptake route 2
References:
1. Browne, M. A., Galloway, T., & Thompson, R. (2007). Microplastic—an emerging contaminant of potential concern?. Integrated environmental assessment and Management, 3(4), pp. 559-561
2. Browne, M. A., Crump, P., Niven, S. J., Teuten, E., Tonkin, A., Galloway, T., & Thompson, R. (2011). Accumulation of microplastic on shorelines woldwide: sources and sinks. Environmental science & technology, 45(21), pp. 9175-9179
5 mg.L-1
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Averagenumberof
microfibres
Microfibre concentration ( )mg.L-1
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