Microplastic Pollution - Presentation

Microplastic Pollution: a potential threat to the intertidal invertebrate food web Zoe Sloan

Microplastic Pollution • Microplastics are generally described as plastic particles

with a diameter of less than 5mm. • There are several ways in which microplastics enter the

marine environment • Microplastics that are commonly recorded in the oceans

include polyethylene (PE), polypropylene (PP) and polystyrene (PS)

• Depending on their origin they can be classified as:• Primary Microplastics • Secondary Microplastics

Distribution of Microplastics

Sediment samples were collected from 18 shores across 6 continents. All 18 shores has microplastics present (Brown et al., 2011)

Interactions with Marine Organisms • Ingestion:

• The most common way that microplastics will interact with marine biota

• Primary- and low-trophic level organisms are particularly susceptible• Translocation:

• After ingestion, microplastics have several possible fates • They can be egested as faeces, taken up by the epithelial lining in the

gut, or translocated to other tissues. • Absorption of Pollutants:

• Microplastics are highly susceptible to contamination by various pollutants.

• Including heavy metals, endocrine disruptors and POPs.

Trophic Transfer of Microplastics

• A study in 2014 by Setala et al., indicated that mesozooplankton could uptake polystyrene (PS) spheres.

• When mysid shrimp were exposed to the contaminated zooplankton, all individual shrimps had PS spheres in their intestines.

The ingestion of microplastics by primary tropic-level organisms, such as phytoplankton and zooplankton, presents a potential for transfer into the food web.

Image Source: Wright et al. 2013

Microplastics and the Intertidal Food Web• Uptake by the Blue Mussel (Mytilus edulis)

• Mussels are suspension feeding bivalves. • Since microplastics have a similar size range to planktonic organisms,

they are considered bioavailable to such invertebrates. • Studies have indicated that mussels are able to uptake microplastics

through feeding.• Transfer to Crabs

• The blue mussel is a key prey species to shore crabs (Carcinus maenas) and the edible crab (Cancer pagurus)

• In 2004, a study by Watts et al., demonstrated that microplastics can be transferred to shore crabs after ingesting contaminated mussels.