All regular visitors of the Dutch coast are familiar with the beachwashed paraffin- or palm oil-like lumps of materials coming ashore. This fatty waste, often yellow, brown to white in colour, is picked at by coastal birds and sometimes eaten by dogs. Tourists keep their kids at distance, one never knows.
This type of litter has its origin in ship tankers cleaning out cargo residues not fully pumped out of the tanks at unloading in the harbour. Coastal municipalities and Rijkswaterstaat have to spend lots of money to clean the beaches, but total cleaning is impossible. For many years during our ‘Beached Bird Surveys’, we have collected lumps of these substances and stored them in aluminium foil in the freezer, hoping for later investigations.
The same litter is also found in stomachs of beached Northern Fulmars. In the early 2000s, we have attempted to include paraffin in stomach contents in the standard monitoring program of ingested plastic litter. However, we failed to convince our funding agency. In part the reason was that the plastic monitoring was commissioned from funds dedicated to marine litter investigations in relation to shipping- and harbour policies.
And in shipping policies, paraffin and palm-oil like substances are not ‘litter’ but discharges from chemical tankers transporting fluids in bulk. Over all these years we have continued to record basic data during the plastic work, but no longer analysed nor reported on such data. Plus we regularly stored samples from the bird stomachs in our freezers.
The Dutch Ministry of Agriculture, Nature and Food Quality (LNV) dedicates part of its research funds for basic research known as ‘kennisbasis (KB)’. In that way the ministry wants to develop basic knowledge for topics that over the next few years are expected to increase in relevance. Relevance for its own LNV policy decisions, but also for industries and other stakeholders. Rapidly increasing media attention for coastal pollution with paraffin-like substances resulted in a decision to fund a small pilot project in 2018 to analyse our fulmar data and to conduct chemical analyses on a number of samples taken from the beaches or from fulmar stomachs.
The report from our pilot study was recently completed. Results show no clear trend in the ingestion of these suspect substances by fulmars: consistently at least one out of each five fulmars has this type of pollutants in the stomach. Quantities of ingested materials vary considerably from small lumps to tens of grams of chemically suspect mud in bloated stomachs and swollen guts. Chemical analyses show approximately equal presence of paraffin and vegetable oil type substances, sometimes mixed with other yet undefined materials.
The impacts on birds are not evident, but clearly these wastes do not belong in the sea, nor in bird stomachs. Contrary to birds, samples from the beach almost all were paraffins. Probably the reason is that palmoils and similar fats become fluid at lower temperatures and can no longer be seen. Also these natural fats are more easily biologically degraded, or are eaten by wildlife. Fulmar stomachs more clearly reflect the situation at sea than what we can learn from coastal samples.
Clearly, it is hoped that this pilot study triggers funds to broaden the fulmar monitoring program on plastics to a system that includes the monitoring of paraffin- or palmfat-like substances. When possible, this should include an adequate level of chemical analyses.