Exploring the occurrence and distribution of contaminants of emerging concern through unmanned sampling from ships of opportunity in the North Sea

• Suitability of existing mobile research infrastructures for monitoring marine contaminants is demonstrated.
• Unmanned bulk-water sampling was successfully employed to detect substances in sub ng/L levels.
• Occurrence of several contaminants of emerging concern shown for the first time in marine waters
• Pharmaceuticals (including an antibiotic) were detected in offshore waters of the North Sea.

Chemical pollution is of concern for the marine environment. New European regulation demands exposure and impact assessment to be conducted in coastal environments in order to define and ensure fulfillment of environmental quality standards. A cost-effective approach for monitoring the over 100,000 km of European coasts is necessary. This proof-of-concept study focuses on the use of unmanned water sampling from a commercial ship of opportunity to implement monitoring of marine contaminants of emerging concern. Marine areas that are not directly affected by river plumes or other direct sources were covered in order to provide information on background pollution. 14 currently used pesticides, 11 pharmaceuticals and personal care products and 3 food additives were detected in water samples through targeted analysis at sub-ng to tenths of ng/L levels in both coastal and offshore areas of the North Sea. Among contaminants, 6 pesticides (dimethoate, fenpropimorph, pendimethalin, propiconazole, tebuconazole and temephos), 3 pharmaceuticals (acetaminophen, naproxen and ketoprofen) and 2 food additives (acesulfame and saccharine) have never been detected before in offshore areas. 4 pesticides (diuron, isoproturon, metazachlor and terbuthylazine), 4 pharmaceuticals (carbamazepine, atenolol, ibuprofen and ketoprofen) and 2 food additives (sucralose and acesulfame) were detected in over 90% of the samples. The antibiotic sulfamethoxazole was detected in 50% of the samples at tenths of pg/L levels, including some offshore areas. Our study highlights that the use of ships of opportunity can provide a key support for the development and cost-effective implementation of marine monitoring of chemical pollutants in Europe and elsewhere.