Fiber sizes in seawater samples from tropical to temperate regions of the Atlantic Ocean

Microlitter size from tropical to temperate regions of the Atlantic Ocean was assessed using the pump-underway ship intake system. Sampling was performed during the PYROWIND oceanographic campaign in the Atlantic Ocean (April 27th – May 19th 2022), on board of the Spanish R/V Hespérides. The research cruise covered an 8,000-km transect, from Brazil (Salvador) to the Strait of Gibraltar. Subsurface water samples were continuously collected through the pump-underway ship intake system during navigation. The water was collected by a pump (BKMKC.1011, TECNUIM) with a Teflon core located in the keel of the vessel at about 4.5 m deep, with a flow rate of 4 m³/h. The pump-underway system had a tap connection to the wet laboratory, to which the filtering device was connected to a hose. The filtering device consisted of a flowmeter attached to a funnel, which enclosed a 63 μm stainless-steel sieve, in order to avoid airborne contamination. The flow ran 24/7 and was divided into samples of 4.15 ± 1.47 m³ (10 L/min; n = 52). All 52 samples were analyzed for the large fraction (≥ 315 μm) and 15 were analyzed for the small fraction (10–315 μm). The large fraction (≥ 315 μm; n = 52) was analyzed on a stereomicroscope (Leica Z16 APO) equipped with a camera (Canon EOS 650D). The filter was horizontally examined from the top left to the bottom right and every relevant particle was photographed. The size of the particles was determined with ImageJ (Schneider et al., 2012). The small fraction (10–315 μm; n = 15) was analyzed using μFTIR (Agilent 620 FTIR microscope with a FPA detector and a Cary 670 FTIR spectrometer) and measured with siMPle (Primpke et al., 2020). Since fibers dominated the large fraction (≥ 315 μm; n = 52), the dataset focuses on the size of the fibers obtained through the large fraction analysis.

本研究采用船载行进式泵吸采样系统，对大西洋热带至温带海域的微塑料碎屑（microlitter）粒径分布开展了评估。采样工作于2022年4月27日至5月19日的大西洋PYROWIND海洋调查航次中实施，搭载平台为西班牙R/V Hespérides号研究船。本次调查航次的采样断面总长8000公里，起于巴西萨尔瓦多，止于直布罗陀海峡。航行期间，通过船载行进式泵吸采样系统持续采集次表层海水样本。次表层海水通过采样泵（型号BKMKC.1011，品牌TECNUIM）采集，该泵的特氟龙（Teflon）泵芯安装于船身龙骨处约4.5米水深位置，采样流量为4 m³/h。船载行进式泵吸采样系统设有通往湿实验室的管路接口，过滤装置通过软管连接至该接口。过滤装置由安装于漏斗的流量计与包裹于漏斗内的63 μm不锈钢筛网组成，以避免空气源性污染。采样流程全天24小时不间断运行，共获取52份单次采样量为4.15 ± 1.47 m³（对应流量10 L/min；n = 52）的海水样本。对全部52份样本开展了大粒径组分（≥ 315 μm）分析，另选取其中15份样本开展小粒径组分（10–315 μm）分析。大粒径组分（≥ 315 μm；n = 52）的分析采用配备佳能EOS 650D相机的徕卡Z16 APO体式显微镜完成。滤膜按从左上至右下的顺序进行水平检视，并对所有目标颗粒进行拍照记录。颗粒粒径通过ImageJ软件（Schneider等人，2012）测定。小粒径组分（10–315 μm；n = 15）的分析采用配备FPA探测器的安捷伦620显微傅里叶变换红外光谱（μFTIR）显微镜与Cary 670傅里叶变换红外光谱仪完成，粒径测量通过siMPle软件（Primpke等人，2020）实现。由于大粒径组分（≥ 315 μm；n = 52）以纤维类颗粒为主，本数据集重点呈现通过大粒径组分分析得到的纤维颗粒粒径数据。