Table 1.

Plastic density in surface waters; studies for which data from individual trawls were available.

Study	Location	n	10–3 Particles/m3				µg/L
			Mean	Std/CV	Min–max	Log-normal	Mean	Std/CV	Min–max	Log-normal
23	N Atlantic	11	9.006	9.224/1.02	0.120–30.761	Yes	0.730	1.293/1.77	0.0015–4.509	Yes
21	N Atlantic	3803*	42.266	114.801/2.72	0.676–2308.856	No (p < 0.001)	0.575	1.561/2.72	0.009–31.400	No (p < 0.001)
24	Arctic/N Pacific	157*	94.185	266.034/2.83	2.2–3140.9	Yes	0.131	0.337/2.77	0. 0001–2.5191	Yes
22	Pacific	196	2612.694	4855.95/1.86	1–32,765	No (bimodal)	4.620	8.317/1.80	0.001–52.969	No (bimodal)
25	Mediterranean	36*	1296.67	1983.49/1.53	100–8920	Yes	2.258	3.454/1.53	0.17–22.8	Yes
26	Australia	136*	31.481	46.47/1.48	2.627–287.621	Yes	1.939	2.863/1.48	0.16–17.72	Yes
27	N Pacific	1058*	217.590	1654.47/7.60	1.028–49267.784	No (p < 0.001)	2.959	22.501/7.60	0.014–670.041	No (p < 0.001)
28	Mediterranean	28*	421.732	848.43/2.01	12.5–3437.5	Yes	6.981	14.046/2.01	0.21–56.91	Yes
20	Mediterranean	10	168.00	103.58/0.62	10–350	Normal	1.374	0.848/0.62	0.08–2.86	Normal
29	Mediterranean	39	1219.27	N.m	N.m	–	2.610	3.786/1.45	0.0025–18.11	Yes
30	Mediterranean	22*	208.182	347.15/1.67	40–1690	Yes	1.704	2.841/1.67	0.33–13.83	Yes
31	Mediterranean	33	1305.869	1312.77/1.01	215.98–5783.77	Yes	5.071	5.097/1.01	0.84–22.46	Yes
32	Mediterranean	74/71*	1002.568	1842.62/1.84	20–11300	Yes	1.751	3.926/2.24	0.011–26.081	Yes
33	Southern Ocean	5	31	41.9/1.35	99	Yes	N.m	N.m	N.m	–
34	Arctic	21*	534.414	706.945/1.32	5.907–2458.07	Yes	0.652	0.975/1.50	0.004–3.524	Yes
35	Australia	22	195	135.25/0.70	40–470	Yes	0.814	0.569/0.70	0.2–2.0	Yes
36	Arctic	13	128	107/0.84	18–310	Yes	N.m	N.m	N.m	–
37	N Atlantic	28	180	205/1.14	35–870	Yes	0.669	0.556/0.83	0.084/2.525	Yes

When data are reported per sea surface area only sampled volume was calculated from the area of the sampling device trawled inside the water. n, sample size; Std/CV, standard deviation/Coefficient of variation; and n.m.,not measured or unavailable data. *Zero values excluded.