Disclaimer: plastic pollution may well kill way more animals besides seabirds and sea mammals. There are 6.20*10^14 wild fish and 1.00*10^20 wild marine arthropods, but only 6.75*10^11 wild mammals.
Summary
1 kg of plastic is emitted to the ocean per capita per year[1].
0.0001 seabirds and 0.00001 sea mammals are killed by marine plastic pollution per capita per year.
200 wild fish are caught per capita per year.
The catch of wild fish is 2 M times as large as the number of seabirds, and 20 M times as large as the number of sea mammals killed by marine plastic pollution.
The data and calculations are presented below.
Data
The plastic emitted to the ocean in 2010 was 8 million tonnes according to OWID (PEO = 8 Mt).
The world population in 2010 was 6.92 billion according to The World Bank (WP = 6.92 G).
Marine plastic debris kills up to 1 million seabirds and 100 thounsand sea mammals each year according to the United Nations (SB = 1 M, and SM = 100 k).
The catch of wild fish is 0.97 to 2.7 trillion/year according to fishcount.org (WFL = 0.97 T/year to WFH = 2.7 T/year).
Calculations
Plastic emitted to the ocean per capita in 2010 (PEOpC): PEO / WP = 8 Gkg / (6.92 G) = 1.16 kg.
Plastic emitted to the ocean to cause one death of a seabird (PEOpDSB): PEO / SB = 8 Mt / (1 M) = 8 t.
Plastic emitted to the ocean to cause one death of a sea mammal (PEOpDSM): PEO / SM = 8 Mt / (0.1 M) = 80 t.
Seabirds killed by plastic marine pollution in 2010, per capita (DSBpC): PEOpC / PEOpDSB = 1.16 / (8 k) = 145 μ (145 seabirds killed per million people).
Sea mammals killed by plastic marine pollution in 2010, per capita (DSMpC): PEOpC / PEOpDSM = 1.16 / (80 k) = 14.5 μ (14.5 sea mammals killed per million people).
Wild fish caught per year (WF): (WFL * WFH)^0.5 = (0.97 * 2.7)^0.5 T = 1.62 T.
Catch of wild fish per capita per year (WFpC): WF / WP = 1.62 T / (6.92 G) = 234.
Ratio between the catch of wild fish and the number of seabirds killed by marine plastic pollution: WFpC / DSBpC = 234 / (145 μ) = 1.62 M.
Ratio between the catch of wild fish and the number of sea mammals killed by marine plastic pollution: WFpC / DSMpC = 234 / (14.5 μ) = 16.2 M.
1 kg is the global value, and it is much smaller for many countries. Most of the countries emit less than 0.1 % of the plastic waste to the ocean (see this map), although 3 % of the global plastic waste is emitted to the ocean.
The number of seabirds and sea mammals killed by marine plastic pollution is quite small relative to the catch of fish
Disclaimer: plastic pollution may well kill way more animals besides seabirds and sea mammals. There are 6.20*10^14 wild fish and 1.00*10^20 wild marine arthropods, but only 6.75*10^11 wild mammals.
Summary
1 kg of plastic is emitted to the ocean per capita per year[1].
0.0001 seabirds and 0.00001 sea mammals are killed by marine plastic pollution per capita per year.
200 wild fish are caught per capita per year.
The catch of wild fish is 2 M times as large as the number of seabirds, and 20 M times as large as the number of sea mammals killed by marine plastic pollution.
The data and calculations are presented below.
Data
The plastic emitted to the ocean in 2010 was 8 million tonnes according to OWID (PEO = 8 Mt).
The world population in 2010 was 6.92 billion according to The World Bank (WP = 6.92 G).
Marine plastic debris kills up to 1 million seabirds and 100 thounsand sea mammals each year according to the United Nations (SB = 1 M, and SM = 100 k).
The catch of wild fish is 0.97 to 2.7 trillion/year according to fishcount.org (WFL = 0.97 T/year to WFH = 2.7 T/year).
Calculations
Plastic emitted to the ocean per capita in 2010 (PEOpC): PEO / WP = 8 Gkg / (6.92 G) = 1.16 kg.
Plastic emitted to the ocean to cause one death of a seabird (PEOpDSB): PEO / SB = 8 Mt / (1 M) = 8 t.
Plastic emitted to the ocean to cause one death of a sea mammal (PEOpDSM): PEO / SM = 8 Mt / (0.1 M) = 80 t.
Seabirds killed by plastic marine pollution in 2010, per capita (DSBpC): PEOpC / PEOpDSB = 1.16 / (8 k) = 145 μ (145 seabirds killed per million people).
Sea mammals killed by plastic marine pollution in 2010, per capita (DSMpC): PEOpC / PEOpDSM = 1.16 / (80 k) = 14.5 μ (14.5 sea mammals killed per million people).
Wild fish caught per year (WF): (WFL * WFH)^0.5 = (0.97 * 2.7)^0.5 T = 1.62 T.
Catch of wild fish per capita per year (WFpC): WF / WP = 1.62 T / (6.92 G) = 234.
Ratio between the catch of wild fish and the number of seabirds killed by marine plastic pollution: WFpC / DSBpC = 234 / (145 μ) = 1.62 M.
Ratio between the catch of wild fish and the number of sea mammals killed by marine plastic pollution: WFpC / DSMpC = 234 / (14.5 μ) = 16.2 M.
This work is licensed under a Creative Commons Attribution 4.0 International License.
1 kg is the global value, and it is much smaller for many countries. Most of the countries emit less than 0.1 % of the plastic waste to the ocean (see this map), although 3 % of the global plastic waste is emitted to the ocean.