by Hannah Tannenbaum
Fisheries catch data are the only real means for the fisheries industry, economists, and environmentalists to ascertain the population status of fished stocks. Therefore, accurate reporting of catch data is of the utmost importance. It was discovered in 2001 that China was drastically over reporting their domestic catch in order to achieve the appearance of uninterrupted expansion and success. China has an immense fishing fleet, but is also outside of agreements regarding EEZ and FAO of the UN, and therefore their catch records are important for global estimates, but particularly unreliable as currently reported. While estimates have been made to correct for decades of over-reporting in Chinese domestic fisheries, they are also major participants in distant-water fisheries. Pauly et al. (2013) used statistical extrapolations to estimate the Chinese distant-water catches and found severe under-reporting compared to the figures reported to FAO. While the interpolations have high levels of uncertainty, they nonetheless suggest immense inaccuracy of global fisheries catch statistics which has wide implications for employment, economics and ecology.
Recent efforts have been made to improve fisheries reporting through more effective statistical measures for domestic production. However the secrecy of Chinese fisheries reports and the lack of statistical systems independent of the government/fisheries organizations themselves undermines the validity of Chinese reports of distant-fleet catches to the UN FAO. In order to estimate the catch data for China’s distant-water fleet, the authors utilized Fermi solutions, inferring unknowns from the known, and a Monte Carlo method to attribute uncertainty values to the estimates.
The steps of this estimation were as follows: 1. Identify nations and years Chinese vessels occupied 2. Record or estimate the number of vessels given local documentation and 3. Assign annual catch estimates by vessel type. These steps were repeated for every nation in whose waters Chinese were found to fish, and then Monte Carlo uncertainty was determined for the overall results. The authors obtained over 500 reports from scientific and non-scientific media sources relating to Chinese vessels in over 93 maritime territories, excluded from only North America, Europe and the Caribbean waters.
It was found that China has severely underreported its distant-water fleet catches. It was estimated that the distant-water annual catch from Chinese vessels is close to 4.6 million t/year whereas the reports to FAO suggest catches of 368,000 t/year. It should be noted that this study was not able to distinguish between legal and illegal catch, as classified as IUU (Illegal, Unreported and Unregulated). Overall the authors suggest it is of the utmost importance that the FAO demand proper reporting and an expansion of fisheries statistics in order for greater accuracy in world food security, economic and environmental estimates.
Pauly, D., Belhabib, D., Blomeyer, R., Cheung, W.W., Cisneros‐Montemayor, A.M., Copeland, D., Harper, S., Lam, V.W., Mai, Y., Manach, F., 2013. China’s distant‐water fisheries in the 21st century. Fish and Fisheries.