Mean Temperature of Catch Shows Impact of Ocean Warming on Fisheries

by Hannah Tannenbaum

Understanding the impact of climate change on marine fisheries viability has important implications for the sustainability of the industry. Cheung, Watson and Pauly (2013) collected catch and supplemental data, and computed mean temperature of catch, MTC from average inferred temperature of over 900 species of exploited fish weighted with their annual catch rates. MTC was inferred from modeled distributions for the years 1970 to 2006. It was shown that there is a positive relationship between increased rate of SST change and increases to MTC, and that global fisheries have responded with ‘tropicalization,’ shifts. Continue reading

Under-reported Overfishing by Chinese Threatens World Fisheries Estimates

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. Continue reading