22 JUNE 2013 • WORLD AQUACULTURE • WWW.WAS.ORG and scallops cultured in Japan came from this region, and over 90 percent of salmon and saury (Scomberesocidae) were fished from these waters (Figure 4). A total of 319 fishing ports, about 10 percent of those in Japan, were damaged in the disaster (Fukada 2011). Seafood processing plants in these prefectures also were damaged (Figure 2a). As of October 2012, damage to fisheries and aquaculture facilities, products, and vessels totaled approximately US$ 16 billion (JFA 2012; Table 2). In Iwate Prefecture, the seawalls or moorings of 108 of 111 fishing ports were destroyed (Fukada 2011; Figure 5). The tsunami destroyed approximately 94 percent of the city’s vessels, the fish market, and most of the wakame seaweed processing factories, refueling centers, and cranes. Iwate’s coastal towns were renowned for their vibrant fishing industry, which resulted from the convergence of the Kuroshio Current from the south and the Oyashio and Tsugaru currents from the north. Japan’s 50 nuclear reactors were shut down after the earthquake and since then only two have been turned back on (BBC 2013). The negative effects of the nuclear crisis at Fukushima Daiichi power plant continue. Much of the 20-km radius around the plant remains off-limits, although radiation levels have dropped roughly 40 percent since the earthquake occurred (Fujita 2013). Daily radiation screenings are conducted, and once fish log consistently negative results over a certain period, test fisheries are reopened (DYO 2013). Since April 2011, the Fukushima Agricultural Technology Centre has inspected approximately 120 specimens/week, sampled by fishing or research vessels (Nemoto et al. 2012; Wada et al. 2012). As of September 2012, 5,988 specimens of 170 species in Fukushima prefecture have been inspected (Wada et al. 2012). Fishing bans remain in effect until radiation readings return to safe levels. A fish caught near the plant in early 2013 still tested at record cesium levels: 5,100 times the safety standard (Fujita 2013). Currently in Fukushima prefecture, test fishing is allowed for 13 species, which include common squid, horsehair crab, giant octopus, and some flounders. With the exclusion of test fishing, catches in Fukushima are landed at only two ports, including Onahama fishing port in Iwaki. Dragnet fishermen report landing only about half of what they did before the disaster. Some species, such as bastard halibut, have shipment restrictions because of radiation levels and must be thrown back. On 1 April 2013, the Nuclear Emergency Response Headquarters lifted the shipping regulation on flounder from Miyagi prefecture, which had been restricted since May 2012 (Mochizuki 2013). Flounder tissue measured 400 Bq/kg of cesium in April 2012, but has not surpassed the guideline value of 100 Bq/kg since September 2012. Concentrations have decreased gradually for some pelagic fishes, seaweed, abalone, and surf clams (Wada et al. 2012). However, most fish, especially demersal species, have not shown a clear decline, suggesting that radioactive cesium is passing through the food web. Some species within the 20 km radius of the Fukushima Daiichi power plant continue to measure over 1000 Bq/kg of cesium (TEPCO 2013). Specimens exceeding the guideline limit mostly have been found in shallower waters south of the nuclear power plant (Wada et al. 2012). Scientists at the Tohoku National Fisheries Research Institute have been surveying fishery resources to assess the after-effects of the tsunami (Choi 2013). The focus has been on abalone and sea urchin, valuable fisheries resources as well as abundant grazers; therefore, these organisms may have a strong influence on the surrounding ecosystem. Preliminary results TABLE 1. Fishery and aquaculture production share of the 7 prefectures from Hokkaido to Chiba (JFA 2012). Production (in tons) Nationwide 7 Prefectures Share (%) Fisheries 4,083,000 2,163,000 53 Aquaculture 1,109,000 423,000 38 TABLE 2. Damages from the March 11, 2011 earthquake and tsunami to fisheries and aquaculture from Hokkaido to Chiba prefectures (as of October 11, 2012: JFA 2012). Category Number Cost (in millions $US) Fishing vessels 28,612 2,306 Fishing ports 319 10,418 Aquaculture facilities - 934 Aquaculture products - 756 Common use facilities 1,725 1,581 TOTAL 15,996 FIGURE 4. Production of fisheries and aquaculture from the 7 prefectures hardest hit by the earthquake and tsunami (JFA 2012). Black bars represent the percent production of these prefectures per the nationwide total for these seafood products. Wakame and laver are seaweeds. Coho is coho salmon.
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