The regional impacts of climate change on coastal environments and the aquaculture of Japanese scallops in northeast Asia: case studies from Dalian, China, and Funka Bay, Japan

Abstract

Climate changes affect coastal environments and aquaculture, threatening food security and economic growth. Japanese scallop (Mizuhopecten yessoensis) culture is economically important for the coastal communities of Dalian, China, and Funka Bay, Japan. In this study, we combined satellite remote-sensing data, in situ observations, and a suitable aquaculture site selection model to explore the interactions between marine environments and climate variability over a recent 10-year period (2003-2012). Our selection of appropriate zones in these two Far Eastern regions and our analyses of climatic event (Arctic Oscillation (AO), winter East Asian monsoon (EAM), and El Niño/La Niña Southern Oscillation (ENSO)) and meteorological (precipitation, temperature, and wind) data allowed us to determine the impacts of climate change on regional coastal environments and prospects for scallop aquaculture. These analyses showed that AO and EAM strongly influenced the aquaculture areas on the Dalian coast through their effects on temperature during winter. We also determined that wind was the main driving force behind regional environmental changes during spring. Conversely, ocean conditions and suitable areas in Funka Bay changed rapidly relative to oceanic and atmospheric circulation. In Funka Bay, areas appropriate for scallop aquaculture and variations in chlorophyll-a concentration (which reflect the availability of algal food for scallops) were strongly correlated with ENSO, precipitation, and air temperature. These correlations demonstrate the influence of oceanic and atmospheric parameters on the productivity of scallop aquaculture in Funka Bay. Adaptation to oceanic and atmospheric changes should be considered when developing plans and management strategies for coastal scallop aquaculture in northeast Asia.

Impact of Oceanographic Environmental Shifts and Atmospheric Events on the Sustainable Development of Coastal Aquaculture: A Case Study of Kelp and Scallops in Southern Hokkaido, Japan

“…Figure 4 shows that the COC slightly affected Funka Bay in 2010, but a strong El Niño event occurred in winter 2010 and January 2010 was extremely cold, thereby reducing the extent of the most suitable areas in March 2010. This finding is corroborated by a previous study [22]. Therefore, suspension culture in the 0-20 m depth range was influenced not only by oceanographic environmental changes, but also by shifts in climate.…”

“…Especially in 2010, the most suitable areas (score 8) decreased to 0% in all the aquaculture zones. This finding is corroborated by a previous study [22] and also was verified by Japanese scallop production statistics for each aquaculture zones in Funka Bay ( Table 2). The productions of Japanese scallop in the aquaculture zones (Date, Abuta, Toyoura, Oshamambe, Yakumo, Mori and Sawara), which were all inside Funka Bay showed a decreasing trend in 2010.…”

“…The environmental shifts that we detected were associated with large-scale variability in conditions in the northwestern Pacific that were related to ENSO events [21,22,30]. Thus, climate change-associated spatial and temporal fluctuations in the COC and TWC should be incorporated into kelp and scallop aquaculture planning along the coast of Funka Bay and other regions of southern Hokkaido.…”

“…Because of the strong El Niño event in 2010 and the extreme cold period in January of that year [22], we generated final SASSM maps for the growing periods of each species in 2009 and 2010 to illustrate effects related to climate changes (Figure 8). The SASSM maps were validated by the location of existing Japanese scallop, Japanese kelp and Gagome culture operation (see Figure 1).…”

“…Based on an understanding of the interaction between aquaculture and the environment, an informed site selection process is likely to be crucial for the sustained development of aquaculture. Our previous work has developed suitable aquaculture site-selection models (SASSMs) for the identification of suitable locations for Japanese kelp and Japanese scallop aquaculture [18][19][20][21][22]. We have now developed SASSMs to identify the most suitable areas for Gagome aquaculture and to examine the potential impacts of oceanographic environmental changes and atmospheric events on the development of scallop and kelp aquaculture in Funka Bay and the remainder of southern Hokkaido.…”