Acta Oceanol. Sin., 2014, Vol. 33, No. 6, P. 63–73 DOI: 10.1007/s13131-014-0490-x http://www.hyxb.org.cn E-mail: [email protected] Composition of fish species in the Bering and Chukchi Seas and their responses to changes in the ecological environment LIN Longshan1*, CHEN Yongjun1, LIAO Yunchih2, ZHANG Jing3, SONG Puqing1, YU Xingguang1, WU Risheng1, SHAO Kwang-tsao2 1 Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China 2 Biodiversity Research Center, Academia Sinica, Taipei 11529, China 3 Fisheries College of Jimei University, Xiamen 361012, China Received 12 March 2013; accepted 20 August 2013 ©The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2014 Abstract Based on trawl surveys in the Bering Sea and Chukchi Sea during the 2010 Chinese National Arctic Research Expedition, fish biodiversity characteristics, such as fish composition, dominant species, biodiversity, and faunal characteristics were conducted. We also discussed the responses of fishes to the quick changes in Arctic climate. The results showed that a total of 41 species in 14 families were recorded in these waters. The dominant species were Hippoglossoides robustus, Boreogadus saida, Myoxocephalus scorpius, Lumpenus fa- bricii, and Artediellus scaber. There were 35 coldwater species, accounting for 85.37%, and six cold temperate species, occupying 14.63%. The habitat types of fish could be grouped as follows: 35 species of demersal fish- es, five benthopelagic fishes, and one pelagic fish. The Shannon–Wiener diversity index (H′) (range between 0 and 2.18, 1.21 on average) was not high, and descended from south to north. Climate change has caused some fishes to shift along their latitudinal and longitudinal distribution around the Arctic and Subarctic areas, and this could lead to the decline of Arctic fishery resources. Key words: Arctic, fish fauna, biodiversity, responses to ecological environment Citation: Lin Longshan, Chen Yongjun, Liao Yunchih, Zhang Jing, Song Puqing, Yu Xingguang, Wu Risheng, Shao Kwang-tsao. 2014. Composition of fish species in the Bering and Chukchi Seas and their responses to changes in the ecological environment. Acta Oceanologica Sinica, 33(6): 63–73, doi: 10.1007/s13131-014-0490-x 1 Introduction et al., 2006; Grebmeier, Cooper et al., 2006; Mueter and Litzow, As one of the most sensitive areas responding to global cli- 2008; Mueter et al., 2009). The effect of climate change on Arc- matic changes (Yu, 2011; Zhang et al., 2011), Arctic seawater is tic fish migration has been a hot topic in international research experiencing increasing surface temperature, melting frozen in recent years (Arctic Writing Group, 2011; Mecklenburg et al., zone, decreasing sea ice, and so on, which have a dramatic im- 2011; Reist et al., 2006; Allison et al., 2005). However, scientific pact on the marine environment, organisms, and biosphere investigations and studies for these two seawaters in China are (Lubchenco, 2011; Kedra et al., 2010). The plentiful oil, gas, only about hydrology (Tang et al., 2001; Chen et al., 2011; Gao et and mineral resources, sailing course, and fishery resources of al., 2003), atmosphere (Wang et al., 2008; Ji et al., 2011), plank- the Arctic Ocean have become the focus of different countries ton (Lin, Yang et al., 2009; Yang and Lin, 2006), and nutrients (Zhang, 2009; Shen et al., 1987). The climatic changes may affect and salinity (Gao et al., 2011; Xing et al., 2011). No studies on the the whole Arctic region and have far-reaching influences on the fishery resources have been conducted by Chinese scientists, ecology and even the fishery resources (Arctic Writing Group, except the acoustic investigation of Theragra chalcogramma in 2011). 1999 (Chen and Zhang, 2001). The Bering Sea, located in the northernmost Pacific Ocean, In our study, we analyzed the trawl investigation data of contains a wide continental shelf and rich fishery resources the 4th Chinese National Arctic Research Expedition in the (Wan et al., 2009). The Chukchi Sea, which is the marginal sea of Bering Sea and Chukchi Sea (58°00.00′–75°19.80′N, 176°12.24′– the Arctic Ocean, is an important source of nutrients, heat, and 157°09.53′W) during July 12–19 and September 1, 2010 in the fresh water for the Arctic Ocean. The nutrients support Arctic Bering Sea, and July 21–August 30, 2010 in the Chukchi Sea. The ecosystems and the heat can influence the ice (Shi et al., 2004). species composition, dominant species, ecological type, and The Bering Strait forms its southernmost limit and connects to species diversity of these two seawaters were analyzed. In order the Bering Sea and Pacific Ocean. Previous studies on the Ber- to compare with the composition and distribution of species in ing Sea and Chukchi Sea were mainly about the composition of the marginal sea of the Northwest Pacific and North Atlantic– fish species (Barber et al., 1997; Norcross et al., 2010), fish dis- Eastern Greenland waters, the present study discussed the rap- tribution (Rand and Logerwell, 2011; Mecklenburg et al., 2011; id responses of fishes to Arctic climate changes and would pro- Busby et al., 2005), and responses to changes in the ecological vide essential data for the fishery resources, ecosystem changes, environment (Robertis and Cokelet, 2012; Grebmeier, Overland and relationship between the ecosystem and the environment. Foundation item: The Chinese Polar Environment Comprehensive Investigation and Assessment Programs under contract Nos CHIN- ARE2012-2015-04-03 and CHINARE2012-2015-03-05; the Polar Science Strategic Research Foundation of China under contract No. 20120105; the Public Science and Technology Research Funds Projects of Ocean under contract No. 201105022-2. *Corresponding author, E-mail: [email protected] 64 LIN Longshan et al. Acta Oceanol. Sin., 2014, Vol. 33, No. 6, P. 63–73 2 Materials and methods al. (1993). Furthermore, temperate water species were divided into warm temperate species and cold temperate species, and 2.1 Station design and sampling method coldwater species were divided into subcold zone species and Specimens were collected using a middle-water Isaacs-Kidd cold zone species. The samples also were sorted into continen- midwater trawl (IKMT) net (9 m long, 4 m2 net mouth area, 20 tal shelf demersal fish, continental shelf benthopelagic fish, mm mesh size), a French-type otter trawl net (2.5 m wide, 0.5 continental shelf pelagic-neritic fish, oceanic pelagic-neritic m high, and 9 m long; 10 mm mesh size), an otter trawl net (1.6 fish, and oceanic bathydemersal fish, according to Froese and m wide, 0.5 m high, and 3 m long; 20 mm mesh size), and a tri- Pauly (2012), Wilson (2012), and Liu and Ning (2011). Fishes angular bottom trawl net (2.2 m wide, 0.65 m high, and 6.5 m were judged as economic fish by Froese and Pauly (2012) and as long; 20 mm mesh size). The speed was about 3–4 kn. Every net migratory fish by Wilson (2012). Fish distribution of the inves- was operated for 10–60 min due to the different seabeds. The tigation waters was referred to Froese and Pauly (2012), Wilson research vessel for the present study was Xuelong. The survey (2012), Liu (2008), and Tetsuji (2002). stations were designed according to latitude. Sampling stations Biodiversity was analyzed by three indices: species diversity were distributed from the Bering Sea basin through the conti- index (H′), evenness index (J′), and richness index (D) (Ludwing nental rise, continental shelf of the Bering Sea, and northern and Reynolds, 1998; Ma, 1994). and southern Bering Strait, to the shelf of the Chukchi Sea and Species diversity was calculated by the Shannon–Wiener di- Chukchi slope (Fig. 1). If the total weight of the catch was less versity index (H′): than 20 kg, all samples were analyzed. If the total weight of the catch was more than 20 kg, the large and rare individuals were H′ = −ΣPiln Pi . (1) selected and then 20 kg was chosen from the remaining catch at random. The samples were first classified: photos were taken, Evenness was calculated by Pielou’s index: and then samples were frozen immediately. The classification J′ = H′/lnS. (2) was based on Nelson (2006), Coad et al. (1995), and Mecklen- burg et al. (2002). The sampling and analysis method were ac- Species richness was calculated by Margalef’s index, which cording to the Marine Investigation Standard (Standardization was the number of the species in a certain limit: Administration of the People's Republic of China, 2007). D = (S−1)/lnN. (3) 2.2 Data analysis The fishes were divided into warmwater species, temper- Pi was the ratio of number of ith and total individuals. S was ate water species, and coldwater species, according to Tian et the number of species. N was the total number of individuals of 80° N 50 100 M06 250 75° SR12 M07 SR11 500 SR10 SR09 Co-10 750 R08 Co-01 1 000 SR07 C05 70° 1 250 R06 C02 1 500 SR03 CC8 2 000 m BS05 2 500 65° BS08 Depth/ BS02 NB09–NB10B 3 000 BB06 NB08B BB05 NB08 3 500 BB02 NB09–NB10 4 000 60° SL01–SL09 B14 4 500 B07 5 000 5 500 55° 6 000 6 500 170° E 180° W 170° 160° 150° French-type otter trawl otter trawl French-type otter trawl and otter trawl triangular bottom trawl middle water IKMT net Fig.1. Stations of the 2010 Arctic Expedition in the Bering Sea and Chukchi Sea. LIN Longshan et al. Acta Oceanol. Sin., 2014, Vol. 33, No. 6, P. 63–73 65 different stations. 36 stations in the present study, which belonged to seven or- The dominant species were determined by the ratio of the ders, 14 families, and 31 genera.