Marine Environment Bulletin 1998

The China Marine Environment Bulletin is prepared on the basis of synthetic analysis and evaluation of the annual data of the State Oceanic Administration from cross-section monitoring, pollution monitoring, ocean station observation, buoy observation, ship reports and special-topic marine surveys. The condition of China¡¯s marine environment in 1998 is hereby announced as follows:

  Marine Environmental Quality

  Marine Environmental Condition

  Marine Environmental Management

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Marine Environmental Quality in 1998

The monitoring results of China¡¯s offshore sea areas in 1998 show that over half of the near-shore water bodies have been seriously polluted, the marine environmental quality continues to deteriorate on the whole and the off-sea waters is being threatened. The major pollutants in the sea water are still inorganic nitrogen, inorganic phosphorus, oils and heavy metals. In 1998, China¡¯s offshore area has accommodated over 10 billion tons of municipal sewage and industrial waste water directly discharged in the coastal regions into the sea, with an annual increase rate of about 5%. In the offshore area, 95% of the inorganic nitrogen, inorganic phosphorus and heavy metals, and over 80% of the oils come from land sources. The excessive discharge of land-based pollutants into the sea is the major cause of the persistent deterioration of environmental quality in the nearshore sea areas.

(I)    Nutrient Salts

1¡¢    Inorganic nitrogen

In 1998, the over-the-standard rate of inorganic nitrogen in the Bohai Sea has amounted to 45%, with an average measured value of 0.25mg/l, which has exceeded the first-class seawater quality standard, and a maximum measured value of 1.66mg/l, which has exceeded the fourth-class seawater quality standard by a factor of 2.1.

The over-the-standard rate of inorganic nitrogen in the Huanghai Sea is 46%, with an average measured value of 0.27mg/l, which has exceeded the first-class seawater quality standard, and a maximum measured value of 2.21mg/l, which has exceeded the fourth-class seawater quality standard by a factor of 34.

The over-the-standard rate of inorganic nitrogen in the East China Sea is as high as 78%, with an average measured value of 0.60mg/l, which has exceeded the fourth-class seawater quality standard; and a maximum measured value of 4.0mg/l, exceeding the fourth-class seawater quality standard by a factor of 7.

The over-the-standard rate of inorganic nitrogen in the South China Sea is 28%, with an average measured value of 0.23mg/l, which has exceeded the first-class seawater quality standard, and a maximum measured value of 1.63mg/l, which has exceeded the fourth-class seawater quality standard by a factor of over 2.2.

2¡¢    Inorganic phosphorus

In 1998, the over-the-standard rate of inorganic phosphorus in the Bohai Sea is 45%, with an average measured value of 0.019mg/l, exceeding the first-class seawater quality standard (0.015mg/l).

The over-the-standard rate of inorganic phosphorus in the Huanghai Sea is 28%, with an average measured value of 0.014mg/l, and a maximum measured value of 0.099mg/l, which has exceeded the fourth-class seawater quality standard (0.045mg/l) by a factor of 1.2.

The over-the-standard rate of inorganic phosphorus in the East China Sea is as high as 76%, with an average measured value of 0.033mg/l, which has exceeded the third-class seawater quality standard (0.030mg/l), and a maximum measured value of 0.127mg/l, which has exceeded the fourth-class seawater quality standard by a factor of nearly 1.8.

The over-the-standard rate of inorganic phosphorus in the South China Sea is 14%, with an average measured value of 0.007mg/l and a maximum measured value of 0.074mg/l, which has exceeded the fourth-class seawater quality standard by a factor of over 0.6.

(II)  Oils

The over-the-standard rates of oils in 1998 are 1%, 6% and 3% in the nearshore waters of the Bohai Sea, Huanghai Sea and South China Sea respectively.

(III) Heavy Metal

Lead: In 1998, the contents of lead in the nearshore waters of the Bohai Sea, Huanghai Sea and East China Sea have generally exceeded the standard, as high as 81%, 85% and 40% respectively and the average measured values are 2.37ug/l and 2.52ug/l in the Bohai Sea and Huanghai Sea respectively, both having exceeded the first-class seawater quality standard by a factor of over 1.

Total mercury: In 1998, the over-the-standard rates of mercury are 42%, 19% and 22% in the coastal waters of the Bohai Sea, Huanghai Sea and East China Sea respectively. The average measured value of mercury content in the Bohai Sea is 0.09ug/l, exceeding the first-class seawater quality standard (0.05ug/l) by a factor of 0.8.

(IV) Chemical Oxygen Demand (COD)

In 1998, the over-the-standard rates of COD are 13%, 2% and 2% in the nearshore waters of the Bohai Sea, East China Sea and South China Sea respectively; The maximum measured value of COD in the Bohai Sea is 2.32mg/l, having exceeded the first-class seawater quality standard (2mg/l).

(V)  Red Tide

Red tide is one of the phenomena marking the level of marine environmental pollution. In 1998, 22 red tides have been monitored in China, of which 10 in the South China Sea, mainly occurring at the Zhujiang River mouth, Daya Bay, west Shenzhen and Yangwang sea area; 5 in the East China Sea, mainly occurring at the Changjiang River mouth, Hangzhou Bay, and Xiaqin sea area; and 7 in the Bohai Sea and Huanghai Sea, mainly occurring in the Yantai sea area, Liaodong Bay, Bohai Bay and Laizhou Bay.   

(VI) Oil Spill

In 1998, one large oil spill accident and over 20 small oil spill accidents have been monitored in China¡¯s nearshore waters.

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Marine Environmental Condition in 1998

(I)    Sea Level

Compared with that in normal years (1975~1986), the national coastal sea level is 6.4 cm higher on the average, i.e., 7.0 cm higher in the Bohai Sea, 7.9 cm higher in the Huanghai Sea, 6.8 cm higher in the East China Sea, 3.6 cm in the Taiwan Straits, and 4.6 cm in the South China Sea.

Compared with that in 1997, the coastal sea level most sea areas of Chine generally rises in 1998, with an average rise of 2.6 cm, i.e., 2.1cm higher in the Bohai Sea, 4.0 cm in the Huanghai Sea, 4.4 cm higher in the East China Sea and 3.2 cm higher in the Taiwan Straits while it is 1.4 cm lower in the South China Sea.

As of 1998, the observations of China¡¯s major tidal gauge stations have continued to indicate an obvious tendancy of sea level rise. The average rate of sea level rise is 2.6 mm/a, i.e., 3.1 mm/a in the Bohai Sea, 2.8 mm/a in the Huanghai Sea, 2.1 mm/a in the East China Sea, 0.8 mm/a in the Taiwan Straits and 3.0 mm/a in the South China Sea.

(II)  Tide

As compared with 1997, the annual average tidal range in the coastal semidiurnal sea areas throughout China decreases 3 cm on an average. The seasonal variations of tidal range are: In the semidiurnal sea area of the Bohai Sea, it is larger in June~August and smaller in winter or spring; in the sea area where the diurnal tide is dominant, the tidal range is also larger in June~August and small in February~April; The maximum tidal range in the coastal Jiangsu, Zhejiang and Fujian occurs in July~August and the minimum in February~March; The seasonal variations of tidal range in the coastal sea areas of Guangdong, Beibu Gulf and Hainan are not obvious. For the variations of the coastal monthly average tidal range throughout China this year, except in the sea areas of the Bohai Sea dominated by the diurnal tide where it is 13 cm, it is about 6 cm in other sea areas. The variation magnitude of tidal range in the coastal sea areas of Jiangsu, Zhejiang, Fujian and Guangdong exceeds 10 cm, with a maximum of 23 cm while that in the coastal sea area of Hainan is small.

According to the data statistics of 28 tidal gauge stations, the annual highest water level in the coastal sea areas of China is generally lower in 1998 than that in 1997. As there are fewer typhoons in 1998, the annual highest water level in the coastal sea areas of Zhejiang, Fujian and Guangdong is lower than that in 1997, which is 100 cm lower in the coastal sea areas of Jiangsu and Zhejiang, but stightly higher than that in 1997 only in the coastal Hainan.

(III) Sea Currents

The sea currents in the nearshore sea areas of China are mainly the tidal currents, the speed of residual current is generally below 50cm/s and the current direction varies with season. In the East China Sea, Kuroshio is the main current system. This year the current speed of Kuroshio remains the same as that in normal years. On the PN cross-section through which the Kuroshio passes near 28¡ã20´N, 127¡ã22´, the maximum current speed measured in January is 134 cm/s, with a current direction of NNE; in April, the maximum speed of surface current measured at 280¡ã26´N, 126¡ã57´ is 175 cm/s with a direction of NE. On the PN cross-section in spring, the flow of the geostrophic current in NE direction is larger than that in normal years.

In 1998, China¡¯s offshore semidiurnal tidal currents begin to decrease while the diurnal tidal currents begin to increase, which is an outstanding characteristic of the change in the China¡¯s offshore tidal currents in 1998. As for the proportions of semidiurnal and diurnal components in the tidal currents of various sea areas, compared with that in 1997, the tidal current increases in some stations, decreases in some other stations and basically remains the same as that in 1997 in still other stations. This has brought about an obvious change in the proper order of China¡¯s offshore strong tidal current zones by current speed.

(IV) Sea Wave

1¡¢    Wave direction

This year the most wind wave directions throughout the coastal sea area are identical with the most wind directions except in the Chengshantou sea area where the most wind wave directions differ greatly from the most wind directions. The most wind wave directions are south by west in the Liaodong Bay, north in the Bohai Bay and Laizhou Bay, south in the northern Huanghai Sea, mainly north and north by east in the coastal waters of the southern Huanghai Sea and East China Sea. The wave directions are ENE and ESE in the Guangdong coastal sea areas of the South China Sea, SE and SW along the west coast of Hainan Island and NNE in the Beibu Gulf.

2¡¢    Wave height

The average wave heights in the coastal sea areas of Bohai Sea, Huanghai Sea, East China Sea and South China Sea change within the ranges of 0.3~0.7m, 0.2~0.7m, 0.6~1.3m and 0.6~1.3m respectively and with the maximum wave heights of 1.0~5.5m, 2.0~5.0m, 2.6~6.0m and 1.7~3.7m respectively. The maximum values of wave height are: 5.5m in the Beihuangcheng sea area of the Bohai Sea, 5.0m in the Lianyungang sea area of the Huanghai Sea, 6.0m in the Beishuang sea area of the East China Sea, and 3.7m in the Zhelang sea area of the South China Sea. The maximum wave height in the entire coastal sea area throughout the year occurs in the East China Sea at the areas adjacent to Fujian and Zhejiang and mainly in February.

This year the number of days when disastrous very rough seas with a wave height of over 4 m occur is smaller than that in normal years, i.e., days in the Bohai Sea (26 days in normal years); 29 days in the Huanghai Sea (95 days in normal years); 87 days in the East China Sea (123 days in normal years); 76 days in the Taiwan Straits ( 90 days in normal years); and 79 days in the South China Sea (169 days in normal years).

3¡¢    Wave period

The average wave periods in the coastal sea areas of the Bohai Sea, Huanghai Sea, East China Sea and South China Sea are all less than 6.0s, of which those in the Bohai Sea and northern Huanghai Sea ( except the Bohai Strait) are less than 2.5s, below 0.4s in the southern Huanghai Sea, larger in the East China Sea and the northeastern South China Sea, i.e., mostly 4.0~6.0 s and about 2.5s in the coastal sea area of Hainan Island and the Beibu Gulf.

(V)  Sea Fog

The sea areas with the largest number of fog days throughout the year are Beihuangcheng in the Bohai Sea, Chengshantou and Shidao in the Huanghai Sea, Nanhu in the East China Sea and Naozhou in the South China Sea, which have 47, 100, 81, 78and 45 fog days respectively. The sea area with the least number of fog days throughout the coastal sea areas of China is the Bayuquan in the Bohai Sea.

(VI) Sea Ice

During November, 1997~March, 1998, the ice condition in the Bohai Sea and northern Huanghai Sea is less serious than that in normal years.

Anaglacial: As compared with that in normal years, it is postponed for 15 days in the north of Liaodong Bay, 10 days in the south; and 20 days in the Bohai Bay and Laizhou Bay. Last ice period: Compared with that in normal years, it is 23 days earlier in the Liaodong Bay and 10 days earlier in the Bohai Bay. Thus it can be seen that the ice period is one month earlier in the Liaodong Bay and Bohai Bay and that the ice period in the Laizhou Bay is only 10 days shortened for nearly 2 months as compared with that in normal years.

The maximum freezing ranges in the Bohai sea and northern Huanghai which occur in the last ten-day period of  ?   are 133 km in the Liaodong Bay, 19 km in the Bohai Bay, about 9 km in the Laizhou Bay and 19 km or so in the northern Huanghai Sea.  

(VII) Seawater Temperature and Salinity

1¡¢    Surface temperature

In winter, the average temperature in various sea areas is: 1.14¡ãC in the Bohai Sea, 5.54¡ãC in the Huanghai Sea, 13.56¡ãC in the East China Sea and 20.88¡ãC in the South China Sea. Compared with that in normal years, it is generally higher in various sea areas: 0.19¡ãC higher in the Bohai Sea, 0.77¡ãC higher in the northern Huanghai Sea, 0.83¡ãC higher in the southern Huanghai Sea, 0.85¡ãC in the East China Sea, 0.67¡ãC higher in the South China Sea, about 1.77¡ãC higher in the sea area near the Changjiang River mouth while it is 0.38¡ãC lower in the coastal sea areas of Zhejiang, Fujian and Guangdong.

In summer, the average temperature in various sea areas is; 25.39¡ãC in the Bohai Sea, 25.98¡ãC in the Huanghai Sea, 27.64¡ãC in the East China Sea, and 29.73¡ãC in the South China Sea. Compared with that in normal years, it is higher in the Bohai Sea, southern Huanghai Sea and South China Sea but lower in the northern Huanghai Sea and East China Sea, i.e., 0.22¡ãC higher in the Bohai Sea, 0.80¡ãC higher in the southern Huanghai Sea, 0.60¡ãC higher in the South China Sea, 0.78¡ãC lower in the northern Huanghai Sea, 0.15¡ãC lower in the East China Sea and 0.44¡ãC lower in the sea area near the Changjiang River mouth while it remains basically the same in the coastal areas of Zhejiang, Fujian and Guangdong. As compared with that in 1977, the average surface temperature is generally somewhat higher in the Bohai Sea, Huanghai Sea, East China Sea and South China Sea.

2¡¢    Surface salinity

In winter, the average salinity in various sea areas is: 31.87 in the Bohai Sea, 32.35 in the Huanghai Sea, 29.73 in the East China Sea and 33.12 in the South China Sea. Compared with that in normal years, it is higher in the Bohai Sea, northern Huanghai Sea and southern Huanghai Sea while it is lower in the East China Sea and South China Sea, i.e., 0.34 higher in the Bohai Sea, 1.61 higher in the northern Huanghai Sea, 0.52 higher in the southern Huanghai Sea, 1.24 lower in the East China Sea, 0.50 lower in the South China Sea and slightly lower near the Changjiang River mouth.

In summer, the average salinity in various sea areas is: 29.93 in the Bohai Sea, 30.87 in the Huanghai Sea, 29.76 in the East China Sea, and 31.61 in the South China Sea. Compared with that in normal years, it is higher in the Bohai Sea and northern Huanghai Sea, but lower in the southern Huanghai Sea, East China Sea and South China Sea, i.e., 0.77 higher in the Bohai Sea, 0.88 higher in the northern Huanghai Sea, 0.24 lower in the southern Huanghai Sea, 0.75 lower in the East China Sea and 1.15 lower in the South China Sea. It is obviously lower by 4.68 in the sea area near the Changjiang River mouth which is affected by the flood of the river. So, compared with that in 1997, the average salinity is lower in the Bohai Sea and East China Sea, basically the same in the Huanghai Sea and slightly higher in the South China Sea.

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Marine Environmental Management in 1998

(I)    National Joint Marine Law-Enforcing Action

Under the unified planning of the State Oceanic Administration, the North Sea, East Sea and South Sea Branches of the State Oceanic Administration together with the oceanic administrations of coastal provinces and municipalities have organized the joint marine law-enforcing actions, sending out over 100 law-enforcing vessels, over 30 sorties and more than 60 ocean supervising vehicles to make an inspection tour of such targets as harbour, anchorage, land-based pollutants discharge and and waste dumping zones, offshore oil platform, wreckage, red tide and aquaculture zone etc., in which they have found over 100 cases in violation of the regulations and ocean damage cases, investigated and prosecuted according to law over 100 illegal cases of all kinds, timely discovered and announced the red tide disasters occurring in China¡¯s jurisdictional waters, among which the two great red tides in the Zhujiang River mouth and the Bohai Sea have aroused the widespread concern of all circles. The joint law-enforcing action has speeded up the integration process of the national marine law-enforcing and supervising work, promoted the development of the sea area utility management, intensified management and protection of the marine environment and resources, and enhanced the ocean awareness and the sense of marine legal systems of the whole nation.

(II)  The Second National Marine Pollution Baseline Survey

To accurately grasp China¡¯s marine environmental quality condition at the end of the century, provide fundamental basis for China¡¯s marine environmental protection plans and programs in the 21st century, promote the sustainable development of socioeconomy in the coastal areas and marine industries and safeguard China¡¯s marine rights and interests, under the leadership of the State Oceanic Administration, all the operational projects on the sea of the Second National Marine Pollution Baseline Survey in which the units under the State Oceanic Administration and the oceanic departments of eleven coastal provinces, municipalities and autonomous regions participated had been completed by the end of October, 1998 and the survey results would be published one after another starting from June, 1999.

The Survey covered China¡¯s jurisdictional sea areas including the interior sea, territorial sea and Exclusive Economic Zone, with the nearshore sea areas as the focal points of the survey, of which the 37 bays, estuaries and the sea areas adjacent to the large-and medium-sized cities such as the Yalujiang River mouth, Liaodong Bay, Bohai Bay, Zhujiang River mouth, Dalian Bay, Jiaozhou Bay, Hangzhou Bay, Meizhou Bay, Daya Bay, Haikou Bay, etc. are the first priorities of the survey. A total of over 1000 survey station sites were deployed in the entire survey area and the survey intervals include spring, summer, autumn and winter. The survey contents include water quality, sediment, organism, radioactivity and pollution sources. Adding up to over 100 items, the survey has collected over 50,000 samples of all kinds, obtained more than 100000 basic data, sent over 200 vessels and nearly 2000 personnel out to sea and covered a total voyage of about 100,000 nautical miles. This is a marine environmental pollution survey ever conducted in China with the largest scale, most extensive coverage and most complete contents and its results are of extremely important practical significance and far-reaching influence.

(III) Work of the Xiamen Demonstration Site for the Project ¡°East Asia Seas Marine Pollution Prevention and Management¡±

The project ¡°East Asia Seas Marine Pollution Prevention and Management¡± is a regional project implemented by the United Nations Development Program (UNDP), Global Environment Facility (GEF) and International Maritime Organization (IMO) with Xiamen of China, Batangas of the Philippines and the Malacca Strait as the demonstration sites of the project. The State Oceanic Administration is the State implementing agency for the Xiamen demonstration program. Formally starting its work in November, 1993 and finishing its work in December, 1998, the Xiamen Demonstration Site has reached its predetermined goals in an all-round way through five years¡¯ organization and implementation, made an effective breakthrough in the mechanism construction for the integrated coastal zone management, explored and put into practice the integrated coastal zone management models such as centralized coordination, expert consultation, legislation in advance, integrated law enforcement, taking all the managerial activities as a whole, and successfully applied the methods of integrated coastal zone management to the prevention and control of marine pollution as well as the development and management of coastal zone resoures, thus realizing the harmony and unity of economic development, social progress and environmental protection and making a positive contribution to the sustainable development of the Xiamen City. The experiences and results obtained by the Xiamen Demonstration Site are of typical guidance to China¡¯s coastal and marine management.

(IV) Marine Nature Reserve Management and Ecological Conservation

To improve the integrated management of typical ecosystems, the State Oceanic Administration provides more guidance to the selection, designation, examination and appraisal, and construction of the local marine nature reserves while doing a good job in the routine supervision and management of the national marine nature reserves. To push forward the experiment on special marine nature reserves, with the help of the Ministry of Land and Resources, it once again submitted to the State Council the application for establishing two special nature reserves of typical importance ¡ªMiaodao Islands of Shandong and Qinzhou Bay of Guangxi.

In July, 1998, the Nanji Islands Nature Reserve of Zhejiang was approved by the UNESCO as a member of the International Man and Biosphere Network. In September of the same year, the Provincial Marine Nature Reserve of Ancient Shell Dykes of Huanghua, Hebei was established.

In order to strengthen marine ecological management and monitor the marine ecological environment, a northern marine ecological monitoring station was set up in the Changli Gold Coast Nature Reserve at the end of 1998 and the first voyage of ecological monitoring and survey has been completed.

(V)  Management of Ocean Dumping and Environmental Protection in the Offshore Petroleum Exploration and Exploitation

With respect to the management of ocean dumping in 1998, efforts were made to check up the temporary dumping zones and implement the Guide to the Selection, Designation and Monitoring of Dumping Zones. In accordance with the Regulations of the People¡¯s Republic of China Concerning the Dumping of Wastes at Sea, the State Oceanic Administration has organized its various branches and part of the coastal provinces and municipalities to strengthen the management work of dumping, signing and issuing a total of 490 permits for wastes dumping with a dumping volume of 1.10 million cubic metres (dredged materials). In addition, technical means have been used to intensify wastes dumping management. By the end of 1998, 68 recorders for wastes dumping voyages have been installed on board the self-propelled wastes dumping vessels and the regulatory system for the navigation data records of wastes dumping vessels has been established in the main. The State Oceanic Administration also carries out unified management of the wastes dumping work in the Hongkong and Macao regions. In 1998, it has accepted six applications from Hongkong for dumping dredged materials, with an approved dumping volume of 1.12 million cubic metres, and signed a memorandum with Macao on ocean wastes dumping.      

With respect to the management of environmental protection in the offshore petroleum exploration and exploitation, this year the State Oceanic Administration has drafted and promulgated the Circular on Testing the Anti-Pollution Facilities of Offshore Oil (Gas) Fields and, in coordination with such agencies as the Legal System Office of the State Council, the State Environmental Protection Administration, etc., made a series of intepretations and explanations for the circular. It has strengthened the management of the anti-pollution facilities of oil platforms, examined and approved 3 oil spill emergency plans, and has checked and approved the chemical oil dispersants. It has also drafted the regulation on the use of mud in the offshore oil exploration and exploitation, on the basis of which, the national standard ¡°Methods for Grade Classification and Testing of Mud Toxicity¡± has been reported to the higher authorities.