Feasibility study report on rare aquatic animal nature reserve

Feasibility Study Report on the Construction of Qingdao Wenchang Fish Rare Aquatic Animal Nature Reserve

I. Geographical overview

The Qingdao Wenchang Fish Rare Aquatic Animal Nature Reserve is planned to be located outside Jiaozhou Bay, northeast of Zhuji Island, east of Dadao Island, five kilometers south of Qingdao City, and adjacent to the island of Dagong Island. District, the central area is located in Nansha area. The sea area has access to the main channel and anchorage of Jiaozhou Bay, and is close to the city and port area of ​​the city. The geographical position is more important.

Second, the natural environment

Submarine landform

The proposed sea area is located in the coastal area southeast of the Ludong Uplift Area. It is the junction of Lingshan Island Depression and Jiaolai Depression. The minimum water depth is 6.8m and the average water depth is 15m. It extends from Nansha to ESE and presents a crescent-shaped spread. .

The sand body is a block of ancient sediments. According to column sampling, drilling and shallow stratigraphic profile, except for the presence of bedrock at the bottom of the northern marginal ditch, the rest are covered by Quaternary loose sediments. The basement is Yanshanian granite. The central part has late-invasive basement veins. Since the end of the Mesozoic granite intrusion, the area is in a stable state and has been eroded by weathering for a long time. From the late Quaternary Pleistocene to the Quaternary, there was a continental alluvial deposit. During this period, a large number of sand and gravel deposits dominated by feldspar quartz, which were formed by weathering of granite, were deposited. This is the main period of sandstone formation in this area. After the alluvial deposits, lakes and swamps were developed. During this period, the sediments were complex in lithology, mainly composed of clay and clayey fine sand. These two ore-forming periods form the main ore body of the M2 deposit. At the beginning of the Holocene seawater, the initial intrusion was a sea-land transitional sedimentation dominated by coarse sand, which was the main formation period of the M1 ore deposit. Later, under the influence of tidal currents, the sediments were re-constructed to form a tidal sand ridge centered on Nansha.

The seabed topography around the sand body is more complicated. Eroded landforms and stacked landforms are very developed. The representative eroded landform is three deep erosion grooves. It extends from the Jiaozhou Bay mouth to the south-south direction. It is 20km long and 2~3.5km wide. The water depth is above 20m and the maximum water depth is 45m. The deep groove on the east and west sides of Zhuji Island has calcium or iron cement mass at the bottom of the trough. Covered with silty clay and clay silt, the water depth is above 20m. Its west branch is a bamboo raft, the flow rate is large, and the bedrock at the bottom of the tank is bare. The flow rate of the east branch is small, and the bottom of the tank is covered with calcareous iron cemented agglomerates and shells of sand, silt, clay and yellow sub-clay; it extends southwest from the east coast of Chidao and extends to Fushan Bay through the wheat island. Deep trough outside Yan'er Island. It is 8km long from east to west and 2.2km wide from north to south, with an average of 1km. Generally, the water depth is 22-23 m. The maximum water depth is 24.5m. The bottom is relatively flat and is covered with calcium, iron cemented agglomerates and shells of sand, silt and clay. The scouring grooves form the natural golden waterway along the coast of Qingdao.

The tidal sand ridges are mainly distributed on both sides of the deep scouring trough of the area, which is the topography of the stacked landforms. There are three main sand ridges in the area, which are long in the direction of the trend and vary in size. The sediments are mainly medium coarse sand, sorted well, with little or no clay. The tidal sand ridge is a deposit formed by the tidal flow during the flow generation process or the flow rate of the water flow is reduced. Controlled by the trend and related to the original terrain. The largest of them is Nansha, which is 5km long from east to west and 0.6km wide from north to south. The eastern end is lurking below the seabed mud surface, and the thickness of the sand layer is about 8m, which is the main yellow sand ore body in this area. The other is Beisha, a sand ridge between the central waterway and the waterway extending from the NEE-SWW outside the wheat island of Chidao. The sand ridges are intermittently distributed, with a length of about 6 km from east to west and a width of about 0.2 to 0.5 km from north to south. There are well-classed sand deposits. The third sand ridge is the large bamboo sand ridge, which appears intermittently on both sides of the bamboo raft waterway. It consists of gravel sand and medium sand, and is sorted well. The above three sand ridges are long strips of sand that are consistent with the direction of the tide. The highest depth of the sand ridge is less than 10m. The sand ridges are arranged in deep grooves, which are arranged radially outside the Jiaozhou Bay. Each sand ridge is made up of many geese. Arranged sand body composition. The sediments on the sand ridge are well-different medium coarse sand, which is the habitat of amphioxus. These sand bodies constitute the natural gold chain along the coast of Qingdao. The above is a significant submarine phenomenon in the area. Others include scouring depressions and underwater shoals, underwater accumulation plains, and underwater sand dams.

Submarine substrate

The submarine sediment types in this area are relatively complex, with modern marine sediments, continental sediments before the late Pleistocene transgression, and the quasi-residual sedimentary central waterways and bamboo rafts formed during the late Pleistocene transgression. The exposed area of ​​the bedrock is surrounded by gravel and coarse sand belt; the southern waterway of Chidao, Wheat Island and Yan'er Island is also a strong stream scouring area, with a slightly less scouring degree, with yellow sub-clay, which is transformed into sand-sand sand. clay.

2. Three tidal sand ridges: The sand deposited on the middle sand is medium-sand, and the sorting property is good. Among them, the medium sand content is dominant. The sediment is semi-circular with Nansha as the center, and the central part is coarse sand. Under the long-term effect of the trend, the sand has coarse grain size, good sorting, and contains very low clay. The coarse sand is followed by medium sand, fine sand and powder. Sand and silt. Due to the large tidal flow velocity near Jiaozhou Bay, the sediments near the bay mouth are thicker, and the farther is thinner, forming a semi-annular distribution pattern.

3. The distribution of the three waterways and the three sand ridges is mainly silty sand, sandy silt sand and sand-silice sand-clay. Among them, silty sand and sandy silt are mainly distributed in Qingdao offshore, while sand-sand-sand-clay is mainly distributed in the coastal area of ​​the Haixi Peninsula of Xuejia Island and the outer sea of ​​Qingdao. The source of the two is different. The sand-sand-silice outside the Haixi Peninsula comes from Jiaozhou Bay. The outer seas of Qingdao come from the northeast to the southwest toward the Shandong Peninsula coastal currents and residual sediments.

4. The finest seabed sediments in this area are silty clay and clay silt. It is mainly distributed in the east and south of the Wankou tidal channel, indicating that it is the main sedimentary area for transporting materials out of the bay.

5. The distribution of sediments in the nearshore zone is mainly controlled by waves, and the median diameter contour is distributed substantially parallel to the contour along the coast.

6. The distribution of residual and residual sediments in the open sea is not covered by modern sediments due to insufficient sediment source. The sediment spread from the shore to the sea only affects the vicinity of Chi Island and Zhuji Island.

Hydrological environment

1, tides

The average sea surface of the sea area is 2.42m, the highest tide height is 5.36m, the average high tide is 3.80m, the lowest low tide is -0.70m, the average low tide is l.02m, the maximum tidal difference is 4.75m, the average tidal range is 2.78m, and the average high tide gap is 4 hours. 40 points, the average rising tide lasted 5 hours and 39 minutes, and the average ebb tide lasted 6 hours and 46 minutes. For the regular half-day tide.

2, current

Flow direction: The overall trend is toward the west, and the trend is toward the east.

Flow rate: The tidal wave in this area belongs to the nature of the forward wave. The maximum flow velocity of the current occurs about 1.5 hours in front of the high and low tides; the minimum flow rate appears in the front of the half tide for about 1.5 hours, which is the moment of the flow. The tidal level rises from the low tide surface to the high tide surface and then falls back to the low tide surface to complete a fluctuation process. The flow rate changes from large to small to large and then small, and finally reaches the maximum change.

3, the waves

Waveform: The sea area is dominated by wind and waves. The average wind wave frequency is 98% for many years. The frequency of wind waves is basically the same every year, and the annual variation is only 2%. The average swell frequency is 69%, and the average swell frequency varies greatly from month to month, with an annual variation of 36%.

Wave direction: There are wind and waves in all directions in the sea area, but most of them are concentrated in E-SW and WNW-NNW. In the years of NW, the wind wave is the most, with a frequency of 10%. Most of the sea swells appear in the E-SW direction and are concentrated in the ESE-SSE direction. Among them, SE has the most swell, and the annual frequency is 26%.

Wave height: The annual average wave height of the sea area is 0.7m, and the average annual wave height is 0.1m. The average wave height change trend is: the first half of the year gradually increases, reaching 0.9m in July, and the second half is gradually decreasing in December and January. It is 0.5m. In terms of seasonal changes, summer wave height is the highest, autumn is second, and winter is the smallest.

Trend: The current trend in the sea area is mainly affected by the left-handed tidal wave of the M2 tidal wave outside the Haizhou Bay in the South Yellow Sea. The trend type is less than or equal to 0.5, and the trend type belongs to the regular half-day trend. The trend of the sea area is completely controlled by the left-handed tidal wave outside the Haizhou Bay, and the trend is counterclockwise rotation. The current flow rate and tidal current velocity of the sea area are relatively large, and it is a strong current flow area.

Residual flow: The residual current during the tide period is strong, the maximum flow rate reaches 267cm/s, the residual current during the small tide is weak, and the maximum flow velocity is only 7.0cm/s. During the small tide, the surface layer shows the shape of the left-lateral circulation.

meteorological

1, the temperature

The area belongs to the north temperate maritime climate. The statistical results from 1960 to 1987 show that the average annual temperature is 12.5 °C, the annual average maximum temperature is 15.8 °C, and the annual average minimum temperature is 9.8 °C. The hottest month appears in August, the monthly average temperature is 25.5 °C, the monthly average maximum temperature is 28.6 °C, the monthly average minimum temperature is 23.3 °C; the coldest month appears in January, the monthly average temperature is -0.2 °C, and the monthly average maximum temperature is 3.0. °C, the monthly minimum temperature is -3.3 °C.

2, wind conditions

The spring and summer seasons of the sea area are dominated by ENE-ESE winds, of which the easterly easterly winds are the most prosperous, and the frequency of E-direction winds is only 20%. In the autumn and winter, the NW-N is the main wind, and the NW winds in winter are especially high, with a frequency of 24%. The average annual wind speed in the sea area is 5.0m/s, and the average monthly wind speed in November is the largest in November, 6.1m/s, and the minimum in June is 3.9m/s. The average annual wind and heavy rain is equal to 8 days of high winds of 51.7 days.

3, precipitation

The annual average precipitation in the sea area is 732.3mm, and the annual minimum precipitation is 23.8mm. The maximum number of precipitation days in each month is the highest in July and the least in January. The maximum daily precipitation is 182mm.

4, fog

The sea fog is frequent in this area, and the summer is the season of sea fog. The southeast wind produces the most fog. Most of the fog occurred in April-July, and the four-month accounted for 80% of the annual average, especially in June and July. The duration of the fog can be up to 9 days

In the investigation of the selected protected area waters outside Jiaozhou Bay in late May 2001, 17 species of 10 genera of phytoplankton were detected, including 15 species of 8 genera, 88.2%; 2 species of 2 genera, accounting for 11.8%. . The variation of phytoplankton ranged from 1439.9 to 2218.15×103cell/m3, and the average number was 1742.70×103cell/m3. The horizontal distribution of phytoplankton gradually decreased from southwest to east, and the coastal waters were slightly higher than offshore waters. The genus Corydalis has a wide range of suitable temperature. In the late May, the dominant species are formed in the sea area. The quantity varies from 1186.42 to 1681.64×103cell/m3, accounting for 75.8-82.3% of the total phytoplankton. The number of phytoplankton is exactly the same as the distribution of phytoplankton. Due to the obvious dominant species of phytoplankton in this area, the proportion of phytoplankton is large, so the diversity index is lower and the purity is higher. The species composition, quantity distribution and community structure index of phytoplankton showed that the number of phytoplankton species in this area was high and the quantity was abundant. It is a suitable spawning ground and feeding ground for fish and shrimp.

Fish eggs, larvae

May is the spawning period for a variety of fish. According to the survey, there are 7 species of fish eggs in the sea, belonging to 4 orders and 7 families. The species of fish eggs are all floating eggs, and their numbers are basically high in the north and low in the south, and the number of eggs is the largest. It can be seen from the species composition and quantity of floating fish eggs that the sea water exploitation in the outer sea of ​​Jiaozhou Bay is an important spawning ground for many economic fish.

However, no larvae and juveniles were found in the survey in early May 2001. In the second half of May, when most of the economic fish were spawning and breeding, the juveniles accounted for a large proportion of the various fish populations and the body weight was small.

Fishery resources

Fish is the main body of marine economic animal resources. It plays a particularly important role in the energy flow of marine ecosystems, and it can continuously provide high-protein foods directly used by humans in resource renewal. Academician Liu Ruiyu of the Chinese Academy of Sciences pointed out in the book "Ecological and Biological Resources of Jiaozhou Bay" that there are more than 100 species of fish in Jiaozhou Bay and adjacent sea areas, of which warm-temperature species account for 61%, warm water species account for 23%, and cold temperature. The species accounted for 17%. The dominant species were cantharidin, barracuda, blue-spotted fish and gingiva. Other dominant species were red-nose scorpion, middle-necked scorpion, thin-striped squid, scorpion, long-snake, scutellaria, octopus, and coke. Tongue, white squid, long scorpionfish, yellow squid, short-snake tongue, oil scorpion, green-finned horse scorpion scorpion, scorpion, silver carp, wood leaf scorpion, Pis called squid, etc., 23 species of fish constitute the tail of the catch 96 %. Although the number of fishery resources and the composition of dominant species have changed in the past 10 years, their species composition should be relatively stable.

Every year from May onwards, a variety of fish have entered the Jiaozhou Bay and coastal waters to lay eggs, bait and fatten. In May and June, the number of spawning species reached 26 and 36, respectively, which is the peak of fish spawning in this sea area. In addition, when the water temperature was high in August, the warm water species distributed in the south entered Jiaozhou Bay through the bay mouth; after the water temperature dropped in October, the warm water species began to leave again. Therefore, the waters outside the mouth of Jiaozhou Bay are not only the spawning and feeding grounds of various fishes, but also the breeding passages for warm-water species of fish.

In the comprehensive survey of fishery resources in the sea area, 29 species of fish were captured, belonging to 27 families and 29 genera. The evaluation results show that the resources of bottom trawling and catching fish are mainly pelagic fish, with a total resource of 317,577 Kg, of which the first resource of jade fish is 306,503 Kg, and the net hourly net is 1930 Kg. It accounted for 94.3% of the total catch; Fangshi Yunxiao ranked second with 6554Kg, Blue Point Stables ranked third with 1153Kg, and Blue-streaked fish ranked fourth with 1088Kg. Other types of resources are below 400 Kg. The bottom trawl captures fish resources mainly in the bottom fish, but the resources are very low, and the total resources are only 808 Kg. A total of 15 invertebrates were investigated. The dominant species was prawn carp. The net amount per hour was 11.6Kg, accounting for 27.3% of the total catch. The second was sputum, and the net hourly yield was 5.5Kg. The total catch was 15.2%; Changlong was the third, with a net hourly net of 4.6Kg, accounting for 9.9% of the total catch. The total resource of invertebrate animals is 4033 Kg. This indicates that the sea area is a place for spawning and breeding of many economic fish.