Swimming creatures
Types and their seasonal variations. 302 species of swimming organisms have been found in Shengsi waters, including 210 species of fish, 75 species of shrimp and crab crustaceans, 11 species of cephalopods and 6 species of jellyfish.
The environmental conditions of each island group are different, and the composition of biological species is also different. There are 82 species of swimming organisms in the Tanhu sea, including 54 species of fish, 27 species of crustaceans, and 1 other species; 86 species of organisms in the Yangshan sea, including 61 species of fish, 21 species of crustaceans, and 4 other species; 163 species of creatures obtained from the Yellow Dragon Point in the Sijiao Sea, including 116 species of fish, 38 species of crustaceans, and 9 other species; 116 species of swimming organisms obtained from Maguan Point, including 66 species of fish, 40 species of crustaceans, and 10 species of other species; 96 species of organisms obtained from the submural point of Shengshan Sea, including 54 species of fish and 33 species of crustaceans. 9 other classes. Through the annual net sampling survey, a total of 246 species of swimming organisms were obtained, including 168 species of fish, 65 species of crustaceans, 9 species of other cephalopods, and 4 species of jellyfish.
The change of seasons, the number of swimming creatures, etc. also changes accordingly.
In the spring, 38 species of swimming organisms were found in the Waters of Tanhu, of which fish accounted for 63.2% and crustaceans 36.8%; 45 species of organisms were obtained from the ocean, of which fish accounted for 77.8% and crustaceans accounted for 22.2%; 72 species of organisms were found in The Yellow Dragon Point, of which 69.4% were fish, 26.4% were crustaceans, and 4.2% were other species; 71 species of organisms were obtained at Maguan Point, of which 57.7% were fish, 39.4% were crustaceans, and 2.9% were other species; and 59 biological species were obtained at the submural point. Fish accounted for 55.9%, crustaceans accounted for 35.6%, and other species accounted for 8.5%.
In summer, 48 species of swimming organisms were obtained in the Tanhu sea, of which fish accounted for 66.7% and crustaceans accounted for 33.3%; 36 species of organisms were obtained in the oceanic sea, of which fish accounted for 61.1%, crustaceans accounted for 36.1%, and other species accounted for 2.8%; Huanglong point obtained 63 species of organisms, of which fish accounted for 61.8%, crustaceans accounted for 30.2%, other classes accounted for 8%; Maguan point obtained 67 species of organisms, of which fish accounted for 65.7%, crustaceans accounted for 28.3%, other classes accounted for 6%; submural points obtained 45 species of organisms, Fish accounted for 55.6%, crustaceans accounted for 28.9%, and other classes accounted for 15.5%.
In autumn, 39 species of organisms were acquired at Tanhu point, of which fish accounted for 56.4% and crustaceans accounted for 43.6%; 23 species of organisms were obtained at ocean points, of which fish accounted for 56.5% and crustaceans accounted for 43.5%; 83 species of organisms were obtained from Huanglong points, of which fish accounted for 66.3%, crustaceans accounted for 26.5%, and other categories accounted for 7.2%; 39 species of organisms were obtained from submural points, of which fish accounted for 64.1% and crustaceans accounted for 35.9%.
In winter, 36 species of organisms were acquired at Tanhu Point, of which fish accounted for 65.8%, crustaceans accounted for 26.3%, and other species accounted for 7.9%; ocean points acquired 58 species of organisms, of which fish accounted for 65.5%, crustaceans accounted for 29.3%, other classes accounted for 5.2%; Huanglong points obtained 80 species of organisms, of which fish accounted for 63.6%, crustaceans accounted for 28.8%, other classes accounted for 7.6%; Maguan point obtained 58 species of organisms, of which fish accounted for 56.9%, crustaceans accounted for 36.2%, other classes accounted for 6.9% 41 species of organisms were acquired at the submural point, of which fish accounted for 56.1%, crustaceans accounted for 36.6%, and other species accounted for 7.3%.
The catch consists mainly of species and distribution. The dominant species of fish caught in the coastal areas are dragon head fish, plum child, anchovy, tongue fish, Chinese hair shrimp, Ann's white shrimp, Ge's long-arm shrimp, yellow crucian carp and so on. The dominant varieties in the sea areas from west to east in the county have also changed to a certain extent. The dominant species in the Tanhu sea area are An's white shrimp, anchovy, ridge-tailed white shrimp, plum boy fish, dragon head fish, Ge's long-arm shrimp, yellow crucian carp, etc.; yangshan sea area is anchovy, plum child fish, An's white shrimp, Chinese pipe whip shrimp, dragon head fish, knife mackerel, Chinese hairy shrimp, Ge's long-arm shrimp, major economic fish juvenile fish, etc.; SiJiao sea area is China's hairy shrimp, dragon head fish, anchovy, concave official whip shrimp, plum child fish, Ge's long-arm shrimp, called girl fish and economic fish juveniles; Shengshan sea area is the juvenile of economic fish such as striped fish, dragon head fish, Chinese hairy shrimp, Ge's long-arm shrimp, seven-star fish, Pipe whip shrimp, plum boy fish, anchovies, yellow crucian carp, blue scale fish, mackerel, etc.
According to the classification calculation, the weight and tail number of fish caught in each sea area were 64.55% and 28.71% of the fish in the swimming organisms of Tanhu Sea, 35.07% and 71.29% respectively, the weight and tail number of fish in Yangshan Sea accounted for 92.65% and 70.42%, the crustaceans accounted for 6.91% and 29.5%, respectively, the weight and tail number of Yellow Dragon Point fish in the Sijiao Sea accounted for 80.17% and 40.39%, and the crustacean accounted for 18.7% and 59.33%, respectively. The weight and tail number of fish at the Maguan point accounted for 81.66% and 53.27%, respectively, the crustaceans accounted for 17.49% and 46.35%, the weight and tail number of the fish at the submural point accounted for 84.7% and 65.5%, the crustaceans accounted for 14.4% and 33.33%, and the rest were cephalopods and jellyfish. The weight of fish, crustaceans, cephalopods and other species in the entire marine area of the county accounted for 80.75%, 18.53%, 0.38% and 0.34% respectively; the tail number accounted for 51.66%, 47.96%, 0.22% and 0.16% respectively.
Intertidal organisms
Species composition and distribution. The intertidal substrate in Shengsi Sea is mainly composed of sand, mud and rock reefs. The degree of coastal openness also significantly affects the composition and distribution of intertidal species. The law of change is that the wave action increases from the hidden coast to the open coast. The nearshore exposed lithofers have the absolute advantage of crustaceans such as the Japanese barnacles and algae; the coastal shielded rock facies have the absolute advantage of the monk oysters among the mollusks; the exposed rock facies of the inshore are dominated by crustaceans such as the Japanese barnacles and algae; the coastal shielded rock facies are dominated by the Japanese barnacles and mollusks among the crustaceans; the exposed rock phases on the far shores are dominated by mollusks such as warty snails, thick-shelled mussels, striped mussels and turtle feet in crustaceans, Japanese barnacles, coelenters and anemones. Since the salinity change of each island gradually increases from the hidden coast to the open coast, the impact of coastal openness on organisms is basically the same as the effect of salinity change.
The biomass and density of the tidal zone of the Tanhu tiger head shielded by the estuary are greater than those in the high tide zone, and the low tide zone is the least. It is estimated that the average biomass of the area is 1585.2 grams per square meter, and the average density is 1477 per square meter, of which the biomass and density of molluscs are 1171.95 grams and 473.3 per square meter, accounting for 73.9% and 47% of the biomass of the region, and the biomass and density of crustaceans are 414 grams and 533.5 per square meter, accounting for 26.1% and 53%, respectively. The remote shore is more than the shielded SiJiao marginal reef, the mid-tidal zone has more organisms than the low-tide zone, the highest high-tide zone, and the highest bio-density low-tide zone, followed by the high-tide zone, the middle tidal zone is the lowest, the average biomass of the zone is 658.9 g per square meter, the average density is 758.4 per square meter, of which the mollusk biomass is 173.3 grams per square meter, accounting for 26.3% of the total biomass, and the density is 645.1 grams per square meter, accounting for 85.1% of the total density. Crustacean biomass was 468.2 g per square meter, or 71.1 per cent, biological density was 113.3 per square meter, or 14.9 per cent, and algal biomass was 17.4 g per square meter, or 2.6 per cent.
Main intertidal organisms in different substrates and island areas. Biological species are closely related to the substrate, and the intertidal biomass and density vary from substrate to island area. The biomass rocky shore is larger than the mud beach, and the beach has the least biomass. Crustaceans and algae on the reef are absolutely dominant. The same species in different island areas, different intertidal zones, biological density is also different, Tanhu tiger head belongs to the estuary coastal phase, the highest number of short coastal snails and rough coastal snails in the highest, of which short coastal snails are the highest in the lower area of the highest zone, 117.6 grams per square meter, 560 per square meter, the middle intertidal zone is the largest proportion of monk hat oysters, white ridge barnacles and toothed snails, of which the monk hat oysters in the middle of the middle tide belt are 6496 grams per square meter, 448, 448, and the white ridge barnacles are 2483.2 grams per square meter in the upper part of the middle tide belt, 3200, Tanhu mudflat belongs to the sand mudflat along the estuary, the climax area is dominated by garden bulbous window crabs, and the middle tide area is dominated by oligo-toothed sand silkworms, intestinal margin moss, colored horn-kissed sand silkworms, pipe margin moss, Chinese hairy mud crabs, arc-edge tide crabs, mud snails, Japanese big-eyed crabs, etc., of which oligo-toothed sand silkworms are distributed in the lower tidal zone, with 256 grams per square meter and 158.
In the gravel beach at the mouth of the Meizui River in the ocean, the climax area is dominated by rough conch and nodular conch, and the middle tide belt is dominated by monk hat oysters, toothed snails, mud barnacles, villous crabs, multi-toothed sand silkworms, soft filament algae, thick membrane algae, angry hard hair algae, intestinal moss and reef membrane, among which monk hat oysters, mud barnacles, and toothed snails have an absolute advantage. The near-shore mud beach of the Ocean Cloud Goose Head Estuary, the high tide area is dominated by Japanese big-eyed crabs and long-legged rectangular crabs, the mid-tide belt is dominated by semi-pleated weave snails and slightly yellow-and-sickle snails, followed by rainbow bright cherry clams, mud snails, bean-shaped fist crabs, and olive pseudo-fist crabs.
Sijiao Qingsha far shore sand mudflat, the middle and low tide areas with sharp knife clams dominate, the middle tide belt also has bean-shaped fist crab, Chinese pentagram crab, semi-pleated weave crab, mud seaweed, sand silkworm and so on. The far shore of sijiao is more shielded, and the high tide zone is dominated by nodule conch and short conch, and the mid-tide zone is dominated by Japanese barnacles, monk hat oysters, thorny oysters, and scaly barnacles, followed by toothed snails, warty snails, deer horn conch, dwarf cap shellfish, small stone cauliflower, stone lettuce, sea lotus, etc.
Flower and Bird Island paste head far shore gravel, low tide zone to filipino hazai, meat ball near the crab dominant, followed by the compound tile small snake snail, tumor lychee snail, rust concave snail, vein red snail, flat-backed snail, sharp teeth, purple sea urchin, horse dung sea urchin and so on.
Intertidal organisms vary in biomass in different seasons, with coastal reef sediments having the largest sediment in spring and the smallest in autumn; nearshore and far-shore reef sediments having the largest sediment in autumn and the smallest in spring; and coastal and nearshore reefs with the highest density of sedimentary organisms in spring and lowest in autumn. In the spring, the biomass and density of flowers and birds with long beaks were the highest, with an average biomass of 4322.8 grams per square meter and an average density of 1326.6, of which polychaetic biomass and density were 10.8 g and 77.8, mollusk biomass and density were 623.8 g and 386, crustacean biomass and density were 3532.4 g and 862.7, and algal biomass was 155.8 g. Weight accounted for 0.25%, 14.43%, 81.72%, and 3.6%, respectively. The different substrate biomass of each island area were, in order, the Tanhuhu Tiger Head Rock Facies, the Shengshan Huangjiaozui Lithography, the SijiaoBianJiaoyan Rock Facies, the Huanglong Dongzuitou Rock Facies, the Qingsha Huangsha Ao Rock Mudflats, the Tanhu Da'ao Tu Sand Mudflats, the Dayangyun Goosehead Mudflats, and the Sijiao Stone Pillar Sand Mudflats.
Intertidal major economic species
Clams. It belongs to the mollusk family Bamboo clams. In the intertidal zone, there are mainly long bamboo clams, sharp knife clams, and clams. Among the intertidal organisms of the distant sand mudflats, the sharp knife clams of the green sand beach Huangsha Ao account for a large proportion, and in the lower and lower tidal zones of the middle tidal zone and the lower and lower layers of the area, the biomass is vertically distributed at 16 and 206.4 g per square meter, 20, 299.8 g and 8 at 117.4 g, respectively.
barnacle. Commonly known as the tentacles, it is a crustacean. On the shore reef, there are mainly Japanese barnacles and scaly barnacles. Japanese barnacles are mainly grown in the lower and middle tide areas of the high tide, distributed in the upper boundary of the scaly barnacles, which is a dominant species. On wavy open or semi-open coasts, black "barnacles" attached are often seen. The breeding period is generally from July to August, and the Japanese Kasa barnacles in the lower area of the high tide zone are 16 and 4.8 grams per square meter; the upper area of the middle tide belt is 324 and 892.8 grams per square meter, the middle area is 320 pieces per square meter, 1295.2 grams, and the lower area is 304 pieces per square meter and 1707.2 grams. Scaly barnacles are distributed in the lower middle tide zone, with 48 pieces per square meter and 311.2 grams.
oysters. Commonly known as oyster yellow, it feeds on diatoms and organic detritus. The monk's hat oyster has a wide range and strong adaptability, and is a broad salinity and broad temperature shellfish. In the inner bay with small wave impact and smooth flow, its growth is most suitable. It is mainly distributed on shore reefs in the wet zone of the middle tide zone. The middle tidal zone of Meishanzui on Dayang Island is 32 and 58.9 grams per square meter; the central area is 16 and 143.4 grams; and the lower area is 64 and 46 grams. The lower zone of the high tide zone of the si reef edge is 16, 18.8 g; the middle tidal zone is 116 and 222.8 g; and the central zone is 144 and 84 g. There are also more oysters in the mid-tide zone.
abalone. In November 1985, 27 heads of wrinkled pan abalone native to the north were introduced from Putuo, and after 6 months of trial breeding, the survival rate reached 96.3%, and the average individual growth was 1 cm. Pro-abalone has the characteristics of still growing in winter and short cycle. In May 1986, the first artificial seedlings of wrinkled pan abalone were successfully carried out in goji berries. In September, a total of 340 heads of abalone were produced in a 1 m³ bait pond and cultured around the Reef of Risci. From 1986 to 1990, a total of 201 cubic meters of nursery water bodies were invested, and more than 800,000 young abalones were bred, of which 630,000 young abalones were bred in 120 cubic meters of water in 1990, 5250 seedlings per cubic meter of water bodies, and 600,000 heads were put into aquaculture.
scallops. In November 1985, 2,600 bay scallops were imported from Putuo, and in May 1986, under the guidance of the Provincial Ocean bureau, seedlings began to be bred, and after 29 days of cultivation, 550,000 baby shells were selected from 2 cubic meters of water, and 110,000 seedlings were obtained in August. As of 1989, a total of 100 cubic meters of water bodies had been invested, 2.1955 million young shells had been cultivated, 1964 cages were cultivated in the county, and 0.67 hectares were cultivated, and the remaining 1.1 million were supplied to Putuo and Sanmen Counties. In October 1990, 110,000 knotted scallops were imported from the north and test-raised in Shengshanhai District.
grouper. It belongs to the fin family, mainly gem spotted fish, six-banded grouper, blue grouper, red-spotted spotted fish, longitudinal banded spotted fish, cloud-striped spotted fish. The grouper subfamily, commonly known as the sea chicken fish, is a warm-water demersal fish that prefers to inhabit the reef area with clear water color, and the main catch season is from July to September every year. In the 1970s and before it was not fully utilized, in the 1980s, grouper exports were developed, generally with an annual output of more than 20 tons, and in the late 1980s there were still 10 tons to 25 tons, but the individual catches were obviously smaller. In 1989, the reef pond culture was carried out in Luhua Township, and in 1990, the use of medium-sized cages to increase the culture was successful. From April to August, 1440 groupers and 2422.77 kg were put in 26 cages in three places, such as goji berries and luhua, which were temporarily raised for 116 days, weighing 2590 kg, an increase of 20.3% over the pre-temporary breeding, the B-grade fish raised by 71.79%, and the C-class fish raised by 93.64%, with a profit of 50,000 yuan. In 1990, the output of fishing and aquaculture was 37 tons.
Source: Shengsi County People's Government