In order to explore the production technology of hackberry seedlings and the propagation of ramie resources, from 1998 to 2001, we conducted a semi-artificial seedling multiplication technology test in the mudflat of Wangzi Island, Binzhou, Shandong Province, and achieved good economic, ecological, and social benefits. , The test results are summarized as follows:
First, materials and methods
1. Conditions in the pilot area The pilot area was selected between the lower part of the tidal flat of the Tidal Flat in Wangzhou Island of Binzhou City and the mid-tide area. The beach surface is flat and stable. There are a large number of spawning groups nearby. The feed biomass is abundant and the water quality is not polluted. The trend is smooth and the sediment concentration is above 70%. Natural seedlings have a high seedling rate, which is convenient for nursing management and harvesting operations.
2. Methods of Seedling Prediction (1) Anatomical methods: Each year from mid-June, every two days to three days, an anatomical observation is performed on the gonadal development of parent crabs, and 10 to 20 broods are dissected each time. The pro-being is mature, so as to make a forecast of the peak time of spawning.
(2) Plankton net trawling survey method: When surveying plankton trawl nets, a number of sections are set up in the survey sea area and the coastline in a vertical direction. The section distance is 500m. Each section is set up with 2 stations, each station is separated by 1000m. The survey was conducted at a high tide. The trawl nets were made using ordinary plankton nets every 5 days. Trapped larvae obtained by trawling were counted immediately after landing.
3. Test Method (1) Sanding: The sand diameter is 0.2mm to 0.5mm, evenly spread on the beach after ebb tide, and the average amount of sand is 1kg per square meter.
(2) shoal beach: With a tooth length of 15cm to 20cm along the coast in parallel with the direction of the beach rake loose, flat.
(3) Insert grass rake: Use a straw 30 cm in length and 10 cm in diameter to be inserted vertically into the beach so that the beach surface is exposed to 10 cm. The average number of rakes per m2 is 1.
(4) Combination of beach and blockage: The method of floodplain is the same as above. After the floodplain, a block is set every 100m to 150m along the direction parallel to the coastline on the surface of the floodplain. The grid height is 80cm, and the mesh size is about 1cm. The sheet is fixed with nets and stakes.
Second, the test situation and results
1. In 1998, comparative tests were conducted on semi-artificial seedlings harvested from Sasha, Reef, and grasslands. The area of ​​each test was 100m50m, and a blank area with the same area was set up. The test area was set at 30 points. From October 14th to 25th of the same year, the seedling volume of semi-artificial seedlings of the clams in the experimental area was investigated and counted. The results showed that the average amount of seedlings in the shading area was 59.45/m2 to 82.8/m2; In the beach area, the average seedlings of C. sibiricus seedlings were 50.96 seeds/m2 to 76.45 seeds/m2, and the seedlings of C. intermedias were 38.22 seeds/m2 to 48.7 seeds/m2. The average volume of seedlings of the clams in the blank area is 25.48/m2 to 36/m2.
2. In 1999, a large-scale semi-artificial seedling was collected from the shoal and grazing land in the large area. The experimental site was 120m long from east to west, 300m wide from north to south and about 540 mus in area. The shoal used a 50HP fishing boat to carry the gingiva along the parallel to the shoreline. Fuping. At the end of September of the same year, the seedling volume of semi-artificial seedlings collected from large-scale floodplain was measured, with a maximum of 163/m2, a minimum of 15/m2, and an average seedling volume of 57.23/m2. The average seedling volume of the C. wenshanensis seedlings was 25.4/m2, and the seedling volume of the C. wenshanensis seedlings in the Cangtan District was 2.25 times the seedling volume of the C. wenshanensis seedlings in the blank area.
3. In 2000, the second time a large area of ​​barnyardgrass semi-artificial seedlings was harvested. The method and location were the same as before. The area of ​​the experimental area was 1000m400m, which was approximately 600 acres. At the beginning of October, the number of seedlings of semi-artificial seedlings collected from the large-scale floodplain was investigated and counted. The results showed that the minimum seedlings in the experimental area were 25 seedlings/m2 and the highest seedlings were 175/m2, with an average of 75/m2. , 2.83 times for the blank area on both sides.
4. In 2001, the semi-artificial seedlings of the clams were combined with the barren beach. In the first half of the clams, the clams were found in the clams of the mid-tidal area (fisherman fisheries). On the beach near the nets), the distribution density of the clams is relatively high. Inspired by this, this seedling-environmental environment was simulated and a simulation experiment was conducted. A large-scale blockage combined with floodplains was used to test the propagation of the semi-artificial seedlings. The site and the floodplain method were the same. The different methods were after the floodplain. On the beach surface, four blocks are designed along the parallel line of the coastline. The grid height is 80cm, and the mesh size is 1cm. The mesh is fixed with nets and stakes, and the area of ​​the seedlings is about 1000 mu. The results of the survey conducted in October and early that year showed that the average seedling volume of the semi-artificial seedlings combined with block and barren lands was 117.5/m2, and the seedlings of the clams were up to 282/m2, with the least amount of seedlings attached. 44/m2, compared with the blank areas on both sides, the amount of seedlings in the experimental area was 4.65 times that of the blank area.
Third, discussion and summary
1. Wenyu's full artificial nursery technology has made new breakthroughs in China, but factory cultivation has not yet produced production capacity. By relying on industrialized seedlings to provide a large number of commercial clam seedlings, there are still difficulties. It is feasible, easy to operate, and cost-effective to combine clams and buntings.
2. The time and site selection for the spawning of the clams are particularly important when it comes to semi-artificial harvesting of clams. In order to accurately understand and grasp the time of the clams' breeding season, according to the survey, from late June to late July, the clams are produced in Bohai Bay. Egg period. Observing the development of pro-occlusion gonads of the clams every 2 days to 3 days, and then using a plankton net to conduct a sea trawl survey, using phytoplankton nets to trawl once every 3 days to 5 days. Once a large number of zooplankton larvae are found on the sea, Blocked and semi-artificial seedlings should be immediately intercepted. Since the clams were distributed between the lower part of the high tide area and the mid-tide area, and the geology was relatively flat and the sand content was high on the beach, it was appropriate to carry out clamming and semi-manual seedlings.
3. The coastal area of ​​Wangzi Island in Binzhou, Bohai Bay is very large. Its sediment quality and water quality are suitable for the growth and breeding of clams. The semi-artificial seedlings in the shading area have the best effect. However, the traffic in this area is inconvenient, and there is a lack of sand resources nearby. The cost is high and the actual operation is difficult. The effect of seedling volume of semi-artificial planting seedlings in Mintan District is slightly worse than that of the shading area, but its cost is lower and it is more convenient to operate. It is an ideal method for semi-artificial harvesting of clams. Through the promotion of the large-scale swale and barrage combined with the method of semi-artificial harvesting of clams, Clam resources have been proliferating. Research on the propagation technology of clams and semi-artificial seedlings has been carried out in the mudflats of Wangzi Island in Binzhou, Bohai Bay, which has improved the economic benefits of tidal flats. Ecological and social benefits.
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