A method for rapid construction of oyster reefs and efficient carbon sequestration based on a predation-defense strategy

Abstract

The present invention discloses a method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy in the field of marine environment restoration technology. The method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy includes the following steps: S1: Investigating the composition structure of macrobenthos and nekton in the sea area for oyster reef construction; S2: Selecting indigenous oyster individuals over 2 years old in the target sea area as artificial breeding parent bodies; S3: Conducting temperature increase and ripening promotion on the selected oyster parent bodies, waiting for production at a constant temperature of 21-25 °C, changing the water by one full volume per day during the ripening promotion period, and the daily bait feeding amount is 20-30*10 4 cells of unicellular algae / ml. Through the application of the predation-defense strategy, the present invention induces the survival instinct of oysters to play, increases the material and energy expenditure of oysters for oyster shell growth, thereby enhancing the carbon sequestration ability of oysters per unit time and realizing the carbon sequestration function of oyster reefs with higher efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of marine environmental restoration, and specifically provides a method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy. Background Art

[0002] An oyster reef is a biological reef system formed by a large number of oysters adhering and growing on the surface of a hard substrate, and is one of the typical habitats in China's marine ranch. An oyster reef is a biological reef structure formed by oysters continuously adhering to oyster shells, aggregating and piling up, and is also known as the "temperate coral reef", playing an important regulatory role in the carbon cycle of the marine ranch ecosystem. Oysters fix carbon in two ways, and the main way is to use calcification to convert HCO3 in water - into CaCO3 shells, thereby fixing a large amount of carbon. The oyster reefs in the marine ranch play ecological functions such as purifying water quality, providing habitats, protecting biodiversity, accelerating the carbon sedimentation rate, and fixing inorganic carbon. However, more than 85% of the oyster reefs globally have degraded and disappeared. The existing construction of oyster reefs relies on the natural proliferation of oysters. Limited by environmental conditions, the reproduction of oysters on the reef is relatively slow, restricting the full play of the ecological role of oyster reefs. Therefore, studying the technology for rapid construction and efficient carbon sequestration of oyster reefs is of great significance for giving full play to the ecological restoration and carbon sequestration functions of marine ranches. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy, so as to solve the problem in the above background art that the existing construction of oyster reefs relies on the natural reproduction of oysters, thus being restricted by environmental conditions, resulting in relatively slow proliferation of oysters on the reef and unable to quickly play the ecological role of oyster reefs.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy, which includes the following steps:

[0005] S1: Investigate the composition structure of macrobenthos and nekton in the sea area for oyster reef construction;

[0006] S2: Select indigenous oyster individuals over 2 years old in the target sea area as artificial breeding parent oysters;

[0007] S3: Heat up and promote the ripening of the selected oyster parent oysters, keep them at a constant temperature of 21-25°C for waiting for spawning, change the water by one full volume per day during the ripening period, and the daily feeding amount is 20-30*10 4 cells of unicellular algae / ml;

[0008] S4: According to the investigation results of S1, determine the breeding period of oyster predators in the target sea area, and set the spawning time of oysters accordingly;

[0009] S5: During the planned spawning time, induce the release of oyster parents by means of air-drying, temperature increase, flowing water and artificial dissection;

[0010] S6: Control the hatching density of oyster fertilized eggs at 30 - 50*10 4 ind / ml, and the hatching water temperature is 23 - 24 °C;

[0011] S7: Control the cultivation density of the D-shaped larvae obtained by hatching at 6 - 8 ind / ml, the cultivation water temperature is 23 - 24 °C, and the daily feeding amount is 1 - 8*10 4 cells of unicellular algae / ml. The bait is mainly composed of chrysophyta, navicula and platymonas. Change the water twice a day, each time 1 / 3 - 1 / 2 of the total volume;

[0012] S8: When 2 / 3 of the larvae show eye spots under microscopic examination, collect the eyed larvae with a 100-mesh silk screen, put them into a live fish bag, 10*10 6 ind / bag, and transport them to the target sea area;

[0013] S9: Spread the larvae in the live fish bag on the water surface and underwater directly above the oyster reef body;

[0014] S10: Set floating balls directly above the oyster reef body. Connect the floating balls and the reef body with a cable. Hang a hanging cage under the floating ball, 5 layers / cage. Place 1 oyster predator selected through the investigation of S1 on each layer. Control the hanging cage to be 0.5 - 1 m above the oyster reef body;

[0015] S11: Feed 1 adult oyster to the caged predators every day, and clean and replace the dead predators in time;

[0016] S12: Remove the hanging cage after 8 weeks, regularly measure the biological indexes such as the shell length and shell weight of the living oysters on the oyster reef in the target sea area, and track and monitor the carbon sequestration capacity of the oyster reef.

[0017] Preferably, the temperature increase range in step S3 is 1 °C / d.

[0018] Preferably, the air-drying time in step S5 is 3 - 5 h, the temperature increase is 2 - 3 °C, and the flowing water time is 0.5 - 2 h.

[0019] Preferably, after artificial dissection in step S5, crush the mantle of the oyster parent, filter it with a 300-mesh sieve, and sprinkle the filtrate near the cultured oyster parents for induction and stimulation.

[0020] Preferably, the arrival time at the target sea area in step S8 is controlled during the slack tide period.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: This method for rapid construction of oyster reefs and efficient carbon sequestration based on the predation-defense strategy induces the survival instinct of oysters to play through the application of the predation-defense strategy, increases the material and energy expenditure of oysters for oyster shell growth, thereby enhancing the carbon sequestration ability of oysters per unit time, and realizing the carbon sequestration function of oyster reefs with higher efficiency. Detailed implementation mode

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the method for rapid construction of oyster reefs and efficient carbon sequestration based on the predation-defense strategy in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] The present invention provides a method for rapid construction of oyster reefs and efficient carbon sequestration based on the predation-defense strategy. By applying the predation-defense strategy, the survival instinct of oysters is induced to play, the material and energy expenditure of oysters for oyster shell growth is increased, thereby enhancing the carbon sequestration ability of oysters per unit time, and realizing the carbon sequestration function of oyster reefs with higher efficiency. The method for rapid construction of oyster reefs and efficient carbon sequestration based on the predation-defense strategy includes the following steps:

[0024] S1: Investigate the composition structure of macrobenthos and nekton in the sea area for oyster reef construction;

[0025] S2: Select indigenous oyster individuals over 2 years old in the target sea area as artificial breeding parent oysters;

[0026] S3: Carry out temperature increase and ripening promotion on the selected oyster parent oysters, with a temperature increase range of about 1°C / d, and keep them at a constant temperature of 21 - 25°C for waiting for spawning. During the ripening promotion period, change the water by one full volume per day, and the daily feeding amount is 20 - 30 * 10 4 cells of unicellular algae / ml;

[0027] S4: According to the investigation results of S1, determine the breeding period of oyster predators in the target sea area, and set the spawning time of oysters accordingly;

[0028] S5: During the planned spawning time, induce the oyster parent oysters to discharge by means of air drying, temperature increase, flowing water, and artificial dissection, etc.;

[0029] Further: Air dry for 3 - 5 h, increase the temperature by 2 - 3°C, and flow water for 0.5 - 2 h;

[0030] Preferably: After dissection, crush the mantle of the oyster parent oyster, filter it with 300 meshes, and sprinkle the filtrate near the cultured oyster parent oysters for induction and stimulation;

[0031] S6: Control the hatching density of oyster fertilized eggs at 30 - 50*10 4 ind / ml, and the hatching water temperature at 23 - 24°C;

[0032] S7: Control the cultivation density of D-shaped larvae obtained by hatching at 6 - 8 ind / ml, the cultivation water temperature at 23 - 24°C, and the daily feeding amount at 1 - 8*10 4 cells of unicellular algae / ml. The bait is mainly composed of Isochrysis galbana, Navicula spp., and Platymonas subcordiformis. Change the water twice a day, each time 1 / 3 - 1 / 2 of the total volume;

[0033] S8: When 2 / 3 of the larvae show eye spots under microscopic examination, collect the eyed larvae with a 100-mesh silk screen, put them into a live fish bag, 10*10 6 ind / bag, and transport them to the target sea area;

[0034] Preferably: Control the arrival time at the target sea area during the slack tide period of the tide;

[0035] S9: Broadcast the larvae in the live fish bag on the water surface and underwater directly above the oyster reef body;

[0036] S10: Set floating balls directly above the oyster reef body, connect the floating balls and the reef body with cables, hang cages under the floating balls, 5 layers / cage, place 1 oyster predator selected through S1 investigation on each layer, and control the cage to be 0.5 - 1 m above the oyster reef body;

[0037] S11: Feed 1 adult oyster to the caged predators every day, and clean and replace the dead predators in time;

[0038] S12: Remove the cages after 8 weeks, regularly measure the biological indexes such as shell length and shell weight of live oysters on the oyster reef in the target sea area, and track and monitor the carbon sequestration capacity of the oyster reef.

[0039] Example

[0040] Taking a certain marine ranch in Sishili Bay as the implementation site, 6400 cubic meters of cubic through-type cement precast components with a side length of 2 m were put in for the construction of oyster reefs. In the year of putting in, through on-site inspection by divers, there were very few attached organisms on the reef body and no oyster fixation was seen. The native oyster in this sea area is Crassostrea gigas, and its predators are Charybdis japonica, Rapana venosa, Asterias rollestoni, etc. Its breeding peak period is from July to October.

[0041] Collect 2-year-old Crassostrea gigas from the subtidal zone near the target sea area in March. After monomer separation and individual washing, 160 healthy and complete Crassostrea gigas parent bodies are obtained;

[0042] The obtained parent bodies are cultured in a floating net cage of 80*60*40 cm in 10 m 3In the indoor nursery pond. After 2 days of temporary rearing and adaptation, temperature increase culture was carried out at a rate of 1°C / d. It stayed at 16°C for 4 days and was kept at a constant temperature of 23°C for spawning. During the ripening period, the water was changed once a day with a full volume, and the daily feeding amount was 20 - 30×10 4 cells of unicellular algae / ml. Residual bait, feces were cleared every day and dead shells were removed;

[0043] On April 19th, after being air-dried for 4 hours, it was placed in water at 25°C, and induced spawning was carried out by dissecting and crushing the mantle membrane, obtaining 10×10 8 eggs;

[0044] The fertilized eggs were placed in a 3×10m 3 nursery pond and hatched at 23°C for 20 hours, with a hatching rate of 97%;

[0045] The hatched D-shaped larvae were placed in 16 10m 3 nursery ponds and cultured at 23°C. The daily feeding amount was 1 - 8×10 4 cells of unicellular algae / ml. The bait mainly consisted of chrysophyceae, navicula, and platymonas. The water was changed twice a day, each time with 1 / 3 - 1 / 2 of the full volume;

[0046] On May 9th, microscopic examination showed that 2 / 3 of the larvae had eye spots. After counting, 9×10 8 inds were collected, packed in 90 live fish bags, oxygenated and transported to the target sea area;

[0047] During the period of tidal slack, eye-spotted larvae were scattered simultaneously in the oyster reef area by boats and divers, and 1 / 3 of the reef body was reserved as the control area;

[0048] On May 9th, floating balls were placed. Since the average high tide level in the target sea area is 8.2m and the oyster reef body is 2m high, the length of the connecting cable between the floating ball and the reef body was set to 7m. A 5-layer hanging cage was placed below the floating ball, and the hanging cage was suspended about 1m above the reef body

[0049] On May 10th, Charybdis japonica was placed in the hanging cage at a density of 1 per layer. At the same time, 1 adult oyster was fed per layer. After that, it was fed once a day, 1 adult oyster per layer each time. Dead Charybdis japonica were replaced in time, and the hanging cage was recovered after 8 weeks;

[0050] Starting from June 10th, the shell length and shell weight of oysters on the predator-induced reef body and the control reef body were measured at a frequency of once a month, and the visual survival rate was recorded;

[0051] After measurement on August 10th, it was statistically obtained that the survival rate and average growth rate of oysters in the induced area were 200% and 137% of those in the control area respectively.

[0052] Although the present invention has been described above with reference to embodiments, various modifications can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention can be combined with each other in any way, and the exhaustive description of these combinations is not given in this specification only for the consideration of saving space and resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for rapid construction of oyster reefs and efficient carbon sequestration based on a predation-defense strategy, characterized in that: The method for rapid construction and efficient carbon sequestration of oyster reefs based on the predation-defense strategy comprises the following steps: S1: Investigate the composition structure of macrobenthos and nekton in the sea area for oyster reef construction; S2: Select indigenous oyster individuals over 2 years old in the target sea area as artificial breeding parent oysters; S3: Warm up and promote the maturation of the selected oyster broodstock, keep them at a constant temperature of 21-25 °C and wait for spawning. During the maturation promotion period, change the water by one full volume daily, and the daily feeding amount is 20-30*10 4 cells of unicellular algae / ml; S4: Determine the breeding period of oyster predators in the target sea area according to the investigation results of S1, and set the spawning time of oysters based on this; S5: During the planned spawning time, induce the parent oysters to discharge by means of air drying, temperature raising, flowing water and artificial dissection; S6: The hatching density of oyster fertilized eggs is controlled at 30 - 50*10 4 ind / ml, and the hatching water temperature is 23 - 24°C; S7: The cultivation density of the hatched D-shaped larvae is controlled at 6-8 ind / ml, the cultivation water temperature is 23-24 °C, and the daily bait feeding amount is 1-8*10 4 cells of unicellular algae / ml. The bait is mainly composed of chrysophytes, small diatoms, and Platymonas subcordiformis. The water is changed twice a day, each time 1 / 3-1 / 2 of the total volume; S8: When 2 / 3 of the larvae show eye spots under microscopy, collect the larvae with eye spots using a 100-mesh silk screen, put them into a live fish bag, at a density of 10*10 6 ind / bag, and transport them to the target sea area; S9: Spread the larvae in the live fish bag on the water surface and underwater directly above the oyster reef body; S10: Set floating balls directly above the oyster reef body, connect the floating balls and the reef body with cables, hang cages under the floating balls, with 5 layers / cage, place 1 oyster predator selected through the investigation of S1 on each layer, and control the cage to be 0.5 - 1 m above the oyster reef body; S11: Feed 1 adult oyster to the caged predators daily, and promptly clean and replace the dead predators; S12: Remove the cages after 8 weeks, regularly measure the biological indexes such as shell length and shell weight of the live oysters on the oyster reef in the target sea area, and track and monitor the carbon sequestration capacity of the oyster reef.

2. The method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy according to claim 1, characterized in that: The temperature increase range in step S3 is 1 °C / d.

3. A method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy according to claim 2, characterized in that: The air drying time in step S5 is 3 - 5 h, the temperature increase is 2 - 3 °C, and the flowing water time is 0.5 - 2 h.

4. A method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy according to claim 3, characterized in that: In step S5, after artificial dissection, crush the mantle of the parent oysters, filter with a 300-mesh silk screen, and sprinkle the filtrate near the stocked parent oysters for induction and stimulation.

5. A method for rapid construction and efficient carbon sequestration of oyster reefs based on a predation-defense strategy according to claim 4, characterized in that: The arrival time at the target sea area in step S8 is controlled during the slack tide period.