Construction method for ecological riprap breakwater, induced cement-based coating and preparation method thereof

A construction method for an ecological riprap breakwater, comprising the following steps:

• (1) surveying a sea area of a breakwater construction position, comprises:
• surveying dominant species of oysters in the sea area and whether the oysters are attached, surveying air temperature, seawater temperature, dissolved oxygen, plankton, total dissolved inorganic nitrogen, active phosphate, active silicate, Ca2+, Zn2+, K+ for the sea area at a plurality of seasons, and
• surveying typhoon times, strength over a plurality of years;
• (2) preparing a concrete settlement substrate, comprises:
• preparing the concrete settlement substrate with a rough surface for the oysters, wherein the concrete settlement substrate for the oysters is one of:
• a slab-shaped settlement substrate, a wave-shaped settlement substrate, and a cylindrical settlement substrate;
• (3) collecting and cultivating oyster larvae, comprises:
• placing the concrete settlement substrate in a predefined larva collection area of the sea area, wherein the oyster larvae are in metamorphosis period,
• stopping collecting the oyster larvae when the oyster larvae reaches a larval density of 15-25 larvae/100 cm2, and
• moving the concrete settlement substrate to a floating cultivation sea area;
• (4) treating rock surface of rocks, comprises:
• cleaning the rock surface to remove debris and chemical contaminants,
• spraying or painting a cement-based coating onto the rock surface to induce settlement of marine sessile organisms;
• (5) placing the rocks, comprises:
• in a concentration period of settlement and metamorphosis of the oyster larvae in the sea area, placing a first plurality of the rocks, each having a volume of mere greater than 1 m3, and covering each rock of the first plurality of the rocks with a first rope;
• covering a second plurality of the rocks with a first plurality of ropes to form a plurality of rock piles, each rock of the second plurality of the rocks having a volume less than 1 m3, wherein internal voidage of each rock pile of the plurality of rock piles is 40%˜60%;
• and
• connecting the rocks using a second plurality of ropes;
• (6) placing the concrete settlement substrate, comprises:
• conveying the concrete settlement substrate in which gonad of the oysters develops into mature stage to the sea area,
• placing the concrete settlement substrate on a rock of the first plurality of rocks or a rock pile of the plurality of rock piles,
• fixing the concrete settlement substrate to the rock of the first plurality of rocks or the rock pile of the plurality of rock piles via a second rope, and,
• feeding algae or replenishing nutritive salts if based on planktonic condition of the sea area;
• and
• (7) monitoring and managing settlement state of the oyster larval, comprises:
• monitoring settlement condition of the oyster larvae;
• when larval settlement density of the oyster larval reaches 30 to 40 larvae/100 cm2, moving away the concrete settlement substrate.