Pacific Pearl Oyster Shell – Nature’s Best Calcium

Lind Marine has been mining historic oyster shell deposits in South San Francisco Bay for use as ag lime soil amendments since 1924. The calcium carbonate in the oyster shells helps to neutralize acidic soils. After the oyster shell deposits are harvested, the shells are barged to and processed in our Petaluma and Collinsville plants and then shipped to agricultural customers throughout the Western United States, Canada and the Pacific Rim. Our customers include: orchards, vineyards, tree farms, golf courses and berry farms, among others.

Flour / Ag Lime is finely ground oyster shell that has a smooth velvety feel. Its texture and high quality make it highly desirable in numerous commercial and agricultural applications, and well as a feed additive. Available in 50 lb. bags, bulk bags, and in bulk.

5 Reasons Oyster Shell Lime gives superior results:

Oyster shell is produced by a living organism Calcium formed in this non-crystalline state is more easily dissolved and utilized by the soil and plants

  1. Particle shape and texture
    Oyster shell calcium is formed in thin, delicate layers that readily break down into flake-shaped particles
    The porosity and irregular shape of the shells exposes an immense surface area that reacts with acids in the soil
    The oyster shell particles anchor themselves in the soil and resist leaching
  2. High calcium carbonate analysis
    Guaranteed minimum calcium carbonate 96%
    Guaranteed minimum calcium 36% (typically 38% – 39%)
    Moisture content less than 1% (average .2%)
  3. Sized specifically to cause a timed release of calcium
    1/3 fine particles to produce a rapid pH change (-325 – 200 mesh)
    1/3 medium particles to replace calcium as it is leached out or taken up by the plant or turf during the growing season (100 to 60 mesh)
    1/3 coarse particles to provide a long-term source of calcium (40 to 20 mesh)
    Approximately 55 lbs. per Cu. Ft.
  4. Oyster shell supplies additional plant growth requirements
    Ten other important nutrients and micronutrients are found in oyster shells


  • AgLime
  • Soil Conditioner
  • Livestock pen and stall freshener


Lay Shell Blend features a variation of shell sizes from 1/8 inch to 3/8 inch, blended together for a uniform shell mix. Promotes optimum dietary calcium utilization for enhancing eggshell quality in layers. Available in 50 lb. Bags.


Grow Shell Blend is designed primarily as a start/grow feed ingredient for young chicks through age 20 weeks. Not recommended for laying hens because the size does not maintain adequate retention time in the gizzard. Available in 50 lb. Bags.



We are currently supplying over 30 million poultry layers in California, Oregon, Washington, British Columbia, and Alberta.

  • Pacific Pearl Brand Oyster Shell has been shown to contribute to an overall eggshell quality program and can pay for itself by reducing under grade eggs and egg loss. Pacific Pearl Oyster Shell is a highly digestible type of calcium, and it is sized specifically for solubility, availability, and retention time in the gizzard.
  • Pacific Pearl Oyster Shell extends the length of the lay cycle, which puts more money in the egg producer’s pocket!
  • For optimal production of quality eggs, Lind Marine recommends adding 3-5% oyster shell to poultry feed from the first day of production, rather than starting with 50% limestone replacement midway through the lay cycle.