Why Oysters?

Over the years, we have seen a tremendous decline in Brevard County’s ecologically important oyster population for several reasons…

OVERHARVESTING: Oysters are a delicious meal for both animals and humans alike, but when they are continuously harvested at a rate faster than they can reproduce, the natural population can’t keep up, and their numbers begin to decline.
OVERHARVESTING: Oysters are a delicious meal for both animals and humans alike, but when they are continuously harvested at a rate faster than they can reproduce, the natural population can’t keep up, and their numbers begin to decline.
HABITAT LOSS: Oysters are intertidal species, meaning they live in areas along the shoreline that experience a natural fluctuation of tides. These areas are popular locations for homes, businesses and marinas, so as coastal development increases, the available habitat for an oyster reef diminishes.
COASTAL CONSTRUCTION: Oysters are intertidal species, meaning they live in areas along the shoreline that experience a natural fluctuation of tides. These areas are popular locations for homes, businesses and marinas, so as coastal development increases, the available habitat for an oyster reef diminishes.
REDUCED WATER QUALITY: Oysters are tremendous filter feeders, but they aren’t able to filter out the overwhelming amount of pollution being introduced into the Indian River Lagoon. They can filter out suspended particles at an astonishing rate of approximately two gallons of water per hour, but unfortunately, solid waste and complex chemical compounds such as fertilizers and pesticides inhibit their filter feeding abilities.
REDUCED WATER QUALITY: Oysters are tremendous filter feeders, but they aren’t able to filter out the overwhelming amount of pollution being introduced into the Indian River Lagoon. They can filter out suspended particles at an astonishing rate of approximately two gallons of water per hour, but unfortunately, solid waste and complex chemical compounds such as fertilizers and pesticides inhibit their filter feeding abilities.
DISEASE: Just like we get colds and flus, oysters suffer from two diseases that are specific to them: Dermo and MSX. These particular diseases can spread and cause the oyster population to decline as a result.
DISEASE: Just like we get colds and flus, oysters suffer from two diseases that are specific to them: Dermo and MSX. These particular diseases can spread and cause the oyster population to decline as a result.
DISEASE: Just like we get colds and flus, oysters suffer from two diseases that are specific to them: Dermo and MSX. These particular diseases can spread and cause the oyster population to decline as a result.
OCEAN ACIDIFICATION: Up to 1/3  of the excess carbon dioxide we emit through the burning of fossil fuels is absorbed by the ocean, where it reacts with seawater to increase ocean acidity and reduce the availability of calcium carbonate, which oysters need to build their shells. This affects oysters like an “osteoporosis of the sea” leaving their shells thinner and more brittle and resulting in developmental delays and deformities. 
BOAT WAKES: Large waves produced by a moving vessel on the Indian River Lagoon can dislodge oysters from the reef. Once the oysters are off the reef, they can’t just walk right back on to it and live happily ever after. Dislodged oysters will roll in the waves, ultimately forming piles in the shallow water, where they will dry out and die. The resulting large piles of oyster shells are referred to as dead margins.

But oysters are considered a keystone species in the Indian River Lagoon, meaning they hold a vital role in keeping the ecosystem balanced. If a keystone species is removed, it negatively affects many other species. So, although they are small in size, oysters are very important to the Indian River Lagoon ecosystem for several reasons…

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Food: Oyster reefs are a food source for a wide variety of species in the Indian River Lagoon that feed directly on the oysters as well as on the critters living on and around oyster reefs.

Habitat: Fondly referred to as the “living razor blade,” oyster reefs provide plenty of hiding places for small critters and juvenile fishes. These tight crevices are a perfect nursery for small fish, and oyster reefs also provide a buffet of food, including algae, crustaceans and phytoplankton, in the surrounding habitat.

Erosion Prevention: Since oysters live along the shoreline, oyster reefs can help to prevent erosion. As damaging waves travel toward the coast, they first hit oyster reefs, which dissipate the wave energy, diminishing its effects on the shore. This decreases the amount of sediment being pulled away from the shoreline, therefore decreasing erosion.

Filter Feeding: Oysters use their gills to pull in water from the lagoon filled with suspended particles, such as algae and muck. Oysters use those particles to provide themselves with nutrients and minerals, and after an oyster has consumed all of the viable nutrients in a particular bit of water, it will spit it back out as cleaner and clearer lagoon water. Oysters filter feed around the clock at a rate of nearly 50 gallons of water per day. That’s more than 1,500 times their body volume. With this tremendous filtering ability, established oyster reefs are essential for improved water quality, which will result in a healthier Indian River Lagoon.

For more information on oysters, check out the Loxahatchee River District’s additional educational materials.

Empowering the Community to act for our Lagoon