Saltwater aquaponics (sometimes called marine aquaponics) is a newer outgrowth of freshwater aquaponics. It presents some fascinating opportunities to produce healthy, affordable and extremely fresh saltwater fish options even to landlocked areas, without the expense and environmental consequences of rapid transportation using fossil fuels. One of the interesting challenges associated with marine systems is that most plants consumed (in the US, at least) do not thrive in saltwater. Even seaweed is commonly used only as a wrapping for sushi in the US. Europeans, in contrast, enjoy both purlsane, which has a taste similar to spinach or watercress, and saltwort, whose taste varies significantly between varieties, is widely enjoyed in Europe, Japan, and elsewhere. Surprisingly, some vegetables that we consider “freshwater” actually tolerate a fairly high amount of salt and can be successfully raised in a marine system, with a little extra care. Tomatoes are an excellent example, but cruciferous vegetables like broccoli, cauliflower and cabbage also work well. Bell peppers will also thrive in saline systems.
The next challenge is choosing a high-demand saltwater fish that is appropriate for aquaponics systems. Tilapia and koi can thrive in tanks of several hundred gallons, but swordfish are unlikely to adapt to such limited space. Red drum is a popular option and boasts a firm, meaty texture. Ocean sunfish are native to tropical waters and offer an intriguing opportunity. Critically endangered in the wild, and heading to extinction, it’s illegal to eat them, but their flesh has a one-of-a-kind taste and is considered a delicacy in some parts of Asia. Marine aquaponics offer many of the same advantages as freshwater aquaponics, with the added benefit of growing fish species that haven’t been exposed to plastics, mercury and other dangers like oil spills that are distressingly common in seawater. Marine aquaponics are a very new enterprise that still merits plenty of study and investigation. Shrimp farms are rapidly expanding even in the midwest, Perhaps it will someday be possible to combine fresh, never-frozen shrimp with luscious vine-ripened tomatoes for a delectable dish in rural Nebraska.
