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- AN INTRODUCTION TO THE
- TOTAL OPAE-ULA ENVIRONMENT
Opae-ula's common name is the Hawaiian Red Anchialine Pond Shrimp. It's endemic (only found in Hawaii), the most common color (especially on the Big Island) is red, it's most often seen in anchialine ponds (or pools), and technically it's a shrimp (even if it looks like a miniature lobster). But the name only describes the "epogeal" environment where they can sometimes be found. It doesn't even hint about their "hypogeal" environment, and this is the more important part to understand!
Increasingly, I think of opae-ula as inhabitants of a dark subterranean world who visit the bright anchialine ponds primarily to feed, and only when they believe the ponds are free of predators.
In Hawaiian legends, they are known to appear in such huge numbers that the bottom of the ponds and even the water itself turns red! Yet at other times not a single opae-ula can be seen in the ponds! There are observations that snorkelers with powerful lights looking deep inside the cracks between layers of lava can spot opae-ula far back where no fish can reach them. Other observations tell of opae-ula coming out at night when the fish are sleeping. There is a need to better understand the hypogeal environment!
1. ANCHIALINE POOLS are near ocean and land-locked bodies of water that does not have any physical connection with the ocean, but may exhibit tidal variations. They are formed by volcanic activity where a low spot is created and fills with water. Salinity varies widely with some being as salty as the ocean, but most being brackish water due to fresh water flowing underground.
2. THE GREATEST OPAE-ULA POPULATION is in the dark subterranean water table around and under the anchialine ponds. Lava is extremely porous and in some places 10% to 25% of the lava is honeycombed with cracks, lava tubes, expansion layers between flows, etc. This provides an extensive "subway system" for opae-ula and if a hole is excavated one mile from the nearest anchialine pond and deep enough to penetrate the water table, there's a fair chance that the hole will fill with water and opae-ula!
3. BRACKISH WATER WELLS drilled 35' to 60' deep in areas where there are no visible opae-ula ponds have pumped up opae-ula! This has happened at Hualalai on the Big Island and at Kahuku and in the middle of Honolulu on the island of Oahu!
4. RAIN TRAVELS TO THE SEA following the path of the lava flows that make up Hawaii. Where the fresh water emerges from the ground near the ocean as springs, ancient Hawaiian villages were created. Many of these springs have a salinity of less than 10 parts per thousand, and although it's possible to taste some saltiness, the water is very drinkable. In some places the salinity is less that 5 parts per thousand and is superior to some municipal water systems! Opae-ula thrive between pure fresh water to water saltier than ocean water!
5. FRESH WATER FLOWS INTO THE OCEAN! Native Hawaiians know of places where they can dive with a sealed gourd to collect fresh water from springs in the ocean. Fishermen tell of akule and opelu with stomachs full of opae-ula that were flushed out into the ocean after major rain storms!
Although we are not used to thinking that we live on porous earth filled with underground tubes and caverns, they do exist and are the primary homes of opae-ula. Opae-ula have evolved in this unique environment. While the anchialine ponds are increasingly becoming less hospitable due to the introduction of alien predator fish, it is very unlikely that opae-ula will ever become endangered. Already there are ponds being placed into conservation where collection is prohibited. Captive breeding has begun. One day, opae-ula will become widely available!
*** Continue to OPAE-ULA'S HYPOGEAL HABITAT
