NOTE:  Since the Micro-Lobster website began in 2003, it has served as an informational resource and clearinghouse for Fuku-Bonsai customers,  associates, public and private researchers, and all who are interested in opae'ula.  THE OPAE'ULA CHALLENGE will be a series of pictorial essays to aid in focusing on one specific problem area at a time.  These problems confront the entire community and comments, additions or corrections are invited.  Email me at     Mahalo!  ~~~David W. Fukumoto (August 2005)
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Part I: Restoring the Anchialine Ponds

          So there is no misunderstanding, it's necessary to make clear that opae'ula are not endangered. But, unless strategic action is taken soon, opae'ula will not be available for future generations. This essay explains both the natural evolution and the accelerating decimation over the last 35 years and attempts to provide information as to the underlying causes of the problem and possible steps to resolve the problems.


          There have never been any historical sightings of opae'ula on Kauai, Hawaii's oldest major island. It is believed that geological evolution has filled any epigeal anchialine ponds and sealed off the hypogeal watertable. But, being a hypogeal specie, opae'ula can and have retreated to the underground watertable and exist where they are not seen in epigeal situations. The evidence is episodic but consistent. Three Oahu examples:

     *    Students filled their containers from the shallow caprock well that draws brackish water from below Blaisdell Center in the middle of Honolulu. When they got back to the University of Hawaii they discovered opae'ula in them. Opae'ula have also come up in north Oahu wells.

     *    After heavy rains, an opae'ula was discovered under a brick sitting on a fresh water seep on an east Oahu beach where there are no nearby ponds.

     *    When construction penetrated the watertable, foundation trenches filled with water and opae'ula appeared.

      A coral sinkhole where opae'ula have been found on Oahu. At low tide, there is little or no water. At high tide the opae'ula come out of the cracks and crevices to feed. Reproduction takes place in the hypogeal portion.

       Many thousands of years ago, sealevel was much higher than it is today and reefs surrounded much of Oahu. Today sealevel is lower and fossil coral reefs cover much of the Ewa plain. Some of the offshore islands are remnants of coral reefs.

        In sharp contrast, the anchialine ponds of the Big Island are in low spots in the lava. This is a man-made pond built by a developer to replace the natural ponds that were filled in during construction of a hotel-resort.

        Within a short time of completion, opae'ula naturally colonized it. Most ponds are small and shallow but there is a full range. Some are collapsed lava tubes. Another is geothermally heated with 95 F water. 

            Opae'ula are most often found in land-locked anchialine ponds (1) that have tidal fluctuations but are not open to the sea. The ponds are their epigeal habitat and over 95% of the ponds have had alien predators accidentally or intentionally introduced into the ponds. The opae'ula retreat into their hypogeal habitat under and around the ponds (2). When a brackish water well penetrates the water table, it can pump up opae'ula (3). Rain hitting the mountain sinks into the earth enroute to the sea (4) and opae'ula adapt from pure fresh water to water saltier than the ocean. After rainstorms, Big Island fisherman report catching fish with stomachs full of opae'ula flushed into the ocean.






       Opae'ula was once abundant enough to be used by native Hawaiians to regularly feed the offshore opelu koas. The photo shows a pristine pond. Opae'ula average 1/2" or less and 1 square foot may have over 500.

        With most staying in the hypogeal section, there may be over 1 million opae'ula in a 500 square foot pond!  It was initially  estimated that 10% can be sustainably collected each month without depleting the population. Recent captive breeding trials show this is a very conservative estimate as the trials produced in excess of 100% increase per year! 


        The ponds were once in pristine condition with an abundance of opae'ula. However, access to the ponds, human activity, and development resulted in the decimation of the opae'ula population. Since the opening of the Queen Kaahumanu Highway that connected the port of Kawaihae with Kailua-Kona in the 1970's, over 95% of the formerly pristine anchialine ponds now have alien predators. While it is illegal to fill in the ponds without a special permit, it is possible to make them part of beautiful landscaped gardens and fill them with colorful attractive carp. 

         The vector control section of the Hawaii State Department of Health also introduce mosquito fish into the ponds in their efforts to reduce the impact if the West Nile Virus should ever appear in Hawaii. Fishermen threw unused live bait into the ponds.   Aquarium hobbyists have also introduced fish into ponds.




         The ancient Hawaiians were highly skilled aquaculturists who utilized the larger anchialine ponds to raise fish. Each year, young mullet fingerlings were caught along the shoreline and released into the ponds where they were fed daily at the same time and the same place. The mullet in the photo are about 16" long and weigh about 2.5 pounds each. When the chiefs requested fish, the largest and fattest was easily netted. Wrapped in seaweed and dipped occasionally in the ocean, runners were able to deliver live fish many miles away!

        There are valid alternate uses for anchialine ponds besides being opae'ula habitats but there are also ill-conceived practices that should be stopped and there is a need for public education.




        Tilapia have been introduced into some ponds to serve as another food fish and the photo shows the round nesting holes they typically create. Tilapia are especially a problem as they are mouth brooders. A sea bird may catch one and occasionally drop it into a new pond. This is believed to be how tilapia was introduced into aquaculture prawn ponds on Kauai and into the Waikoloa Anchialine Pond Preservation Area. Initially they were not noticed, but during the record high tides of the spring of 2004, the pond complex merged into a single large pond and the tilapia spread throughout the makai ponds.

        Some introductions were well intentioned. Hawaii's aku (tuna) fishing industry depends on having silvery nehu to use as chum to keep the aku in a feeding frenzy while they are being hooked. With nehu becoming scarce, Mexican mollies were introduced into the ponds to increase. Unfortunately, mollies dive and take the aku away from the boats. Now the mollies are invading more ponds.

          The unavailability of opae'ula is due to the introduction of alien predators, and not due to the decimation of populations by collectors! To allow the original populations to bounce back, REMOVE THE ALIEN PREDATORS!

       This is a pond that was invaded by molies and the fish disrupt the ecological balance.  The fish prey upon the opae'ula and in having to retreat into the hypogeal habitat, are not able to keep the algae under control.  As shown in the photo, this results in excessive blooms of filamentous algae which continues to grow enough to float to the  surface encouraging other predator insect species (e.g. dragon flies, water boatmen, etc.) to inhabit the pond.  

       The surface layers of algae exposed to the hot sun die and at night these floating mats sink to the bottom adding to the organic debris and eutrophication of the pond.  Mats of these algae that do not rise to the surface are smothered and anaerobic conditions are created with the release of toxic hydrogen sulfide.  If left uncorrected, the pond basically becomes a stinking mess and a health hazard to the public.  Over time, the rotted debris and organic detritus will eventually seal off the pond from any tidal inflow and prevent any future recruitment of opae'ula.

       The fish reproduce and their larger volume of waste products increase  the nutrient levels in these pools and further promotes the buildup of organic matter, silt and exotic plants.  Anchialine ponds have a relatively short geological lifespan. Over time, they fill up with silt and organic matter and become grasslands or forests. The introduction of alien predator fish greatly decreased the lifespan of an anchialine pond!

       When there are no predators, opae'ula can increase dramatically and ponds can contain huge populations with the bottom of the ponds appearing red!  Populations are naturally controlled as ponds with limited food still have small populations even without alien predators. The native Hawaiians were once able to sustainably harvest large quantities of opae'ula for food and to use as bait. Once predators are removed it will be possible to establish prudent sustainable harvesting procedures. 

          Hawaii has over 80% of the known anchialine ponds in the world and 95% or more of these already containing predators. The number of anchialine ponds without alien predators are steadily decreasing because without rotenone there is no legal way to remove alien predators! Especially troubling is the increasing number of reports of the appearance of Tahitian Prawns (Macrobrachium lar) in previously pristine anchialine ponds.

          Tahitian Prawns were introduced into Hawaii in 1956 from Guam with some released into a Molokai stream and later Manoa Stream on Oahu. Nine years later, an adult was caught in a Big Island stream. Reproduction is based upon release of eggs and planktonic larvae into the sea where currents distribute them widely. Tahitian Prawns have the ability to delay their metamorphosis into post larvae stages if fresh water is not present. Somehow they are able to penetrate and complete their life cycles completely within the anchialine ponds.

        There are numerous reasons why opae'ula are declining and it's easy to lament and try to establish blame. But the challenge is to find viable workable solutions beginning with: "How can we preserve and restore anchialine ponds?"


         Each pond restoration must address the current condition and the state of geological evolution that has already taken place. If trees and grasses have already begun to encroach and grow in the ponds, these must be removed along with excess algae that may have developed. Over time, ponds fill with silt that seals off the hypogeal environment and this must also be removed. In the construction of Mauna Lani Resort there was a major commendable effort and it took over one year to dredge out accumulated silt to restore the natural ponds.

          There is a proven method to remove alien predators which includes fishes and the introduced Tahitian Prawns that have been able to penetrate the anchialine ponds and which can complete their life cycle within the anchialine ponds. Tahitian Prawn is not a hypogeal specie and would be vulnerable to rotenone.

 *     Rotenone was effectively used in the past when there was less regulatory oversight by several natural resource managers in both the private and public sectors.

*      Rotenone is the only pesticide that will be supported by all segments of the community due to its past history of effectiveness and there is concern about other untested pesticides.

*       Rotenone breaks down rapidly and the opae'ula return even before all residue is dispersed.

*       Rotenone has a neutralizing potassium permanganate protocol but some believe it is not necessary and are concerned that the potassium permanganate is more harmful.

*        Rotenone is approved as a fish-killer.


          NOTE:  For the latest information regarding the use of rotenone to remove alien predators from anchialine ponds, please go to THE OPAE'ULA CHALLENGE;  Part Ia: Rotenone Status Update Report.

          The information that follows provides some background information but may now be either not applicable or irrelevant.  It remains posted to provide a better understanding of the frustrations we endured in efforts to restore anchialine ponds!




          There has been no action because the Hawaii Department of Health has very effectively established an intimidating roadblock that prevents the application of rotenone in anchialine ponds by certified applicators by making permits impossible to obtain. They have done this by:

 *      Creating administrative rules that allows only the staff of the Department of Land and Natural Resources (DLNR) to apply pesticides in waterways.  This effectively eliminates and prevents 100% of all experienced applicators who have first hand knowledge and experiences in applying rotenone in anchialine ponds.  DLNR does not have any staffers who have the necessary Certified Pesticide Applicators License and it will take time to train such staff.  DLNR's most experienced individuals that have opae'ula knowledge are stationed in Honolulu and their knowledge is of the creature rather than Big Island anchialine ponds. DLNR's Big Island staff do not have knowledge, interest, or experience in applying rotenone in anchialine ponds.  DLNR does not have any funding or mandate for this additional responsibility. It is vital that the administrative rules which have the force of law be amended as it effectively establishes insurmountable obstacles to crafting a solution. If that was the objective of Hawaii Department of Health, they've done an extraordinary job and must be publicly acknowledged for their achievements. But whoever had that objective should also be publicly identified and made to justify why they should have the authority to establish such objectives or to be paid for doing so.

*       Making it impossible to obtain National Pollution Discharge Elimination System (NPDES) Permits.  The Hawaii Department of Health is the designated administrator for the federal Clear Water Act which requires a NPDES permit to apply pesticides in waterways. HDOH has established bureaucratic justification with their administrative rules to justify refusal to issue a NPDES permit. They were almost successful in  preventing the removal and treatment of Salvinia molesta at Lake Wilson by refusing to issue the NPDES permit.  They are very successful in preventing the application of rotenone to remove alien predator fish from anchialine ponds. If that was the objective of Hawaii Department of Health, they've done an extraordinary job and must be publicly acknowledged for their achievements. But whoever had that objective should also be publicly identified and made to justify why they should have the authority to establish such objectives or to be paid for doing so.

           It is necessary to eliminate this roadblock to remove alien predators from the anchialine ponds. This is a complex issue that overlaps and includes elements of the Clean Water Act, administered in Hawaii by the Hawaii Department of Health (HDOH), and the Federal Fungicide and Rodenticide Act (FIFRA), administered in Hawaii by the Hawaii Department of Agriculture (HDOA). There is federal oversight by the Environmental Protection Agency (EPA). All actions must be based upon case law that is not yet fully settled and being made by the Ninth Circuit Court of Appeals whose decisions have the force of law in Hawaii.

*        The March 2001 Headwaters v. Talent case heard by the 9th Circuit was based on a fish kill from the use of acrolein, which is used to keep irrigation canals free of flora and fauna.  The irrigation canal leaked into a stream which then resulted in killing a considerable number of fish in a stream (fish killed included Salmon, Steelhead, and others).  The 9th Circuit Court of Appeals ruled that an National Pollution Discharge Elimination System (NPDES) Permit was required for any use of a pesticide in waterways.  The Hawaii Department of Health is authorized to issue NPDES permits in Hawaii.  This case law now stands in the 9th Circuit states, including Hawaii.  Thus, for the use of any pesticide in waterways (including anchialine ponds) in Hawaii, an NPDES permit is required.  

*        EPA has attempted through policy to mitigate the impact of this decision by developing a policy on the use of pesticides in waters.  However, in 9th Circuit States, the Headwaters v. Talent decision, requiring a NPDES permit for pesticides use contaminating waterways is law, and unless the law is changed by Congress, it will continue.  The Clean Water Act also has a citizen's suit provision which enables citizens to initiate civil action if the State or EPA fail to act on a violation of the Clean Water Act.

*        The Hawaii Department of Health (HDOH) claims jurisdiction under the Federal Clean Water Act and has established "Administrative Rules" prohibiting any agency with the exception of Hawaii Department of Land and Natural Resources (DLNR) to apply any pesticide into any body of water. HDOH does not explain why past University or past private applicators will be prohibited from applying rotenone. There is a lot of confusion about their position. They were supposed to have a list of pesticides cleared for use but to date, pesticides have not yet been cleared. It is debatable whether HDOH has the capability to effectively administer the application of pesticides.

*        Within DLNR, the agency named by HDOH to be the sole applicator of pesticides in waterways, since the director of the Division of Aquatic Resources (DAR) retired, there does not seem to be any person with authority to act on this issue. Without an approved pesticide list and without any experience in applying rotenone if it were eventually cleared, DAR would need to learn to apply it. DAR has no budgeted funds for this additional new responsibility.  However, DAR includes two of the most knowledgeable resource individuals that should be consulted and utilized as advisors. But it is counter-productive to saddle them with new responsibilities that will take them away from their current important duties. It is very debateable that DLNR should be required to be involved as this will greatly complicate matters and prevent effective addressing of the problem. 

*        Hawaii Department of Agriculture (HDOA) traditionally has jurisdiction over pesticides under the Federal Fungicide and Rodenticide Act (FIFRA) and has a long-standing pesticide applicators certification program that it has effectively administered.  HDOA already has existing authority to certify applicators of rotenone. HDOA has also a stated interpretation that the current rotenone label allows use in anchialine ponds to remove alien predator fish and that no "Hawaii brackish water or anchialine pond exemption" is necessary. 

*         It must be made clear that this series of litigation decisions and guidance pertains primarily to the issuance of National Pollution Discharge Elimination System (NPDES) permit as required by the Clean Water Act (CWA) and was not intended to permanently shift jurisdiction over all pesticides to HDOH. 

*      When the Department of Agriculture was requested to use herbicides to control Salvinia molesta at Lake Wilson, they were aware of the need to get an NPDES permit, but were unable to do so.  Since the herbicide used (Aquamaster) was registered for use in waterways to control weeds, the chemical was applied, and the weed was controlled. However,  because of the potential for a citizen's suit under the Clean Water Act because no NPDES permit was obtained, the Department of Agriculture had received confirmation from the Attorney General that the application of herbicides to Lake Wilson was an action of the State.  Thus, if any citizens' suits were initiated, the State would provide legal representation.  Without that assurance, it would have been difficult to proceed because individuals applying the herbicide might be sued. 

           At this point, the issue is:  "Will the Hawaii Department of Health issue a NPDES permit to allow certified pesticide applicators to apply rotenone to remove alien predator fish in anchialine ponds?"

            There is a compelling need for such action and the confusion has delayed implementing an action plan.  Part of the reason that there has been no resolution is that there has not been enough public support to encourage governmental agencies to resolve the problem.  


           As the first step,  there should be an interdepartmental conference of those in the Hawaii Department of Health's Clean Water Division and the Hawaii Department of Agriculture Aquaculture and Pesticide Branches to first meet to resolve this problem.  Names of authoritive individuals will be forwarded to provide any needed information.  The objectives of such a conference should include:

*      To determine if the Department of Health will issue a NPDESD permit to certified pesticide applicators to apply rotenone to control alien fish in anchialine ponds.   If they cannot or will not, there should be clear reasons why the permits will not be issued so each reason can be appropriately addressed. To assure that a decision is made, it would be appropriate for a formal submittal of such an application by a holder of a Category 5 Aquatic Pesticide Applicator License.

*      To develop recommendations to amend the administrative rules.  The rules currently only authorize DLNR personnel to apply pesticides. The rules should be amended to allow those with Category 5 Aquatic Pesticide Applicator Licenses issued by the Hawaii Department of Agriculture Pesticide Branch to also apply pesticides in waterways. It should not be difficult to obtain legislative sponsors for such legislation and to develop public testimony support to enact passage.  

*       If legislative action is required, find a vehicle to allow immediate application of pesticides in waterways in lieu of a NPDESD permit. This could begin with a declaration of a state of emergency by the Mayor of Hawaii County (supported by a Hawaii County Council resolution) and/or by the Governor of the State of Hawaii. There are a number of parlimentary or governance tools that can be used to allow immediate actions while permanent solutions are pursued and enacted.


           Getting rotenone cleared for immediate use by certified applicators to remove alien predators from anchialine ponds is the first priority for all who are concerned about anchialine ponds and opae'ula. This must be done on an emergency basis, as once fully established, it will be more difficult to remove the invasive species. Once the immediate objective is accomplished,  all unnecessary regulatory obstacles must be removed while retaining sufficient controls.

            There are many other steps that must be taken to meet "The Opae'ula Challenges!"  It is necessary to have a statewide survey of all anchialine pond resources to determine their present status and whether additional regulatory protections must be enacted.  There must be removal of obstacles that prevent private developers, foundations, and community groups from preserving, restoring, and conserving anchialine ponds. Captive breeding must be encouraged and supported and a way must be found for those interested in captive breeding to obtain broodstock.

            These are areas that the Division of Aquatic Resources of the Hawaii State Department of Land and Natural Resources have capabilities to make major contributions.  DLNR has both educational and enforcement capabilities and this would be a preferred role for them. The Department of Education and the University system should also be involved as well as private owners of lands that include anchialine ponds and private companies like Fuku-Bonsai.  With the participation of all sectors of the community who have interests,  we can address the first challenge of restoring the anchialine ponds.


            This information is formatted to present as clear a picture as I can. There may be errors; and if so I would appreciate being corrected.  But, if the information is correct, I hope a solution can be developed during a meeting of HDOH Clean Water Branch and HDOA Aquaculture / Pesticide.  Please call me if more information is needed or if I can be of assistance to facilitate such a resolution.

          Sincerely,   ~~~David W. Fukumoto
                                  President & founder, Fuku-Bonsai Inc. 
                                  August 22, 2005
          PO Box 6000 (17-856 Olaa Road), Kurtistown, Hawaii 96760
          Phone (808) 982-9880; email:  URL:

           This essay is Part I of a series titled: "THE OPAE'ULA CHALLENGE"  in the Micro-Lobster website within Fuku-Bonsai's larger website and is posted at and is subject to being updated.

Copyright 2005, Fuku-Bonsai Inc.  Permission given to reproduce for private non-publishing purposes if printed in its entirety and provided the date of the essay and this notice is included. "True Indoor Bonsai" and "The Amazing Hawaiian Micro-Lobsters!" are trademarks of Fuku-Bonsai Inc.       


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