REPORT DOCUMENTATION FORM WATER RESOURCES RESEARCH CENTER UniverSity of Hawaii at Manoa 1 Report 2FCST Number Technical Report No. 147 Category 06-G 4 Report Date October 1982 Population Biology in SNo. of Small Hawaiian Streams Pages ix + 60 bNo. of 'NO. of Tables 14 I Figures 17 8Author(s) 9Grant Agency Robert A. Kinzie, III Office of Water Policy, John I. Ford U.S. Department of the Interior 10Grant/Contract No. 14-34-0001-1113; A-080-HI IlDescriptors: *Fish Populations, *Freshwater Fish, *Fish Genetics, *Crustaceans, *Biology, Ecology, Streams Identifiers: *Lentipes concolor, *Threatened Species, Maui, Kauai, Molokai, Oahu, Hawaii Island l~Abstract (Purpose, method, results, conclusions) Intensive stream surveys were conducted on Maui and Kauai in Hawaiian island streams during October 1979 through 1982 to investigate whether the presence of predaceous eleotrids in terminal reaches of low-gradient streams excluded the rare goby, Lentipes concolor, from this habitat and restricted it to higher elevations. An attempt was also made to determine whether a correlation exists between seasonality of stream discharge patterns and the two life history parameters (spawning and recruitment) of the indigenous, diadromous species. Two small perennial streams, Puaaluu and Pepeiaolepo, on the island of Maui, and another small stream, Maunapuluo, on the precipi­ tous Na Pali Coast of Kauai were selected as study areas. Although evidence indicated that Eleotris sandwicensis preys upon gobies and rarely coexists with Lentipes, many other factors influence the effectiveness of Eleotris as a predator. Factors affecting the distribution and abundance of Lentipes are complex. No sharply defined periodicity was found in the recruitment of diadromous fishes, crustaceans, or mollusks. In-stream factors, among­ stream and among-island differences in physical and biotic parameters apparently make recruitment into small Hawaiian streams an event in which chance plays a dominant role. In larger streams these stochastic processes may be averaged out and populations of these indigenous animals are more stable. The importance of these physical, biotic factors in determining the disturbance of populations of native stream fauna is discussed. 2540 Dole Street Holmes Hall 283 • Honolulu Hawaii· U.S.A. POPULATION BIOLOGY IN SMALL HAWAIIAN STREAMS Robert A. Kinzie, III John I. Ford Technical Report No. 147 October 1982 Research Project Technical Completion Report for Ecologic and Geohydrologic Characteristics of the Critical Habitat for Hawaiian Stream Life Project No.: A-080-HI Grant Agreement No.: 14-34-0001-1113 Project Investigator: Robert A. Kinzie, III Prepared for UNITED STATES DEPARTMENT OF THE INTERIOR The work upon which this report is based was supported in part by federal funds provided by the United States Department of the Interior, as autho­ rized under the Water Research and Development Act of 1978, as amended. WATER RESOURCES RESEARCH CENTER University of Hawaii at Manoa Honolulu t Hawaii 96822 AUTHORS: Robert A. Kinzie, III Associate Professor Department of Zoology University of Hawaii at Manoa Honolulu, Hawaii 96822 John 1. Ford Fishery Biologist U.S. Fish and Wildlife Service Division of Ecological Services Honolulu, Hawaii Contents of this publication do not necessarily reflect the views and policies of the United States Department of the Interior, nor does mention of trade names or com­ mercial products constitute their endorsement or recom­ mendation for use by the United States Government. $IO.OO/copy Checks payable to: Research Corporation, University of Hawaii Mail to: University of Hawaii at Manoa Water Resources Research Center 2540 Dole St., Holmes Hall 283 Honolulu, Hawaii 96822 Tel.: (808) 948-7847 or -7848 v ABSTRACT Intensive stream surveys were conducted on Maui and Kaua'i in Hawaiian island streams during October 1979 through 1982 to investigate whether the presence of predaceous eleotrids in terminal reaches of low-gradient streams excluded the rare goby, Lentipes concolor, from this habitat and restricted it to higher elevations. An attempt was also made to determine whether a correlation exists between seasonality of stream discharge patterns and the two life history parameters (spawning and recruitment) of the indigenous, diadromous species. Two small perennial streams, Pua'aluu and Pepeiaolepo, on the island of Maui, and another small stream, Maunapuluo, on the precipi­ tous Na Pali Coast of Kaua'i were selected as study areas. Although evidence indicated that Eleotris sandwicensis preys upon gobies and rarely coexists with Lentipes, many other factors infZuence the effectiveness of Eleotris as a predator. Factors affecting the distribution and abundance of Lentipes are complex. No sharply defined periodicity Was found in the recruitment of diadro­ mous fishes, crustaceans, or mollusks. In-stream factors, among-stream and among-island differences in physical and biotic parameters apparently make recruitment into small Hawaiian streams an event in which chance plays a dominant role. In larger streams these stochastic processes may be averaged out and populations of these indigenous animals are more stable. The impor­ tance of these physical, biotic factors in determining the disturbance of populations of native stream fauna is discussed. vii CONTENTS ABSTRACT. , •.. v 1 INTRODUCTI ON. ... t" '!.." RESEARCH OBJECTIVES . .. ,., .. t , • • • • '! . .. 2 SCOPE OF STUDY .. .. ,.. 3 SITE DESCRIPTIONS . • • .. , , . 6 Pua'alu'u Stream, Maui. ,•" 'l! • . .. , .. 6 Pepeiaolepo Strea~, Maui . " • t • , • , 6 Maunapul uo Stream, Kaua'i .. .." ....,. 10 METHODOLOGY ..... t , , .. , II ,•• 13 DISCUSSION OF RESULTS. • .. ,,, 'II , 15 SPECIES ACCOUNTS. .. 18 Macrobrachium lar (Fabricius). 18 Macrobrachium grandimanus (Randall). 30 Atya bi sul cata Randall ........ 30 'Neritina granosa Sowerby . 35 Eleotris sandwicensis Vaillant and Sauvage. 36 Awaous stamineus (Valenciennes). 37 Sicyopterus stimpsoni Gill 40 Lentioes concolor (Gill) 46 POPULATION SIZE ESTIMATES 50 Method One 51 Method Two ..... 51 GENETIC VARIABILITY OF STREAM POPULATIONS 53 CONCLUSIONS ... 53 ACKNOWLEDGMENTS. .' 56 REFERENCES. .. 57 viii Figures 1. Map of Hawai'i's Major Islands and Study Areas. 4 2. Sampling Sites of Pepeiaolepo and Pua'alu'u Streams, East Maui 7 3. Stream Profile of Pua'alu~ Stream Stations, Maui .. 8 4. Stream Profile of Pepeiaolepo Stream Stations, Maui . 8 5. Sampling Sites of Maunapuluo Stream, Kaua'i ..... 11 6. Stream Profile of Maunapuluo Stream Stations, Kaua'i. 12 7. Water Temperature in Maunapuluo, Pepeiaolepo, and Pua'alu'u Streams, 1980-1982 . 17 8. Stream Discharge from Maunapuluo, Pepeiaolepo, and Pua'alulu Streams, 1980-1982 .. 21 9. Monthly Rainfall, Wainiha (Kaua'i) and Kipahulu (Maui) Stations 22 10. Percent of Berried Macrobrachium lar in Pepeiaolepo Stream, Maui, 1980-1982 ..........•.......... A 24 11. Percent of Juvenile Macrobrachium lar in Pepeiaolepo Stream, Maui. ..... .. .......•.... 26 12. Cumulative Percent of Size Classes of Macrobrachium lar in Pepeiaolepo Stream, Maui ...... .. .. -.-. .. 27 13. Waioho'okalo, Pelekunu, Pap~laua, Wailau, and Lelekoa~ Stream Sites, Northeastern Coast, Moloka'i . 29 14. Percent of Berried Atya bisulcata in Pua'alulu Stream, Maui . 32 15. Percent of Berried.81Y..a. bisylcata in Maunapuluo Stream, Kaua'i . 33 16. Study Streams Along Northern Coas t of Kaua Ii . 38 17. Map of East Maui and Study Streams . 44 Tables 1. Current Zoogeographic Status of Crustaceans, Fishes, and a Gastropod in Hawaiian Streams ···· ····· · ····· · 2 2. Temperature, Conductivity, and pH Measurements, Maunapuluo Stream, Kaua'i, 1980-1982 . ····· · ·· · ·· ···· 16 3. Temperature, Conductivity, and pH Measurements, Pua'alu'u Stream, Maui, 1980-1982. ···· · ·· ····· · · 19 4. Temperature, Conductivity, and pH Measurements, Pepeiaolepo, Hahalawe, and Maluhianaiwi Streams, Maui, 1980-1982 · · · · · 20 5. Stream Discharre, Palikea Stream (Maui) and Wainiha River Kaua'i). ... ·· ·· · · · ······ · · 23 6. Mean Size and Number of Eleotris sandwicensis Captured in Pepeiaolepo Stream, Maui, 1980-1982. ·· · · · ··· 36 7. Mean Size and Number of Awaous stamineus Caputred in Pua la 1u'u Stream, Maui, 1980-1982. ·· ······ ·· ···· · 40 8. Mean Size and Number of Sicyopterus stimpsoni Captured in Pua'al u1u Stream, Maui, 1979-1982 . 43 9. Mean Size and Number of Sicyopterus stimpsoni Captured in Maunapuluo Stream, Kaua'i, 1980-1981 . 43 10. Mean Size and Number of Sicyopterus stimpsoni Captured in Pepeiaolepo Stream, Maui, 1980-1982 . 45 11. Mean Size and Number of Lentipes concolor Captured in Pua'al u1u Stream, Maui, 1979-1982 ....•.... 48 12. Mean Size and ny~er of Lentipes concolor Captured in Maunapul uo Stre9-lJI, Kg,ua'i"';"'ll8g~1981 ...•.... 48 13. Population Estimates Of Lentipes and Sicyopterus stimpsoni in Pua'alu'u Stream, Maui . 52 14. Electrophoretic Study Results of Gene Frequencies and Sample Sizes of Sicyopterus stimpsoni and Neritina granosa from Kaua'i, Maui, and O'ahu Streams . 54 INTRODUCTION Streams on oceanic high islands are of considerable interest because of the relationship between their ephermeral nature and the evolutionary and ecological peculiarities of their life forms. Familiar freshwater fauna from continental rivers are absent from oceanic islands because these pri­ mary freshwater fishes are physiologically incapable in surviving trans­ oceanic crossings (Ford and Kinzie 1982). Thus, the biotic invasion and radiation in Hawaiian streams is a paradigm of island evolution. Hawaiian streams