Proposed Graduate Research

Kosrae State, Federated States of Micronesia

Brian Lynch: brianl@comfsm.fm

 

Introduction

For the past five years, I have been living and working in the Federated States of Micronesia (FSM). I arrived in 1996 as a Peace Corps Volunteer. My assignment was to work with the Chuuk State Department of Marine Resources as an advisor. Specifically, my job was to work with and train local counterparts in techniques for monitoring the local marine resources. I trained seven Chuukese counterparts to conduct line-intercept coral reef surveys while we proceeded to document much of the macrofauna found within Chuuk Lagoon. We also initiated a study to determine abundances of several popular reef food resources including sea cucumbers, giant clams, and trochus. At the conclusion of these surveys, my counterparts and I made management recommendations to the state in an effort to protect these resources. During my two years in Chuuk, I also volunteered to teach a course (Marine Ecology and Conservation) to juniors and seniors at Chuuk High School.

After my Peace Corps service ended, I took an instructor position with the College of Micronesia (COM), teaching Marine Biology every semester along with Aquaculture, Zoology, and Environmental Studies once per year. I have also actively served on two committees and advised marine science students.

While teaching at COM, I began working with Dr. Donald Buden, a herpetologist, on a project (Buden et al., in press) he was working on. Upon completion of this project, we began surveying headwater streams in Pohnpei, investigating the presence and abundance of decapods (Buden et al. in prep, a) and native fishes (Buden et al. in prep, b). Resulting from this work, we identified one undescribed goby in the Genus Lentipes, one undescribed shrimp species, and another goby (Sicyopterus lagocephalus) unknown to Micronesia, but found in the Comoros Islands and other regions to the west of Pohnpei.

My research experience has made me very aware that there is a great need for basic ecological survey work to be conducted in Micronesia. In my work in Pohnpei, we were able to find undescribed species with no outside funding and with very few resources at our disposal. High volcanic islands separated from other substantial landmasses by hundreds of ocean miles offer a unique study opportunity. The trophic levels are more easily defined when compared to typical stream ecosystems. Island endemism is high, but the number of species is generally low, especially above the first major waterfall where most euryhaline species are unable to inhabit (Parenti and Maciolek, 1993). According to Kido (1996), this is largely due to the limited food base consisting of few algae and aquatic insect species hence the diversity of food types plays a significant role in the construction of an aquatic community (Tilman, 1982). In Pohnpei, Sicydiine gobies, freshwater eels, and shrimps are the dominant life forms above the first waterfall in each of the streams I investigated. Many Pacific islands are undergoing rapid changes due to population increase, development, global warming, and the increased threat of exotic species introductions, all the while, many of these isolated islands lack the capacity, personnel, or the incentive to document and study the flora and fauna most threatened by this rapid development.

The freshwater eel Anguilla marmorata is widely distributed throughout the Pacific, but existing literature is almost exclusively in regards to the distribution of this species (Williamson & Boetius, 1993). The occurrence of A. marmorata in headwater streams on isolated Pacific islands surely makes them a top predator in these systems of limited biota, but there is scanty reference to this, and no literature (that I have found) to document this.

Amphihydromous Sicydiine gobies occur in clear, tropical and subtropical streams on high volcanic islands throughout Oceania, but are confined to freshwater in juvenile and adult life stages (Myers, 1949; Maciolek, 1978; and Fukui, 1979). Manacop (1953) reported goby eggs being spawned on rock surfaces and hatching within a two days of fertilization. Transparent goby larvae are then carried with stream currents into estuarine waters where several weeks are spent as ichthyoplankton (Fitzsimons et al. 1990). Upon entering the mouth of coastal streams, Erdman (1961,1986) reported that developing larvae transform into juveniles before ascension upstream. Sicydiine gobies are able to use fused pelvic fins (forming a suction disk) to make their way up tropical mountain streams of steep gradients including waterfalls (Maciolek, 1978; Fukui, 1979). In a previous study conducted in Pohnpei, (Buden et al., in prep, b) collected 33 gobies above 400m in elevation.

In Pohnpei State, the commercial farming of sakau (kava) has expanded greatly in the last five years. Most of the sakau is grown in upland forests that have been clear-cut along riverbanks. This trend has increased in popularity due to re-occurring crop losses during El Nino years. Kosrae, another high, volcanic island state in the FSM is less populous and has not been developed to the extent of Pohnpei. Little information is currently available regarding the fauna of Kosrae. With exception to an ongoing mangrove research project, Kosrae is not the focus of any recent or current research projects. For these reasons, and my experience living and working in Micronesia, I am proposing to conduct graduate research in Kosrae State, FSM.

Study Area

Kosrae is a high, volcanic island state located at 5 N, 163 E. It is the eastern most and least populous (~9,000) of the four states comprising the Federated States of Micronesia. Most Kosraens inhabit the coastal lowlands; there has been little development of the rugged, mountainous interior. Kosraen state officials expressed interest in further developing agriculture, fisheries, and tourism during the 2nd FSM Economic Summit.

According to Chin et al. (1983), there are 28 named streams in Kosrae. Anguilla eels, gobiid fishes, and shrimps are native to these waters (unpublished interviews) but there are no published reports regarding the riverine biota of Kosrae.

Research Objectives

The Federated States of Micronesia have received a little attention ecologically and biologically. I believe it’s important to conduct initial surveys to document the species present in Kosraen streams. From this initial inventory, my research objectives will be to:

  1. Document and describe habitat characteristics in relation to Sicydiine goby species abundances.
  2. Determine predator and prey trophic levels for Sicydiine goby species and the freshwater eel Anguilla marmorata.
  1. In collaboration with taxonomists, I will prepare species descriptions of all undescribed Sicydiine gobies that are collected from Kosrae.

 

Methods

Initial sampling will be conducted in all 28 named streams as well as other perennial streams if time permits. A series of stations will be designated at varying elevations. Sampling will involve backpack electroshocking and follow procedures set forth by Reynolds (1996). Vertebrates and crustaceans will be collected, counted, measured sexed, some will be marked for release, and others will be preserved. Electrofishing effort will be recorded as distance covered and seconds of shock time. The CPUE will then be correlated against the mark-recapture population estimates to determine any relationship. By using Variable Implant Elastomer (VIE), I will be able to complete an underwater visual census of fish populations (Dolloff et al. 1996, Guy et al. 1996). Using standard mark-recapture calculations, I will determine fish and shrimp abundances. An underwater census will also be conducted outside of the fished areas in order to estimate migration and mortality of marked fish.

Nishimoto & Fitzsimons (1986) believe that Macrobrachium lar may feed on the Hawaiian mountain goby Lentipes concolor. From my previous work in Micronesia (Buden et al., in press, a), I am aware of this large shrimp’s presence in Micronesian streams. I will also determine what role the large mottled eel Anguilla marmorata plays as a top predator in Kosraen streams. By conducting gut analysis of these large eels at various elevations, I will look at species selection compared to the abundance of each goby species at a series of elevations. The digestive tract of sacrificed eels will be removed, tied off, and injected with formalin. The gut contents will then be measured, sorted, and composition based on dry weight and frequency will be determined. From this research, I will be able to quantitatively diagram prey consumption at varying elevations. I am also considering the possibility of tying this to biomass production of A. marmorata. Using data obtained from mark-recapture, I can then estimate the production. To recapture fishes, I will use a variety of nets to avoid the repeated use of electrofishing.

References to Project Description

Buden, D. W., D. B. Lynch, and T. Leberer, In prep, a. Decapod Crustaceans of

the Headwater Steams of Pohnpei, Eastern Caroline Islands, Federated States

of Micronesia.

Buden, D. W., D. B. Lynch, and R. E. Watson, In Prep. b. The Gobiid Fishes

(Teleostei: Gobioidei: Sicydiinae) of the Headwater Streams of Pohnpei,

Eastern Caroline Islands, Federated States of Micronesia.

Buden, D. W., D. B. Lynch, and G. R. Zug. 2000. Recent records of exotic

reptiles on Pohnpei, Western Caroline Islands, Micronesia. Pacific Science, in

press.

Chin, S., G. Tateishi, and J. Yee. 1983. Water Resources Data, Hawaii and

other Pacific Areas Water Year 1983, Volume 2. USGS Water Data Report HI-

83-2.

Doloff, A., J. Kershner, R. Thurow. 1996. Underwater Observation. Pg. 533-554

in B. Murphy and D. Willis eds., Fisheries Techniques, American Fisheries

Society, Bethesda Maryland.

Erdman, D. S. 1961. Notes on the biology of the gobiid fish Sicydium plumieri in

Puerto Rico. Bull. Mar. Sci. Gulf Carib. 11: 448-456.

Erdman, D. S. 1986. The green stream goby, Sicydium plumieri in Puerto Rico.

Trop. Fish Hobbyist 34: 70-74.

Fukui, S. 1979. On the rock-climbing behavior of the goby, Sicyopterus

japonicus. Japan. J. Ichthyol. 26: 84-88.

 

Guy, C., H. Blankenship and L. Nielsen. 1996. Tagging and Marking. Pg. 353-

384 in B. Murphy and D. Willis eds., Fisheries Techniques, American Fisheries

Society, Bethesda Maryland.

Kido, M. H. 1996. Diet and food selection in the endemic Hawaiian

Amphihydromous goby, Sicyopterus stimpsoni (Pisces: Gobiidae).

Environmental Biology of Fishes 45: 199-209.

Maciolek, J. A. 1977. Taxonomic status, biology, and distribution of Hawaiian

Lentipes, a diadromous goby. Pacific Science. 31: 355-362.

Manacop, P. 1953. The life history and habits of the goby Sicyopterus

extraneus Herre (Anga) Gobiidae, with an account of the goby-fry fisheries of

Cagayan River, Oriental Misamis Province, Mindanao, Philippines. Philippine J.

Fish. 2: 1-58.

Myers, G. S. 1949. Usage of anadromous, catadromous, and allied terms for

migratory fishes. Copeia 1949: 89-97.

Nishimoto, R. T. and J. M. Fitzsimons. 1986. Courtship, territoriality and

coloration in the endemic Hawaiian freshwater goby Lentipes concolor. pp.

811-817. In: T. Uyeno, R. Arai, T. Taniuchi, and K. Matsuura (ed.) Indo-

Pacific Fish Biology: Proceedings of the Second Conf. On Indo-Pacific

Fishes, Ichthyological Society of Japan, Tokyo.

Parenti, L. R., and J. A. Maciolek. 1993. New sicydiine gobies from Ponape and

Palau, Micronesia, with comments on systematics of the subfamily

Sicydiinae (Teleostei: Gobiidae). Bulletin of Marine Science 53:945-972.

Reynolds, J. 1996. Electrofishing. Pg. 221-254 in B. Murphy and D. Willis eds.,

Fisheries Techniques, American Fisheries Society, Bethesda Maryland.

Tilman, D. 1982. Resource competition and community structure. Princeton

University Press, Princeton. 296pp.