Metadata: Identification_Information: Citation: Citation_Information: Originator: Dr. Richard E. Brock Originator: Sea Grant Originator: University Of Hawaii at Manoa Originator: Dr. Jamse E.T. Moncur Originator: Water Resources Research Center Originator: University Of Hawaii at Manoa Publication_Date: Unknown Title: COMMUNITY STRUCTURE OF FISH AND MACROBENTHOS AT SELECTED SITES IN THE VICINITY OF THE MOKAPU OCEAN OUTFALL, OAHU, HAWAII, 1998 Description: Abstract: This report provides the results of the first quantitative survey of the coral reef communities in the vicinity of the Mokapu Ocean Outfall in Kailua Bay, Oahu, Hawaii. This survey, conducted in April and July 1998, focuses on benthic and fish community structure and is designed to detect community changes that may be mediated by the release of treated sewage through the outfall. The Kailua Regional Wastewater Treatment Plant (WWTP), which has been operational since 1977, releases a little more than 13 mgd of secondary treated sewage through a 1.55-km-long discharge pipe at a depth of 32 m. If impacts are occurring to marine communities from a point-source discharge, their effects will be most evident in proximity to the source and less obvious with distance from the source. The sampling strategy used in this study focuses on quantifying the degree of development of marine communities adjacent to and at distances from the discharge source. This strategy should allow delineation of impacts if they are occurring. The results of this first survey indicate that the marine communities in the study area are diverse, with well-developed fish and coral components. This is particularly evident on the Mokapu Ocean Outfall diffuser (Transect T-1) where a high-biomass, diverse fish community occurs. This well-developed fish community is related to the shelter created by the diffuser pipe and basalt armor rock, as well as to the release of organic particles in the treated effluent which serve as a food resource for some fish species. The development of corals as measured in terms of live coverage in the diffuser pipe community is about half that found at the more distant sampling sites. However, a second sampling site (Transect T-2) located parallel to and 15 m away from the diffuser has coral coverage very similar to that found elsewhere in Kailua Bay. These data suggest that if the operation of the Kailua Regional WWTP is having an impact on marine communities, it is very limited in scope and scale. Purpose: Determine the status of the marine resources in the vicinity of the discharge in an effort to quantitatively ascertain if any impacts are occurring to the coral reef biota. Supplemental_Information: NOAASupplemental: Entry_ID: Unknown Sensor_Name: visual census Sensor_Name: SCUBA Source_Name: Water Resources Research Center/Sea Grant Annual Outfall Monitoring Originating_Center: University of Hawaii Storage_Medium: ASCII, MS Word Reference: None Online_size: 526 kilobytes Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19980427 Ending_Date: 19980731 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: Annually Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -157.73333 East_Bounding_Coordinate: -157.7166 North_Bounding_Coordinate: 21.45 South_Bounding_Coordinate: 21.4333 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Coastal studies Theme_Keyword: biological survey Theme_Keyword: coral survey Theme_Keyword: Coral reef monitoring and assessment Theme_Keyword: substatum percent cover (coral, algal, rock, sand) Theme_Keyword: macroinvertebrate census Theme_Keyword: fish census Theme_Keyword: fish species Theme_Keyword: fish biomass Theme_Keyword: invertebrate species Theme_Keyword: coral species Theme_Keyword: algal species Place: Place_Keyword_Thesaurus: None Place_Keyword: Pacific Ocean Place_Keyword: Hawaii Place_Keyword: Oahu Place_Keyword: Kailua Bay Place_Keyword: Windward Oahu Place_Keyword: Mokapu Place_Keyword: Kaneohe Marine Corp Station Stratum: Stratum_Keyword_Thesaurus: None Stratum_Keyword: Benthic Access_Constraints: None Use_Constraints: Dataset credit required Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Dr. Richard Brock Contact_Organization: Sea Grant/University of Hawaii Contact_Position: Principal Investigator Contact_Address: Address_Type: mailing address Address: 2525 Correa Rd, HIG 213 City: Honolulu State_or_Province: Hawaii Postal_Code: 96822 Country: USA Contact_Voice_Telephone: 808-956-2859 Contact_Electronic_Mail_Address: brockr@hawaii.edu Data_Set_Credit: Water Resources Research Center University Of Hawaii at Manoa Sea Grant Department of Environmental Services City and County of Honolulu Native_Data_Set_Environment: ASCII text, MS Word Data_Quality_Information: Logical_Consistency_Report: see Process Step Completeness_Report: The surveys were 100% complete Lineage: Process_Step: Process_Description: SAMPLING STATIONS: Station A is located at the diffuser in water ranging from 29.6 to 32.0 m in depth. It was established to sample the communities resident to the diffuser as well as directly adjacent to it. The location of this station is at the lower depth limit for safe diving, where considerable time must be spent underwater gathering data. Station B is located about 2.7 km south-southwest of the diffuser and 400 m south of Mokolea Rock at a depth of 20 m (approximately 1.8 km from shore). Station C is located halfway between Mokolea Rock and the shore of Kailua Bay (1.7 km inshore of Mokolea Rock in water ranging from 5.2 to 6.7 m in depth. At Stations A and B two 20-m transect lines each were permanently established using metal stakes and plastic-coated no. 14 copper wire. At Station C only one 20-m transect line was established using the same procedure. The transects at Stations B and C have an orientation that is approximately parallel to shore. At Station A one transect was positioned on top of the diffuser pipe and the second on the natural substratum parallel to the diffuser pipe but about 15 m to the north. The two transects at Station B sample approximately the same benthic communities, thus providing some replication. On each transect are five permanently marked locations (0 m, 5 m, 10 m, 15 m, and 20 m) for making cover estimates of benthic community components using a 1 m ? 1 m quadrat. The quadrat is placed at the -1 to 0 m, 4 to 5 m, 9 to 10 m, 14 to 15 m, and 19 to 20 m marks on the transect line. METHODOLOGY: Background: ----------- Wastewaters of mainly domestic origin are pumped and secondary treated prior to discharge through the Mokapu Ocean Outfall diffuser at a rate of approximately 14.5 million gallons per day (0.64 m3/s), 5,083 ft (1.55 km) offshore, at a depth of 105 ft (32 m) offshore of Mokapu Peninsula. Sources that feed into the diffuser include the Kailua Regional Wastewater Treatment Plant (WWTP) (13.0 mgd or 0.57 m3/s) and Kaneohe Marine Corps Air Station WWTP (1.5 mgd or 0.07 m3/s). The discharge pipe is 48 inches (1.2 m) in diameter and 4,120 ft (1.26 km) in length, and the diffuser portion is 963 ft (0.29 km) in length. The diffuser has 80 discharge ports spaced 12 feet (3.7 m) apart, alternating from one side of the pipe to the other. These ports are located at the springline (midline) of the discharge pipe. The first 30 ports are not open because of the less than maximum flow presently being discharged through the diffuser. The remaining 50 ports are operational, with the 20 most-shoreward ports being 4.5 inches (11.4 cm) in diameter, the next 15 being 5 inches (12.7 cm) in diameter, and the final 15 being 5.5 inches (14.0 cm) in diameter. The diffuser terminates with a 5.5-inch-diameter port and a half-circle port that is 8 inches (20.3 cm) in diameter. Prior to the development of this plant and outfall, sewage from the Kailua area received secondary treatment and was discharged into Kailua Bay via a relatively short outfall offshore of Kapoho Point. The discharge depth was less than 12 m. In recent years controversy has arisen regarding the impact that sewage effluent discharged from the Mokapu Ocean Outfall may have on inshore coral reef species. Because of these concerns, the City and County of Honolulu contracted the University of Hawaii Water Resources Research Center to determine the status of the marine resources in the vicinity of the discharge in an effort to quantitatively ascertain if any impacts are occurring to the coral reef biota. This report presents the findings of the first field survey conducted in April and July 1998. Strategy: --------- Marine environmental surveys are usually performed to evaluate the feasibility of, and ecosystem response to, specific proposed activities. Appropriate survey methodologies reflect the nature of the proposed action(s). An action that may have an acute impact (such as channel dredging) requires a survey designed to determine the route of least harm and the projected rate and degree of ecosystem recovery. Impacts that are more chronic or progressive require different strategies for measurement. Management of chronic stress to a marine ecosystem requires identification of system perturbations that exceed boundaries of natural fluctuations. Thus a thorough understanding of normal ecosystem variability is required to separate the impact signal from background noise. Infrequent natural events may add considerably to the variability or background noise measured in a marine community. Rare storm events not withstanding, the potential impacts occurring to the Kailua Bay marine ecosystem are most probably those associated with chronic or progressive stresses. Because of the proximity of urbanization, marine communities in Kailua Bay are subjected to an array of impacts not encountered in Hawaii coral communities that front undeveloped coastlines. Thus a sampling strategy must attempt to separate impacts due to the discharge of wastewater treatment plant effluent on coral reef communities from a host of nonpoint perturbations occurring in the waters of Kailua Bay. Almost 42,000 people live in Kailua town (Statistics and Data Support Branch, State of Hawaii, 1997). Growth of this windward community began in the mid-1950s with improvements to the Pali Highway, making the commute between Kailua and Honolulu much faster. In 1977 the Kailua Regional WWTP, with a design capacity of 15.25 mgd (0.67 m3/s), began operation to handle the wastewaters of the growing Kailua population. In the outlying areas of Kailua (such as Lanikai), sewage continued to be handled by cesspools. Cesspools and urban use of fertilizers, among other factors, contribute toward providing opportunities for nonpoint-source materials to enter the sea. The Mokapu Ocean Outfall discharge into Kailua Bay may be considered in terms of gradients. There are numerous gradients owing to point-source and nonpoint-source (such as Kawainui Canal and Kaelepulu Stream) inputs into Kailua Bay from the urbanization of much of the watershed. Because many of these inputs have been occurring for a considerable period of time, the species composition and functional relationships of the benthic and fish communities at any given location in the waters of Kailua Bay are those that have evolved under the influence of these ongoing perturbations. As noted above, if impacts are occurring to the coral reef communities in Kailua Bay owing to sewage effluent discharged from the outfall offshore of Mokapu Peninsula, they are probably chronic in nature and would probably be manifested as slow shifts in the structure of the communities so affected. Gradients of stress or impact should be evident with distance from the impact source(s). Thus, to quantitatively define these impacts, one should monitor these communities through time in areas suspected of being impacted as well as in similar communities at varying distances away from the suspected source(s). This rationale has been used in developing the sampling strategy for this study. Materials and methods: ---------------------- The quantitative sampling of macrofauna in marine communities presents a number of problems, many of which are related to the scale on which one wishes to quantitatively enumerate organism abundance. Marine communities in Kailua Bay may be spatially defined in a range on the order of a few hundred square centimeters (such as the community living in a Pocillopora meandrina coral head) to many hectares (such as areas which are covered by major biotopes). Because considerable interest focuses on visually dominant corals, diurnally exposed macroinvertebrates, and fishes, we designed a sampling program to delineate changes that may be occurring in communities at this scale. Fish abundance and diversity are often related to small-scale topographical relief over short linear distances. A long transect may bisect a number of topographical features (e.g., coral mounds, sand flats, and algal beds), thus sampling more than one community and obscuring distinctive features of individual communities. To alleviate this problem, a short transect (20 m in length), which has proved to be adequate for sampling many Hawaii benthic communities (see Brock 1982; Brock and Norris 1989), is used. Information is collected at each transect location using methods including a visual assessment of fishes, a quadrat survey of the benthos for cover estimates of sessile forms (e.g., algae, corals, and colonial invertebrates), and a visual assessment of diurnally exposed motile macroinvertebrates. Fish censuses are conducted over a 4 m x 20 m corridor (the permanent transect line). All fishes within this area to the water's surface are counted. A single diver equipped with scuba, slate, and pencil enters the water, then counts and notes all fishes in the prescribed area (method modified from Brock 1954). Besides counting the individuals of all fishes seen, the length of each is estimated for later use in the determination of fish standing crop by linear regression techniques (Ricker 1975). Species-specific regression coefficients have been developed over the last thirty years by the author and others at the University of Hawaii, the Naval Undersea Center (see Evans 1974), and the Hawaii Division of Aquatic Resources using weight and body measurements of captured fishes; for many species the coefficients have been developed using sample sizes in excess of a hundred individuals. To reduce the bias caused by the flight of wary fishes, the census taker enters the water, locates the transect site, and commences with the census of fishes. The same individual (the author) performs all fish censuses to reduce bias related to the experience or inexperience of the census taker. Besides divers frightening wary fishes, other problems with the visual census technique include underestimating cryptic species such as moray eels (family Muraenidae) and nocturnal species such as squirrelfishes (family Holocentridae) and bigeyes or oaweoweo (family Priacanthidae). This problem is compounded in areas of high relief and coral coverage that afford numerous shelter sites. Species lists and abundance estimates are more accurate for areas of low relief, although some fishes with cryptic habits or protective coloration, such as scorpionfishes or nohu (family Scorpaenidae) and flatfishes (family Bothidae), might still be missed. Another problem is the reduced effectiveness of the visual census technique in turbid water. This is compounded by the difficulty of counting fishes that move quickly or are very numerous. Additionally, bias related to the experience of the census taker should be considered in making comparisons between surveys. Despite these problems, the visual census technique is probably the most accurate, nondestructive assessment method currently available for counting diurnally active fishes (Brock 1982). A number of methods are utilized to quantitatively assess benthic communities at each station, including the placing of 1 m x 1 m quadrats at marked locations on each transect for repeated measurements. The quadrats are used to estimate coverage of corals and other sessile forms. Cover estimates are all recorded as percent cover. Diurnally exposed motile macroinvertebrates greater than 2 cm in some dimension are censused in the same 4 m x 20 m corridor used for the fish counts. Macrothalloid algae encountered in the 1 m x 1 m quadrats are quantitatively recorded as percent cover. Emphasis is placed on those species that are visually dominant, and no attempt is made to quantitatively assess the multitude of microalgal species that constitute the algal turf so characteristic of many coral reef habitats. During fieldwork, an effort is made to note the presence of any green sea turtles (a threatened species) within or near the study sites. INSTRUMENT TYPES: SCUBA Visual census REFERENCES: Alevizon, W., R. Richardson, P. Pitts, and G. Serviss. 1985. Coral zonation and patterns of community structure in Bahamian reef fishes. Bull. Mar. Sci. 36:304-318. Anderson, G.R.V., A.H. Ehrlich, P.R. Ehrlich, J.D. Roughgarden, B.C. Russell, and F.H. Talbot. 1981. The community structure of coral reef fishes. Am. Nat. 117:476-495. Brock, R.E. 1982. A critique on the visual census method for assessing coral reef fish populations. Bull. Mar. Sci. 32:269-276. Brock, R.E., C. Lewis, and R.C. Wass. 1979. Stability and structure of a fish community on a coral patch reef in Hawaii. Mar. Biol. 54:281-292. Brock, R.E., and J.E. Norris. 1989. An analysis of the efficacy of four artificial reef designs in tropical waters. Bull. Mar. Sci. 44:934-941. Brock, V.E. 1954. A preliminary report on a method of estimating reef fish populations. J. Wildlife Mgmt. 18:297-308. Connell, J. 1978. Diversity in tropical rain forests and coral reefs. Science 199:1302- 1310. Dollar, S.J. 1982. Wave stress and coral community structure in Hawaii. Coral Reefs 1:71-81. Eckert, G.J. 1985. Settlement of coral reef fishes to different natural substrata and at different depths. Proc. 5th Int. Coral Reef Congr. 5:385-390. Evans, E.C. (editor). 1974. Pearl Harbor biological survey final report. Report No. NUC-TN-1128, Naval Undersea Center, Hawaii Laboratory. Gladfelter, W.B., and E.H. Gladfelter. 1978. Fish community structure as a function of habitat structure on West Indian patch reefs. Rev. Biol. Trop. 26(Supplement 1):65-84. Goldman, B., and F.H. Talbot. 1975. Aspects of the ecology of coral reef fishes. In Biology and Geology of Coral Reefs, Vol. III, Biology 2, ed. O.A. Jones and R. Endean, pp. 124-154. New York: Academic Press. Grigg, R. 1983. Community structure, succession and development of coral reefs in Hawaii. Mar. Ecol. Prog. Ser. 11:1-14. Grigg, R., and J. Maragos. 1974. Recolonization of hermatypic corals on submerged lava flows in Hawaii. Ecology 55:387-395. Hiatt, R.W., and D.W. Strasburg. 1960. Ecological relationships of the fish fauna on coral reefs of the Marshall Islands. Ecol. Monogr. 30:65-127. Hobson, E.S. 1974. Feeding relationships of teleostean fishes on coral reefs in Kona, Hawaii. Fish. Bull. 72:915-1031. Jones, R.S. 1968. Ecological relationships in Hawaiian and Johnston Island Acanthuridae (surgeonfishes). Micronesica 4:309-361. Ogden, J.C., and J.P. Ebersole. 1981. Scale and community structure of coral reef fishes: A long-term study of a large artificial reef. Mar. Ecol. Prog. Ser. 4:97-104. Parrish, J.D., and 22 others. 1984. Trophic relationships of nearshore fishes in the Northwestern Hawaiian Islands. In Proc. 2nd Symp. Resource Investigations Northwestern Hawaiian Islands, vol. 1, ed. R.W. Grigg and K.Y. Tanoue, pp. 221- 225. UNIHI-SEAGRANT-MR-84-01, University of Hawaii Sea Grant College Program, Honolulu. Parrish, J.D., M.W. Callahan, and J.E. Norris. 1985. Fish trophic relationships that structure reef communities. Proc. 5th Int. Coral Reef Congr., Tahiti, vol. 4, pp. 73-78. Ricker, W.E. 1975. Computation and interpretation of biological statistics of fish populations. Bull. Fish. Res. Bd. Canada 191. 382 pp. Risk, M.J. 1972. Fish diversity on a coral reef in the Virgin Islands. Atoll Res. Bull. 153:1-6. Sale, P.J. 1977. Maintenance of high diversity in coral reef fish communities. Am. Nat. 111:337-359. Shulman, M.J. 1984. Resource limitation and recruitment patterns in a coral reef fish assemblage. J. Exp. Mar. Biol. Ecol. 74:85-109. Shulman, M.J., J.C. Ogden, J.P. Ebersole, W.N. McFarland, S.L. Miller, and N.G. Wolf. 1983. Priority effects in the recruitment of juvenile coral reef fishes. Ecology 64:1508-1513. Statistics and Data Support Branch, State of Hawaii. 1997. State of Hawaii data book. Statistics and Data Support Branch, Research and Economic Analysis Division, Department of Business, Economic Development and Tourism, State of Hawaii, Honolulu. 664 pp. Walsh, W.J. 1983. Stability of a coral reef fish community following a catastrophic storm. Coral Reefs 2:49-63. Walsh, W.J. 1985. Reef fish community dynamics on small artificial reefs: The influence of isolation, habitat structure, and biogeography. Bull. Mar. Sci. 36:357-376. Woodley, J.D., and 19 others. 1981. Hurricane Allen\306s impact on Jamaican coral reefs. Science 214:749-755. Process_Date: Unknown Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Dr. Richard Brock Contact_Organization: Sea Grant/University of Hawaii Contact_Position: Principal Investigator Contact_Address: Address_Type: mailing address Address: 2525 Correa Rd, HIG 213 City: Honolulu State_or_Province: Hawaii Postal_Code: 96822 Country: USA Contact_Voice_Telephone: 808-956-2859 Contact_Electronic_Mail_Address: brockr@hawaii.edu Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: FILE FORMATS: All files given as MS WORD 97 documents and redundant text files. FILENAME SIZE COMMENT MOFM98.DOC 267776 Original data report with tables mo98doc.txt 40246 Original data report in text format without tables mo98app.doc 46080 mo98app.txt 3183 Appendix: Results of the Quantitative Visual Fish Censuses Conducted at Five Locations in Kailua Bay, Oahu, Hawai, in 1998 mo98tb1.doc 27136 mo98tb1.txt 1323 TABLE 1. Summary of Biological Observations made at Transect T-1 on the Mokapu Ocean Outfall Diffuser on 27 July 1998. mo98tb2.doc 26112 mo98tb2.txt 1357 TABLE 2. Summary of Biological Observations made at Transect T-2, 15 m North of and Parallel to the Mokapu Ocean Outfall Diffuser Pipe on Natural Substratum, on 31 July 1998. mo98tb3.doc 27648 mo98tb3.txt 1386 TABLE 3. Summary of Biological Observations made at Transect T-3 (Station B) South of Mokolea Rock in Kailua Bay on 27 April 1998. mo98tb4.doc 27648 mo98tb4.txt 1361 TABLE 4. Summary of Biological Observations made at Transect T-4 (Station B) South of Mokolea Rock in Kailua Bay on 27 April 1998. mo98tb5.doc 28672 mo98tb5.txt 1491 TABLE 5. Summary of Biological Observations made at Transect T-5 Inshore of Mokolea Rock in Kailua Bay on 27 April 1998. mo98tb6.doc 24064 mo98tb6.txt 735 TABLE 6. Summary of Biological Parameters Measured at the Five Transect Locations in the 1998 Survey NOTE: the text version of the MS WORD tables is of the following form: column header(s) row header(s) (row for each column header field) additional row header(s) (row for each column header field given above, if a value is not given, then the respective row is blank) additional row header(s) .... .... For example, the text version of mo98tb6.doc starts out: Transect Parameter T-1 T-2 T-3 T-4 T-5 No. of Algal Species 2 0 2 2 2 this would appear in the mo98tb6.doc file as: Transect Parameter T-1 T-2 T-3 T-4 T-5 No. of Algal Species 2 0 2 2 2 Entity_and_Attribute_Detail_Citation: None Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: NOAA/NESDIS/National Oceanographic Data Center Contact_Person: Data Access Group, User Services Team Contact_Address: Address_Type: mailing and physical Address: SSMC-3 Fourth Floor Address: 1315 East West Highway City: Silver Spring State_or_Province: MD Postal_Code: 20910-3282 Country: USA Contact_Voice_Telephone: 301-713-3277 Contact_Facsimile_Telephone: 301-713-3302 Contact_Electronic_Mail_Address: services@nodc.noaa.gov Hours_of_Service: 8am-5pm, Monday through Friday Resource_Description: NODC Accession Number 0000173 Distribution_Liability: NOAA makes no warranty regarding these data,expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA, NESDIS, NODC and NCDDC cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: MS Excel, and ACSII CSV Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://data.nodc.noaa.gov/accession/0000173 Fees: Prices vary depending on data set, output medium and ordering mechanism. A standard handling charge, with additional costs for special handling, may be added to the basic cost of the data. Ordering_Instructions: Prepayment by check, money order or bank card is required. Orders may be placed via fax, email, regular mail, telephone or via the NNDC Online Store. Metadata_Reference_Information: Metadata_Date: 20090915 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Mr. Patrick C. Caldwell Contact_Organization: NOAA/NESDIS/NODC/NCDDC Contact_Position: Hawaii/US Pacific Liaison Contact_Address: Address_Type: mailing Address: 1000 Pope Road, MSB 316 Address: Dept. of Oceanography Address: University of Hawaii at Manoa City: Honolulu State_or_Province: Hawaii Postal_Code: 96822 Country: USA Contact_Voice_Telephone: (808)-956-4105 Contact_Facsimile_Telephone: (808) 956-2352 Contact_Electronic_Mail_Address: caldwell@soest.hawaii.edu Hours_of_Service: 8 AM to 5 PM weekdays Contact_Instructions: check services@nodc.noaa.gov if not available Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998