Museum Teclinical Report No. 45 STATUS SURVEY OF THE PEARL DARTER (PERCINA AURORA) IN THE FASCAGOULA RIVER SYSTEM Henry L. Bart, Jr. and Royal D. Suttkus Department ofBiology Tulane University New Orleans, LA Funded by U. S. Fish and Wildlife Service Project No. E-1, Segment 10 Mississippi Department ofWildlife, Fisheries, and Parks Museum ofNatural Science 111 N. Jefferson Street Jackson, MS 39201 1996 FINAL PROJECT REPORT STATE; Mississippi Project El-1, Segment 10 STUDY TITLE: Status Survey of the Pearl Darter {Percina aurora) in the Pascagoula River System PRINCIPAL INVESTIGATORS: Henry L. Bart, Jr. and Royal D. Suttkus PROBLEM AND NEED STATEMENT The Pearl darter, Percina aurora is a recently described species closely allied to the channel darter, Percina copelandi (Suttkus et al. 1994). The species is known only from the Pearl and Pascagoula river drainages in Louisiana and Mississippi. It has long been the subject of conservation concern because itis uncommon, infrequently collected, andwhen found, usually occurs in low numbers. Deacon et al. (1979) and Williams et al. (1989) assigned the Pearl darter the status of "threatened" due to "present and threatened habitat destruction in Louisiana and Mississippi." Gilbert and Burgess (1980) referred to the species as extremely rare and bordering on extinction. The species does appear to have been eliminated from the Pearl River drainage. The last time pearl darters were collected from that system was August 1973, this despite the fact that one of us (RDS) has been taking any as 64 fish collections per year from middle and lower reaches of the Pearl River since that time in connection with environmental monitoring work. Collecting efforts in the Pascagoula River drainage have been infrequent in comparison to efforts in the Pearl River drainage. Pascagoula River records of P. aurora in the Tulane Fish collection cover the period August 1958 to April 1987, but represent far fewer lots (10) and specimens (45) than the lot (121) and specimen (544) totals from the Pearl River drainage. Dr. Stephen T, Ross and students at the University of Southern Mississippi (USM) have collected p. aurora on several occasions since that time. The more recent dates of collection of P. aurora in the Pascagoula River system suggests that species still survives there. However, little else is known about the status of the Pascagoula River population. STUDY OBJECTIVES This study was conducted to assess the status of the Pascagoula River population of the Pearl darter, and to assemble other necessary information for evaluating the Pearl darter for possible federal listing. The objectives were to determine present Pascagoula River system distribution of the species and relate this to the historical distribution; determine critical habitat requirements of the species; and assess adverse man-made or natural impacts on remaining stocks. METHODS Records of all previous collections of the Pearl darter in the Pascagoula River drainage were assembled. Specimens in all but two of the lots were examined by us to verify the taxonomic identification. In the other two cases, the identity of specimens was confirmed by ichthyologists at the institutions where the specimens are housed. Sites in the Pascagoula River system where the Pearl darter was previously collected, and other nearby sites, were surveyed to determine the species present distribution and status. Most of the collections were made with small seines, the primary sampling gear used by earlier workers. A backpack electrofisher was used to sample sites with rocky outcrops. We sampled over substrates that we expected to produce Percina in general and P. aurora in particular. This included shallow gravel riffles and rock outcrops, deep gravelly to sandy channels and pools below shallow riffles. We planned to measure habitat conditions (depth, current, substrate, structure) in the vicinity of all Pearl darter captures. Measurements were to be made at 1 m intervals along five cross-stream transects spaced 1-m apart. RESXJLTS AND DISCUSSION Summary of Pascagoula River Drainage Records of Percina auroroai A total of 45 specimens of P. aurora has been taken from the Pascagoula River Dr. to date. Records for these collections are summarized below bycounty, lot (catalog) number with institutional acronym, number of specimens (in parentheses), location, and date. Institutional acronyms are as follows: NLU = Northeast Lx>uisiana University; TU = Tulane University Museum of Natural History; USM = University of Southern Mississippi; USNM = United States National Museum; UT = University of Tennessee. JACKSON COUNTY: USNM 129182 (6), Pascagoula R. at Dead Lake, collected by Samuel F. Hildebrand, 12 May 19^33. STONE COUNTY: TU 144228 Black Cr. at large loop along right bank, SE Board and Horseshoe lakes (T2S, RlOW, Sec 2), 30 November 1985^ PERRY COUNTY: TU 144698 {1), Black Cr. at Miss Hwy 318 (TIS, RlOW, Sec 34), 4 April 1986, and TU 148420 (3), 24 April 1987. USM 8148 (3), Leaf R., 1.1 mi downstream of Wingate Bridge, 23 October 1989; USM 9137 (1), Leaf R., 2.8 mi below Hwy 29, 7 August ELi- •• •• 1990; USM 9575 (1), LeafR., 4.6 mi above Hwy 29, 2 August 1990: USM 8785 (2), LeafR., 5 mi upstream from Hwy 29, 9 March 1^. COVINGTON COUNTY: USM 6151 (2), Okatoma Cr., 1.2 airmi SSanford, 5October 1979. GEORGE COUNTY: USM 4293 ^), Pascagoula R., 1.3 mi above Jackson County line, 23June 1988; TU 65841 (3), Pascagoula R., \i 6 mi SE Benndale (T3S, R8W, Sec 1), 14 November 1970, and TU 89772 (2), 13 July 1^; TU 100135 (^, Pascagoula R. along right bank opposite Merrill (TIS, R7W, Sec 19), 22 October 1976; TU 100159 (2), Pascagoula R. and lower Leaf River along right bank, 0.5 mi W Merrill (TIS, R7W, Sec 19), 22 October 1^7^ and TU 100202 ^ 29 October 1976. JONES COUNTY: NLU 20547 (^, Leaf R. at mouth of Eastabutchie Branch (T6N, R13W, Sec 33), 7 October 1971; USM 17286 1/2 km downstream of Eastabutchie Bridge, 17 October 1994 (identity verified by Stephen T. Ross, University of Southern Mississippi). GREENE COUNTY: USM 4444 (1), Chickasawhay R. at bend about 1.8 mi above Mineral Branch, 6 August 1^88; USM 4242 Chickasawhay R., 3.3 mi above Mineral Branch, 19 June 12SS; USM 4975 (1), Chickasawhay R., 4.6 mi below Hwy 63, 17July 1988. CLARKE COUNTY: TU 19379 (1), Chickasawhay R. at US Hwy 45, 1 mi S Shubuta (TION, R7W, Sec 10), 21 August 1958. LAUDERDALE COUNTY: TU 121097 (J), Chunky Cr., 4 mi NUS Hwy 11 at Enterprise (T5N, RUE, Sec 36), 18 August 1979; UT 91.2159 (1^ Chunky Cr. at Interstate Hwy 59, 18 May 1981 (identity verified by David A. Etnier, University of Tennessee). Field Survey of sites of previous capture: A total of 30 collections was made between 18 September and 21 December 1996. Collections were made at all 19 sites of former capture, and 11 new sites that were either close to sites of previous capture or appeared to offer favorable habitat. Collecting effort was confined to fall and early winter to take advantage of low stream flows and to minimize impact on young and reproductive age fish. Ten of the collections were preserved and are now archived at TU for permanent record. Number of specimens in the lOafeinved collections total 2239. At the other collections sites, fish were identified in the field and released-aljve. Pearl darters were not taken or seen in any of the collections made during this survey. The most recent collection was a single adult specimen collected from the Leaf River below Eastabutchie Bridge in October 1994 by students of Dr. Ross of USM. Except for the omission of the pearl darter, faunal composition does not appear to have changed much at prior collection sites. Four species of Percina were encountered: the freckled darter, P. lenticula; the black banded darter, P. nigrofasctata; the dusky darter, P. sciera; and tjje-saddlebackrdarter^ P. vigitrJnThe^ent survey, darters accounted for between 17 and 46 percent of total catch (mean = 31%) at sites with extensive hard substrate (gravel and rocky outcrops), Percina spp. accounted for between 8 and 31 percent of catch (mean = 17%). Darters and Percino. made up much smaller proportions of samples from sites with extensive sand and limited gravel/rock bottom (averaging 5% and 2.5% of catch, respectively). The percentages are comparable to those recorded in the previous collections. Previous collecting efforts suggest that the pearl darter is extremely rare in the Pascagoula River drainage. Only 19 pearl darters were taken out of 19,300 total fish in the 10 previous TU collections containing the species. This translates to roughly 2 specimens per. collection or 0.01% ofall fish in the 10 collections. Dr. Ross and students at USM provided an estimate of rarity of P. aurora based on total sampling effort in streams in the Pascagoula River drainage known to support the species (data from the "Mississippi Freshwater Fishes database ). Out of379 collections taken since 1974 totalling 81,514 fish specimens (all species) from mainstem portions ofthe Chunky, Leaf, Pascagoula, and Chickasawhay rivers, and Black and Okatoma creeks (possibly including some coliectfeft^j^m upper reaches of the latter two creeks where the pearl darter likely does not naturally occur), pearTdaftej^s^? in all) were taken in only 10 collections (2.6% of collections). This translates to only one capture of 1.7 specimens in every 38collections (W.T. Slack personal communication). Divided over thetotal number of specimens, only one pearl darter was taken for every 4,795 specimens (0,02% of all specimens taken). This suggest that 30 collections over the span of three months (our effort) is not a sufficient amount of effort to produce specimens of P. aurora. The4au^gestliumber of individuals taken at any one time in the Pascagoula River drainage was six individuals taken by Samuel Hildebrand in the^owerJPascagoulaJEiive in 1933.