Title: Feasibility of identifying essential fish habitat based on acoustic monitoring of temporal and spatial patterns of sound production. Part I. Identification of soniferous species in Cape Cod waters.

Principal Investigators: Rodney A. Rountree, Department of Natural Resources and Conservation, UMASS-Amherst

Objectives: To conduct a survey of estuarine and beach waters around Cape Cod to catalogue the diversity of soniferous fishes in the region and to provide data to validate the association of specific calls with specific species. Species of special interest include Atlantic cod, haddock, striped searobin, black sea bass, bluefish and weakfish. In addition, we are likely to collect data on numerous other regional species (Table 1).

Statement of the Problem: Research aimed at the identification of fish nursery habitats has become increasing important to the management of both marine fishes and the coastal habitats themselves. The importance of this type of research has recently been emphasized by the adoption of Essential Fish Habitat (EFH) provisions by the U.S. Congress as part of the reauthorization of the Magnuson-Stevens Fishery Conservation and Management Act (Oct. 1996). Essential Fish Habitats are defined as "those waters and substrate necessary for fish for spawning, feeding or growth to maturity." The reauthorization of the Magnuson-Stevens Fishery Conservation and Management Act in 1996, therefore, has led to an explosion in research aimed at identifying fish habitats. The most rapid advances in this area have arguably been made towards defining habitats necessary for juvenile fish growth in estuarine habitats, less emphasis has been placed on identification of spawning habitats (Kneib 1997, Able 1999, Deegan et al., in press). The major obstacles to determining EFH for cryptic as well as large highly mobile fishes is that of choosing the right sampling time, gear and location out of a wide array of choices. Often knowing where to begin the search is the most difficult part of the process. For example, for many years it was thought that summer flounder larvae entering northern estuaries failed to survive the winter and that older juveniles recruited from southern nursery grounds. It was only when marsh creeks were intensively investigated that these ideas were refuted (Rountree and Able 1992). We propose that passive acoustic techniques can be a valuable tool for the identification of essential fish habitats for soniferous species. These techniques can allow for rapid surveys of large areas to pinpoint habitats frequented by soniferous species, particularly during spawning events. Further monitoring of temporal patterns in sound production would allow investigators to design conventional sampling programs targeting optimal locations and times, thus greatly increasing the efficiency of field studies. Although over 150 species of fish from 36 families are known to vocalize (Fish and Mowbray 1970), this likely represents a small fraction of the species capable of some type of vocal communication. Recent advances in acoustic technologies and acoustic tomography theory have led to increased interest in their use for in situ studies of animal behavior (Lobel et al. 1995, Mann and Lobel 1995a,b, 1997). Studies of fish sounds can provide a wealth of data on temporal and spatial distribution patterns, habitat use, and spawning, feeding, and predator avoidance behaviors. However, few in situ studies of behaviors associated with fish sounds have been attempted (Tavolga 1980). Long-term studies of sounds recorded at specific sites have been used to suggest temporal patterns in spawning events and seasonal movements (Fish et al. 1952, Breder 1968). Alternatively, investigators have attempted to locate spawning aggregations by listening for fish sounds along transects. For example, sounds produced by sciaenid fishes during spawning have been used to locate spawning aggregations and identify critical estuarine spawning habitats (Saucer and Baltz 1993, Luczkovich et al. 1999). The technique of identifying essential fish habitat through location of vocal individuals and/or aggregations is especially promising for cryptic species that are otherwise poorly studied with conventional methods. Unfortunately the utility of this approach is hampered by the lack of well-described sound characteristics for most marine fishes. Quantification of the correlations between specific behaviors and specific sounds are particularly lacking. This problem is so critical that it has lead to the publication of temporal and habitat use patterns of fishes based on erroneous attribution of sounds to specific species (Grant Gilmore, Dynamic Corporation, Kennedy Space Center, Fl, Personal Communication, Joseph Luczkovich, East Carolina University, Greenville, NC, Personal Communication). Therefore, before acoustic monitoring of fish sounds can be used to provide EFH data for New England species, data validating their sound characteristics must be obtained.

Methodology: The soniferous activities of fishes will be monitored in day and night sampling within the coastal waters of Cape Cod on a periodic basis throughout the year. Sampling will be conducted from shore on beaches, docks, piers and canals as well as from small boats within the inshore coastal waters. Fish sounds will be collected using a portable hydrophone and recorded either to standard cassette tapes (when collected audio only data) or to VHS videotapes (when simultaneously collecting audio and video). Sampling methodologies will be based on successful pilot trials recently conducted by the PI in New Jersey and Cape Cod estuaries. An underwater video camera equipped with infrared lights for night viewing and an underwater hydrophone (Bandwidth 12-35,000 Hz, sensitivity -161db) will be used to simultaneously capture audio and video data for recording to a portable VCR. A Sea-Trak GPS video overlay interface will allow the video recording to be continuously stamped with data from the GPS, including time, date, and location. This will provide valuable documentation during audio and video data post-processing (a major improvement over the pilot trials conducted this summer and fall). When using a small boat, the engine will be shut down at each sampling location to reduce audio disturbance. Audio/video monitoring will be conducted from either an anchored or drifting boat, depending on the situation. Environmental data will also be collected at this time, including depth, temperature, salinity, and turbidity. At each shore, or boat, sampling location data will be collected using one of four methods 1) undisturbed natural control method, 2) attraction of fishes to the camera with bait chum, and 3) attraction of predators to the camera with a tethered live bait (shrimp, crab, or commercially available live bait fishes), and 4) hook-n-line fishing for fishes to record stress sounds during capture (audio only). These methods have proven effective in the preliminary trials and have provided preliminary in situ data to verify the calls of black sea bass, striped searobin, scup and weakfish to date. The first method simply provides data on sounds produced at a location prior to the introduction of baits and will be used prior to the other methods at each location whenever possible. Bottom fishes such as searobins, black sea bass, tautog and scup are particularly well attracted to chum cans placed in front of the camera, while tethering live bait works better for more mobile predators like bluefish, weakfish and striped bass. Tethering provides the interesting bonus of allowing us to record the attack behavior of these predators. Although it is generally difficult to get video recordings of fishes captured by hook-n-line in low visibility waters, it is possible to correlate the timing of calls with the timing of capture to verify distress calls of fishes. Because it is relatively easy to monitor the sound of fishing lines hitting the water (even over relatively great distances and in very noisy environments), the sound of fish fighting the line, and often the sound of fishes being thrown back into the water, another bonus from the study may be the demonstration of the potential of acoustic techniques to monitor fishing activities (particularly from fixed shore points like bridges, docks and piers).

We expect to obtain sufficient data to describe the in situ sounds produced by the target species in the Cape cod area and to publish a paper demonstrating the usefulness of passive recording of fish sounds as a tool for the identification of essential fish habitats, as well as for the study of the soniferous behavior of fishes. These findings would support future proposals to Sea Grant and NURP to utilize these techniques to study habitat use patterns of estuarine and coastal marine fishes in the region.

Literature cited

Able, K.W. 1999. Measures of juvenile fish habitat quality: examples from a National Estuarine Research Reserve. Pp. 134-147. In: L.R. Benaka (ed.). Fish habitat: essential fish habitat and rehabilitation. American Fisheries Society, Symposium 22, Bethesda, Maryland.

Breder, C.M., Jr. 1968. Seasonal and diurnal occurrences of fish  sounds in a small Florida Bay. Bull. Am. Mus. Nat. Hist. 138(6):329-278.

Deegan, L.A., J.E. Hughes and R.A. Rountree. (in press). Salt marsh support of marine transient species: fact or fiction? In: Weinstein, M., and D. Kreeger (eds). Proceedings of the Special International Conference: Concepts and Controversies in Tidal Marsh Ecology, held April 5-9, 1998 at Vineland, NJ

Fish, M.P., A.S. Kelsey, Jr., and W.H. Mowbray. 1952. Studies on  the production of underwater sound by North Atlantic coastal fishes. J. Mar. Res. 11:180-193.

Fish, M.P., and W.H. Mowbray. 1970. Sounds of Western North  Atlantic fishes. Johns Hopkins Press,Baltimore, MD. 205 p.

Hawkins, A.D., and K.J. Rasmussen. 1978. The calls of gadoid fish. J. Mar. Biol. Ass. U.K. 58:891-911.

Kneib, R.T. 1997. The role of tidal marshes in the ecology of estuarine nekton. Oceanography and Marine Biology: an Annual Review 35:163-220.

Lobel, P.S., and D.A. Mann. 1995. Spawning sounds of the damselfish, Dascyllus albisella (Pomacentridae), and relationship to male size. Bioacoustics 6(3):187-198.

Luczkovich, J.J., M.W. Sprague, S.E. Johnson, and R. C. Pullinger. 1999. Delimiting spawning areas of weakfish Cynoscion regalis (Family Sciaenidae) in Pamlico Sound, North Carolina using passive hydroacoustic surveys. Bioacoustics 10:143-160.

Mann, D.A., J. Bowers-Altman, and R.A. Rountree. 1997. Sounds  produced by the striped cusk-eel Ophidion marginatum (Ophidiidae) during courtship and spawning. Copeia 1997(3):610-612.

Mann, D.A., and P.S. Lobel. 1995a. Passive acoustic detection of  fish sound production associated with courtship and spawning. Bull. Mar. Sci. 57(3):705-706.

Mann, D.A., and P.S. Lobel. 1995b. Passive acoustic detection of  sounds produced by the damselfish, Dascyllus albisella (Pomacentridae). Bioacoustics 6:199-213.

Mann, D.A., and P.S. Lobel. 1997. Propagation of damselfish (Pomacentridae) courtship sounds. J. of the Acoustical Society of America 101(6):3783-3791.

Rountree, R.A., and K.W. Able. 1992. Foraging habits, growth, and temporal patterns of salt marsh creek habitat use by juvenile summer flounder in New Jersey. Transactions of the American Fisheries Society 121(6):765-776.

Saucier, M.H., and D.M. Baltz. 1993. Spawning site selection by  spotted seatrout, Cynoscion nebulosus, and black drum, Pogonias cromis, in Louisiana. Env. Biol. Fish. 36:257-272.

Tavolga, W.N. 1980. Hearing and sound production in fishes in  relation to fisheries management. P.102-123, In: Bardach, J.E., J.J. Magnuson, R.C. May, and J.M. Reinhart (eds.). Fish Behavior and its use in the capture and culture of fishes. ICLARM Conference Proceedings 5, 512 p. International Center for Living Aquatic Resources Management, Manila, Philippines.

Table 1. Partial list of species known to be capable of sound production based on field and/or laboratory studies, and which occur at least seasonally in New England (Long Island to Maine) estuarine and shelf waters (Fish et al. 1952, Fish and Mowbray 1970, Hawkins and Rasmussen 1978, Tavolga 1980, Mann et al. 1997).  *Sound production capability assumed based on the presence of anatomical structures usually associated with vocalization. Primary target species are shown in bold type. ⁺Secondary target species.