Did you know that fishes make sounds? In fact, over 150 species on the East Coast of the U.S. can vocalize. And that's likely to be a vast underestimate, because few scientists have attempted to study fish sounds in our temperate coastal waters. Did you know that many fishes, right here on Cape Cod are highly vocal (see list in Table 1)? In this demonstration you will get to hear the sounds of just a few of the vocal species on Cape Cod (see illustrations below).

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.

 Click on the fish illustration to hear an example of its sound.

The haddock is an important commercial species in New England. It, like its close relative the Atlantic cod, is highly vocal. Cod and haddock vocalize primarily during the spawning season, when males set up temporary territories and defend them against rival males. Females are attracted by the male's call. Both species, like most gadids (cod fishes and hakes), have a large highly specialized "sonic" muscle that they use to drum against the swim bladder to produce a "thumping" or drumming sound (Figure 1). Work by Tony Hawkins and his colleagues in Europe have shown that haddock have a complex vocal behavior pattern that can be used to identify specific stages of courtship (Fig. 2).

Figure 1. Haddock sonic muscles (from Templeman and Hodder 1958).

The striped cusk-eel is a highly vocal species thought to occur from New York to Florida. However, my recent work on Cape Cod reveals that this species is also very abundant in our estuarine and coastal waters. In fact, it is very abundant right here in the Waquoit Reserve. Cusk-eels are nocturnal and only come out of their burrows at night. Male cusk-eels set up a loud chorus at sunset during the summer to attract females for mating. They spawn nearly every night, with the female laying a small clutch of eggs in a gelatinous mass that looks just like a Ctenophore (comb jelly).

The crevalle jack is a summer visitor to Cape Cod. The juveniles grow rapidly during the summer and migrate south in the fall. This species is highly vocal, and fishers often hear it protesting loudly when caught by hook-n-line. Little is known of its vocal behavior.

The weakfish is a prized gamefish from New England to Florida. It is a member of the large family of "drum" fishes (Sciaenidae) which are important fishery species, especially in the south. Like most of the drum fishes, the weakfish is highly vocal and produces vigorous croaking sounds when threatened and during spawning.

The striped searobin and its cousin the northern searobin are prolific sound producers. Have you ever caught one while fishing, only to hear it loudly yelling for its freedom? Little is known about this abundant and beautiful fish.

The longhorn sculpin produces a quite, but obvious sound when handled. Commercial fishers call it the "buzz bomber" because it buzzes and vibrates in your hand when held. Little is known about the vocal behavior of this abundant northern fish. Until recently no one even knew how the fish produced its sound!

The northern puffer is unusual in many ways. The kids will love its distinctive sound! It also occurs from Cape Cod to Florida. Unfortunately, nothing is known about its vocal behavior.

Why should scientists, and YOU for that matter, care about fish sounds?

1) Applications

1. Location of calling fishes allows identification of essential fish habitat (EFH)
2. Continuous monitoring allows determination of daily and seasonal activity patterns
3. Together with underwater video allows more detailed studies of fish behaviors
4. Can be used to passively monitor anthropogenic impacts on EFH, and fish reaction to fishing activities
5. With data on the sound characteristics of specific behaviors, can allow researchers to examine all of the above in regards to a specific behavior (e.g., spawning)

1. Advantages
1. Non-destruction, non-invasive
2. Inexpensive relative to other technologies
3. Long-term data acquisition capabilities
4. Capability of remote monitoring
5. High profile educational tool, increased public interest
6. Works at night without bias (versus video)

 

2. What can you do with the data?
1. Web access to time-lapse or real time fish sounds - education and public interest
2. Supplement long term monitoring of species diversity, particularly of cryptic soniferous species
3. Seasonal temporal patterns of occurrence at a locality (i.e., when species first occur/or first become vocally active)
4. Daily cycle in vocal activity
5. Infer temporal patterns of local spawning for species with tight correlations between specific calls and spawning behavior
6. Monitor temporal patterns in noise pollution at each locality
7. Monitor sources of noise pollution (passing ships, small boats, trawling, scalloping, other activities can be distinguished)
8. Examine potential impact of noise pollution on soniferous behaviors such as spawning activity
9. With a single simple omni-directional hydrophone can get crude indicator of species abundance/spawning intensity (much more information can be derived from more sophisticated array systems)