Sound localization and auditory response capabilities in the round goby (Neogobius melanostomus).

A fundamental role of vertebrate auditory systems is determining the direction of a sound source. While fish show directional responses to sound, sound localization remains in dispute. Determining directionality is the ability to distinguish between the left or right side, while localization is being able to determine where in space the origin is. The species used in the current study, Neogobius melanostomus (round goby) uses sound in reproductive contexts, with both male and female gobies showing directed movement towards a calling male. A two-choice laboratory experiment was used (active versus quiet speaker) to analyze behaviour of gobies in response to sound stimuli. When conspecific male spawning sounds were played, gobies moved in a direct path to the active speaker, suggesting true localization to sound. Of the animals that responded to conspecific sounds, 85% of the females and 66% of the males moved directly to the sound source. Auditory playback of natural and synthetic sounds showed differential behavioural specificity. Of gobies that responded, 89% were attracted to the speaker playing Italian goby (Padogobius martensii) sounds, 87% to a 100 Hz tone burst, 62% to white noise, and 56% to black goby (Gobius niger) sounds. During the round goby call, swimming speed to the playing speaker was doubled, and the angle standard deviation was two times more direct than during any other sound playback. Results suggest a strong localization of the round goby to a sound source, with some differential sound specificity. This research is the first to explicitly quantify the ability of a fish to localize a sound source.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .R65. Source: Masters Abstracts International, Volume: 44-03, page: 1304. Thesis (M.Sc.)--University of Windsor (Canada), 2005

Development of form and function in peripheral auditory structures of the zebrafish (Danio rerio)

Investigations of the development of auditory form and function have, with a few exceptions, thus far been largely restricted to birds and mammals, making it difficult to postulate evolutionary hypotheses. Teleost fishes represent useful models for developmental investigations of the auditory system due to their often extensive period of posthatching development and the diversity of auditory specializations in this group. Using the auditory brainstem response and morphological techniques we investigated the development of auditory form and function in zebrafish ~Danio rerio) ranging in size from 10 to 45 mm total length. We found no difference in auditory sensitivity, response latency, or response amplitude with development, but we did find an expansion of maximum detectable frequency from 200 Hz at 10 mm to 4000 Hz at 45 mm TL. The expansion of frequency range coincided with the development of Weberian ossicles in zebrafish, suggesting that changes in hearing ability in this species are driven more by development of auxiliary specializations than by the ear itself. We propose a model for the development of zebrafish hearing wherein the Weberian ossicles gradually increase the range of frequencies available to the inner ear, much as middle ear development increases frequency range in mammals

Biotic and Human Vulnerability to Projected Changes in Ocean Biogeochemistry over the 21st Century

Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions

Differential acoustic response specificity and directionality in the round goby, Neogobius melanostomus

The ability to differentiate and localize conspecific calls from the ambient soundscape is particularly challenging for aquatic animals because of the increased wavelength, and concomitant increased distortion, of sound underwater. The increased wavelength is especially problematic for fish because of the relatively small space between their two ears, making interaural comparisons difficult. We presented round goby with conspecific calls, two heterospecific calls (Padogobius bonelli and Gobius niger), white noise and a 100 Hz tone burst to ascertain the effects of sound structure on localization abilities. The round goby has no obvious hearing specializations, causing theory to predict that it should not be able to localize sounds. In the laboratory, fish were presented with a silent speaker and a speaker playing one sound of interest and their behavioural response was quantified. In all trials except those using Gobius niger calls, fish preferentially selected the playing speaker over the silent but the intensity of this response differed with sound type. When the round goby call was played, fish came closer to the speaker and swam faster when responding. Also, the ability to directionalize the sound, measured by examining the path taken to the speaker, was significantly better when the conspecific call was played than when other sounds were presented. While it is still unclear how the round goby is able to directionalize the conspecific call, it appears clear they can directionalize, and possibly localize, conspecific calls as well as differentiate between call types

Attraction and localization of round goby (Neogobius melanostomus) to conspecific calls

Many species of fish use auditory cues as part of their reproductive repertoire but intended receivers must be able to localize sounds to make full use of this information. Specialized couplings between the ear and swim bladder are thought to be critical for acoustic localization, yet species without specialized connections use acoustic cues in reproductive displays. In an attempt to better understand mechanisms of acoustic localization, we used the round goby (Neogobius melanostomus), a hearing generalist, to assess responses to calls in the lab and field. The call used for playback was recorded in the field from an actively displaying male round goby and consisted of a series of low frequency pulses. In the field, playback of the call resulted in a significant enhancement of approaches toward, and entries into, an experimental arena as compared to when the sound was off. There was no effect on the amount of time spent near the speaker however. In the lab, males and females responded actively when calls were played and females showed a significant attraction to the playing speaker. Responses were highly directional with little angular deviation, suggesting true localization to the sound source. While the sensory mechanisms allowing round gobies to selectively respond to conspecific vocalizations remain unknown, it is clear that they do show highly directional responses to acoustic cues in both laboratory and field settings

FishTrack22: An Ensemble Dataset for Multi-Object Tracking Evaluation

Tracking fish in optical underwater imagery contains a number of challenges not encountered in terrestrial domains. Video may contain large schools comprised of many individuals, dynamic natural backgrounds, variable target scales, volatile collection conditions, and non-fish moving confusors including debris, marine snow, and other organisms. Lastly, there is a lack of public datasets for algorithm evaluation available in this domain. FishTrack22 aims to address these challenges by providing a large quantity of expert-annotated fish groundtruth tracks, in imagery and video collected across a range of different backgrounds, locations, collection conditions, and organizations. Approximately 1 million bounding boxes across 45k tracks are included in the release of the ensemble, with potential for future growth in later releases

Design and implementation of a Bottomfish Fishery independent survey in the Main Hawaiian Islands

Commercial and recreational fishing are important to the economy and culture of Hawaii. The deep-slope bottomfish commercial fishery preferentially targets seven high value "Deep-7" species (i.e, six snappers and one grouper, hereafter referred to as bottomfish). The NOAA Pacific Islands Fisheries Science Center (PIFSC) Stock Assessment Program is responsible for regularly conducting assessments of bottomfish. To improve abundance estimates, Ralston et al. (2004) recommended development of a fishery-independent survey using available "advanced technologies". This goal of this technical report was to improve stock assessments through optimal design and implementation of a bottomfish fishery-independent survey for the Deep-7 bottomfish complex in the main Hawaiian Islands (MHI) with three primary objectives: 1. Evaluate the most effective survey gears for obtaining species-specific spatial sizestructured abundance metrics of the Hawaiian bottomfish stock; 2. Conduct quantitative gears intercalibration studies to determine the relative fishing power of the multiple gears to be used in the survey; 3. Detail the required methodologies for efficient conduct of a multi-gear fisheryindependent survey of the MHI bottomfish stocks

The Modular Optical Underwater Survey System

The Pacific Islands Fisheries Science Center deploys the Modular Optical Underwater Survey System (MOUSS) to estimate the species-specific, size-structured abundance of commercially-important fish species in Hawaii and the Pacific Islands. The MOUSS is an autonomous stereo-video camera system designed for the in situ visual sampling of fish assemblages. This system is rated to 500 m and its low-light, stereo-video cameras enable identification, counting, and sizing of individuals at a range of 0.5–10 m. The modular nature of MOUSS allows for the efficient and cost-effective use of various imaging sensors, power systems, and deployment platforms. The MOUSS is in use for surveys in Hawaii, the Gulf of Mexico, and Southern California. In Hawaiian waters, the system can effectively identify individuals to a depth of 250 m using only ambient light. In this paper, we describe the MOUSS’s application in fisheries research, including the design, calibration, analysis techniques, and deployment mechanism

National Oceanic and Atmospheric Administration Report 53

The following document conducts stock assessment reports on deep-slope bottomfish along the State of Hawaii. The goal of this report is to improve stock assessments through optimal design and implementation of a fishery-independent survey for the Deep-7 bottomfish complex in the main Hawaiian Islands