Oceanography Commons^™

Evaluating The Fish Aggregation Effect Of Wind Turbine Facilities By Using Scientific Echo Sounder In Nanlong Wind Farm Area, Western Taiwan, Ting-Chieh Huang, Hsueh-Jung Lu, Jia-Rong Lin, Shih-Hsuan Sun, Kou-Wei Yen, Jing-Yi Chen

Journal of Marine Science and Technology–Taiwan

During the stages of construction and operation of the wind power facilities, fishery and fishery resources in the wind farm areas will certainly be changed greatly. One of the major concern is the aggregation effect of wind turbines facility. We use scientific echo sounder together with scuba diving to survey fish aggregations in the wind farm areas. In order to obtain echoes very near the facility, we use tilt beam angle instead of traditional vertical one. Variation of target strength varies while using tilted beam angle were discussed both by ex-situ and in-situ experiment. In ex-situ experiment, we measured TS …

Site Fidelity And Return Trips Of Visually And Olfactorily Inhibited Black Rockfish (Sebastes Schlegelii) Individuals Tracked By Acoustic Telemetry, Mitsuki Kuroda, Yoshinori Tatsu, Yuya Ueda, Hokuto Shirakawa, Kenji Minami, Kazushi Miyashita, Makoto Tomiyasu

Journal of Marine Science and Technology–Taiwan

For fish of the genus Sebastes, which have strong site fidelity, understanding the characteristics of their return trips and how their sensory cues influence behavior will be useful for conservation and resource management. Here, we conducted a behavioral tracking study for the black rockfish Sebastes schlegelii using acoustic telemetry and sensory inhibition. We compared aspects of the return process for individuals in a control group (CNT), and fish in blind (BLD) and olfactory inhibition (OLF) conditions. Nine individuals were released 850 m from the fishing site, and all of them returned. However, the time taken to complete the return varied, …

Geospatial And Acoustic Application In An Artificial Reef Site Of South Korea, Myounghee Kang, Rina Fajaryanti, Kyounghoon Lee, Eun-A Yoon, Woo-Seok Oh, Eunbi Min, Young-Jae Shin, Yong-Suk Choi, Byung-Ho Yi, Hui Zhang, Doojin Hwang

Journal of Marine Science and Technology–Taiwan

Artificial reefs are important since they provide additional habitat leading to increasing abundance and biomass of marine biota. In a Bukchon artificial reef, Jeju Island, South Korea, environment data, artificial reef properties, and acoustic data in four seasons were integrated to visualize and examine their connections using a geographic information system (GIS). As a result, regarding the spatial and temporal distributions of fishes, January had the lowest Nautical Area Scattering Coefficient (NASC, m2/nm2) and June had the highest NASC, and relatively high NASC was observed from 5 to 30 m deep throughout seasons. The influential circle (effective distance from reef) …

Rapid Warming Events In A Small Coastal Upwelling Embayment, Tatjana E. Ellis

Physics

Temperature variability in the nearshore coastal ocean influences various biological processes and can drive changes in biodiversity and habitat range. Despite recent progress, there are still significant gaps in the understanding of drivers of temperature variability in upwelling bays, particularly at higher frequencies. In this study, we analyzed a decade of nearshore temperature measurements both inside and outside a small coastal embayment located in central California [San Luis Obispo (SLO) bay], as well as temperature data from satellites, to characterize rapid warming events. We found that rapid warming events, defined using rates of temperature change across different thresholds, occurred more …

Spatial And Temporal Variability Of Circulation Patterns Within A Small Coastal Embayment During An Upwelling/Relaxation Cycle, Laurent F. Siroit

Physics

In eastern boundary current systems, wind-driven coastal upwelling is the dominant diver of physical, chemical, and biological variability. Near coastal embayments, complex circulation patterns develop during upwelling forcing, and time-dependent descriptions of these patterns for smaller systems (i.e., width and length scales ≤ 20 km) are limited. In this study, we analyze surface and subsurface current patterns in relation to upwelling wind forcing in San Luis Obispo (SLO) Bay, a small coastal upwelling embayment in central California, to investigate the formation and evolution of an upwelling jet and surface current convergence region during a large upwelling-relaxation event. We found that …

Comparison Of Fish Assemblages Aggregated By Artificial Reefs Using Scuba Diving And Acoustic Surveys, Hsueh-Jung Lu, Jia-Rong Lin, Ting-Chieh Huang, Sunarti Sinaga

Journal of Marine Science and Technology–Taiwan

To determine the aggregation effect of artificial reefs (ARs), we conducted surveys in 16 artificial reefs in Taiwan by using the scientific echo sounder, Simrad EY-60 (200 KHz), along with sighting by scuba divers. Scuba diving was conducted within the reef structures (r ¼ 20 m), whereas acoustic surveys were conducted over a wider range (r ¼ 100 m), with five repeating transects over the ARs. We compared the results obtained from the two methods among 16 artificial reefs in the coastal waters of Taiwan to determine the consistency of the quantitative information between the two methods and to investigate …

Study On The Behavior Of Peled (Coregonus Peled ) Around A Set Net By Ultrasonic Biotelemetry System In A Plateau Lake, China, Jing Liu, Keiichi Uchida, Leiming Yin, Yong Tang, Yoshinori Miyamoto, Binbin Xing

Journal of Marine Science and Technology–Taiwan

Sayram Lake is a plateau cold-water lake located in northwestern China. Peled (Coregonus peled ) was introduced to Sayram Lake from Russia in 1998. The behavior characteristics of peled in Sayram Lake are important for fishery resource proliferation, effective fishing, and sustainable development. In this study, we used an ultrasonic biotelemetry system to track the fish around a large-scale set net in Sayram Lake. The purpose of this study is to study the behavior characteristics of the peled and to provide suggestions for the improvement of the set net. The results showed that the fish released in the playground of …

Seasonal Dynamics In Fish Distribution And Abundance Revealed By An Acoustic Survey In Coastal Waters Of The Suzu Area, Kochi Prefecture, Japan, Yanhui Zhu, Kenji Minami, Yuka Iwahara, Kentaro Oda, Koichi Hidaka, Osamu Hoson, Koji Morishita, Sentaro Tsuru, Masahito Hirota, Hokuto Shirakawa, Kazushi Miyashita

Journal of Marine Science and Technology–Taiwan

For Japan's fishery, it is essential to conduct sustainable and efficient fishery owing to the decline in fish catch as well as the fisher population. To obtain information that contributes to sustainable and efficient fishery, we researched appropriate set-net locations with regard to fish distribution, abundance, and environmental characteristics. We conducted surveys from 2017/5 to 2018/2 in the Suzu coastal area, Kochi Prefecture, where the only main industry is set-net fishery. We investigated the seasonal relationships between fish school characteristics, including distribution and size, and marine environmental conditions in the Suzu coastal area, using a quantitative echo sounder (KSE300 SONIC, …

Development Of A Biomass Assessment Method Using Fisheries Echo Sounder For Monitoring Whitebait Fishery In Shizuoka Prefecture, Japan, Kenichi Kobayashi, Yanhui Zhu, Daichi Oshiyama, Kenji Minami, Hokuto Shirakawa, Kazushi Miyashita

Journal of Marine Science and Technology–Taiwan

Coastal fisheries constitute the second most important sector in fishery production in Japan, following offshore fisheries. Thus, spatial evaluation of coastal fishing grounds and understanding of the changes in biomass are important for the sustainable use of fishing resources. For the assessment of spatial fish biomass, a quantitative echo sounder is used, but such a device is not mass produced and involves a high cost. In the present study, we examined the feasibility of biomass assessment using typical commercial fisheries echo sounders that are widely used and cheaper than quantitative echo sounders. Therefore, we aimed to verify the validity of …

Acoustic Survey For Estimating Density Of Anchovy Schools In The South Sea Of Korea, Eunbi Min, Eun-A Yoon, Sung-Tae Kim, Seong Yong Moon, Hyun Woo Kim, Shelly Salim, Taejong Kang, Doo-Jin Hwang

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Estimating The Sampling Efficiencies Of A Framed Midwater Trawl And Ring Net For Zooplankton Using An Acoustic Method, Zhen Lu, Tohru Mukai, Yasuzumi Fujimori, Kohji Iida

Journal of Marine Science and Technology–Taiwan

It is well known that there is bias using different sampling gear, such as a framed midwater trawl (FMT) and a ring net, when measuring the density and length distribution of target species. This limit is characterized by the sampling efficiency of the gear. Acoustic monitoring can be used to determine the sampling efficiencies of this gear, as its noninvasive, wide-range sweeps provide more reliable estimates of absolute abundance of the target species. The density measured by the gear can then be standardized by multiplying the initial density measurement by the derived sampling efficiency. In this study, we compared the …

In Situ Broadband Acoustic Measurements Of Age-0 Walleye Pollock And Pointhead Flounder In Funka Bay, Hokkaido, Japan, Kohei Hasegawa, Naizheng Yan, Tohru Mukai

Journal of Marine Science and Technology–Taiwan

Measurements of the broadband acoustic backscattering from fish should improve acoustic discrimination between species. The pulse compression processing of broadband systems can be used to measure acoustic backscattering with high range resolution and improve signal-to-noise ratio. This may increase opportunities for in situ target strength (TS) measurements, the preferred method of collecting TS data. To evaluate the availability of TS spectra for acoustic discrimination, three Simrad EK80 wideband transceivers and split-beam transducers of 70, 120, and 200 kHz were used to collect in situ frequency responses of TS from age-0 juvenile walleye pollock and pointhead flounder, a swimbladderless flat-fish, distributed …

Volume Scattering And Echo Integration In Fisheries Acoustics Revisited, Masahiko Furusawa

Journal of Marine Science and Technology–Taiwan

Echo integration is the most important method in fisheries acoustics. The basis of the method is volume scattering theory, and the theory assumes that many fish are randomly and homogeneously distributed broader than a beam spread. In actual acoustic surveys, however, we encounter various distributions for which these assumptions do not hold. It is the echo integration method that hypothetically fulfills these assumptions. In this paper, we review the volume scattering theory and the echo integration method historically and theoretically and confirm their bases. We then point out some misunderstandings affected by historical constraints such as the persistence of time …

Ecosytem Services: Delivering Decision-Making For Salt Marshes, Philine S. E. Zu Ermgassen, Ronald Baker, Michael W. Beck, Kate Dodds, Sophus O. S. E. Zu Ermgassen, Debbrota Mallick, Matthew D. Taylor, R. Eugene Turner

Faculty Publications

No abstract provided.

Variability Of Usa East Coast Surface Total Alkalinity Distributions Revealed By Automated Instrument Measurements, Christopher W. Hunt, Joseph Salisbury, Douglas Vandemark, Steffen Aßmann, Christopher Melrose, Rik Wanninkhof, Kumiko Azetsu-Scott

Faculty Publications

Seawater total alkalinity (TA) is one important determinant used to monitor the ocean carbon cycle, whose spatial distributions have previously been characterized along the United States East Coast via discrete bottle samples. Using these data, several regional models for TA retrievals based on practical salinity (S) have been developed. Broad-scale seasonal or interannual variations, however, are not well resolved in these models and existing data are highly seasonally biased. This study reports findings from the first long duration deployment of a new, commercially available TA titrator aboard a research vessel and the continuous underway surface TA measurements produced. The …

Organic Matter Spatial And Temporal Patterns In Coastal Sands Of Long Bay, South Carolina, Kayla B. Christofferson

Honors Theses

Sandy coastlines serve crucial functions to coastal economies and coastal ecology alike. In the past, organic-poor sands were considered of lower importance than organic-rich muds. Recent studies showed that sands’ low organic matter concentrations are due to high biogeochemical cycling rates, driven by rapid physical exchange, but remain infrequently studied. I present time-series of sand mass-loss-on-ignition (LOI, an organic matter proxy) profiles from February 2017 onwards at multiple sites along Long Bay, South Carolina. LOI profiles exhibit subsurface maximum values, unlike the typical decrease with depth in muddy sediments. I hypothesize that organic matter distribution with depth is affected by …

Isolated Point Discharges Into Coastal Swashes As Nutrient Sources To Coastal Waters, Mary E. Olsen

Honors Theses

Coastal water quality in the Grand Strand of South Carolina is directly influenced by human activities. Nutrient-rich runoff, stemming from numerous anthropogenic sources, finds its way into coastal waters through freshwater inputs often through tidal creeks, termed swashes. In order to better describe the amount of nutrient inputs into Singleton Swash and White Point Swash, we examine anthropogenic runoff from isolated identifiable point discharges and their nutrient concentrations. We report concentrations of dissolved inorganic nitrogen (DIN, as the sum of nitrate, nitrite and ammonium) and phosphate in discharge and creek water. We hypothesize that nutrient concentrations of isolated, minor point …

Small-Scale Resuspension And Redistribution Of Surface Sediments In The Northeast Gulf Of Mexico, Austin Harris

Master's Theses

Following the release of ~4.9 million barrels of oil into the Gulf of Mexico from the Macondo wellhead, a vast area of the seafloor contained recently deposited marine sediments contaminated by the oil spill. The initial deposition of these contaminated marine sediments was likely not the end of the journey for the particles. Downslope gravitational processes and events of increased current speed in the deep ocean setting can result in recently deposited sediments to resuspend and be moved laterally with the current flow, increasing the area effected by the oil spill. Erosion experiments performed in a closed-loop resuspension flume were …

Assessing The Real-Time Lagrangian Predictability Of The Operational Navy Coastal Ocean Model In The Gulf Of Mexico, Lea Kristen Locke

Dissertations

This study quantitatively assesses the drift predictive skill of Fleet Numerical Meteorology and Oceanography Center’s (FNMOC’s) operational ocean models which are used to support a wide range of military and civilian applications. Overall, the findings of this work support the recommendation of spatial filtering for regional-scale ocean model velocity fields used in deep-water drift applications. In conjunction with filtering, the use of a pure particle drift algorithm is suggested for short-term forecasts and a drift algorithm including a sub-grid scale, random flight, parameterization for predictions requiring extended forecast predictions.

Drift prediction skill is quantified through metrics of in-cloud percentage, distance …

Microplankton Dynamics In The River-Dominated Mississippi Bight, Adam D. Boyette

Dissertations

The Mississippi Bight (MSB) is a river-dominated continental margin influenced by multiple large river systems, including the Mississippi River, Alabama and Tombigbee rivers via Mobile Bay, and numerous smaller rivers, creeks, and bayous. This is part of a biologically-rich ecosystem that supports the second largest fishery industry by volume in the United States. Despite our understanding of the linkages between primary production with higher trophic levels, there remains limited studies quantifying these trophic interactions in this system. Microplankton (µm) community dynamics and trophic connectivity between primary producers and heterotrophic protists represent a critical nexus influencing overall biological productivity in this …