<p>Sound is a key sensory modality for Hawaiian spinner dolphins. Like many other marine animals, these dolphins rely on sound and their acoustic environment for many aspects of their daily lives, making it is essential to understand soundscape in areas that are critical to their survival. Hawaiian spinner dolphins rest during the day in shallow coastal areas and forage offshore at night. In my dissertation I focus on the soundscape of the bays where Hawaiian spinner dolphins rest taking a soundscape ecology approach. I primarily relied on passive acoustic monitoring using four DSG-Ocean acoustic loggers in four Hawaiian spinner dolphin resting bays on the Kona Coast of Hawai‛i Island. 30-second recordings were made every four minutes in each of the bays for 20 to 27 months between January 8, 2011 and March 30, 2013. I also utilized concomitant vessel-based visual surveys in the four bays to provide context for these recordings. In my first chapter I used the contributions of the dolphins to the soundscape to monitor presence in the bays and found the degree of presence varied greatly from less than 40% to nearly 90% of days monitored with dolphins present. Having established these bays as important to the animals, in my second chapter I explored the many components of their resting bay soundscape and evaluated the influence of natural and human events on the soundscape. I characterized the overall soundscape in each of the four bays, used the tsunami event of March 2011 to approximate a natural soundscape and identified all loud daytime outliers. Overall, sound levels were consistently louder at night and quieter during the daytime due to the sounds from snapping shrimp. In fact, peak Hawaiian spinner dolphin resting time co-occurs with the quietest part of the day. However, I also found that humans drastically alter this daytime soundscape with sound from offshore aquaculture, vessel sound and military mid-frequency active sonar. During one recorded mid-frequency active sonar event in August 2011, sound pressure levels in the 3.15 kHz 1/3rd-octave band were as high as 45.8 dB above median ambient noise levels. Human activity both inside (vessels) and outside (sonar and aquaculture) the bays significantly altered the resting bay soundscape. Inside the bays there are high levels of human activity including vessel-based tourism directly targeting the dolphins. The interactions between humans and dolphins in their resting bays are of concern; therefore, my third chapter aimed to assess the acoustic response of the dolphins to human activity. Using days where acoustic recordings overlapped with visual surveys I found the greatest response in a bay with dolphin-centric activities, not in the bay with the most vessel activity, indicating that it is not the magnitude that elicits a response but the focus of the activity. In my fourth chapter I summarize the key results from my first three chapters to illustrate the power of multiple site design to prioritize action to protect Hawaiian spinner dolphins in their resting bays, a chapter I hope will be useful for managers should they take further action to protect the dolphins.</p> / Dissertation

Whale-watching provides economic opportunities worldwide and particularly proliferates in developing countries, such as the Philippines. The sustainability of whale-watching is increasingly debated as these activities also negatively impact cetaceans through changes in behavior, communication, habitat use, morbidity, mortality, and life-history parameters. This study evaluated the total annual cost, revenue, and profit of whale-watching operators in Bais, Philippines, and predicted the changes in the population for spinner dolphin Stenella longirostris with varying levels of whale-watching effort. Total revenue was 3,805,077 PHP ($92,478 USD) while total cost was 5,649,094 PHP ($137,294 USD) with a discount rate of ten percent. The total annual profit of whale-watching in Bais was – 1,844,017 PHP (– $44,817 USD). On average, each operator in Bais lost 160,350 PHP ($3,897 USD) per year from whale-watching. Through time, the spinner dolphin population decreased as it was exposed to more vessels, causing effort to increase, and thus decreased profit for operators. Under current whale-watching effort, the spinner dolphin population was predicted to decrease by 94 percent in 25 years. If Bais reduced effort in their operations to only three vessels whale-watching per day, the spinner dolphin population increased to 80 percent of its initial population size. This was the first study to predict the spinner dolphin population and estimate the total annual profit from whale-watching in Bais, Philippines. It provided data to locals for efficient, profitable, and sustainable decisions in whale-watching operations.

Made available in DSpace on 2014-12-17T15:36:53Z (GMT). No. of bitstreams: 1 LiisaH.pdf: 524666 bytes, checksum: 8ed111d1e268e386d58d4e05b903d400 (MD5) Previous issue date: 2009-09-12 / Studies indicate that spinner dolphins use the Ba?a dos Golfinhos, in Fernando de Noronha Archipelago, for resting, reproduction, parental care and protection against shark attacks. The present study had the purpose of verifying the seasonality of spinner dolphin newborns and calves in relation to the months of the year and the pluviometric seasons (dry and rainy), as well as their interaction with the number and gender of accompanying adults and their positioning in relation to the adults (vertical, horizontal, and depth) in the above mentioned bay. The analysis were made out of photo records of dolphins collected between 2000 and 2006 (seasonality) and between 1995 and 2006 (interaction) both using ad libitum sampling method during free dives. To determine the age category, the reason between the smaller dolphin s total body length and the bigger dolphin s total body length was calculated. The dolphins were then divided into three age groups: adults, newborns and calves. Those with total body length &#8805; 170cm were considered adults, newborns up to 105cm, and calves from 106cm to 128cm. In addition, the secondary characters described in literature were used to identify newborns and calves. The adults had dimensions of total lenght &#8805;170cm , the newborns until 105cm and calves between 106cm and 128cm. I addition, secondary characteristics described in the literature were used to indentify newborns and calves. The number of spinner dolphin newborns was greater in the month of April and higher during the rainy season. Throughout the months and pluviometric seasons (pluviometer/pluvial metric), the number of calves did not have a significant difference. Concerning to the presence of newborns and calves age groups at Ba?a dos Golfinhos, there was not a significant difference. It was possible to identify the gender of the escorting adults as (42), 95.24% being females and 4.76% males. Newborns were more frequently seen in the company of two adults, whereas calves were more often accompanied by more than two adults However, there was not a significant difference for the newborns, whereas for the calves there was a significant difference for those classified as loners and those accompanied by more than two adults. When in vertical positioning, the newborns and calves were more frequently observed in inferior position with some difference demonstrated between some of that. While in horizontal positioning both age groups were more often seen in posterior position, also with differences between them. In the depth perspective newborns and calves were positioned anterior, however with significant difference for the calves. The occurrence of a peak of newborns in the months of April may indicate the existence of a birth seasonality pattern for the beginning of the rainy season, with births scattered throughout the year. The results for the positions and escorting of newborns and calves are related to protection and suckling. These conditions reinforce the importance of the area when it comes to the care for offspring, which calls for the creation of conservation rules to the area, especially during those months with greater occurrence of newborns / Estudos indicam que golfinhos-rotadores utilizam a Ba?a dos Golfinhos de Fernando de Noronha para descanso, cuidado parental, acasalamentos e prote??o contra tubar?es. O presente estudo objetivou verificar a sazonalidade de ocorr?ncia de rec?m-nascidos e filhotes de golfinhos-rotadores durante os meses do ano e esta??es pluviom?tricas (seca e chuvosa), e a intera??o destes quanto ? quantidade e sexo de adultos acompanhantes, posicionamento dos rec?m-nascidos e filhotes em rela??o aos adultos (entre as dimen??es vertical, horizontal e profundidade) na referida enseada. As an?lises foram desenvolvidas a partir de registros fotogr?ficos dos golfinhos coletados entre 2000 e 2006 (sazonalidade) e entre 1995 e 2006 (intera??o), ambos atrav?s de amostragem ad libitum em mergulhos livres. Para a determina??o das faixas et?rias, calculou-se a raz?o entre o comprimento total do golfinho menor pelo maior mais pr?ximo a ele na mesma fotografia. Os golfinhos foram divididos em tr?s classes et?rias: adultos, rec?m-nascidos e filhotes. Indiv?duos adultos apresentavam propor??es de comprimento total &#8805;170cm, rec?m-nascidos at? 105cm e filhotes entre 106cm e 128cm. Em adi??o, foram utilizados caracteres secund?rios descritos na literatura para identificar rec?m-nascidos e filhotes. O maior n?mero de rec?m-nascidos foi registrado no m?s de abril e maior na esta??o chuvosa. Em rela??o ao n?mero de filhotes, n?o houve diferen?a significativa ao longo dos meses e nas esta??es pluviom?tricas. N?o houve diferen?a significatica com rela??o faixas et?rias de rec?m-nascidos e filhotes presentes na Ba?a dos Golfinhos. Entre os adultos acompanhando rec?m-nascidos e filhotes, no caso em que foi poss?vel identificar o sexo dos indiv?duos (42), 95,24% eram f?meas e 4,76% machos. Os rec?m-nascidos estavam em companhia mais freq?ente de 2 adultos, e os filhotes com mais de 2 adultos. Por?m, n?o foi registrada diferen?a para os rec?m-nascidos, ao contr?rio dos filhotes, que diferiram significativamente entre estar sozinho e os demais acompanhamentos. Com rela??o aos posisionamentos nas tr?s dimen??es analisadas, para o posicionamento vertical os rec?m-nascidos e filhotes estavam mais na posi??o inferior, demonstrando diferen?as entre algumas delas. Para a posi??o horizontal, os rec?m-nascidos e filhotes encontravam-se mais posterior, tamb?m com diferen?as entre elas. Com rela??o ? perspectiva profundidade, rec?m-nascidos e filhotes estavam posicionados na frente, por?m apresentou-se diferen?a significativa somente para os filhotes entre as demais. A presen?a do pico de ocorr?ncia de rec?m-nascidos no m?s de abril pode indicar a exist?ncia de um padr?o sazonal de nascimento no in?cio da esta??o das chuvas, por?m tamb?m com a exist?ncia de nascimentos difusos no decorrer do ano. As posi??es e acompanhamentos dos rec?m-nascidos e filhotes se relacionam ? prote??o e amamenta??o. Essas condi??es refor?am a import?ncia da ?rea para o cuidado da prole, necessitando de regras de acesso ? ?rea, principalmente durante os meses com maior ocorr?ncia de rec?m-nascidos

Spinner dolphins (Stenella longirostris) were surveyed and photographed during the Spring/Summer of 2004-2007 in the Southern Tañon Strait region of the Philippines. Over 17,000 images of dorsal fins were taken during the study period for photoidentification purposes. The study area (approximately 100 Km2) is a popular site for cetacean-watching and more recently underwent oil exploration and drilling. A photographic database of 329 unique spinner dolphin dorsal fins was produced, and used to assess abundance and life history characteristics using DARWIN software. An overall abundance estimate (2004-2007) of 1118 individuals (990-1246 with a 95% confidence interval) was obtained using the POPAN feature of MARK software. These mark-recapture results reveal that approximately 28% (n= 92) of the identified individuals (n= 329) were present in the study area in at least two of the four study years. This information is necessary to gain a better understanding of the ecology and life history characteristics of small cetaceans in the Tafton Strait, and in the development of conservation, education, and habitat protection programs designed to protect these cetaceans from human impacts. This project is part of a long-term ongoing study of the small cetaceans in the Southern Tañon Strait.