Pacific Grove, CA, United States
Pacific Grove, CA, United States

Time filter

Source Type

Marshall C.D.,Texas A&M University at Galveston | Marshall C.D.,Texas A&M University | Wang J.,University of Hawaii at Manoa | Rocha-Olivares A.,Research Center Cientifica Educacion Superior Of Ensenada | And 5 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2014

Adult green turtles (Chelonia mydas) are unusual relative to other sea turtles in that they are predominately herbivorous. This herbivorous diet is reflected in the serrated morphology of their beak, bite performance and the relative morphometrics of their heads. Recent bite performance data in loggerhead turtles (Caretta caretta), which are known for their durophagous capability, have demonstrated that bite force is correlated with head morphometrics. The objective of this study was to characterize bite force in green turtles and correlate bite performance with head and carapace morphometrics. We predicted that maximum bite force in green turtles would be less in magnitude relative to loggerheads, but would be positively correlated with head morphometrics. Therefore, mass, straight carapace length, straight carapace width, greatest head width, height, and length were collected with bite force from free-ranging green turtles from Punta Abreojos, Baja California Sur, Mexico and Otsuchi, Japan. Subjects ranged from 10.9 to 48. kg, with straight carapace length and width ranged from 40.6. cm to 71.9. cm (mean. =. 56.3. ±. 8.5. cm) and from 33.5. cm to 55.9. cm (mean. =. 44.8. ±. 5.7. cm), respectively. A bite force apparatus was used to collect bite performance from subjects. The maximum bite force was 303. N. Mean head width, head height, and head length were 8.7. ±. 1.2, 8.2. ±. 1.1, and 11.5. ±. 1.5. cm, respectively. Bite force was lower in magnitude than reported for loggerhead turtles as predicted but still strong enough to process algal and plant matter, as well as crush many hard prey items. Simultaneous measurements of body and head size, and the use of non-linear reduced major axis regression, show that bite force scaled isometrically relative to body size and head size. Simple correlation showed that all logged transformed morphometrics were good predictors of logged bite performance, but an AICc-based weighted regression showed that body mass, followed by head width and head height, were better predictors of bite force than carapace size. © 2013 Elsevier B.V.


Wang J.H.,University of Hawaii at Manoa | Fisler S.,Ocean Discovery Institute | Swimmer Y.,National Oceanic and Atmospheric Administration
Marine Ecology Progress Series | Year: 2010

Visual cues play important roles in sea turtle foraging behavior and likely influence their interactions with fishing gear. Altering these cues may be a useful strategy to reduce the incidental catch of sea turtles in various fisheries. We examined the potential effectiveness of 3 visual cues-shark shapes placed along the length of the gill net, illumination of nets by LED lights, and nets illuminated with chemical lightsticks-in reducing bycatch of green sea turtles Chelonia mydas in gill nets. We then adapted these potential deterrents into commercial bottom gill net fishery to quantify their effects on target fish catch rates and the catch value. Our results indicate that the presence of shark shapes significantly reduced the mean catch rates of green turtles by 54% but also reduced target catch by 45% and, correspondingly, catch value by 47%. In contrast, nets illuminated by LED lights significantly reduced mean sea turtle catch rates by 40% while having negligible impacts on target catch and catch value. Similarly, nets illuminated by chemical lightsticks also significantly reduced mean sea turtle catch rates by 60% while having no significant impact on target catch and catch value. These results illustrate the potential for modifying fishing gear with visual deterrents to effectively reduce sea turtle catch rates. © Inter-Research 2010 · www.int-res.com.


Wang J.,University of Hawaii at Manoa | Barkan J.,Ocean Discovery Institute | Fisler S.,Ocean Discovery Institute | Godinez-Reyes C.,Comision Nacional de A reas Naturales Protegidas | Swimmer Y.,National Oceanic and Atmospheric Administration
Biology Letters | Year: 2013

Fisheries bycatch of marine animals has been linked to population declines of multiple species, including many sea turtles. Altering the visual cues associated with fishing gear may reduce sea turtle bycatch. We examined the effectiveness of illuminating gillnets with ultraviolet (UV) light-emitting diodes for reducing green sea turtle (Chelonia mydas) interactions. We found that the mean sea turtle capture rate was reduced by 39.7% in UV-illuminated nets compared with nets without illumination. In collaboration with commercial fishermen, we tested UV net illumination in a bottom-set gillnet fishery in Baja California, Mexico. We did not find any difference in overall target fish catch rate or market value between net types. These findings suggest that UV net illumination may have applications in coastal and pelagic gillnet fisheries to reduce sea turtle bycatch. © 2013 The Author(s) Published by the Royal Society. All rights reserved.


Talley D.,University of San Diego | Goodwin L.,Ocean Discovery Institute | Ruzic R.,Ruzic Consulting Inc. | Fisler S.,Ocean Discovery Institute
Marine Ecology | Year: 2011

Across the United States there is increasing concern about the dwindling scientific workforce and the lack of students prepared for careers in the sciences. To build future leadership in this arena, we must employ innovative approaches that generate young peoples' interest and develop their capabilities so that an increased number will pursue and be prepared for careers in scientific fields. Marine ecology is an ideal platform to engage young people in the sciences, develop their skills across multiple disciplines, and prepare them to face the complex challenges that lie ahead. In response, Ocean Discovery Institute, a non-profit organization, has developed Ocean Leaders, a model program to empower young people to become tomorrow's scientific leaders. Using evaluation data that span the 5years of the program, we asked how this model can affect participants' interest and performance in science and how it can contribute directly to the field of marine ecology. Content assessments, surveys, interviews, and tracking data reveal that 73% of Ocean Leader students during this period have declared majors in science and conservation fields, scored higher on standardized science tests relative to their peers, and contributed to ecological research through 10 publications and more than 30 scientific presentations. Using a framework analogous to adaptive management strategies, key components of the program (including in-depth interactions with scientists and rigorous college readiness coursework) have been identified, resulting in an increased number of students who are interested in and ready to pursue science careers. Critical to this model is the partnership between scientists and a non-profit organization. Although this model may not easily be replicated in its entirety, aspects of this collaboration and the strategies employed can help to simultaneously advance the field of marine ecology and scientific leadership and understanding. © 2011 Blackwell Verlag GmbH.


Bresnahan P.J.,University of California at San Diego | Wirth T.,University of California at San Diego | Martz T.R.,University of California at San Diego | Andersson A.J.,University of California at San Diego | And 6 more authors.
Methods in Oceanography | Year: 2016

A novel chemical sensor package named "WavepHOx" was developed in order to facilitate measurement of surface ocean pH, dissolved oxygen, and temperature from mobile platforms. The system comprises a Honeywell Durafet pH sensor, Aanderaa optode oxygen sensor, and chloride ion selective electrode, packaged into a hydrodynamic, lightweight housing. The WavepHOx has been deployed on a stand-up paddleboard and a Liquid Robotics Wave Glider in multiple near-shore settings in the Southern California Bight. Integration of the WavepHOx into these mobile platforms has enabled high spatiotemporal resolution pH and dissolved oxygen data collection. It is a particularly valuable tool for mapping shallow, fragile, or densely vegetated ecosystems which cannot be easily accessed by other platforms. Results from three surveys in San Diego, California, are reported. We show pH and dissolved oxygen variability >0.3 and >50% saturation, respectively, over tens to hundreds of meters to highlight the degree of natural spatial variability in these vegetated ecosystems. When deployed during an extensive discrete sampling program, the WavepHOx pH had a root mean squared error of 0.028 relative to pH calculated from fifty six measurements of total alkalinity and dissolved inorganic carbon, confirming its capacity for accurate, high spatiotemporal resolution data collection. © 2016 Elsevier B.V..


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: AISL | Award Amount: 249.99K | Year: 2013

This Pathways project from the Ocean Discovery Institute (ODI) seeks to develop and pilot a program model designed to fill an identified gap in citizen science research and practice literature: how to effectively engage and better understand how to foster participation among people from under-represented groups in citizen science research. The ODI model is designed around six principles: (1) leaders who are reflective of the community, (2) science that is locally relevant, (3) guided, as opposed to self-guided, experiences, (4) direct interactions with scientists, (5) progressively increasing responsibilities for participants who express interest, and (6) removing barriers to participation, such as transportation, language, family involvement and access to technology.

The project addresses environmentally degraded, crime-ridden local canyons, a locally relevant STEM-related issue, and leverages the Southern California Coastal Water Research Projects (SCCWRP) regional citizen science effort focused on identifying the sources and pathways of trash through regional watersheds. The scientific research components of the project focus on four canyons in the area, employing sampling methods developed by SCCWRP. Youth who are part of other ODI programs and who have demonstrated leadership and interest in science, work with the project team to scaffold family and youth participation in project activities taking place during afterschool and weekend time. Based on continued participation in the project, community participants can become more involved in the project, starting as new scientists and moving through returning scientists to expert scientists roles. The project evaluation seeks to identify the role and importance of the components of the proposed model with respect to participation, retention, and learning by participants from groups under-represented in STEM. The dissemination products of this Pathways project include a white paper describing the model and lessons learned as well as presentations to community groups and education and citizen science practitioners.

Based on insights from the iterative approach to the model during this Pathways study, a subsequent full-scale development project would seek to engage citizen science projects around the nation in adapting the model to increase participation of individuals from groups underrepresented in STEM, including building out ODIs citizen science programming.


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 25.00K | Year: 2011

For the past decade, Ocean Discovery Institute has been empowering diverse youth from an urban district to protect our oceans and natural environment, improve the health of our communities and strengthen our quality of life. Ocean Discovery Institute is the only non-profit in the San Diego region using the ocean as an educational tool to capitalize on young peoples instinctive attraction to the sea and build knowledge of our planets defining feature. Ocean Discovery Institute leads a series of initiatives that incorporate education, scientific research and environmental stewardship. Currently these initiatives reach over 4,500 low-income students and community members each year. All of Ocean Discovery Institutes programming is provided tuition-free.

Loading Ocean Discovery Institute collaborators
Loading Ocean Discovery Institute collaborators