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Full-Text Articles in Life Sciences

Patterns Of Life History And Habitat Use Of An Important Recreational Fishery Species, Spotfin Croaker, And Their Potential Fishery Implications, Jonathan Williams, Jeremy Claisse, Daniel Pondella, Lea Medeiros, Charles Valle, Michael Shane Nov 2012

Patterns Of Life History And Habitat Use Of An Important Recreational Fishery Species, Spotfin Croaker, And Their Potential Fishery Implications, Jonathan Williams, Jeremy Claisse, Daniel Pondella, Lea Medeiros, Charles Valle, Michael Shane

Daniel Pondella

Spotfin croakers Roncador stearnsii, a prized recreational catch, were collected throughout the Southern California Bight, primarily as bycatch from a long-term, scientific gill-net collection effort. The maximum otolith-based age in the present study was 24 years—14 years greater than in a previous scale-based aging study. Multiple models were used to estimate mean length at age, including models that utilize larvae as well as juveniles and adults, and the model selection results suggest sexual dimorphism in growth patterns. The juvenile and adult catch per unit effort reflected a clear pattern of habitat selectivity, with fish strongly preferring soft-bottom habitats. Catches …


El Niño Periods Increase Growth Of Juvenile White Seabass (Atractoscion Nobilis) In The Southern California Bight, Jonathan Williams, Larry Allen, Mark Steele, Daniel Pondella Nov 2012

El Niño Periods Increase Growth Of Juvenile White Seabass (Atractoscion Nobilis) In The Southern California Bight, Jonathan Williams, Larry Allen, Mark Steele, Daniel Pondella

Daniel Pondella

Studies of the impact of El Niño periods on marine species have usually focused on negative, highly visible eVects, e.g., decreasing growth rates or increasing mortality due to a decline in primary productivity in typically nutrient rich upwelling zones; but positive effects related to elevated water temperature are also known. This study examined how the growth rate of juvenile white seabass, Atractoscion nobilis, responded to changes in ocean temperature in an El Niño period (1997–1998) in the northern portion of the Southern California Bight, USA. Growth rates of juvenile white seabass during their first 4 years of life were …


Life History, Ecology, And Long-Term Demographics Of Queenfish, Eric Miller, Jonathan Williams, Daniel Pondella, Kevin Herbinson Nov 2012

Life History, Ecology, And Long-Term Demographics Of Queenfish, Eric Miller, Jonathan Williams, Daniel Pondella, Kevin Herbinson

Daniel Pondella

Queenfish Seriphus politus were collected at coastal power plants from San Clemente to Ventura, California. Power functions best described relations between otolith length, width, or weight and either standard length (SL) or total body weight. The length–weight relationship was described by the following equation: weight 1⁄4 10􏰀5 3 SL3.09. Individuals were aged to 12 years by using sagittal otolith sections. Females grew at a significantly faster rate than males. Both sexes reached 50% maturity by 100 mm SL, or shortly after age 1. The total annual instantaneous mortality coefficient was estimated at 0.42. Catalina Harbor (on the windward side of …


Comparing Volunteer And Professionally Collected Monitoring Data From The Rocky Subtidal Reefs Of Southern California, Usa, David Gillett, Daniel Pondella, Jan Freiwald, Kenneth Schiff, Jennifer Caselle, Craig Shuman, Stephen Weisberg Apr 2012

Comparing Volunteer And Professionally Collected Monitoring Data From The Rocky Subtidal Reefs Of Southern California, Usa, David Gillett, Daniel Pondella, Jan Freiwald, Kenneth Schiff, Jennifer Caselle, Craig Shuman, Stephen Weisberg

Daniel Pondella

Volunteer-based citizen monitoring has increasingly become part of the natural resources monitoring framework, but it is often unclear whether the data quality from these programs is sufficient for integration with traditional efforts conducted by professional scientists. At present, the biological and physical characteristics of California’s rocky reef kelp forests are concurrently monitored by two such groups, using similar methodologies—underwater visual census (UVC) of fish, benthic invertebrates, and reef habitat, though the volunteer group limits their sampling to transects close to the reef surface and they use a more constrained list of species for enumeration and measurement. Here, we compared the …