Reflecting a statewide trend, students in Santa Clara, San Mateo and Santa Cruz counties slipped this year in academic performance, while their schools also stalled in campaigns to narrow the gap between high- and low-achieving groups of students, according to standardized test scores released Thursday.

The score decline ends eight straight years of gains in achievement in math and English, as measured on California's Standardized Testing and Reporting assessments, a battery of tests administered each spring.

State Superintendent of Public Instruction Tom Torlakson, in a prepared statement, ignored the losses and focused on nearly a decade of gains shown on the STAR test: "While we all want to see California's progress continue, these results show that in the midst of change and uncertainty, teachers and schools kept their focus on students and learning."

With a few exceptions, state and local STAR scores show marginal declines across grade spans and subject areas.

In Santa Clara County, the percentage of students scoring at least proficient dropped less than 1 percent in English and math. Proficiency numbers dropped 0.4 percentage points for science -- measured in grades 5, 8 and 10 -- and for other high school science classes 1.5 percentage points.

County schools Superintendent Xavier De La Torre noted that although local schools have reached a plateau, they continue to outperform the state. He said that the next push is to improve preschool to provide the foundation for achievement. Reform, he said, "begins by making a significant investment in our children, like pre-kindergarten programs."

In San Mateo and Santa Cruz counties, English and math proficiency rates also fell.

The numbers released Thursday paint a stark picture of educational disparity in Santa Clara and San Mateo counties, home to many of the highest-achieving schools in the state. Not only has progress in attaining widespread proficiency generally slowed or reversed, but the racial achievement gap has not narrowed.

Take Santa Clara County's scores for Algebra I, the focus of an intense push by schools, nonprofit advocates and philanthropists. On the one hand, more students tested proficient or better, defying the downward trend in other subjects. Proficiency reached 42 percent, up from 40 percent.

But dissecting that figure reveals that 80 percent of Asian students tested proficient, but only 21 percent of Latino students did, the same as in the two previous years. Still, algebra proficiency among Latinos has increased dramatically over nine years ago, when it was only 8 percent.

The gap is nearly as wide in Santa Clara County reveal results for math in grades 2 to ¿7: Proficiency was 92 percent for Asians, 83 percent for whites, and 53 percent for Latinos. After narrowing last year, the white-Latino gap grew by a point. In 10th grade science, proficiency was 83 percent among Asians and 38 percent among Latinos, according to results culled by the Santa Clara County Office of Education.

A similar gap exists in San Mateo County. Latino math scores are 30.7 percentage points lower than those of whites, compared with a 20 percentage-point gap statewide. And in science, the white-Latino gap is 38.6 percentage points in San Mateo County, versus 28.2 percent in the state.

The divergent scores reflect white families' affluence, said Nancy Magee of the San Mateo County Office of Education. While Latino scores in San Mateo County are comparable to Latino scores statewide, white students outscore their statewide peers by more than 10 percentage points in English. Magee said, "When you look at the rest of the white population in California, they don't have the socioeconomic benefits that a lot of kids enjoy in San Mateo County."

From the STAR data, the state compiles a single score, known as the Academic Performance Index, for each school and district in the state. API results will be released next month, according to the California Department of Education.

With California adopting new national curriculum standards, Thursday likely marks the last release of STAR test results. The state is drafting new, computer-based tests that are expected to be more rigorous.

Donna Jones of the Santa Cruz Sentinel contributed to this report. Contact Sharon Noguchi at 408-271-3775. Follow her at Twitter.com/NoguchiOnK12.