LOCAL ELECTIONS : Here Are Issues, Candidates on the Ballot for San Diego County Voters : Key races: Rep. Jim Bates’ tough challenge and the race to replace a tarnished Sheriff Duffy are in spotlight.

Elections for a new San Diego County sheriff and on several high-profile propositions ranging from growth management to the use of pound animals for medical research head the ballot that San Diego voters will face at the polls today.

After enduring a lengthy campaign that, in several major races, ended amid a confusing blur of acrimony and distortion, local voters will confront the daunting challenge of wading through a ballot that includes 627 candidates seeking 296 positions, as well as 55 propositions. Most voters will cast ballots on slightly more than half of those propositions, which include 28 statewide measures, four countywide issues and 23 propositions on city and local district ballots.

Polls throughout San Diego County will be open today from 7 a.m. to 8 p.m. Voters uncertain of their polling place or who experience other Election Day problems can contact the voter registrar’s office at 565-5800 or 694-3400 for assistance.

Among the elections that will be most closely watched today are ones in which countywide voters will select a replacement for Sheriff John Duffy and in which two incumbents--Rep. Jim Bates (D-San Diego) and freshman Assemblyman Jeff Marston (R-San Diego)--face tough reelection battles.

The candidates competing to succeed Duffy, who is retiring after an often controversial 20-year career, are Assistant Sheriff Jack Drown and Sheriff’s Capt. Jim Roache, who also serves on the San Diego city school board.

In the 45th Congressional District race, Bates faces his toughest Republican opponent since winning the seat eight years ago, in former Navy fighter pilot Randall (Duke) Cunningham. Although the district is heavily Democratic, Bates’ sanction by the House Ethics Committee last year on sexual-harassment charges, combined with rising anti-incumbent sentiment nationwide, have allowed Cunningham’s well-financed campaign to become a formidable obstacle to Bates’ bid for a fifth two-year term.

Marston, meanwhile, faces the same candidate he already has defeated twice this year--former Democratic San Diego City Councilman Mike Gotch--in his effort to retain the 78th Assembly District seat that he won in a special election last June.

The county’s other congressmen, Assembly and state Senate incumbents are heavy favorites in their races, most of which feature only token opposition.

The initiatives and propositions appearing on local ballots include a handful dealing with the volatile topic of growth management, a staple in San Diego politics.

Propositions D and M, two growth measures that the building industry abandoned after spending tens of thousands of dollars to qualify for the county and city of San Diego ballots, respectively, would establish a so-called transportation impact fee to make new development help pay for new major roads, freeways and expansion of the San Diego Trolley.

Although builders decry those fees as too high, opponents complain that the measures would raise only about one-third of the money needed to pay the public costs associated with growth. Skeptical of builders’ motives, some critics have also accused developers of cleverly trying to pass the initiatives by distancing themselves from the two measures.

Two other growth and open-space issues appear on the city’s ballot. Proposition E asks voters to authorize a $100-million bond for the acquisition or improvement of parks and open space, and Proposition L would amend San Diego’s charter to require public approval of the sale of 80 acres or more of city-owned land.

Other major ballot measures include Propositions A and B, both of which would have potentially far-reaching effects on the San Diego County Sheriff’s office. Proposition A would create a citizens law enforcement review board to evaluate the Sheriff’s Department’s performance, while Proposition B would enable the county Board of Supervisors to establish a separate county Department of Corrections, thereby taking away management of local jails from the sheriff.

Although it is only an advisory measure, Proposition C, which asks voters’ opinion on whether San Diego County should continue to provide pound animals for medical research, also has drawn considerable attention simply because of the growing controversy surrounding the topic. Another non-binding measure on the city’s ballot deals with whether San Diego should develop a comprehensive plan for upgrading the city’s public library system by 1992.