Environmentalists disagree over whether outdated oil rigs off the coast of Long Beach, Calif., can become an addition to the marine ecosystem. EUREKA OIL PLATFORM OFF CALIFORNIA COAST — Eight miles off the coast of Long Beach, Calif., the oil rig Eureka, which has stood here for 40 years, is a study in contrasts. From a distance, it looks like just another offshore platform, an artifact of the mod