Scientists from around the world will gather this week in California for an annual conference to discuss everything from the secret pathologies of dolphins to a count of the creatures in the seas and the 50th birthday of the laser.

Up to 8,000 participants from 50 countries are expected to attend 176th annual conference of the American Academy for the Advancement of Science (AAAS), which begins Thursday in San Diego and this year centers around the theme "bridging science and society."

The aim is to get "every scientist and engineer to make their work both beneficial and understandable, and on society to discover again the excitement and hope that research and its findings offer," Nobel chemistry laureate Peter Agre, who is president of the AAAS, said in a statement.

At the conference, participants - be they scientist or engineer, student or mere enthusiast - will have a wide choice of events to attend, with symposia covering a bevy of scientific branches, from astronomy to zoology.

Doubters and defenders of climate change could lock horns at discussions about global warming, including the release of a study on geo-engineering and whether we can cool down the planet that we have heated up.

The lessons on health and well-being that dolphins can give to humans will be the topic of another symposium, while yet another will offer a sneak peek at the final report of the 10-year census of marine life, which has discovered "unusual creatures" in the ocean, including a tubeworm that drills for oil and a crab with hairy legs.

Some of the symposia will cover eclectic subjects - such as how dust in the atmosphere could counteract climate change - while others touch on topics that are hot conversation, such as what role science and technology will play as the United States and Russia downsize their nuclear arsenals.

Medicine will be center-stage at many of the symposia, including the one on chemicals that affect the risk of contracting breast cancer or another on the staggering projected benefits of testing everyone for HIV/AIDS and immediately treating those found to be infected with the virus.

Most of the symposia-leaders will be from US universities, although professors and scientists from Australian, Belgian, British, Canadian, German, Italian, Polish, South African and Swiss institutions will be among international presenters at the conference, which runs until Monday.

At the weekend, part of the San Diego conference center will be turned into a giant, hands-on science fair for families, and, separately, the head of the World Federation of Science Journalists will officially launch a three-year mentoring program for science reporters in Africa and the Arab world.