Carefully avoiding the squirting sea anemone, the students tiptoed around the Half Moon Bay tide pools, searching for starfish and other sea critters.

One of the two AP Environmental Science classes visited Pillar Point at Half Moon Bay to collect data on tidepool populations for an organization called LiMPETS on March 17. The other class will go on April 23. Students assessed the tidepool populations of about 50 species including algae, snails, hermit crabs, mollusks, coral and starfish.

“It’s nice to be able to do a project where you go to a different habitat,” science teacher Andrew Willats said. “Sometimes when I do labs, we do things just so you can learn how they’re done and they don’t have a real purpose. The nice thing about this is that it has a greater purpose.”

LiMPETS, a private organization, works with marine sanctuaries to conduct long-term ecological research, Willats said. Students contribute to and have access to the organization’s database that now has 15 years of information. The data helps to show patterns in population growth and decline.

“They have a number of sites up and down the coast they bring student groups out to on different dates over many years,” Willats said. “A lot of the ecological problems that we want answers to can’t be answered unless we have lots and lots of data over many years.”

The data students collected helped show that the starfish population is rapidly decreasing due to a wasting disease along the west coast.

Senior Kathy Caldwell was in one of the groups that searched for starfish and only found two in an area where there would have been 50 or 60 just a few years before.

“It’s one thing to learn about it in the class, but then to actually go out and see the effects of this particular disease makes the class much more meaningful,” Willats said.

For junior Calvin Polvorosa, the field trip was a meaningful application of the skills he has learned in class.

“Trips like this are good because it gets you out into the real world. You get to experience what it would be like to be a researcher in that field,” Polvorosa said

“Field trips are what we remember,” Willats said. “You’ re going to have years and years of classroom learning, but you will remember a time you went out the beach.”