Our three weeks on Catalina Island are coming to a close this Friday. It has been an exhausting trip -- we work 6:30 am to 6 pm on four different projects, most of which require either being on a boat in the sun for several hours, or SCUBA diving. We're based out of the University of Southern California Wrigley Institute for Environmental Studies, which provides us with boats, SCUBA tanks, housing, and even lab space and animal facilities if we need them. This year, we're living in Two Harbors, which is a tiny little town two miles from the Wrigley. Two Harbors only really gets going on the weekend, when visiting boaters and campers roll in and keep the bar (yes, singular) open until a rollicking 10 pm.
Looking north over Two Harbors, with Cat Harbor in the foreground and Isthmus Cove (the side of the island where we have primarily trapped for the past seven years) in the background. The island is never this green in the summer! Photo by the Catalina Island Company.
1. Moray trapping: As usual, we're continuing our long-term study of the demographics, morphology, diet, and abundance of California moray eels (Gymnothorax mordax) around Catalina Island. We put out special eel traps in the evening, using anchovies to lure the eels in. In the morning, we pull the traps up, lightly anesthetize the eels, take measurements, and then release them back to the same reef where we caught them, unharmed. Led by: Dr. Rita Mehta. For more information on the eels, see our published work on habitat preferences, dispersal, and feeding behavior, and prey size that have utilized this dataset.
Low point: Only sometimes catching anything in our extra small "minnow" traps, which we were hoping would bring in the youngest eels on the reef.
High point: Getting an eel that was so large it was the same length as Rita's 6-year old daughter!
Chris and Sam on the moray boat, going home after processing eels. You can just barely make out Wrigley in the background beyond the prow of the second boat. Photo by K. Voss.
2. Octopus wrangling: We are surveying injuries suffered by California two-spot octopuses (Octopus bimaculatus) as part of a larger effort to understand predator-prey interactions in the reef. We use SCUBA to find them in their dens, and then carefully examine them underwater to assess the condition of their arms. It's challenging, but fun! Led by: PhD student Kelley Voss, will be using this data for part of her dissertation work.
Low point: On the second octopus dive, I accidentally left two bags of equipment on the bottom and couldn't find them even after a lot of searching. We ended up ordering more supplies, but they took a long time to arrive and we lost several days of diving (don't worry, we made up the time).
High point: The equipment mysteriously reappeared on the dock two weeks later -- we were all jumping up and down and yelling like maniacs. Plastic pollution averted!
3. Ichthyoplankton fishing : I have been using plankton light traps to catch tiny baby fish to assess the composition of ichthyoplankton in different parts of the island -- see my previous post for more details on the traps I built. Led by: Myself! Look for a paper using the data in the future.
Low point: Already being soaking wet by 6 am.
High point: Catching multiple small morays in the light traps at Cat Harbor, which is actually the entirely opposite side of the island (thus, the name Two Harbors). One of these had an unusual bright yellow patterning that we've never seen before (see image on right; photo by R. Mehta) and another was the smallest eel Rita has ever caught, at 345 mm.
4. Kelpfish catching: Undergraduate Noe Castaneda is looking to see if pattern, coloration, and algal association affects the ability of giant kelpfish (Heterostichus rostratus) to obtain food. We use SCUBA to catch kelpfish and assess algal diversity where we caught them. We then bring the fish back to the boat, take a few measurements and wash out their stomachs, and then release them unharmed back to the reef. Led by: UCSC undergraduate and Wrigley Research Experience for Undergraduate participant Noe Castaneda.
Low point: One of the days on the boat lasted nearly 7 hours (we missed lunch, which was the worst part!)
High point: Seeing soupfin sharks (Galeorhinus galeus) every time we dove at the site around the corner from the Wrigley.
Soupfin shark at dive site Intakes. They are considered harmless, but are very curious! Photo by B. Chang.
A special shout-out to our volunteers, assistants, and research techs this season:
- Brenna Chang, a recent UCSC graduate interested in animal husbandry whose creative problem-solving and diving skills were helpful at many turns.
- Samantha Gartner, a UCSC alum headed off to graduate school at UChicago this fall, who is a seasoned moray pro by this point.
- Maddie Miller, a UCSB undergraduate hired on by Rita to nanny the kids who ended up being a crucial part of the research team as a primary data recorder and boat driver.
- Chris Law, another PhD student in the Mehta lab (studying mustelids, not eels!) who was always willing to go the extra mile to help out, and who cooked some amazing meals.
- Jack Redwine, Rita's husband, medical guru, scientific diver, and adventure dad.
- Lily & Maggie Redwine, who kept us constantly entertained with their antics!
Most of the 2018 field crew, minus Chris (who was taking the photo) and Jack. Photo was taken after our hike up the mountain behind Wrigley. Catalina is a beautiful place and we are lucky to have the opportunity to study the marine ecosystems surrounding the island!