The 2014 Catalina MBQ has officially drawn to a close. It was an amazing experience for both students and teaching staff alike! We are so proud of our group for jumping in to their experiments and making the most of their time on the island from day 1! I hope you enjoy some of my favorite photos I took along the way (others with photo credits indicated).
We quickly settled in to our beautiful island home for our 5 week stay at the Wrigley Marine Science Center.
Views of WMSC from ‘Megastrea Mountain’ and the road to town
Spent many hours exploring the intertidal and subtidal areas around Two Harbors and beyond.
Lovely intertidal zonation patterns and adventures in underwater research
We explored by kayak, snorkeling, free diving, and a few on SCUBA.
Julia on an urchin quest, Kim & Lexey Kayaking, Dawn & Colin practicing the giant stride!
Made friends with the locals.
A few of the colorful and friendly invertebrates, fishes, reptiles, and mammals we saw!
Refined our ping pong and pool skills and celebrated halloween!
Carving pumpkins and getting in costume for the big night and beach party!
Even fit in some volleyball and mountain climbing!
Enjoying some time on land too!
But mostly we were near, on, or in the water.
(Photo credit: Dovi Kacev, Dawn Bailey, Dawn Bailey)
Many groups spent time separately in the field, but the trip to Little Harbor gave us the chance to all be working (and playing) in the same place together.
Though our time on the island went far to quickly, we accomplished a lot! Here are the abstracts of the research papers produced by the class based on their field research during our stay.
Intertidal distributions, abundance and shell characteristic differences between Snails and the Blue Banded Hermit Crab, Pagurus samuelis
Alexa Dalmau-Jones & Kimberly Mak
Hermit crabs and snails have a unique relationship that resembles commensalism where snails must be deceased to provide shells for hermit crabs to protect their soft abdomens. This creates the possibility that hermit crab shell utilization is affected by the abundance of snails and the physical attributes of shells. Depending on the hermit crab species, mobility can range from 1-2 meters a day to a hundred meters day (Hazlett, 1981). Therefore, each hermit crab species has a different potential to find new shells to occupy. To examine patterns of snail and hermit crab abundance in the rocky intertidal areas of Santa Catalina Island, California field surveys were conducted between October 20th to November 20th, 2014. Snail, hermit crab, and empty shell abundances were recorded across 8 to 15 haphazardly placed quadrats from each of the 6 locations. Quadrats without hermit crabs were excluded. Of 1,167 hermit crabs recorded, 1,148 were Pagurus samuelis, therefore other hermit crab species were omitted from further analysis. Throughout all locations except for one, the abundance of snail species was proportionate to the species of shell occupied by hermit crabs, with Tegula spp. as the most common snail and the most common shell occupied by P. samuelis. No relationship was found between the number of snails and P. samuelis present across all locations. In addition to species identification, all shells were measured and evaluated for percent algal and invertebrate coverage, damage, and size. There was no significant difference in the coverage or damage levels of snails; however P. samuelis were found to significantly occupy shells with zero coverage and zero damage compared to all other levels of coverage. These results suggest that environmental factors and snail distribution inhibit hermit crabs’ potential to occupy preferred shells.
The effect of microhabitat variations on the distribution of and endosymbionts in Anthopleura sola and A. elegantissima
Noor AlAlusi & Kelly Wong
Two species of sea anemones, Anthopleura sola and A. elegantissima, have been shown to host different proportions of two types of endosymbiont algae, zooxanthellae and zoochlorellae, based on their location in the intertidal. The amount of variation in temperature and UV exposure between microhabitats in the same region can have a major impact on the anemone’s endosymbiont composition. This study consisted of three components: 1) Variation in endosymbionts with shore height in A. sola; 2) Variation in endosymbionts with rock face in A. elegantissima; and 3) Variations in the distribution of A. elegantissima on different rock faces in the rocky intertidal areas on Santa Catalina Island, CA. Results revealed that regardless of shore height or rock face, all A. sola and A. elegantissima organisms sampled contained only zooxanthellae and no zoochlorellae. At three of seven sites, one rock face had an average percent cover of A. elegantissima that was significantly different from at least two of the other faces. The rock faces that had the different percent cover were the bottom face in Two Harbors Campground, the top face in Catalina Harbor East, and the south face in Cherry Cove South. Since differences are highly sitespecific, it is likely that unique characteristics of each site can account for these differences. We suggest that the observed differences in A. elegantissima distribution are attributable to the loose sediment found in Two Harbors Campground, above average wave action and rock height at Catalina Harbor, and large cliffs on the south side of Cherry Cove South.
The effects of marine reserve design on sea urchins and their predators off Santa Catalina Island
Satthea Khay & Colin Shew
Sea urchins have been widely reported to impact the community structure of their ecosystems. Marine Protected Areas (MPAs) reduce fishing pressures on key urchin predators, which may reduce urchin populations via a trophic cascade effect. Additionally, urchins and higher trophic levels can be effected by the bottom-up effects of primary producers. In this study, surveys were conducted to count and determine the density of urchins (Strongylocentrotus purpuratus, Strongylocentrotus franciscanus, and Centrostephanus coronatus); urchin predators, the California sheephead (Semicossyphus pulcher) and the California spiny lobster (Panulirus interruptus); and quantify algal abundance. Surveys were conducted in rocky subtidal habitats along 30-meter transects in three areas under different levels of protection on Santa Catalina Island, California, USA, at depths of 1-3 meters and 9-11 meters. Urchin densities were highest in unprotected areas and lower in invertebrate-protected and no-take areas on both shallow and deep surveys. Sheephead densities were highest in the no-take areas and lower in the invertebrate reserve and unprotected areas on the deep surveys, and only counted in the no-take areas in shallow water. Spiny lobster densities only differed on deep water surveys and were highest in the invertebrate-protected areas and lower in the other two. These patterns are consistent with an effect of top-down controls on urchin and lobster populations. No correlative evidence of bottom-up effects of producers on urchin densities were observed. Overall, the abundance of organisms of different trophic levels appears to be sensitive to the particular regulations instituted by a reserve.
Brittle Star Distributions in Intertidal and Shallow Subtidal Regions around Santa Catalina Island
Kirsten Denicola & Jordan Beasley
Brittle stars that reside in areas closer to shore are observed to live under rocks in the intertidal and subtidal areas during the daytime to avoid predation (Summers and Nybakken, 2000). Not all rocks shelter brittle stars, but the ones that do reveal trends in brittle star distributions and substrate preference. Four sites at the northern end of Santa Catalina Island, California were surveyed under randomly selected rocks by recording the number of brittle stars in relation to possible factors that may influence brittle star abundance including rock size, substrate type, distance from shore, and presence of sea urchins. We found that sea urchin presence, rock distance from shore, and rock size each have significant influences on brittle star abundance. Brittle stars were significantly more abundant under rocks with sea urchins present, at distances 7‐15 meters from shore, and larger sized rocks. These components are interconnected with other factors that shape these brittle star distributions.
We thank you all for helping to make this a wonderful experience and wish you all the best as you finish your time at UCLA!
Saying goodbye to the island was a bit sad as we sped off on the Miss Christi, but the memories will last forever!
Farewell Santa Catalina Catalina Island (for now…)!
Laura K Jordan, PhD