Marine debris harbor unique, yet functionally similar cryptofauna communities.

Human-made debris is entering the ocean at alarming rates. These artificial structures are becoming habitats for small marine taxa known as cryptofauna. Cryptofauna are among the most essential reef taxa; however, little is known about these organisms, let alone their fate considering degrading coral reefs and increasing anthropogenic disturbance. The current study explores differences in naturally occurring cryptofauna biodiversity compared to those inhabiting benthic marine debris. To explore this difference, we measured invertebrate diversity from autonomous reef monitoring systems (ARMS) located on patch reefs along the Middle Florida Keys Reef Tract. ARMS were used as a proxy for natural structure to compare to marine debris removed from five reef locations. Plastic debris was the most abundant of all the debris material collected. Wood and concrete were identified as covariates since they are sourced from wooden lobster traps. Taxa diversity varied significantly between ARMS and debris, indicating that each structural unit contained significantly different and diverse communities. The most influential taxa identified included commensal shrimps, hermit crabs, brittle stars, segmented worms, and several families of crabs. Additionally, while functional richness increased with taxa richness for ARMS communities, debris communities showed decreasing functional richness and high functional similarity, suggesting a specialization of debris-specific taxa. Overall, these data assist in better understanding the marine community ecology surrounding anthropogenic marine debris for future debris removal and management practices for comprehensive reef health.

University Experiences of Marine Science Research and Outreach Beyond the Classroom.

Climate and ocean literacy are two of the most important challenges facing society today. However, many students lack exposure to these topics upon entering college. As a result, these students must rely on learning climate literacy and ocean conservation through experiences outside of those provided in the traditional undergraduate classroom. To fill this gap, we initiated a marine science professional development program to expose undergraduate students to ocean literacy principles and climate change concepts through marine ecology research and educational outreach. This study evaluates the effects of our undergraduate experiential learning for individuals involved in our research team, our educational outreach team, or both. Clemson University alumni that participated in our program were surveyed to determine educational and professional gains in three areas related to: (1) knowledge; (2) careers; and (3) attitudes. Multiple linear and logistic regressions were used to understand the relationships between gains and program type, mentor experience, and duration of program enrollment. In addition, we evaluated demographic covariates including age, ideology, and gender. Our study found that perceived knowledge of marine science and science communication skills increased with positive mentor experience. Alumni that rated their experience with their mentors highly also indicated that the program was important to their careers after graduation. Students who participated in any program for a prolonged period were more likely to indicate that marine science was important to their careers. These students were also more likely to continue their education. Additionally, we saw that a sense of belonging and identity in science, as well as the understanding of climate change threat on the marine environment, all increased with longer program involvement, more than the type of experience (research versus outreach). Overall, we found that both the research and outreach programs offered opportunities for advancements in knowledge, careers, and attitudes. These results provide evidence that experiential learning has the potential to increase student engagement and understanding of climate change and ocean literacy communication as well as a sense of belonging in science-oriented fields.

Evidence of local adaptation in a waterfall-climbing Hawaiian goby fish derived from coupled biophysical modeling of larval dispersal and post-settlement selection.

BACKGROUND: Local adaptation of marine and diadromous species is thought to be a product of larval dispersal, settlement mortality, and differential reproductive success, particularly in heterogeneous post-settlement habitats. We evaluated this premise with an oceanographic passive larval dispersal model coupled with individual-based models of post-settlement selection and reproduction to infer conditions that underlie local adaptation in Sicyopterus stimpsoni, an amphidromous Hawaiian goby known for its ability to climb waterfalls. RESULTS: Our model results demonstrated that larval dispersal is spatio-temporally asymmetric, with more larvae dispersed from the southeast (the Big Island) to northwest (Kaua'i) along the archipelago, reflecting prevailing conditions such as El Niño/La Niña oscillations. Yet connectivity is nonetheless sufficient to result in homogenous populations across the archipelago. We also found, however, that ontogenetic shifts in habitat can give rise to adaptive morphological divergence when the strength of predation-driven post-settlement selection crosses a critical threshold. Notably, our simulations showed that larval dispersal is not the only factor determining the likelihood of morphological divergence. We found adaptive potential and evolutionary trajectories of S. stimpsoni were greater on islands with stronger environmental gradients and greater variance in larval cohort morphology due to fluctuating immigration. CONCLUSIONS: Contrary to expectation, these findings indicate that immigration can act in concert with selection to favor local adaptation and divergence in species with marine larval dispersal. Further development of model simulations, parameterized to reflect additional empirical estimates of abiotic and biotic factors, will help advance our understanding of the proximate and ultimate mechanisms driving adaptive evolution, population resilience, and speciation in marine-associated species.