Overview
Our research group focuses on applied questions in fisheries management and conservation biology. Our approaches to these questions are varied, but typically involve both fieldwork and analytic techniques. We maintain active field programs both locally, and in the tropics. Lab members have particular strengths in quantitative theory and tools, including stock assessment, time series analysis, mark-recapture analysis, and stable isotope mixing model theory and methods.
Grouper Moon Project
The Grouper Moon Project is a collaborative conservation program between Reef Environmental Education Foundation (REEF), the Cayman Islands Department of the Environment, and Scripps Institution of Oceanography studying Nassau Grouper (Epinephelus striatus) – a social and ecological corner stone of Caribbean’s coral reefs. The research focuses on Little Cayman, which has one of the largest (and one of just a few) known spawning aggregations of Nassau Grouper in the Caribbean. Over 4,000 individuals “group” at a single location for ~10 days following winter full moons. Since the project’s inception in 2002, Brice Semmens has been a lead scientist on the project. The research team has coordinated annual efforts to monitor and study the aggregation. The project has grown in scope to include: Nassau Grouper Education Program, Baby Grouper Adrift! Satellite Drifter Project, Marine Protected Areas and Spawning Aggregation research, and an ambient acoustics research program.
CalCOFI
“The California Cooperative Oceanic Fisheries Investigations (CalCOFI) are a unique partnership of the California Department of Fish & Wildlife, NOAA Fisheries Service and Scripps Institution of Oceanography. The organization was formed in 1949 to study the ecological aspects of the sardine population collapse off California. Today our focus has shifted to the study of the marine environment off the coast of California, the management of its living resources, and monitoring the indicators of El Nino and climate change. CalCOFI conducts quarterly cruises off southern & central California, collecting a suite of hydrographic and biological data on station and underway. Data collected at depths down to 500 meters include: temperature, salinity, oxygen, phosphate, silicate, nitrate and nitrite, chlorophyll, transmissometer, PAR, C14 primary productivity, phytoplankton biodiversity, zooplankton biomass, and zooplankton biodiversity. “
CCFRP
“CCFRP is a partnership of people and communities interested in fisheries sustainability. By combining the expertise and ideas of fishermen and scientists, we have successfully established protocols to gather information for fisheries management.”
The Semmens Lab was enthusiastic to participate in the first statewide 2017 California Collaborative Fisheries Research Program along with five other academic partners. We conducted 12 hook-and-line surveys of rocky reef and kelp habitats (< 37 m) inside three Marine Protected Areas (MPAs) and nearby reference areas off San Diego and Laguna Beach. The project led by PhD student Erica Jarvis Mason was a great success thanks to our volunteer science crew, the angling public, and members of the recreational fishing industry who worked together to catch, tag, and release 1,123 fish representing 37 species. We collect data on species composition, lengths, and catch rates that will be important for assessing MPA effectiveness. We have 8 trips scheduled for July and August 2018 out of Mission Bay and Oceanside. If you are a student and interested in volunteering with our science crew this summer please contact etmason@ucsd.edu.
Please check for tags next time you are out fishing and please tell your friends!
If you catch a tagged fish, please record the species, length, depth, and location and contact catchreporter@gmail.com or call 858-534-2156. You can also download our App at http://www.cooperativefishtagging.org/download-app
Citizen Science
For those looking to volunteer and add to marine research:
“Reef Environmental Education Foundation (REEF) protects marine life through education, service, and research. REEF facilitates programs that actively engage divers, snorkelers, and other marine enthusiasts in marine conservation. This is primarily accomplished through the Volunteer Fish Survey Project. Since its launch in 1993, this citizen science program has generated one of the largest marine life databases in the world. In 2020, the database surpassed 250,000 surveys conducted at almost 15,000 sites throughout the world’s oceans by over 16,000 volunteer divers and snorkelers worldwide.”
Stock Assessment
The Coastal Angler Tagging Cooperative is a partnership between the recreational fishing community, California Department of Fish and Wildlife, San Diego Oceans Foundation, and Scripps Institution of Oceanography. We are working together to measure population dynamics of three highly important marine bass species in the genus Paralabrax. We are integrating tag-recapture and acoustic telemetry methods to quantify population abundance, growth, mortality, and movement patterns of the three species in southern California. With help from thousands of recreational anglers, we will use this essential information in future stock assessments.
Stable Isotopes
Brice Semmens and his colleagues develop and refine Bayesian methods for stable isotope mixing model analyses. They first described a novel Bayesian framework (MixSIR) for mixing model analysis that incorporated uncertainty in the isotopic signatures of both predators (mixtures) and prey (sources) in two Ecology Letters publications in 2008 and 2009. In 2011, Semmens et al. published a hierarchical version of the mixing model formulation that incorporates individual (and group-level) diet variability among predators, and demonstrates how to use information theoretic approaches to evaluate data support for alternate mixing model parameterizations. Semmens Lab Ph.D. student, Brian Stock is currently developing MixSIAR, a GUI tool that incorporates recent developments in mixing model tools. MixSIAR represents a collaborative effort between many of the researchers involved in developing mixing model theory to date.