Center for Biostatistics and Modeling

office logoThe Center for Biostatistics and Modeling (CBM) provides biostatistical and data management support to the researchers and managers of the Florida Fish and Wildlife Conservation Commission. In addition to providing general consulting services, the center helps researchers and managers:

  • Develop data management strategies.
  • Design studies and perform analyses.
  • Contribute to the publication of FWC agency reports and research manuscripts.
  • Serve as co-investigators on research grants.
  • Provide training on statistical software and analytical methodologies.

Staff provide specialized knowledge that ensures studies are valid and efficient, data analyses are appropriate, and translate the work into high-quality and easy-to-understand graphics so that study results can be conveyed to partners, peers, and the public.

Each member of the CBM team brings a unique specialty to the group, including backgrounds in linear mixed models, multivariate statistics, and Bayesian methodologies. To provide a wide base of support, staff are located at the St. Petersburg headquarters, the Gainesville Wildlife Research Laboratory and the Gainesville Fisheries Research Laboratory. While the focus of the center’s work is within FWC, they have also collaborated with agency partners such as the U.S. Geological Survey, the University of Florida, and the U.S. Fish and Wildlife Service.

The goal for every research project is to ensure the validity as well as improve the quality of the data collected. With this goal in mind staff ensure the best science for management. As the research and management conducted by the FWC can vary, so can the topics that the team works on.

For example, CBM staff were recently contacted by freshwater fisheries researchers to provide statistical support during the analysis phase of a project to estimate the distribution of the imperiled Suwannee Moccasinshell, a freshwater mussel exclusively found within the Suwannee river basin in Florida and Georgia. To accomplish this, a suite of statistical analyses called occupancy models were developed for researchers to estimate the distribution of the species, while accounting for variation in survey effort across years, and determine the impact of springs discharge on species occurrence. This statistical expertise enabled the biologists to determine where Moccasinshells are most likely to persist within the basin and the environmental conditions that are necessary to ensure the survival of the species.

graph showing results

Legal catch and bycatch from stone crab traps fished without a cull ring (control, traditional trap) or with cull rings of different sizes. Cull rings reduced bycatch while maintaining legal claw catch.

Researchers and managers can contact staff at any time before, during, and after a project has been completed, but the center can provide the greatest benefit when they become involved with a project right at the beginning. For example, stone crab researchers contacted staff to assist with the design and analysis of an excluder ring study. Excluder rings are used by commercial blue crab fishermen to reduce bycatch in their traps. Stone crab researchers were interested in developing and testing these devices for the Florida stone crab fishery. To determine the effectiveness of the rings, researchers needed to know how many experimental traps should be fished, and for how long. Staff developed a statistical model that could determine the most appropriate excluder ring size; one that would maximize legal catch of crabs but minimize bycatch. This recommended excluder ring was then deployed by a commercial fisherman for field testing, with promising results. The field results collected by the fishermen validated what the researchers had suspected: excluder rings can drastically reduce the amount of bycatch (and therefore wasted effort by the fishermen) while maintaining the same level of catch for legal crabs.

In addition to researchers, the CBM also works directly with land managers and staff from all of FWC’s divisions. For example, in 2010 the Division of Hunting and Game Management wanted to determine what the impact on the number of deer harvested would be if they expanded hunting regulations to allow for crossbow hunting during archery season. They contacted CBM and asked the team to develop a model that would estimate the impact of crossbow hunting in Florida on harvest numbers and hunting opportunities. The team needed to consider historical harvest and hunter numbers in the state, as well as recent trends, and incorporated trends from neighboring states with crossbow hunting to come up with an estimate. These results were presented directly to the commission and were instrumental in the ultimate decision to allow crossbow hunting in Florida during the archery season.

For the Center for Biostatistics and Modeling, work will never be finished. While analyzing data to answer one question, they often identify new and exciting questions, as well as make new discoveries, which can contribute to new research projects. To further scientific understanding and support resource management the Center aims to document the high caliber of work conducted by FWC by publishing in the grey literature or through peer-reviewed manuscripts. The field of statistics is constantly evolving, which means staff must continually stay abreast of new and exciting statistical advances to provide the most appropriate advice and assistance. Staff continually research new statistical methodologies in the published literature and seek out specialized training opportunities which are available through universities or at conferences. This knowledge-base and statistical toolkit is always expanding, which allows the center to be a continual asset to the agency.