The Siders lab leverages diverse quantitative approaches from across ecology and fisheries science to aid natural resource management, generate robust ecological inference, and develop new analytical approaches. We use the challenges of data deficiency and big data to drive innovation, integration, and collaboration in our research.
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Protected Species Population Assessment — As part of a collaboration with the NOAA Pacific Islands Fisheries Science Center, NOAA Pacific Islands Regional Office, and the Western Pacific Regional Fisheries Management Council, Dr. Siders models the trajectory of two populations of protected sea turtle species: western Pacific Leatherbacks and north Pacific Loggerheads. This species are caught incidentally on the Hawai'i and American Samoa pelagic longline fisheries. Using a Bayesian population trend estimation and a "take" model with demographic and fishery stochasticity, the team estimated negligible impacts of the Hawai'i shallow-set, deep-set, and the American Samoa longline fishery on the two populations. Unfortunately, other external threats are negatively impacting the trend of western Pacific Leatherbacks, which are likely to go extinct before the end of the century. Our findings are published in two NOAA Technical Memoranda: TM-PIFSC-95 & TM-PIFSC-101 covering the Hawaii shallow-set pelagic longline fishery for Swordfish, the Hawaii deep-set pelagic longline fishery for Bigeye Tuna, and the American Samoa pelagic longline fishery for Albacore and Yellowfin Tuna. This is an active area of research that supports Biological Opinions and Section 7 consultations under the Endangered Species Act, discussions of spatial management and best practices at the WPRFMC, and contributes to intergovernmental management of protected species in the Pacific.
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Brazilian Guitarfish — Led by Dr. Fabio Caltabellotta, Dr. Siders developed a Bayesian age-growth model for Pseudobatos horkelii, Pseudobatos percellens, and Zapteryx brevirostris in southern Brazil. The resulting model was used to estimate age and growth parameters for these three priority guitarfish species listed as Critically Endangered, Near Threatened, and Vulnerable by the International Union for the Conservation of Nature. Now published: doi: 10.1111/jfb.14123
![]() (Above) Bowtie sections of guitarfish vertebrae for the three Brazilian guitarfish species showing off the classic banding patterns left behind by annual growth spurts. (Left) Age-growth relationships for three Brazilian Guitarfish species. Age is on the x-axis in units of years and growth is on the y-axis in units of centimeters of total length.
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Brazilian Electric Ray — Led by Dr. Fernanda Rolim, a postdoc at Universidade Estadual Paulista in São Paolo, Brazil, Dr. Siders extended the Brazilian guitarfish model to estimate two-dimensional growth of Narcine brasiliensis, the Brazilian Electric Ray, in southern Brazil. The joint estimation of length-weight and age-growth parameters was added along with derivations of age at maturity, longevity, and mortality at age. A significant component was incorporating uncertainty in size at birth into the von Bertalanffy growth model.
Now published: doi: 10.1111/jfb.14378 |
![]() (Above) Silhouettes of Goblin Sharks through the ages. (top) 1898 in the description of the species by David Starr Jordan. (top middle) 1904 by King Bragança of Portugal. (top bottom) 1909 by Hussakof and the renaming of Mitsukurina to Scapanorhynchus for a time. (bottom) 1981 by Cadenat and Blache in Requins de Méditerranée et d' Atlantique.
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Goblin Shark — Led by Dr. Siders and Dr. Fabio Caltabellotta, we estimated the first age-growth relationship for Goblin Sharks (Mitsukurina owstoni), one of the largest deepwater sharks. Fabio developed a method to highlight the classic banding pattern that allowed an age reading on a specimen caught in Brazil in 2008. I developed a Bayesian age-growth model that used back-calculated lengths at age from this specimen, data on maximum male sizes, and data on size at birth to estimate the first age-growth parameters for the species. We are excited to age more specimens in the future. Now published: doi.org/10.1071/MF19370
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Initial research was funded by the University of Florida Biodiversity Institute and was focused on dimensions of pelagic shark biodiversity in the North Pacific. For this work we assembled 38 traits from 1225 records from 130 sources, 260 pictographs from seven sources, and 631 teeth photographs from 79 jaw specimens! Using all this trait data, the research identified ten functional groups largely split by life history strategy, habitat, as well as dentition and diet. We found that only bathymetric zone really separated the functional groups of sharks across a suite of macro ecological gradients. Check out the full paper here.
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