Tim Grabowski, PhD
Unit Leader - Hawaii Cooperative Fish and Wildlife Research Unit
Research Interests
Tim is interested in the behavioral and physiological ecology of fishes and applying these fields to management and conservation issues. His research tends to focus on the reproductive ecology of fishes as well as local adaptation and population structuring.
Teaching Interests
Tim currently teach field ichthyology and foundations of ecology and conservation biology at Texas Tech University. He also teaches a summer course at the University of Iceland examining the effects of anthropogenic impacts, such as climate change and commercial fisheries, on the marine environment.
Professional Experience
Unit Leader, Hawaii Cooperative Fishery Research Unit, 2016-
Assistant Unit Leader, Texas Cooperative Fish and Wildlife Research Unit, 2010-2016
Education and Certifications
Ph D Clemson University 2006
MS Texas A&M University 2002
BS Texas A&M University 1999
Science and Products
What can volunteer angler tagging data tell us about the status of the Giant Trevally (ulua aukea) Caranx ignobilis fishery in Hawaii: revisiting data collected during Hawaii’s Ulua and Papio Tagging Project 2000-2016
Evaluating habitat associations of a fish assemblage at multiple spatial scales in a minimally disturbed stream using low‐cost remote sensing
Thyroid endocrine disruption and external body morphology of Zebrafish
Assessing the feasibility of using acoustic monitoring for Burbot conservation, management, and production
Evaluation and refinement of Guadalupe Bass conservation strategies to support adaptive management
Application and utility of a low-cost unmanned aerial system to manage and conserve aquatic resources in four Texas rivers
Deployment of paired pushnets from jet-propelled kayaks to sample ichthyoplankton
Evidence from data storage tags for the presence of lunar and semilunar behavioral cycles in spawning Atlantic cod
Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems
Spawning behavior in Atlantic cod: analysis by use of data storage tags
Distribution and habitat associations of juvenile Common Snook in the lower Rio Grande, Texas
Backcasting the decline of a vulnerable Great Plains reproductive ecotype: identifying threats and conservation priorities
Science and Products
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Filter Total Items: 29
What can volunteer angler tagging data tell us about the status of the Giant Trevally (ulua aukea) Caranx ignobilis fishery in Hawaii: revisiting data collected during Hawaii’s Ulua and Papio Tagging Project 2000-2016
Giant Trevally (ulua aukea) Caranx ignobilis is one of the most highly prized and frequentlytargeted nearshore species. However, there is very little information on its current status inHawaiian waters. This study uses mark-recapture data collected as part of recreational anglertagging program conducted by the Hawaii Department of Land and Natural Resources-Divisionof Aquatic Resources during 2000AuthorsTimothy B. Grabowski, Erik C. FranklinEvaluating habitat associations of a fish assemblage at multiple spatial scales in a minimally disturbed stream using low‐cost remote sensing
Habitat heterogeneity at multiple scales is a major factor affecting fish assemblage structure. However, assessments that examine these relationships at multiple scales concurrently are lacking. The lack of assessments at these scales is a critical gap in understanding as conservation and restoration efforts typically work at these levels.A combination of low‐cost side‐scan sonar surveys, aerial iAuthorsBrandon D. Cheek, Timothy B. Grabowski, Preston T. Bean, Jillian R. Groeschel, Stephan J. MagneliaThyroid endocrine disruption and external body morphology of Zebrafish
This study examined the effects thyroid-active compounds during early development on body morphology of Zebrafish (Danio rerio). Three-day postfertilization (dpf) larvae were exposed to goitrogen [methimazole (MZ, 0.15 mM)], combination of MZ (0.15 mM) and thyroxine (T4, 2 nM), T4 (2 nM), or control (reconstituted water) treatments until 33 dpf and subsequently maintained in reconstituted water unAuthorsPrakash Sharma, Timothy B. Grabowski, Reynaldo PatiñoAssessing the feasibility of using acoustic monitoring for Burbot conservation, management, and production
Burbot Lota lota is the sole freshwater representative of the cod-like fishes and supports subsistence, commercial, and recreational fisheries worldwide above approximately 40° N. It is a difficult species to manage effectively due to its preference for deep-water habitats and spawning activity under the ice in winter. Like other gadiform fishes, Burbot use acoustic signaling as part of their matiAuthorsTimothy B. GrabowskiEvaluation and refinement of Guadalupe Bass conservation strategies to support adaptive management
Burbot Lota lota is the sole freshwater representative of the cod-like fishes and supports subsistence, commercial, and recreational fisheries worldwide above approximately 40° N. It is a difficult species to manage effectively due to its preference for deep-water habitats and spawning activity under the ice in winter. Like other gadiform fishes, Burbot use acoustic signaling as part of their matiAuthorsTimothy B. GrabowskiApplication and utility of a low-cost unmanned aerial system to manage and conserve aquatic resources in four Texas rivers
Low-cost unmanned aerial systems (UAS) have recently gained increasing attention in natural resources management due to their versatility and demonstrated utility in collection of high-resolution, temporally-specific geospatial data. This study applied low-cost UAS to support the geospatial data needs of aquatic resources management projects in four Texas rivers. Specifically, a UAS was used to (AuthorsTimothy W. Birdsong, Megan Bean, Timothy B. Grabowski, Thomas B. Hardy, Thomas Heard, Derrick Holdstock, Kristy Kollaus, Stephan J. Magnelia, Kristina TolmanDeployment of paired pushnets from jet-propelled kayaks to sample ichthyoplankton
Accessing and effectively sampling the off-channel habitats that are considered crucial for early life stages of freshwater fishes constitute a difficult challenge when common ichthyoplankton survey methods, such as push nets, are used. We describe a new method of deploying push nets from jet-propelled kayaks to enable the sampling of previously inaccessible off-channel habitats. The described rigAuthorsMatthew R. Acre, Timothy B. GrabowskiEvidence from data storage tags for the presence of lunar and semilunar behavioral cycles in spawning Atlantic cod
Understanding the environmental processes determining the timing and success of reproduction is of critical importance to developing effective management strategies of marine fishes. Unfortunately it has proven difficult to comprehensively study the reproductive behavior of broadcast-spawning fishes. The use of electronic data storage tags (DSTs) has the potential to provide insights into the behaAuthorsTimothy B. Grabowski, Bruce J. McAdam, Vilhjalmur Thorsteinsson, Gudrún MarteinsdóttirInteracting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems
Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. OurAuthorsThomas A. Worthington, Shannon K. Brewer, Nicole Farless, Timothy B. Grabowski, Mark S. GregorySpawning behavior in Atlantic cod: analysis by use of data storage tags
Electronic data storage tags (DSTs) were implanted into Atlantic cod captured in Icelandic waters from 2002 to 2007 and the depth profiles recovered from these tags (females: n = 31, males: n = 27) were used to identify patterns consistent with published descriptions of cod courtship and spawning behavior. The individual periods of time that males spent exhibiting behavior consistent with being pAuthorsTimothy B. Grabowski, Vilhjalmur Thorsteinsson, Gudrún MarteinsdóttirDistribution and habitat associations of juvenile Common Snook in the lower Rio Grande, Texas
Common Snook Centropomus undecimalis were once abundant off the Texas coast, but these populations are now characterized by low abundance and erratic recruitment. Most research concerning Common Snook in North America has been conducted in Florida and very little is known about the specific biology and habitat needs of Common Snook in Texas. The primary objective of this study was to describe theAuthorsCaleb G. Huber, Timothy B. Grabowski, Reynaldo Patiño, Kevin L. PopeBackcasting the decline of a vulnerable Great Plains reproductive ecotype: identifying threats and conservation priorities
Conservation efforts for threatened or endangered species are challenging because the multi-scale factors that relate to their decline or inhibit their recovery are often unknown. To further exacerbate matters, the perceptions associated with the mechanisms of species decline are often viewed myopically rather than across the entire species range. We used over 80 years of fish presence data collecAuthorsThomas A. Worthington, Shannon K. Brewer, Timothy B. Grabowski, Julia Mueller