Dr. Jeffrey Webb

Lead Invertebrate Taxonomist

Rhithron’s invertebrate taxonomy team is led by Dr. Jeff Webb, an internationally recognized authority on aquatic invertebrates. His dissertation work at Purdue University was on the diversity and systematics of the Heptageniid mayflies of the world. Prior to his career at Rhithron, Jeff coordinated the DNA barcoding of the Ephemeroptera , Plecoptera, and Trichoptera of the world at the Biodiversity Institute of Ontario at the University of Guelph. He was a research fellow at the Taxonomy Research and Information Network at LaTrobe University, Australia, where he contributed to the morphological and molecular systematics of the aquatic fauna of Australia.

Jeff holds 5 current SFS Level II certifications in Eastern and Western EPT and General Arthropods, along with North American Oligochaeta. He has presented workshops on the western and northern North American Ephemeroptera at the Joint Aquatic Sciences Meeting (JASM) in Portland, Oregon and at the annual meeting of the Southwest Association of Freshwater Invertebrate Taxonomists (SAFIT) in Long Beach, California. Jeff has written more than 50 scientific papers, and he continues to publish on the systematics of aquatic invertebrates.

Sean Sullivan

Taxonomy Department Supervisor

Aquatic Ecologist

Sean Sullivan manages and supervises Rhithron’s invertebrate taxonomy and phycology teams. Sean holds 4 current SFS Level II certifications in Eastern and Western EPT and General Arthropods. His thesis work at the University of Montana involved aquatic invertebrate community responses to restoration in a mining-influenced stream: he also completed post graduate work in statistical modeling. He has extensive experience in the analysis and interpretation of aquatic invertebrate and algal data. He has published studies on the effects of ecological stressors and remediation efforts on invertebrate and algal assemblages.

Dr. Andrew Fasbender

Lead Chironomid/Oligochaete Taxonomist

Dr. Andrew Fasbender leads Rhithron’s chironomid and oligochaeta taxonomy team. For his dissertation  at Iowa State University, he studied the taxonomy and systematics of the ptychopterid flies of North America. Andrew serves as a peer reviewer for several scientific journals related to invertebrate taxonomy. He holds 4 current SFS Level II certifications in Eastern and Western Chironomidae, Western EPT, and Oligochaeta.

Dr. Clinton Davis

Lead Phycologist

Dr. Clint Davis leads Rhithron’s phycology team, providing project oversight and managing quality assurance for algal processing and taxonomy. He researched the ecology of Great Basin periphyton for his dissertation work at the University of Nevada, Reno. He also studied and contributed to the development of biological condition indices applicable to rivers and reservoirs in the western United States as a postdoctoral researcher at the Desert Research Institute. He has authored several papers on the ecology of freshwater diatoms, soft algae, and phytoplankton and has over 12 years of experience in the taxonomy and ecology of algae, phytoplankton, and zooplankton.

Rebecca Spring

Quality Assurance Officer

Rebecca Spring is the Quality Assurance Officer for Rhithron’s invertebrate taxonomy team, providing data comparisons and calculation of quality control parameters for taxonomy and enumeration. Prior to her career at Rhithron, Becca worked as a member of research and field teams for the US Forest Service, Idaho Fish and Game, and the Oregon Department of Fish and Wildlife. She currently holds 4 SFS Level II certifications in Eastern and Western EPT and Chironomidae.

Brett Moore

Invertebrate Taxonomist

Brett Moore holds 4 current SFS Level II certifications in Eastern and Western EPT and General Arthropods. At Rhithron, he has been responsible for the compilation of dichotomous keys to the larvae and pupae of simuliid flies. Prior to his work at Rhithron, Brett was a conservation specialist for the Montana Department of Fish, Wildlife and Parks, and a fisheries biologist with the California Department of Fish and Game and the Wyoming Fish and Game Department. His thesis work at California State University examined the influence of fine particulate matter on the distribution of aquatic invertebrate assemblages.

Dr. Heera Malik


Dr. Heera Malik provides analysis for periphyton and phytoplankton samples, identifying both diatoms and non-diatom algal forms. She earned her Ph.D. at the University of Maine, where she studied changes in diatom assemblages in arctic lakes due to climate change. Heera also studied the effects of oil spill contamination on algal communities in the Gulf of Mexico.

Dennis Vander Meer


Dennis Vander Meer trained in diatom and soft algal taxonomy at the Lakeside Laboratory of the University of Northern Iowa. He has contributed to the taxonomy of Nearctic Diatoms by authoring pages on the Diatom Taxonomy Website (Diatoms of the United States). Dennis has been providing diatom taxonomic determinations at Rhithron for more than 10 years.